# Bulletin de veille du réseau d'écotoxicologie terrestre et aquatique N°45

Colette Bertrand, Christian Mougin, Annette Bérard, Céline Pelosi, Soizic

Morin, Olivier Crouzet, Pascale Karmasyn-Veyrines

► To cite this version:

Colette Bertrand, Christian Mougin, Annette Bérard, Céline Pelosi, Soizic Morin, et al.. Bulletin de veille du réseau d'écotoxicologie terrestre et aquatique N°45. 2020, 10.15454/BGEP-SC64. hal-02911011v2

HAL Id: hal-02911011

https://hal.inrae.fr/hal-02911011v2

Submitted on 13 Jul 2021

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<figure><img src="image_1.png" /></figure>
# Bulletin de veille du réseau d'écotoxicologie terrestre et aquatique

<figure><img src="image_2.png" /></figure>

N° 45, Juin 2020

Réalisé par l'équipe de veille sur la période du 1er mai au 30 juin 2020.

Colette Bertrand, Christian Mougin (UMR 1402 EcoSys), Annette Berard, Céline Pélosi (UMR 1114 EMMAH), Soizic Morin (UR 1454 EABX), Olivier Crouzet (UPFS - OFB) et Pascale Karmasyn-Veyrines (DipSO)

Destinataires : les membres de la liste : [ecotox@inrae.fr](mailto:ecotox@inrae.fr)

## Edito

Voici notre 45ème bulletin de veille, toujours dense ! Nous remercions les nombreux lecteurs qui ont répondu à notre enquête portant sur votre percpetion du bulletin. Nous vous présenterons prochainement les résultats ainsi que nos propositions d'évolution. Dans ce bulletin, nous amorçons une thématique « biocontôle » concernant l'impact des molécules d'origine biologique.

Nous vous proposons dans ce bulletin une tribune portant sur la bioaccumulation et le transfert trophique de contaminants dans les écosystèmes aquatiques : challenges & perspectives pour le réseau Ecotox. Le texte est également disponible sous forme de fiche thématique en téléchargement sur notre site ECOTOX :
https://www6.inrae.fr/ecotox/Productions/Fiches-thematiques/Fiche-thematique-N-27-juin-2020

N'oubliez pas de nous transmettre les informations que vous souhaitez diffuser, notamment vos publications que nous pourrions avoir oubliées.

L'équipe vous souhaite un bel été et une bonne lecture de ce bulletin !

Contact : [veille-ecotox@inrae.fr](mailto:veille-ecotox@inrae.fr)
<table><tr><td>Resistant fungi isolated from contaminated uranium mine in Brazil shows a high capacity to uptake uranium from water</td><td>30</td></tr><tr><td>Understanding the influence of glyphosate on the structure and function of freshwater microbial community in a microcosm</td><td>31</td></tr><tr><td>Species-specific sensitivity of three microalgae to sediment elutriates</td><td>31</td></tr><tr><td>Effects of oxytetracycline on growth and chlorophyll a fluorescence in green algae (Chlorella vulgaris), diatom (Phaeodactylum tricornutum) and cyanobacteria (Microcystis aeruginosa and Nodularia spumigena)</td><td>31</td></tr><tr><td>Ecotoxicological effects of alpha-cypermethrin on freshwater alga Chlorella sp.: Growth inhibition and oxidative stress studies</td><td>32</td></tr><tr><td>The potential assessment of green alga Chlamydomonas reinhardtii CC-503 in the biodegradation of benz(a)anthracene and the related mechanism analysis</td><td>32</td></tr><tr><td>Nanoplastics Promote Microcystin Synthesis and Release from Cyanobacterial Microcystis aeruginosa</td><td>33</td></tr><tr><td>Biofilm alters tetracycline and copper adsorption behaviors onto polyethylene microplastics</td><td>33</td></tr><tr><td>Metabolomic, functional, and ecologic responses of the common freshwater fungus Neonectria lugdunensis to mine drainage stress</td><td>34</td></tr><tr><td>Resistance of cyanobacteria Microcystis aeruginosa to erythromycin with multiple exposure</td><td>34</td></tr><tr><td>Interaction of Cyanobacteria with Nanometer and Micron Sized Polystyrene Particles in Marine and Fresh Water</td><td>35</td></tr><tr><td>Mechanism of lead bioaccumulation by freshwater algae in the presence of organic acids</td><td>35</td></tr><tr><td>Age-related physicochemical differences in ZnO nanoparticles in the seawater and their bacterial interaction</td><td>35</td></tr><tr><td>Biofilms grown in aquatic microcosms affect mercury and selenium accumulation in Daphnia</td><td>36</td></tr><tr><td>Portable Microalgal Biosensor for Herbicide Monitoring</td><td>36</td></tr><tr><td>Enhanced production of laccase from gamma irradiated endophytic fungus: A study on biotransformation kinetics of aniline blue and textile effluent decolourisation</td><td>37</td></tr><tr><td>The combined toxicity influence of microplastics and nonylphenol on microalgae Chlorella pyrenoidosa</td><td>37</td></tr><tr><td>Insights Into the Biodegradation of Lindane (gamma-Hexachlorocyclohexane) Using a Microbial System</td><td>38</td></tr><tr><td>Comparison of the Level and Mechanisms of Toxicity of Carbon Nanotubes, Carbon Nanofibers, and Silicon Nanotubes in Bioassay with Four Marine Microalgae</td><td>38</td></tr><tr><td>Co-metabolism of sulfamethoxazole by a freshwater microalga Chlorella pyrenoidosa</td><td>38</td></tr><tr><td>Treatment enhances the prevalence of antibiotic-resistant bacteria and antibiotic resistance genes in the wastewater of Sri Lanka, and India</td><td>39</td></tr></table>

<table><tr><td>ERA / PUBLICATIONS SCIENTIFIQUES / MICROBIOLOGIE ET CONTAMINANTS</td><td>39</td></tr><tr><td>Alleviation of Cd phytotoxicity and enhancement of rape seedling growth by plant growth-promoting bacterium Enterobacter sp. Zm-123</td><td>40</td></tr><tr><td>Evaluating the protection of bacteria from extreme Cd (II) stress by P-enriched biochar</td><td>40</td></tr><tr><td>Self-cleaning of very heavily oil-polluted sites proceeds even under heavy-metal stress while involved bacteria exhibit bizarre pleomorphism</td><td>40</td></tr><tr><td>Isolation and Identification of Endosulfan Degrading Native Bacterial Consortium from Agricultural Soils</td><td>41</td></tr><tr><td>A beneficial role of arbuscular mycorrhizal fungi in influencing the effects of silver nanoparticles on plant-microbe systems in a soil matrix</td><td>41</td></tr><tr><td>Pesticide bioremediation in liquid media using a microbial consortium and bacteria-pure strains isolated from a biomixture used in agricultural areas</td><td>42</td></tr><tr><td>Interactions of microplastics and cadmium on plant growth and arbuscular mycorrhizal fungal communities in an agricultural soil</td><td>42</td></tr><tr><td>Insights Into the Microbial Degradation and Biochemical Mechanisms of Neonicotinoids</td><td>43</td></tr><tr><td>Long-term effects of copper exposure to agricultural soil function and microbial community structure at a controlled and experimental field site</td><td>43</td></tr><tr><td>Antimony-oxidizing bacteria alleviate Sb stress in Arabidopsis by attenuating Sb toxicity and reducing Sb uptake</td><td>44</td></tr><tr><td>Deciphering metal toxicity responses of flax (Linum usitatissimum L.) with exopolysaccharide and ACC-deaminase producing bacteria in industrially contaminated soils</td><td>44</td></tr><tr><td>Can Toxicities Induced by Insecticide Methomyl be Remediated Via Soil Bacteria Ochrobactrum thiophenivorans and Sphingomonas melonis?</td><td>45</td></tr><tr><td>Bioremediation potency of multi metal tolerant native bacteria Bacillus cereus isolated from bauxite mines, kolli hills, Tamilnadu - A lab to land approach</td><td>45</td></tr></table>
<table><tr><td>Cd heavy metal and plants, rather than soil nutrient conditions, affect soil arbuscular mycorrhizal fungal diversity in green spaces during urbanization</td><td>46</td></tr><tr><td>Effects of lead (Pb) in stormwater runoff on the microbial characteristics and organics removal in bioretention systems</td><td>46</td></tr><tr><td>Geo-distribution pattern of microbial carbon cycling genes responsive to petroleum contamination in continental horizontal oilfields</td><td>47</td></tr><tr><td>Effects on soil microbial community after exposure to neonicotinoid insecticides thiamethoxam and dinotefuran</td><td>47</td></tr><tr><td>Distribution pattern of antibiotic resistance genes and bacterial community in agricultural soil samples of Wuliangsuhai watershed. China</td><td>48</td></tr><tr><td>Lignin degradation and nutrient cycling by white rot fungi under the influence of pesticides</td><td>48</td></tr><tr><td>Fungi and Arsenic: Tolerance and Bioaccumulation by Soil Saprotrophic Species</td><td>49</td></tr><tr><td>Co-selection of antibiotic-resistant bacteria in a paddy soil exposed to As (III) contamination with an emphasis on potential pathogens</td><td>49</td></tr><tr><td>Purification and characterization of salivarian acid B from Streptomyces sp. M4 possessing antifungal activity against fungal phytopathogens</td><td>50</td></tr><tr><td>Potential risks of antibiotic resistant bacteria and genes in bioremediation of petroleum hydrocarbon contaminated soils</td><td>50</td></tr><tr><td>Shifts in microbial community, pathogenicity-related genes and antibiotic resistance genes during dairy manure piled up</td><td>51</td></tr><tr><td>Indole-3-acetic acid synthesizing chromium-resistant bacteria can mitigate chromium toxicity in Helianthus annuus L.</td><td>51</td></tr><tr><td>Growth enhancement and cadmium uptake efficiency in Medicago sativa by endophytic bacteria isolated from Datura innoxiad</td><td>52</td></tr><tr><td>Screening of Heavy Metal-Immobilizing Bacteria and Its Effect on Reducing Cd2+ and Pb2+ Concentrations in Water Spinach (Ipomoea aquatic Forsk.)</td><td>52</td></tr><tr><td>Responses of soil bacterial community and Cd phytoextraction to a Sedum alfredii-oilseed rape (Brassica napus L. and Brassica juncea L.) intercropping system</td><td>53</td></tr><tr><td>Dissipation of S-metolachlor and butachlor in agricultural soils and responses of bacterial communities: Insights from compound-specific isotope and biomolecular analyses</td><td>53</td></tr><tr><td>Effect of Indigenous Microbial Consortium on Bioleaching of Arsenic from Contaminated Soil by Shewanella putrefaciens</td><td>54</td></tr><tr><td>Enantioselective effects of imazethapyr residues on Arabidopsis thaliana metabolic profile and phyllosphere microbial communities</td><td>54</td></tr><tr><td>Structural and functional responses of bacterial and fungal communities to multiple heavy metal exposure in arid loess</td><td>55</td></tr><tr><td>A comparative study on the antibiotic resistance pattern of soil bacterial communities in flood affected and unaffected areas of kothamangalam municipality</td><td>55</td></tr><tr><td>The Cultivable Bacterial Microbiota Associated to the Medicinal Plant Origanum vulgare L.: From Antibiotic Resistance to Growth-Inhibitory Properties</td><td>55</td></tr><tr><td>The Impact of Pesticides on the Microbial Community of Agrosoddy-Podzolic Soil</td><td>56</td></tr><tr><td>Monitoring antibiotic resistomes and bacterial microbiomes in the aerosols from fine, hazy, and dusty weather in Tianjin, China using a developed high-volume tandem liquid impinging sampler</td><td>56</td></tr><tr><td>Effects of cadmium perturbation on the microbial community structure and heavy metal resistome of a tropical agricultural soil</td><td>57</td></tr><tr><td>New Insights into the Microbial Degradation of D-Cyphenothrin in Contaminated Water/Soil Environments</td><td>57</td></tr><tr><td>Responses of soil microbial biomass and enzyme activity to herbicides imazethapyr and flumioxazin</td><td>58</td></tr><tr><td>Effects of Cd on soil microbial biomass depend upon its soil fraction distribution</td><td>58</td></tr><tr><td>Biodegradation of Allethrin by a Novel Fungus Fusarium proliferatum Strain CF2, Isolated from Contaminated Soils</td><td>59</td></tr><tr><td>Microbial remediation of a pentachloronitrobenzene-contaminated soil under Panax notoginseng: A field experiment</td><td>59</td></tr><tr><td>Screening strains for microbial biosorption technology of cadmium</td><td>60</td></tr><tr><td>Sulfamethoxazole affects the microbial composition and antibiotic resistance gene abundance in soil and accumulates in lettuce</td><td>60</td></tr></table>
<table>
  <tbody>
    <tr>
      <td>Effect of multiple heavy metals pollution to bacterial diversity and community structure in farmland soils</td>
      <td>60</td>
    </tr>
    <tr>
      <td>Designing of dual biosensor system for detection of zinc and chromium from contaminated soil using saponin biosurfactant and bioluminescence bacteriand</td>
      <td>61</td>
    </tr>
    <tr>
      <td>The influence on biosorption potentials of metal-resistant bacteria Enterobacter sp. EG16 and <i>Bacillus subtilis</i> DBM by typical red soil minerals</td>
      <td>61</td>
    </tr>
    <tr>
      <td>Heavy metals-resistant bacteria (HM-RB): Potential bioremediators of heavy metals-stressed <i>Spinacia oleracea</i> plantd</td>
      <td>62</td>
    </tr>
    <tr>
      <td>Suppression treatment differentially influences the microbial community and the occurrence of broad host range plasmids in the rhizosphere of the model cover crop <i>Avena sativa</i> L.</td>
      <td>62</td>
    </tr>
    <tr>
      <td>Development and performance evaluation of native microbial consortium for multi metal removal in lab scale aerobic and anaerobic bioreactor</td>
      <td>63</td>
    </tr>
    <tr>
      <td>Taxonomic and functional analysis of soil microbial communities in a mining site across a metal(loid) contamination gradient</td>
      <td>63</td>
    </tr>
    <tr>
      <td>Effects of Cd and Pb on diversity of microbial community and enzyme activity in soil</td>
      <td>64</td>
    </tr>
    <tr>
      <td>Adaptation of soil fungi to heavy metal contamination in paddy fields-a case study in eastern China</td>
      <td>64</td>
    </tr>
    <tr>
      <td>Response of microbial community composition in soils affected by coal mine exploitation</td>
      <td>65</td>
    </tr>
    <tr>
      <td>Biodegradation of diazinon by fungal strain <i>Apergillus niger</i> MK640786 using response surface methodology</td>
      <td>65</td>
    </tr>
    <tr>
      <td>Effects of di-n-butyl phthalate and di-2-ethylhexyl phthalate on pollutant removal and microbial community during wastewater treatment</td>
      <td>66</td>
    </tr>
    <tr>
      <td>Removal and biomineralization of Pb2+ in water by fungus <i>Phanerochaete chrysoporium</i></td>
      <td>66</td>
    </tr>
    <tr>
      <td>Remedial potential of bacterial and fungal strains (<i>Bacillus subtilis</i>, <i>Aspergillus niger</i>, <i>Aspergillus flavus</i> and <i>Penicillium chrysogenum</i>) against organochlorine insecticide Endosulfan</td>
      <td>67</td>
    </tr>
    <tr>
      <td>Microbial degradation of two highly persistent fluorinated fungicides - epoxiconazole and fludioxonil</td>
      <td>67</td>
    </tr>
    <tr>
      <td>The bacterial microbiota in florfenicol contaminated soils: The antibiotic resistome and the nitrogen cycle</td>
      <td>67</td>
    </tr>
    <tr>
      <td>Effect of Long-Term Pesticides and Chemical Fertilizers Application on the Microbial Community Specifically Anammox and Denitrifying Bacteria in Rice Field Soil of Jhenaidah and Kushtia District, Bangladesh</td>
      <td>68</td>
    </tr>
    <tr>
      <td>Characterization and Identification of Naphthalene Degrading Bacteria Isolated from Petroleum Contaminated Sites and Their Possible Use in Bioremediation</td>
      <td>68</td>
    </tr>
    <tr>
      <td>World within world: Intestinal bacteria combining physiological parameters to investigate the response of <i>Metaphire guillelmi</i> to tetracycline stress</td>
      <td>69</td>
    </tr>
    <tr>
      <td>Longitudinal screening of antibiotic residues, antibiotic resistance genes and zoonotic bacteria in soils fertilized with pig manure</td>
      <td>69</td>
    </tr>
    <tr>
      <td>Dissolved organic matter does not promote glyphosate degradation in auto-heterotrophic aquatic microbial communities</td>
      <td>70</td>
    </tr>
    <tr>
      <td>Destruction of Cell Topography, Morphology, Membrane, Inhibition of Respiration, Biofilm Formation, and Bioactive Molecule Production by Nanoparticles of Ag, ZnO, CuO, TiO2, and Al2O3 toward Beneficial Soil Bacteria</td>
      <td>71</td>
    </tr>
    <tr>
      <td>Study of Arsenic-Contaminated Soil Bacterial Community Using Biochip Technology</td>
      <td>71</td>
    </tr>
    <tr>
      <td>Probing the single and combined toxicity of PFOS and Cr(VI) to soil bacteria and the interaction mechanisms</td>
      <td>72</td>
    </tr>
    <tr>
      <td>Ecological responses of soil microbial abundance and diversity to cadmium and soil properties in farmland around an enterprise-intensive region</td>
      <td>72</td>
    </tr>
    <tr>
      <td>Microbial strategies in non-target invasive <i>Spartina densiflora</i> for heavy metal clean up in polluted saltmarshes</td>
      <td>72</td>
    </tr>
    <tr>
      <td>Co-presence of the anionic surfactant sodium lauryl ether sulphate and the pesticide chlorpyrifos and effects on a natural soil microbial community</td>
      <td>73</td>
    </tr>
    <tr>
      <td>Bioaugmentation assisted mycoremediation of heavy metal and/metalloid landfill contaminated soil using consortia of filamentous fungi</td>
      <td>73</td>
    </tr>
    <tr>
      <td>Sequential microbial-photocatalytic degradation of imidacloprid</td>
      <td>74</td>
    </tr>
    <tr>
      <td>Metagenomic applications in microbial diversity, bioremediation, pollution monitoring, enzyme and drug discovery. A review</td>
      <td>74</td>
    </tr>
    <tr>
      <td>Effects of biodegradable plastic film mulching on soil microbial communities in two agroecosystems</td>
      <td>75</td>
    </tr>
    <tr>
      <td>Bacterial community diversity in the rhizosphere of nickel hyperaccumulator plant species from Borneo Island (Malaysia)</td>
      <td>75</td>
    </tr>
    <tr>
      <td>Cadmium influences the litter decomposition of <i>Solidago canadensis</i> L. and soil N-fixing bacterial communities</td>
      <td>75</td>
    </tr>
    <tr>
      <td>Characterization of a high cadmium accumulating soil bacterium, <i>Cupriavidus</i> sp. WS2</td>
      <td>76</td>
    </tr>
    <tr>
      <td>Lead toxicity induced phytotoxic impacts on rapeseed and clover can be lowered by biofilm forming lead tolerant</td>
      <td></td>
    </tr>
  </tbody>
</table>
<table><tr><td>bacteria</td><td>76</td></tr><tr><td>The metolachlor degradation kinetics and bacterial community evolution in the soil bioelectrochemical remediation</td><td>77</td></tr><tr><td>Carbon and nitrogen cycling in a lead polluted grassland evaluated using stable isotopes (delta C-13 and delta N-15) and microbial, plant and soil parameters</td><td>77</td></tr><tr><td>Inoculation of Cd-contaminated paddy soil with biochar-supported microbial cell composite: A novel approach to reducing cadmium accumulation in rice grains</td><td>78</td></tr><tr><td>Zeolite-supported nanoscale zero-valent iron for immobilization of cadmium, lead, and arsenic in farmland soils: Encapsulation mechanisms and indigenous microbial responses</td><td>78</td></tr><tr><td>Assessing microbial degradation degree and bioavailability of BDE-153 in natural wetland soils: Implication by compound-specific stable isotope analysis</td><td>78</td></tr><tr><td>Comparative characterization of microbial communities that inhabit arsenic-rich and antimony-rich contaminated sites: Responses to two different contamination conditions</td><td>79</td></tr><tr><td>Transcriptome profiling of the fungus Aspergillus nidulans exposed to a commercial glyphosate-based herbicide under conditions of apparent herbicide tolerance</td><td>79</td></tr><tr><td>Resistant fungi isolated from contaminated uranium mine in Brazil shows a high capacity to uptake uranium from water</td><td>80</td></tr><tr><td>New insights into the microbial degradation and catalytic mechanism of synthetic pyrethroids</td><td>80</td></tr><tr><td>Algae-based heavy metal remediation in acid mine drainage: a review</td><td>81</td></tr><tr><td>Bacterial abundance along a gradient of heavy metal contaminated soils in the region of Zlatitsa-Pirdop valley, western Bulgaria</td><td>81</td></tr><tr><td>Complete genome sequencing and comparative genomic analyses of Bacillus sp. S3, a novel hyper Sb(III)-oxidizing bacterium</td><td>82</td></tr><tr><td>Kinetic Study of the Biodegradation of Acephate by Indigenous Soil Bacterial Isolates in the Presence of Humic Acid and Metal Ions</td><td>82</td></tr><tr><td>Modulations in growth, structure, cell viability and antioxidant enzyme of a nodule bacterium Mesorhizobium ciceri induced by pesticides</td><td>82</td></tr><tr><td>Effect of Fe-Mn-Ce modified biochar composite on microbial diversity and properties of arsenic-contaminated paddy soils</td><td>83</td></tr><tr><td>Ecotoxicological effects of mesotrione on enzyme activity and microbial community in agricultural soils</td><td>83</td></tr><tr><td>Ecological remediation of petroleum - contaminated soil based on microbial degradation</td><td>84</td></tr><tr><td>Atrazine Bioremediation and Its Influence on Soil Microbial Diversity by Metagenomics Analysis</td><td>84</td></tr><tr><td>Responses of Bacterial and Fungal Community Structure to Different Rates of 1,3-Dichloropropene Fumigation</td><td>85</td></tr><tr><td>Co-occurrence of antibiotic, biocide, and heavy metal resistance genes in bacteria from metal and radionuclide contaminated soils at the Savannah River Site</td><td>85</td></tr><tr><td>The Arsenic Methylation Cycle: How Microbial Communities Adapted Methylarsenicals for Use as Weapons in the Continuing War for Dominance</td><td>86</td></tr></table>

<table><tr><td>ERA / PUBLICATIONS SCIENTIFIQUES / MICROBIOLOGIE ET BIOCONTROLE</td><td>86</td></tr><tr><td>Methyl t-butyl ether-degrading bacteria for bioremediation and biocontrol purposes</td><td>86</td></tr><tr><td>Determinations of in vitro Antagonistic Effects of Microbiomes Isolated from Vermicompost Against Major Plant Fungal Disease Agents of Vegetables</td><td>87</td></tr></table>

<table><tr><td>ERA / PUBLICATIONS SCIENTIFIQUES / PESTICIDES ET FAUNE SAUVAGE</td><td>87</td></tr><tr><td>Nest-boxes for raptors as a biological control system of vole pests: High local success with moderate negative consequences for non-target species - ScienceDirect</td><td>87</td></tr><tr><td>Mediation of Oxidative Stress Toxicity Induced by Pyrethroid Pesticides in Fish</td><td>88</td></tr><tr><td>Toxic Elements in Blood of Red-Necked Nightjars (Caprimulgus Ruficollis) Inhabiting Differently Polluted Environments</td><td>88</td></tr><tr><td>Longitudinally Monitored Lifetime Changes in Blood Heavy Metal Concentrations and Their Health Effects in Urban Birds</td><td>88</td></tr><tr><td>From seeds to plasma: Confirmed exposure of multiple farmland bird species to clothianidin during sowing of winter cereals</td><td>89</td></tr><tr><td>Assessment of the effects of early life exposure to triphenyl phosphate on fear, boldness, aggression, and activity in</td><td></td></tr></table>
<table><tr><td>Japanese quail (Coturnix japonica) chicks</td><td>89</td></tr><tr><td>Organochlorine pesticides in feathers of three raptor species in southern Brazil</td><td>89</td></tr><tr><td>Trace element distribution in tissues and risk of exposure of ruddy shelduck wintering in Nanhaizi Wetland, Baotou, China</td><td>90</td></tr><tr><td>Uptake, Metabolism, and Elimination of Fungicides from Coated Wheat Seeds in Japanese Quail (Coturnix japonica)</td><td>90</td></tr><tr><td>Oxidative state of the frugivorous bat Sturnira lilium (Chiroptera: Phyllostomidae) in agricultural and urban areas of southern Brazil</td><td>90</td></tr><tr><td>Crop protection and biodiversity in agro-ecosystems</td><td>91</td></tr><tr><td>Mercury in fish from streams and rivers in New York State: Spatial patterns, temporal changes, and environmental drivers</td><td>91</td></tr><tr><td>Anthropogenic factors affecting wildlife species status outcomes: why the fixation on pesticides?</td><td>91</td></tr><tr><td>Pesticides and conservation of large ungulates: Health risk to European bison from plant protection products as a result of crop depredation</td><td>92</td></tr><tr><td>Evaluation of Mercury Contamination in Iranian Wild Cats Through Hair Analysis</td><td>92</td></tr><tr><td>Mercury bioaccumulation in tropical bats from a region of active artisanal and small-scale gold mining</td><td>92</td></tr></table>

<table><tr><td>ERA / PUBLICATIONS SCIENTIFIQUES / PESTICIDES / CLIMAT ET VDT/ENCHY</td><td>93</td></tr><tr><td>Acute toxicity, oxidative stress and DNA damage of chlorpyrifos to earthworms (Eisenia fetida): The difference between artificial and natural soils</td><td>93</td></tr><tr><td>Metal oxide nanoparticles facilitate the accumulation of bifenthrin in earthworms by causing damage to body cavity</td><td>93</td></tr><tr><td>Acute and chronic toxicity of the fungicide carbendazim to the earthworm Eisenia fetida under tropical versus temperate laboratory conditions</td><td>93</td></tr><tr><td>Do Long-Term Continuous Cropping and Pesticides Affect Earthworm Communities?</td><td>93</td></tr><tr><td>Effects of ciprofloxacin exposure on the earthworm Eisenia fetida</td><td>93</td></tr><tr><td>Towards a spatiotemporally explicit toxicokinetic-toxicodynamic model for earthworm toxicity</td><td>94</td></tr><tr><td>Synthesis of earthworm trace metal uptake and bioaccumulation data: Role of soil concentration, earthworm ecophysiology, and experimental design</td><td>94</td></tr><tr><td>Environmental risk for aquatic and terrestrial organisms associated with drift from pesticides used in soybean crops</td><td>94</td></tr><tr><td>Wormcasts produced by three earthworm species (Alma millsoni, Eudrilus eugeniae and Libyodrilus violaceus) exposed to a glyphosate-based herbicide reduce growth, fruit yield and quality of tomato (Lycopersicon esculentum)</td><td>94</td></tr><tr><td>Is nano ZnO/chlorpyrifos mixture more harmful to earthworms than bulk ZnO? A multigeneration approach</td><td>94</td></tr><tr><td>Residue and toxicity of cyantraniliprole and its main metabolite J9Z38 in soil-earthworm microcosms</td><td>95</td></tr><tr><td>The Toxic Effects of Sulfoxaflor Induced in Earthworms (Eisenia fetida) under Effective Concentrations</td><td>95</td></tr></table>

<table><tr><td>DROIT ET POLITIQUE DE L'ENVIRONNEMENT</td><td>95</td></tr><tr><td>Aquatic Pollutants - Transfer Project</td><td>95</td></tr><tr><td>Le réseau d'épidémiosurveillance financé par le plan Ecophyto - Réorientations à opérer</td><td>95</td></tr></table>

<table><tr><td>REGLEMENTATION / DROIT</td><td>96</td></tr><tr><td>Acide perfluorooctanoïque (PFOA), ses sels et les composés apparentés au PFOA</td><td>96</td></tr><tr><td>Substances actives beflubutamide, bénalaxyl, benthiavalicarb, bifénazate, boscalid, bromoxynil, captane, cyazofamid, diméthomorphe, éthéphon, étoxazole, famoxadone, fenamiphos, flumioxazine, fluoxastrobine, folpet, formétanate, métribuzine, milbémectine, Paecilomyces lilacinus - souche 251, phenmedipham, phosmet, pirimiphos-méthyl, propamocarbe, prothioconazole et S-métolachlore : prolongation de la validité de l'approbation</td><td>96</td></tr><tr><td>Enregistrement, l'évaluation et l'autorisation des substances chimiques, ainsi que les restrictions applicables à ces substances (REACH)</td><td>97</td></tr><tr><td>Mise sur le marché des produits phytopharmaceutiques : approbation renouvelée de la substance active «carvone»</td><td>97</td></tr><tr><td>Mise sur le marché des produits phytopharmaceutiques : non-approbation de l'extrait de propolis en tant que</td><td>97</td></tr></table>
<table><tr><td>substance de base</td><td>97</td></tr><tr><td>Mise sur le marché des produits phytopharmaceutiques : approbation de la substance de base «L-cystéine»</td><td>98</td></tr><tr><td>Mise sur le marché des produits phytopharmaceutiques : non-approbation des racines de Saponaria officinalis L. en tant que substance de base</td><td>98</td></tr><tr><td>Mise sur le marché des produits phytopharmaceutiques : approbation de la substance active «sénécioate de lavandulyle» en tant que substance à faible risque</td><td>98</td></tr><tr><td>Dérogation temporaire d'épandage par voie aérienne de produits phytopharmaceutiques pour les vignes dans les départements de l'Aude et de l'Hérault</td><td>98</td></tr><tr><td>Modalités d'épandage des boues issues du traitement des eaux usées urbaines pendant la période de covid-19</td><td>98</td></tr><tr><td>Mise sur le marché des produits phytopharmaceutiques : approbation de la substance active «foramsulfuron» renouvelée</td><td>99</td></tr><tr><td>Approbation de la substance active « métalaxyl-M » et restreignant l'utilisation de semences traitées avec des produits phytopharmaceutiques contenant cette substance</td><td>99</td></tr><tr><td>Produits biocides «HYPRED's octanoic acid based products» : règlement d'autorisation de l'Union</td><td>99</td></tr><tr><td>Famille de produits biocides «SOPURCLEAN» : règlement d'autorisation de l'Union</td><td>99</td></tr></table>

<table><tr><td>PUBLICATIONS DU RESEAU ECOTOX</td><td>100</td></tr><tr><td>New insights into methylmercury induced behavioral and energy-related gene transcriptional responses in European glass eel (Anguilla anguilla)</td><td>100</td></tr><tr><td>Field measurement and modelling of chlorotoluron and flufenacet persistence in unamended and amended soils</td><td>100</td></tr><tr><td>Combined thermal and insecticidal stresses on the generalist predator Macrolophus pygmaeus</td><td>101</td></tr><tr><td>Plants in the Light of Ionizing Radiation: What Have We Learned From Chernobyl, Fukushima, and Other "Hot" Places?</td><td>101</td></tr><tr><td>Assessment of residential exposures to agricultural pesticides: A scoping review</td><td>102</td></tr><tr><td>Spatio-temporal assessment of the polychlorinated biphenyl (PCB) sediment contamination in four major French river corridors (1945-2018)</td><td>102</td></tr><tr><td>Seasonal monitoring of cellular energy metabolism in a sentinel species, Dreissena polymorpha (bivalve): Effect of global change?</td><td>103</td></tr><tr><td>Dissipation of S-metolachlor and butachlor in agricultural soils and responses of bacterial communities: Insights from compound-specific isotope and biomolecular analyses</td><td>103</td></tr><tr><td>Towards a spatiotemporally explicit toxicokinetic-toxicodynamic model for earthworm toxicity</td><td>104</td></tr><tr><td>Anther-smut fungi from more contaminated sites in Chernobyl show lower infection ability and lower viability following experimental irradiation</td><td>104</td></tr><tr><td>Ex situ environmental risk assessment of polluted soils using threshold guide values for the land snail Cantareus aspersus</td><td>105</td></tr><tr><td>Miscanthus x giganteus culture on soils highly contaminated by metals: Modelling leaf decomposition impact on metal mobility and bioavailability in the soil-plant system</td><td>105</td></tr><tr><td>Undernutrition combined with dietary mineral oil hastens depuration of stored dioxin and polychlorinated biphenyls in ewes. 1. Kinetics in blood, adipose tissue and faeces</td><td>106</td></tr><tr><td>Undernutrition combined with dietary mineral oil hastens depuration of stored dioxin and polychlorinated biphenyls in ewes. 2. Tissue distribution, mass balance and body burden</td><td>106</td></tr><tr><td>Impact assessment of legacy wastes from ancient mining activities on current earthworm community</td><td>107</td></tr><tr><td>Proteogenomics-Guided Evaluation of RNA-Seq Assembly and Protein Database Construction for Emergent Model Organisms</td><td>107</td></tr><tr><td>Removal of organic micropollutants in anaerobic membrane bioreactors in wastewater treatment: critical review</td><td>108</td></tr><tr><td>Biotic and Abiotic Factors Influencing Arsenic Biogeochemistry and Toxicity in Fluvial Ecosystems: A Review</td><td>108</td></tr><tr><td>Field evaluation of one Cu-resistant somaclonal variant and two clones of tobacco for copper phytoextraction at a wood preservation site</td><td>109</td></tr><tr><td>Cross talk: Two way allelopathic interactions between toxic Microcystis and Daphnia</td><td>109</td></tr><tr><td>Usability of the bivalves Dreissena polymorpha and Anodonta anatina for a biosurvey of the neurotoxin BMAA in freshwater ecosystems</td><td>110</td></tr><tr><td>Dissolved organic matter does not promote glyphosate degradation in auto-heterotrophic aquatic microbial communities</td><td>110</td></tr></table>
<table><tr><td>Thiamethoxam induces transgenerational hormesis effects and alteration of genes expression in <i>Aphis gossypii</i></td><td>111</td></tr><tr><td>A sepiolite-based formulation for slow release of the herbicide mesotrione</td><td>111</td></tr><tr><td>Effects of sewage sludge supplementation on heavy metal accumulation and the expression of ABC transporters in <i>Sinapis alba</i> L. during assisted phytoremediation of contaminated sites</td><td>112</td></tr><tr><td>Modeling chlordecone toxicokinetics data in growing pigs using a nonlinear mixed-effects approach</td><td>112</td></tr><tr><td>Spinosad application in an apple orchard affects both the abundance of the spider Araneus diadematus and its web construction behaviour</td><td>113</td></tr><tr><td>Target and non-target impact of systemic insecticides on a polyphagous aphid pest and its parasitoid</td><td>113</td></tr><tr><td>Cadmium distribution in mature durum wheat grains using dissection, laser ablation-ICP-MS and synchrotron techniques</td><td>114</td></tr><tr><td>Effects of Pollution on Fish Behavior, Personality, and Cognition: Some Research Perspectives</td><td>114</td></tr><tr><td>To what extent can the biogeochemical cycling of mercury modulate the measurement of dissolved mercury in surface freshwaters by passive sampling?</td><td>114</td></tr><tr><td>Modelling assisted phytoremediation of soils contaminated with heavy metals - Main opportunities, limitations, decision making and future prospects</td><td>115</td></tr><tr><td>Impacts of metallic trace elements on an earthworm community in an urban wasteland: Emphasis on the bioaccumulation and genetic characteristics in <i>Lumbricus castaneus</i></td><td>115</td></tr><tr><td>Potential Use of Earthworms to Enhance Decaying of Biodegradable Plastics</td><td>116</td></tr><tr><td>Genotoxicity in the rivers from the Brantas catchment (East Java, Indonesia): occurrence in sediments and effects in <i>Oreochromis niloticus</i> (Linn AE us 1758)</td><td>116</td></tr><tr><td>Determination of polycyclic aromatic hydrocarbon (PAH) contents in micro-volumes of the whole blood and liver of Red Kite by a simplified GC-MS/MS method</td><td>117</td></tr><tr><td>Health risk assessment to dioxins, furans and PCBs in young children: The first French evaluation</td><td>117</td></tr><tr><td>Improving Silver Birch (<i>Betula pendula</i>) Growth and Mn Accumulation in Residual Red Gypsum Using Organic Amendments</td><td>118</td></tr><tr><td>Inorganic Mercury and Methyl-Mercury Uptake and Effects in the Aquatic Plant <i>Elodea nuttallii</i>: A Review of Multi-Omic Data in the Field and in Controlled Conditions</td><td>118</td></tr></table>

<table><tr><td>OUVRAGES / RAPPORTS / ACTES DE CONGRES</td><td>119</td></tr><tr><td>Exposure and Risk Assessment of Pesticide Use in Agriculture: 1st Ed. Approaches, Tools and Advances</td><td>119</td></tr></table>

<table><tr><td>REVUE DE PRESSE / ALTERNATIVES / BIOPESTICIDES</td><td>119</td></tr><tr><td>Alternatives au glyphosate : le travail du sol est le levier principal en grandes cultures</td><td>119</td></tr><tr><td>Alternative aux phytos Amoeba engage la procédure d'homologation en Europe de son biocide naturel</td><td>119</td></tr></table>

<table><tr><td>REVUE DE PRESSE / ASSOCIATIONS</td><td>120</td></tr><tr><td>Baisse supposée des pesticides : le ministère de l'Agriculture fait ce jour un coup de com' sur des chiffres provisoires</td><td>120</td></tr><tr><td>La commission de l'environnement du Parlement européen exige de la future stratégie européenne sur les produits chimiques une approche axée prioritairement sur la santé</td><td>120</td></tr><tr><td>Produits phytos - 44 % de pesticides vendus en 2019</td><td>121</td></tr><tr><td>Pac et Green Deal L'eurodéputé B. Biteau veut aller plus loin dans la réduction des pesticides</td><td>121</td></tr><tr><td>Le cuivre utilisé en bio est-il biodégradable ? Oui... mais en fait non, selon Générations Futures (!)</td><td>121</td></tr><tr><td>Action locale UFC-Que Choisir -Épandages agricoles -Pas près de nos habitations !</td><td>122</td></tr><tr><td>Des pesticides dans le bio à cause de l'UE ? C'est déjà le cas et l'UE n'y peut rien...</td><td>122</td></tr><tr><td>Tell USDA to Reject Bayer-Monsanto's Multi-Herbicide Tolerant Corn</td><td>123</td></tr><tr><td>Bayer-Monsanto Chalks Up Court Victory to Take Cancer Warning Off Roundup™-Glyphosate in California, Makes Case for Fundamental Overhaul of Pesticide Law</td><td>123</td></tr><tr><td>Bayer-Monsanto, Committed to Continued Sales of Roundup™-Glyphosate, Announces $10.9 Billion Settlement with Cancer Victims, Protects Company from Future Trials by Jury</td><td>123</td></tr><tr><td>Insecticides the Pesticide Industry Said Were "Safer for Bees" Found to Stress and Kill Honey Bees</td><td>124</td></tr><tr><td>Pollinator Week: We Protect People at Greatest Risk When We Protect Pollinators and the Environment from Toxic Pesticides</td><td>124</td></tr><tr><td>Débat national sur la future Pac Les thématiques environnementales au cœur des contributions</td><td>124</td></tr></table>
<table><tbody><tr><td>N'importons pas l'agriculture que nous ne voulons pas !</td><td>125</td></tr><tr><td>Alimentation : La Commission européenne veut transformer champs et assiettes</td><td>125</td></tr><tr><td>Réduction des distances d'épandage des pesticides : Le Conseil d'État retire deux textes litigieux mais ne retient pas l'urgence du retrait des dérogations</td><td>125</td></tr><tr><td>Federal Court Halts Use of Drift-Prone Dicamba on Millions of Acres of GE Soy and Cotton</td><td>125</td></tr><tr><td>Report Finds Monocropping and Toxic Pesticides Threaten Brazil's Native Bees as Country's President Challenges Environmental Protection</td><td>126</td></tr><tr><td>Participez à la consultation sur la nouvelle stratégie de l'UE sur les produits chimiques !</td><td>126</td></tr><tr><td>L'appel de Gil Rivière-Wekstein à Didier Guillaume sur l'interdiction du glyphosate en 2021 : « Il est temps de faire le bon choix »</td><td>126</td></tr><tr><td>Les preuves ne cessent de s'accumuler sur la dangerosité du BPA</td><td>127</td></tr><tr><td>Agriculture bio : le tabou des pesticides... y compris de synthèse !</td><td>127</td></tr><tr><td>Ingrédients dans les cosmétiques : le résorcinol épinglé, l'aluminium blanchi</td><td>127</td></tr><tr><td>I'd want more tools than just a hammer</td><td>128</td></tr><tr><td>High time for the EU to protect us from exposure to chemical mixtures</td><td>128</td></tr><tr><td>The Pesticide Atrazine and 200 Other Toxic Chemicals Found in Fracking Wastewater; Contamination Goes Unregulated</td><td>128</td></tr><tr><td>Occupational Exposure to Pesticides, and Other Environmental Chemicals Increase Risk of Developing ALS</td><td>129</td></tr><tr><td>Billet du président -Pesticides - Premier recul gouvernemental</td><td>129</td></tr><tr><td>EPA sneaks approval for harmful herbicide</td><td>129</td></tr><tr><td>DDT Metabolite (DDE) and Other Banned Pesticides Found in Blood Sample of African American Women in Detroit</td><td>129</td></tr><tr><td>Pilot Study Links Celiac Disease to Endocrine Disrupting Long-Lived Chemicals, like DDT, in the Environment</td><td>130</td></tr><tr><td>Exposition cumulée aux résidus de pesticides : l'Efsa conclut à l'absence de risque</td><td>130</td></tr><tr><td>Anses : des études complémentaires sur le potentiel cancérogène du glyphosate</td><td>130</td></tr><tr><td>Alerte aux pucerons : les betteraviers démunis à cause des mesures dites « environnementales »</td><td>131</td></tr><tr><td>Pourquoi il est urgent de soutenir l'Initiative Citoyenne Européenne pour une sortie des pesticides « Sauvez les abeilles et les agriculteurs » ?</td><td>131</td></tr><tr><td>Retour sur l'affaire glyphosate : affaire de gros sous aux USA, combat idéologique en Europe</td><td>131</td></tr><tr><td>Billet du président -Pesticides - L'inadmissible décision gouvernementale !</td><td>131</td></tr><tr><td>Glyphosate : toujours pas de solution pour le remplacer et une échéance qui approche en plein chaos économique</td><td>132</td></tr><tr><td>Animal Fodder - A Driver of the Global Highly Hazardous Pesticides (HHPs) Industry</td><td>132</td></tr><tr><td>One Quarter of Global Insect Population Lost Since 1990</td><td>132</td></tr><tr><td>Monarch Butterfly Larvae Adversely Affected by Pesticide Drift from Contiguous Soybean and Maize Crop Fields</td><td>132</td></tr></tbody></table>

<table><tbody><tr><td>REVUE DE PRESSE / RECHERCHE ET MEDIAS</td><td>133</td></tr><tr><td>Microplastic pollution accumulates heavily in coastal areas such as fjords and estuaries</td><td>133</td></tr><tr><td>Convention citoyenne pour le climat : les mesures agricoles pourraient être adoptées par Emmanuel Macron</td><td>133</td></tr><tr><td>Environmental Persistent Organic Pesticides in the Serum and Breast Milk of Lactating North Carolina Women</td><td>134</td></tr><tr><td>Common food additive causes adverse health effects in mice</td><td>134</td></tr><tr><td>Effects from low-level concentrations of harmful chemicals preserved in three generations of fish</td><td>134</td></tr><tr><td>Entry point for curbing the evolution of antibiotic resistance discovered</td><td>134</td></tr><tr><td>More evidence of causal link between air pollution and early death</td><td>135</td></tr><tr><td>Global pollution estimates reveal surprises, opportunity</td><td>135</td></tr><tr><td>Air pollution, smoking and built environment are associated with an increase risk of childhood obesity</td><td>135</td></tr><tr><td>New data reveals even low levels of air pollution triggers gene expression</td><td>136</td></tr><tr><td>Study: Air pollution major risk for cardiovascular disease regardless of country income</td><td>136</td></tr><tr><td>Présence de pesticides dans l'eau : Générations futures interpelle à nouveau le Gouvernement</td><td>136</td></tr><tr><td>Effondrement mondial des insectes : deux ONG dénoncent l'agriculture industrielle</td><td>136</td></tr><tr><td>Metabolomic Profiling to Inform Use of Surrogate Species in Ecological Risk Assessments</td><td>137</td></tr><tr><td>Coal-tar-sealant major source of PAH contamination in Great Lakes tributaries</td><td>137</td></tr><tr><td>Living near oil and gas wells may increase preterm birth risk</td><td>138</td></tr><tr><td>Genomic surveillance of antibiotic resistance in the Philippines established</td><td>138</td></tr></tbody></table>
<table><tr><td>PFAS present throughout the Yadkin-Pee Dee river food chain</td><td>138</td></tr><tr><td>New killing mechanism discovered in 'game-changing' antibiotic</td><td>138</td></tr><tr><td>Microplastic background pollution in the Curonian Spit beach</td><td>138</td></tr><tr><td>Researchers developing quick and simple method of glyphosate detection</td><td>139</td></tr><tr><td>Thousands of tons of ocean pollution can be saved by changing washing habits</td><td>139</td></tr><tr><td>Une ONG publie un atlas des insectes pour dénoncer l'usage des phytos</td><td>139</td></tr><tr><td>Data gaps hamper monitoring of heavy metals that threaten arctic communities</td><td>139</td></tr><tr><td>Impact of Diflubenzuron on Bombus Impatiens Microcolony Development</td><td>140</td></tr><tr><td>Gold mining with mercury poses health threats for miles downstream</td><td>140</td></tr><tr><td>Study demonstrates association between exposure to air pollution and vascular damage</td><td>140</td></tr><tr><td>Exploring the neurological impact of air pollution</td><td>140</td></tr><tr><td>Un nouvel outil européen pour recenser les perturbateurs endocriniens</td><td>141</td></tr><tr><td>Novel bioaccumulative compounds found in marine bivalves</td><td>141</td></tr><tr><td>Antibiotic-destroying genes widespread in bacteria in soil and on people</td><td>141</td></tr><tr><td>Pour le député UE P. Canfin, l'État doit financer les alternatives au glyphosate</td><td>141</td></tr><tr><td>La Commission lance une consultation sur l'utilisation durable des pesticides</td><td>142</td></tr><tr><td>Stratégie « De la ferme à la fourchette » : la Commission européenne fixe le cap pour 2030</td><td>142</td></tr><tr><td>Zones de non traitement : le recours du collectif des maires antipesticides rejeté en référé</td><td>142</td></tr><tr><td>You cannot avoid microplastics</td><td>142</td></tr><tr><td>Clay layers and distant pumping trigger arsenic contamination in Bangladesh groundwater</td><td>143</td></tr><tr><td>Filtering out toxic chromium from water</td><td>143</td></tr><tr><td>USF researchers find human-driven pollution alters the environment even underground</td><td>143</td></tr><tr><td>Pétition : France Grandes Cultures appelle à stopper la suppression des produits phytos</td><td>144</td></tr><tr><td>Ouverture d'un fonds de 30 M€ pour accompagner les agriculteurs</td><td>144</td></tr><tr><td>Phytosanitaires et ZNT Recours devant le tribunal administratif contre des préfets</td><td>144</td></tr><tr><td>Protection des riverains : 30 millions d'euros pour accompagner la mise en place des ZNT</td><td>144</td></tr><tr><td>Reach : vers une restriction de la fabrication et de l'utilisation des PFAS</td><td>145</td></tr><tr><td>Microplastique : les plus hauts niveaux jamais mesurés, découverts au fond de la Méditerranée</td><td>145</td></tr><tr><td>Cocktail de pesticides dans l'alimentation : la réglementation actuelle est suffisante selon l'Efsa</td><td>145</td></tr><tr><td>Antibiotic exposure can 'prime' single-resistant bacteria to become multidrug-resistant</td><td>146</td></tr><tr><td>Adsorbent material developed with PET bottles for the removal of antibiotics from water</td><td>146</td></tr><tr><td>Health impacts of pollution upon indigenous peoples</td><td>146</td></tr><tr><td>RIT scientists develop first 3D mass estimate of microplastic pollution in Lake Erie</td><td>146</td></tr><tr><td>Exposure to air pollution during pregnancy is associated with growth delays</td><td>147</td></tr><tr><td>How atrazine regulations have influenced the environment</td><td>147</td></tr><tr><td>CDC Finds Sharp Rise in Home Poisonings Tied to Disinfectant and Sanitizer Use during Covid-19 Pandemic; Safer Products Available</td><td>147</td></tr><tr><td>Report de 3 mois du délai de commercialisation du chlorprophame (CIPC)</td><td>147</td></tr><tr><td>ZNT : des députés dénoncent une réduction des distances d'épandage</td><td>148</td></tr><tr><td>Réduction des pesticides : les pistes du coordinateur interministériel pour vraiment changer les pratiques</td><td>148</td></tr><tr><td>Pesticides : les ONG s'attaquent aux chartes dérogeant aux distances minimales d'épandage</td><td>148</td></tr></table>
# Bioaccumulation et transfert trophique de contaminants dans les écosystèmes aquatiques : challenges & perspectives pour le réseau Ecotox

## Une question interdisciplinaire rassemblant écotoxicologues et chimistes

Plusieurs écotoxicologues et chimistes environnementaux membres ou sympathisants du réseau ECOTOX INRAE ont contribué, au cours de la dernière décennie, aux travaux menés dans le thème de recherche « Réponses biologiques et écologiques aux contaminations du milieu aquatique », animé par Jeanne Garric au sein de l'ancien Département Eaux d'Irstea<fnref n="1" />. Dans ce contexte, et sous l'impulsion de Marc Babut, s'est formé en 2015 un groupe de travail focalisé sur la question de la bioaccumulation des contaminants dans les milieux aquatiques continentaux. Cette initiative avait, entre autres, permis de constituer un collectif de 14 scientifiques (tableau 1) qui ont tous participé à ce thème de recherche (comme chercheur, post-doc ou doctorant), en vue de rédiger un article de synthèse sur le sujet. L'objectif était de rassembler les connaissances et d'identifier les principaux challenges scientifiques concernant la bioaccumulation dans les biofilms aquatiques (associés au périphyton, au compartiment sédimentaire ou aux litières végétales immergées) et son rôle dans le transfert des contaminants le long des chaînes trophiques (Bonnineau et al., 2020). Il s'agissait ainsi de :

i) rappeler les mécanismes responsables de la bioaccumulation dans ces assemblages microbiens,

ii) dresser un état des lieux des méthodes disponibles pour détecter, identifier et quantifier les contaminants bioaccumulés,

iii) proposer une revue critique de la littérature décrivant la bioaccumulation dans les biofilms et ses conséquences pour les chaînes trophiques et,

iv) identifier des perspectives de recherche pour mieux appréhender cette question complexe mais majeure pour améliorer les procédures d'évaluation des risques et impacts écotoxicologiques directs et indirects dans les écosystèmes aquatiques contaminés.

L'objectif de cette tribune libre est de présenter les principales conclusions de ce travail et de proposer des perspectives qui pourraient être déclinées à l'échelle du réseau ECOTOX. Cela pourrait notamment permettre de renforcer les liens entre les écotoxicologues et les chimistes environnementaux en fédérant les acteurs de ces deux disciplines autour de questions de recherche communes, transposables à différents types de contaminants ou d'écosystèmes.

<footnote n="1">¹ Jusqu'en 2018, les thèmes de recherche (TR, au nombre de 12) constituaient l'entité structurante des recherches au sein des Départements Irstea. Regroupant des équipes de différentes Unités (UR ou UMR), ils étaient notamment chargés de la programmation et de l'évaluation scientifique (sous l'égide du Département auquel ils étaient rattachés).</footnote>
<table><caption>**Tableau 1 :** Liste des contributeurs, par ordre alphabétique, à l'article de synthèse Bonnineau et al. (2020)</caption><thead><tr><td>Nom Prénom</td><td>Affiliation actuelle</td><td>Nom Prénom</td><td>Affiliation actuelle</td></tr></thead><tbody><tr><td>Artigas Joan</td><td>UCA, UMR LMGE</td><td>Lebrun Jérémie</td><td>INRAE, UR HYCAR</td></tr><tr><td>Babut Marc</td><td>INRAE, UR RiverLy</td><td>Margoum Christelle</td><td>INRAE, UR RiverLy</td></tr><tr><td>Bonnineau Chloé</td><td>INRAE, UR RiverLy</td><td>Mazzella Nicolas</td><td>INRAE, UR EABX</td></tr><tr><td>Chaumet Betty</td><td>CNRS/UPS, UMR ECOLAB</td><td>Miège Cécile</td><td>INRAE, UR RiverLy</td></tr><tr><td>Dabrin Aymeric</td><td>INRAE, UR RiverLy</td><td>Morin Soizic</td><td>INRAE, UR EABX</td></tr><tr><td>Faburé Juliette</td><td>AgroParisTech/INRAE, UMR ECOSYS</td><td>Pesce Stéphane</td><td>INRAE, UR RiverLy</td></tr><tr><td>Ferrari Benoît</td><td>Centre Ecotox (Suisse)</td><td>Uher Emmanuelle</td><td>SU (UPMC), UMR LAMS</td></tr></tbody></table>

## La bioaccumulation des contaminants par les communautés microbiennes benthiques

Dans les écosystèmes d'eau douce, les communautés microbiennes benthiques jouent un rôle écologique majeure par leur contribution aux cycles biogéochimiques (e.g. production primaire, dégradation de la matière organique). Ces assemblages microbiens complexes sont composés de différents micro-organismes (bactéries, cyanobactéries, micro-algues, hyphomycètes, protozoaires...) vivant en étroite interaction au sein d'une matrice de substances polymériques extracellulaires (EPS). Ces communautés microbiennes sont attachées à différents substrats : les communautés périphytiques (ou périphyton) se retrouvent sur les cailloux et sont dominées par les organismes autotrophes alors que les organismes hétérotrophes dominent les assemblages microbiens associés respectivement aux sédiments et aux litières végétales immergées.

En écotoxicologie, ces communautés microbiennes sont reconnues (et utilisées) comme des indicateurs pertinents de l'exposition aux contaminants en milieu aquatique et des effets toxiques qui en résultent. Les contaminants présents dans l'eau de surface (sous forme dissoute ou particulaire) sont susceptibles d'entrer en contact avec les biofilms, de s'y associer et de s'accumuler. Cette accumulation peut s'opérer soit à l'intérieur ou à la surface des micro-organismes ou soit dans la matrice EPS, via différents mécanismes : sorption, accumulation ou séquestration (pour les métaux) comme illustré par la Figure 1.

<figure><img src="image_3.png" /><figcaption>**Figure 1 :** Représentation schématique des interactions possibles entre contaminants et biofilms microbiens naturels</figcaption></figure>

Le développement des méthodes analytiques a permis d'améliorer la quantification des contaminants accumulés dans les biofilms. Ces méthodes sont présentées plus en détail dans l'article de synthèse (Bonnineau et al. 2020). Si les premières études dans les années 90 étaient centrées sur les métaux, les développements analytiques de la dernière décennie ont également permis la détection et la quantification dans les biofilms des contaminants organiques (e.g. HAPs, PCBs, pesticides, substances pharmaceutiques dont les antibiotiques). Cependant, la très grande majorité des études de bioaccumulation porte sur le périphyton pour lequel il est notamment possible de déterminer la distribution des contaminants (en particulier les métaux) dans ce type de biofilm (e.g. fraction intra-cellulaire vs fraction liée à la matrice). La
distribution des contaminants dans les biofilms peut également être observée de manière plus précise grâce aux méthodes d'imagerie comme la microscopie confocale laser à balayage. Néanmoins, aucune technique ne permet à ce jour de quantifier les contaminants accumulés dans les communautés microbiennes attachées aux sédiments ou à la litière de feuilles indépendamment de leur substrat.

Une méta-analyse réalisée sur 24 études publiées, et détaillée dans l'article de synthèse (Bonnineau et al. 2020), a mis en avant l'importante diversité des contaminants retrouvés dans le périphyton (toutes les classes sont représentées ; Fig. 2). Les contaminants organiques apparaissent comme des composés fortement bioaccumulables, les facteurs de concentrations les plus élevés ayant été observés pour les composés halogénés comme l'hexachlorobenzène ou les PCBs (Fig. 2). Une grande variété de contaminants (e.g. métaux, HAPs, résidus pharmaceutiques, pesticides) a également été identifiée dans les sédiments, sans qu'il soit possible de distinguer les contaminants réellement bioaccumulés par les communautés microbiennes de ceux liés uniquement au substrat. Les études sur les communautés microbiennes associées à la litière de feuille sont plus rares mais ont pu démontrer l'association de métaux, d'herbicides et de fongicides sur la litière de feuille immergée et colonisée par du biofilm, sans pouvoir là encore identifier la fraction réellement accumulée dans ce compartiment microbien.

<figure><img src="image_4.png" /><figcaption>**Figure 2 :** Facteur de bioconcentration (log(BCF)) pour le biofilm périphytique (n=304), données issues de 22 études publiées.</figcaption></figure>

**Cercle plein :** observations sur le terrain ; cercle vide : observations lors d'expérimentations en laboratoire.

HAP : hydrocarbure polycyclique aromatique, PCB : polychlorobiphényle, HCH : hexachlorocyclohexane, TBEP : tris(butoxyethyl)phosphate, DCPU : N-(3,4-dichlorophenyl)urea, DCPMU : N-(3,4-dichlorophenyl)-N-(methyl) urea, DDTs : dichlorodiphenyltrichloroethane

## Contribution aux transferts des contaminants dans les réseaux trophiques aquatiques

Dans les écosystèmes aquatiques d'eau douce, le biofilm, qui représente une ressource nutritive importante pour de nombreux macro-organismes (e.g. insectes, escargots, poissons, crevettes), joue un rôle pivot entre le réseau trophique vert (qui s'appuie sur la production primaire) et le réseau trophique brun (qui s'appuie sur l'apport de matière organique allochtone) (Bonnineau et al., 2020 ; Zou et al., 2016). De ce fait, il est potentiellement un acteur important du devenir et du transfert des contaminants dans ces réseaux trophiques. Cependant, nos recherches bibliographiques ont mis en évidence un nombre assez limité de travaux autour de cette question (Bonnineau et al. 2020). Quelques expériences en mésocosmes ont mis en évidence le transfert de métaux bioaccumulés dans le périphyton aux organismes consommateurs et ces travaux sont complétés par de rares études prenant en compte des contaminants organiques ou des nanoparticules. Il existe donc à ce jour un vrai déficit de connaissance concernant les
différents facteurs qui peuvent influencer le rôle des communautés microbiennes benthiques dans l'accumulation des contaminants dans les réseaux trophiques aquatiques.

## Conclusion & perspectives

Cette revue de la littérature illustre les interactions entre les contaminants et les communautés microbiennes benthiques et montre l'importance de ces communautés dans la dynamique spatio-temporelle des contaminants dans les milieux aquatiques continentaux. Cependant, d'importantes disparités de connaissances entre les différents types de biofilm (périphyton vs. communautés microbiennes attachées au sédiment ou à la litière de feuille) ou de contaminants (métaux vs. composés organiques) ont été mises en évidence, révélant les défis à relever pour améliorer notre compréhension du rôle des communautés microbiennes dans la dynamique des contaminants dans les écosystèmes aquatiques et leur transfert au sein des réseaux trophiques. Plus particulièrement, les défis ci-dessous sont essentiels à relever :

* Améliorer les méthodes analytiques pour quantifier les métaux et les composés organiques accumulés par les communautés microbiennes benthiques, indépendamment de leur substrat ;

* Mieux comprendre le lien entre les cinétiques de transfert, d'accumulation et de transformation des contaminants et leur toxicité pour les communautés microbiennes ;

* Préciser le rôle des communautés microbiennes dans la remobilisation ou le transport des polluants dans les milieux aquatiques ;

* Évaluer l'impact du changement climatique (e.g. sécheresse, hausse de température) sur la bioaccumulation des contaminants dans les biofilms et leur dynamique.

A l'intersection entre chimie environnementale, écotoxicologie, écologie, microbiologie, la résolution de ces problématiques requiert des collaborations étroites entre disciplines, qui pourraient se développer au sein du réseau Ecotox.

## Contacts

**Chloé Bonnineau & Stéphane Pesce** : INRAE, UR RiverLy, Villeurbanne.

chloe.bonnineau@inrae.fr; stephane.pesce@inrae.fr

**Juliette Faburé** : Université Paris-Saclay, INRAE, AgroParisTech, UMR ECOSYS, Versailles

juliette.fabure@agroparistech.fr

<figure><img src="image_5.png" /></figure>

## Pour en savoir plus

Bonnineau, C.; Artigas, J.; Chaumet, B.; Dabrin, A.; Faburé, J.; Ferrari, B. J. D.; Lebrun, J. D.; Margoum, C.; Mazzella, N.; Miège, C.; Morin, S.; Uher, E.; Babut, M.; Pesce, S. (2020) Role of Biofilms in Contaminant Bioaccumulation and Trophic Transfer in Aquatic Ecosystems: Current State of Knowledge and Future Challenges. In: Reviews of Environmental Contamination and Toxicology (Continuation of Residue Reviews). Springer, New York. doi.org/10.1007/398_2019_39.

## Bibliographie citée

Zou K, Thebault E, Lacroix G, Barot S (2016) Interactions between the green and brown food web determine ecosystem functioning. Funct Ecol. https://doi.org/10.1111/1365-2435.126
ERA / PUBLICATIONS

SCIENTIFIQUES /

COMMUNAUTES

MICROBIENNES

AQUATIQUES

Ecotoxicological effects of
sulfonamides and
fluoroquinolones and their
removal by a green alga
(Chlorella vulgaris) and a
cyanobacterium
(Chrysosporum ovalisporum)

Authors: Chen S, Zhang W, Li JY, Yuan MZ, Zhang JH, Xu F, Xu HT, Zheng XY, Wang LQ

Source: ENVIRONMENTAL POLLUTION
263:114554, 2020, DOI:
10.1016/j.envpol.2020.114554

**Abstract:** In recent years, antibiotic pollution has become worse, especially in China. In this study, the ecotoxicological effects of four frequently used antibiotics with different lipophilic degrees (log Kow) (sulfadiazine (SD), sulfamethazine (SM2), enrofloxacin (ENR), and norfloxacin (NOR)) at four concentrations of 1, 5, 20, and 50 mg L-1 were examined using batch cultures of green alga *Chlorella vulgaris* and cyanobacterium *Chrysosporum ovalisporum* for 16 days based on changes in chlorophyll fluorescence parameters (chl a, Fv/Fm, and Phi PSII) and responses of the antioxidant system. Besides, the antibiotics removal efficiencies of the two microalgae were investigated. Sulfonamides (SD and SM2) had no significant inhibitory effect on the growth of *C. ovalisporum*, but had an inhibitory effect on *C. vulgaris*, whereas fluoroquinolones (ENR and NOR) significantly inhibited *C. ovalisporum*. The activities of superoxide dismutase, catalase, and glutathione reductase suggested that *C. vulgaris* was more tolerant to these antibiotics than *C. ovalisporum*. The increased malondialdehyde level in both algae indicated their tolerance against antibiotics. When compared with *C.*

*ovalisporum*, *C. vulgaris* presented better capacity to remove antibiotics. In summary, the four antibiotics exerted time- or concentration-dependent ecotoxicological effects on the microalgae examined, whereas the microalgae could remove the antibiotics based on the log Kow of the antibiotics. The findings of this study contribute to effective understanding of the ecotoxicological effects of antibiotics and their removal by microalgae.

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Microplastics provide new
microbial niches in aquatic
environments

Authors: Yang YY, Liu WZ, Zhang ZL, Grossart HP, Gadd GM

Source: APPLIED MICROBIOLOGY AND BIOTECHNOLOGY Early Access, 2020, DOI: 10.1007/s00253-020-10704-x

**Abstract:** Microplastics in the biosphere are currently of great environmental concern because of their potential toxicity for aquatic biota and human health and association with pathogenic microbiota. Microplastics can occur in high abundance in all aquatic environments, including oceans, rivers and lakes. Recent findings have highlighted the role of microplastics as important vectors for microorganisms, which can form fully developed biofilms on this artificial substrate. Microplastics therefore provide new microbial niches in the aquatic environment, and the developing biofilms may significantly differ in microbial composition compared to natural free-living or particle-associated microbial populations in the surrounding water. In this article, we discuss the composition and ecological function of the microbial communities found in microplastic biofilms. The potential factors that influence the richness and diversity of such microbial microplastic communities are also evaluated. Microbe-microbe and microbe-substrate interactions in microplastic biofilms have been little studied and are not well understood. Multiomics tools together with morphological, physiological and biochemical analyses should be combined to provide a more comprehensive overview on the ecological role of microplastic biofilms. These new microbial niches have so far
unknown consequences for microbial ecology and environmental processes in aquatic ecosystems. More knowledge is required on the microbial community composition of microplastic biofilms and their ecological functions in order to better evaluate consequences for the environment and animal health, including humans, especially since the worldwide abundance of microplastics is predicted to dramatically increase.

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## Behavior of tetracycline and polystyrene nanoparticles in estuaries and their joint toxicity on marine microalgae *Skeletonema costatum*

**Authors:** Feng LJ, Shi Y, Li XY, Sun XD, Xiao F, Sun JW, Wang Y, Liu XY, Wang SG, Yuan XZ

**Source:** ENVIRONMENTAL POLLUTION 263(A):114453, 2020, DOI: 10.1016/j.envpol.2020.114453

**Abstract:** Polystyrene nanoplastics (PS NPs), which are newly emerging as particulate pollutants, are one of the most abundant plastic types in marine debris. Although there has been extensive research on microplastics, the sorption behavior of PS NPs in surface waters remains unknown. In addition, in the previous joint toxicity studies, the concentration of organic pollutant in the joint system was based on the EC50 of this pollutant, rather than the actually amount of this pollutant adsorbed on nanoplastics (NPs). In this study, the sorption behavior of PS NPs with different surface charges in the surface water of estuaries and joint toxicity of that absorbed tetracycline antibiotic in equilibrium were investigated for the first time. Because of the electrostatic repulsion, salting-out effect, and partition function, the sorption capacity of tetracycline antibiotic by differently charged PS NPs was enhanced with increasing salinity. The biological effects of exposure to tetracycline-saturated PS NPs were complicated, which can be attributed to the surface characteristics of mixtures such as hydrophobicity and charges. Thus, the role of NPs in the natural environment as a carrier of antibiotics may provide an alternative for antibiotic inputs from inland water to coastal

marine water, which would not only change the environmental fate and ecotoxicology of antibiotics and NPs, but also pose challenges to the safety of coastal aquaculture and marine ecosystem.

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## Combined effects of 17 beta-estradiol and copper on growth, biochemical characteristics and pollutant removals of freshwater microalgae *Scenedesmus dimorphus*

**Authors:** Li SX, Chu RY, Hu D, Yin ZH, Mo F, Hu TY, Liu CC, Zhu LD

**Source:** SCIENCE OF THE TOTAL ENVIRONMENT 730:138597, 2020, DOI: 10.1016/j.scitotenv.2020.138597

**Abstract:** Contamination by estrogens and heavy metals can cause great environment concern and necessitate efficient approaches for their removals. In this study, the combined effects of 17 beta-estradiol (E2) and Cu(II) on microalgae growth and biochemical characteristics were investigated. Results showed that 1 mg/L Cu(II) promoted the growth of *Scenedesmus dimorphus*, while 2 mg/L Cu(II) exhibited growth inhibition, compared with the same concentration of E2. Biochemical characteristics including enzyme activities as well as the contents of chlorophyll, protein and carbohydrate were significantly affected by the coexistence of E2 and Cu(II) after 12 d of cultivation. *S. dimorphus* exhibited high E2 and Cu(II) removal efficiencies (89.9% of E2 and 76.6% Cu(II) under the coexistence of 0.5 mg/L E2 and 1 mg/L Cu(II), respectively). Lower concentration of Cu(II) might serve as a bridge during E2 removal by *S. dimorphus* while competitive adsorption of Cu(II) and E2 occurred under the condition of excessive Cu(II). Results could confirm that *S. dimorphus* was a potential bioresource for the effective removal of E2 and Cu(II).

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## Pesticide Mixtures Cause Short-Term, Reversible
# Effects on the Function of Autotrophic Periphyton Assemblages

**Authors:** Bighiu MA, Gottschalk S, Arrhenius A, Goedkoop W

**Source:** ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY Early access, 2020, DOI: 10.1002/etc.4722

**Abstract:** In a laboratory experiment we investigated the effects of pesticide mixtures on the structure and function of freshwater biofilms, with focus on their photoautotrophic component. We identified 6 herbicides and 1 fungicide commonly found in Swedish streams at relatively high concentrations and created 3 ternary mixtures that were tested in concentration series ranging from observed environmental concentrations to up to 100 times higher. Biofilms were exposed to these pesticide mixtures for 8 d and then allowed to recover for another 12 d. Our results show a rapid and consistent inhibition of photosynthesis after just 24-h exposure to the highest test concentration of pesticides, as well as in some treatments with lower concentrations (i.e., 10 times the environmental level), on exposure. Interestingly, the observed effects were reversible because biofilm photosynthesis recovered rapidly and completely in clean media in all but one treatment. In contrast to the functional response, no effects were observed on the algal assemblage structure, as assessed by diagnostic pigments. We conclude that the pesticide mixtures induce a rapid but reversible inhibition of photosynthesis, without short-term effects on biofilm structure.

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# Selective grazing behaviour of chironomids on microalgae under pesticide pressure

**Authors:** Neury-Ormanni J, Doose C, Majdi N, Vedrenne J, Traunspurger W, Morin S

**Source:** SCIENCE OF THE TOTAL ENVIRONMENT 730:138673, 2020, DOI: 10.1016/j.scitotenv.2020.138673

**Abstract:** The herbicide diuron and the insecticide imidacloprid are amongst the most

frequently detected pesticides in French rivers, and each is known to affect many aquatic organisms. However, the question of whether and how both pesticides together might induce multi-stress conditions, which could induce indirect effects such as the modification of biological interactions within freshwater microbial communities has not received much attention. This study was undertaken to determine the effect of diuron and imidacloprid alone and in combination on the feeding behaviour of chironomid larvae.

An initial experiment measured the impact of the different contamination conditions at environmental concentrations (5 µg L-1 for each pesticide) on the grazing rate of chironomids on three microalgae species, independently. Two diatom species, Gomphonema gracile (two different morphotypes: normal and teratogen) and Planothidium lanceolatum, and one green alga Desmodesmus sp. were offered as food, during 24 h. Chironomids grazing rates varied according to the pesticide and algae species. Indeed, diuron impacted algae more strongly and probably affected their palatability, leading chironomids to increase grazing pressure on less nutritionally interesting algae. Imidacloprid, by targeting insect larvae, increased or inhibited their grazing capacity depending on the food source.

In a second experiment (cafeteria design), the food selectivity of chironomids on previous algae was determined under similar contamination conditions during 4 h: under diuron, larvae switched equally between the microalgae and were asmobile as in the control without pesticide. However, imidacloprid and the pesticidemixture condition altered chironomid movements and grazing behaviour.

By investigating the impact of an herbicide and an insecticide, alone and in combination, on the responses of food (algae growth rate) and biological (mortality) and behavioural (mobility, food selection) responses of chironomid larvae, this study provided new insights on the direct and indirect effects of pesticide contamination on a simplified trophic web.

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# Effects of Combined Ag and ZnO Nanoparticles on Microbial Communities from
## Crab Orchard Creek, Illinois, USA

**Authors:** Campobasso M, Peiravi M, Xia CJ, Liang YN, Liu J

**Source:** JOURNAL OF ENVIRONMENTAL ENGINEERING 146(7):04020067, 2020, DOI: 10.1061/(ASCE)EE.1943-7870.0001745

**Abstract:** The widespread use of Ag and ZnO nanoparticles (NPs) in commercial products has raised concern of their potential adverse impact on humans and the environment. These NPs most commonly enter the environment from the effluents of wastewater treatment plants (WWTPs). To understand the impact of these NPs on microbial communities, this study focused on adding environment-relevant concentrations of Ag (1 µg/L), ZnO (0.1 µg/L), and Ag+ZnO (1 µg/L+0.1 µg/L) to water collected from where the Carbondale Southeast WWTP effluent mixes with Crab Orchard Creek in IL, USA. Nanoparticles-spiked samples were withdrawn immediately and after 72 h for dynamic light scattering analysis. Optical density analysis by ultraviolet-visible spectroscopy, quantitative PCR analysis, and deoxyribonucleic acid sequencing were also conducted after 72 h. The results showed that ZnO NPs, at the studied concentration, were toxic, as a decrease in microbial biomass at Day 3 compared to the Control was reached, with an increase in mass fraction of nanoscale particles over time. However, when ZnO NPs were added in combination with Ag NPs, the adverse impact of ZnO NPs was mitigated, as an increase in microbial biomass was reached compared to the Control at Day 3, with a decrease in mass fraction of nanoscale particles over time. Ag NPs alone, at the studied concentration, did not bring significant impact on the microbial biomass. The relative abundance of the bacterial population affected the most by the addition of NPs was Firmicutes, with an increase in 13.74% compared to the Control when Ag+ZnO NPs were added. This study demonstrated the response of microbial communities to increased environment-relevant concentrations of NPs in a short period of time. The result will provide information that may aid in the preparation of guidance or regulations related to discharge of mixtures of NPs to surface water.

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## Chronic exposure to CuO nanoparticles induced community structure shift and a delay inhibition of microbial functions in multi-species biofilms

**Authors:** Miao LZ, Wang PF, Hou J, Ning DL, Liu ZL, Liu SQ, Li TF

**Source:** JOURNAL OF CLEANER PRODUCTION 262:121353,2020, DOI: 10.1016/j.jclepro.2020.121353

**Abstract:** Periphytic biofilms have served as a potentially important environmental media of contaminants removal and an important indicator of the health of aquatic systems. When the nanoparticles (NPs) released, they are likely to encounter periphytic biofilms, and then their ecosystem functioning might be changed. Here, we explored the long-term (28 days) impacts of CuO NPs (mM magnitude) on the microbial biomass, metabolic activities, community structure and associated ecosystem-level processes in multi-species biofilms inoculated from lake water. Slight aggregation of CuO NPs was observed during the exposure experiment. All of the algal, fungal, and bacterial community structure in biofilms were already altered by seven days of exposure to 0.781 and 7.81 mM CuO NPs, but a series of functional endpoints did not show clear differences, suggesting the functional redundancy within biofilm communities. After 28 days, however, a wide range of microbial endpoints that are specific to autotrophs (photosynthetic yield) or heterotrophs (basal respiration) or enzymes that represent the target communities were significantly affected. These decreases matched with the total copper content in biofilms, and indicated the negative effects of CuO NPs on the primary production and nutrient cycling of biofilms. Overall, the response of biofilms to CuO NPs produced a slow and delayed effect on microbial-mediated functions over community structure. These results highlight the highly sensitive responses of biofilms in fresh water to CuO NP, suggesting that CuO NPs (at environmentally relevant doses) would, although changes are slow, affect the biofilms' functioning and services, such as their sustainability for purification of polluted surface water.

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Microplastics affect sedimentary microbial communities and nitrogen cycling

Authors: Seeley ME, Song B, Passie R, Hale RC

Source: NATURE COMMUNICATIONS 11:1, 2020, DOI: 10.1038/s41467-020-16235-3

**Abstract:** Microplastics are ubiquitous in estuarine, coastal, and deep sea sediments. The impacts of microplastics on sedimentary microbial ecosystems and biogeochemical carbon and nitrogen cycles, however, have not been well reported. To evaluate if microplastics influence the composition and function of sedimentary microbial communities, we conducted a microcosm experiment using salt marsh sediment amended with polyethylene (PE), polyvinyl chloride (PVC), polyurethane foam (PUF) or polylactic acid (PLA) microplastics. We report that the presence of microplastics alters sediment microbial community composition and nitrogen cycling processes. Compared to control sediments without microplastic, PUF- and PLA-amended sediments promote nitrification and denitrification, while PVC amendment inhibits both processes. These results indicate that nitrogen cycling processes in sediments can be significantly affected by different microplastics, which may serve as organic carbon substrates for microbial communities. Considering this evidence and increasing microplastic pollution, the impact of plastics on global ecosystems and biogeochemical cycling merits critical investigation. Plastic pollution has infiltrated every ecosystem, but few studies have quantified the biogeochemical or ecological effects of plastic. Here the authors show that microplastics in ocean sediment can significantly alter microbial community structure and nitrogen cycling.

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Microalgal Metallothioneins and Phytochelatins and Their Potential Use in Bioremediation

Authors: Balzano S, Sardo A, Blasio M, Chahine TB, Dell'Anno F, Sansone C, Brunet C

Source: FRONTIERS IN MICROBIOLOGY 11:517, 2020, DOI: 10.3389/fmicb.2020.00517

**Abstract:** The persistence of heavy metals (HMs) in the environment causes adverse effects to all living organisms; HMs accumulate along the food chain affecting different levels of biological organizations, from cells to tissues. HMs enter cells through transporter proteins and can bind to enzymes and nucleic acids interfering with their functioning. Strategies used by microalgae to minimize HM toxicity include the biosynthesis of metal-binding peptides that chelate metal cations inhibiting their activity. Metal-binding peptides include genetically encoded metallothioneins (MTs) and enzymatically produced phytochelatins (PCs). A number of techniques, including genetic engineering, focus on increasing the biosynthesis of MTs and PCs in microalgae. The present review reports the current knowledge on microalgal MTs and PCs and describes the state of art of their use for HM bioremediation and other putative biotechnological applications, also emphasizing on techniques aimed at increasing the cellular concentrations of MTs and PCs. In spite of the broad metabolic and chemical diversity of microalgae that are currently receiving increasing attention by biotechnological research, knowledge on MTs and PCs from these organisms is still limited to date.

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Nanoplastics exposure modulate lipid and pigment compositions in diatoms

Authors: Gonzalez-Fernandez C, Le Grand F, Bideau A, Huet A, Paul-Pont I, Soudant P

Source: ENVIRONMENTAL POLLUTION 262:114274, 2020, DOI: 10.1016/j.envpol.2020.114274

**Abstract:** The impact of nanoplastics (NP) using model polystyrene nanoparticles amine functionalized (PS-NH2) has been investigated on pigment and lipid compositions of the marine diatom Chaetoceros neogracile, at two growth phases using a low (0.05 µg mL-1) and a high (5 µg mL-1) concentrations for 96 h. Results evidenced an impact on pigment composition
associated to the light-harvesting function and photo-protection mainly at exponential phase. NP also impacted lipid composition of diatoms with a readjustment of lipid classes and fatty acids noteworthy. Main changes upon NP exposure were observed in galactolipids and triacylglycerol's at both growth phases affecting the thylakoids membrane structure and cellular energy reserve of diatoms. Particularly, exponential cultures exposed to high NP concentration showed an impairment of long chain fatty acids synthesis. Changes in pigment and lipid content of diatom's cells revealed that algae physiology is determinant in the way cells adjust their thylakoid membrane composition to cope with NP contamination stress. Compositions of reserve and membrane lipids are proposed as sensitive markers to assess the impact of NP exposure, including at potential predicted environmental doses, on marine organisms.

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## Impact of polystyrene nanoparticles on marine diatom Skeletonema marinoi chain assemblages and consequences on their ecological role in marine ecosystems

**Authors:** Bellingeri A, Casabianca S, Capellacci S, Faleri C, Paccagnini E, Lupetti P, Koelmans AA, Penna A, Corsi I

**Source:** ENVIRONMENTAL POLLUTION
262:114268, 2020, **DOI:** 10.1016/j.envpol.2020.114268

**Abstract:** Marine diatoms have been identified among the most abundant taxa of microorganisms associated with plastic waste collected at sea. However, the impact of nano-sized plastic fragments (nanoplastics) at single cell and population level is almost unknown. We exposed the marine diatom *Skeletonema marinoi* to model polystyrene nanoparticles with carboxylic acid groups (PS-COOH NPs, 90 nm) for 15 days (1, 10, 50 µg/mL). Growth, reactive oxygen species (ROS) production, and nano-bio-interactions were investigated. No effect on diatom growth was observed, however Dynamic light scattering (DLS) demonstrated the

formation of large PS aggregates which were localized at the diatoms' fultoportula process (FPP), as shown by TEM images. Increase production of ROS and reduction in chain length were also observed upon PS NPs exposure (p &#60; 0.005). The observed PS-diatom interaction could have serious consequences on diatoms ecological role on the biogeochemical cycle of carbon, by impairing the formation of fast-sinking aggregates responsible for atmospheric carbon fixation and sequestration in the ocean sea floor.

S. marinoi exposure to PS NPs caused an increase of intracellular and extracellular oxidative stress, the reduction of diatom's chain length and the adhesion of PS NPs onto the algal surface.

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## Interplay between extracellular polymeric substances (EPS) from a marine diatom and model nanoplastic through eco-corona formation

**Authors:** Grassi G, Gabellieri E, Cioni P, Paccagnini E, Faleri C, Lupetti P, Corsi I, Morelli E

**Source:** SCIENCE OF THE TOTAL ENVIRONMENT
725:138457, 2020, **DOI:** 10.1016/j.scitotenv.2020.138457

**Abstract:** The occurrence of nanoplastics in oceans' surface waters is no more a hypothesis and it could severely affect marine organisms from different trophic levels. Nanoscale particles interaction with dissolved natural organic matter (NOM) significantly influence their behaviour and consequently bioavailability and toxicity to marine species. Extracellular polymeric substances (EPS) are among the main components of the NOM pool in seawater yet have been so far little investigated for their effect in altering the physical-chemical properties of nanosized objects. Here we employed EPS from marine diatom Phaeodactylum tricornutum to study the evolution of an eco-corona formation upon incubation with 60 nm carboxylated polystyrene nanoparticles (PS-COOH NPs), as proxy for nanoplastics in seawater. EPS significantly
reduced PS-COOH NPs aggregation rate compared to biomolecule free natural seawater (NSW) and caused the formation of complexes constituted by both carbohydrate and protein components. Size Exclusion Chromatography (SEC) revealed four main distinct groups of peaks, spanning from high (100 kDa) to low molecular weight (20 kDa) molecules, characterized by a high chemical heterogeneity. The lowering of the chromatographic signals detected after EPS incubation with PS-COOH NPs, mainly in the eluates at high molecular weight, suggests that an important fraction of EPS remained adsorbed on PS-COOH NPs. In agreement, SDS-PAGE analysis of proteins adsorbed on PS-COOH showed the occurrence of an eco-corona formed by proteins in the range of molecular weight 30-100 kDa. No toxicity to diatoms was observed upon PS-COOH exposure (72 h, 1-100mg L-1) even by adding a further source of exogenous EPS during exposure. Moreover, the addition of EPS reduced ROS production, even when cells were incubated with PS-COOH NPs at 10 and 50 mg L-1, suggesting an antioxidant scavenging activity of EPS.

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## An exploratory study of benthic diatom communities in stormwater ponds of different land uses and varying biocide contamination

**Authors:** Minelgaite G, van Alst N, Stephansen DA, Bollmann UE, Bester K, Fejerskov ML, Nielsen AH, Vollertsen J

**Source:** AQUATIC ECOLOGY Early Access, 2020, DOI: 10.1007/s10452-020-09773-x

**Abstract:** Stormwater retention ponds receive a variety of urban and highway pollutants that may have adverse effects on water-dwelling organisms. In this exploratory study, the benthic diatom community composition at genus level of nine such ponds servicing highway, residential, industrial, and mixed industrial/residential catchments was examined. Thirteen biocides were measured in the pond water as one of the possible explanatory factors for diatom taxonomic variability. The uppermost 1 cm of sediment was sampled, and a total of 50 diatom

genera were identified. Moderate to high similarities were found among the diatom communities of the ponds. Two genera, namely Navicula and Nitzschia, were the most abundant and accounted for 19-47% of the relative abundance in the ponds. Estimated relative abundances of diatom genera and measured biocide concentrations in the ponds were grouped according to land use. Highway ponds were found to be significantly different from ponds servicing residential and industrial catchments, while no significant differences were found between residential and industrial ponds. The presence of biocides alone could not explain diatom taxonomic variability, although some evidence was found that communities differed depending on the catchment type of the ponds. The results of this exploratory study are an important contribution to future works investigating stormwater diatom communities, where combined effects of biocides and other stormwater contaminants and community stressors, e.g., metals, PAHs, road salt, should be explicitly looked at.

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## Differential Effects of the Allelochemical Juglone on Growth of Harmful and Non-Target Freshwater Algae

**Authors:** Park MH, Kim K, Hwang SJ

**Source:** APPLIED SCIENCES-BASEL 10(8):2873, 2020, DOI: 10.3390/app10082873

**Abstract:** Alelopathy has been applied to control nuisance algae in aquatic systems, but the effects of allelochemicals on the broad spectrum of algae are not well understood. We investigate algicidal effects of the allelochemical juglone on the bloom-forming, harmful algae *Microcystis aeruginosa* and *Stephanodiscus hantzschii*, and on several non-target algal species including cyanobacteria (Anabaena flos-aquae, *Oscillatoria curviceps*, and *Phormidium subfuscum*), diatoms (*Asterionella formosa*, *Fragilaria crotonensis*, and *Synedra acus*), and green algae (*Chlorella vulgaris*, *Scenedesmus ecornis*, and *Scenedesmus quadricauda*), in laboratory and field enclosure bioassays. Under three treatment concentrations (0.01, 0.1, and 1 mg L-1) of juglone, *Microcystis* cell density is significantly reduced by 35-93%. Concentrations of 0.1 and 1 mg L-1 inhibits
Stephanodiscus growth almost equally (66% and 75%, respectively). To contrast, juglone produces a stimulatory allelopathic effect on three green algae, and other tested diatoms showed hormesis. Overall, the cyanobacteria are more sensitive to juglone than the green algae and diatoms. These results indicate that the allelopathic effects of juglone on microalgae vary depending on their characteristic cellular morphology and anatomy.

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# Influence of biofilm on the transport and deposition behaviors of nano- and micro-plastic particles in quartz sand

**Authors:** He L, Rong HF, Wu D, Li M, Wang CY, Tong MP

**Source:** WATER RESEARCH 178:115808, 2020, DOI: 10.1016/j.watres.2020.115808

**Abstract:** Biofilm, community of bacteria ubiquitously present in natural environment, may interact with plastic particles and affect the transport of plastic particles in environment. The significance of biofilm (Escherichia coli) on the transport and deposition behaviors of three different sized plastic particles (0.02 µm NPs, 0.2 µm MP and 2 µm MP) were examined under both 10 mM and 50 mM NaCl solutions by comparing the breakthrough curves and retained profiles of plastic particles in bare sand versus those in biofilm-coated sand. Regardless of ionic strengths, the presence of biofilm increases the deposition of all three sized plastic particles in porous media. Via employing X-ray microtomography imaging (XMT) and Scanning electron microscope (SEM), we find that the presence of biofilm could narrow the flow path especially near to the inlet of the column and increase the surface roughness of porous media (by decreasing DLVO repulsive interaction), which contributes to the enhanced deposition of plastic particles. Extracellular polymeric substances (EPS) present on the biofilm are found to contribute to the enhanced deposition of plastic particles. Packed column experiments, quartz crystal microbalance with dissipation (QCM-D) as well as parallel plate flow chamber experiments all show that three major

components of EPS, proteins, polysaccharide, and humic substances all contribute to the enhanced deposition of plastic particles. O-H and N-H groups present on cell surfaces are highly likely to form hydrogen bond with plastic particles and increase the deposition plastic particles. Elution experiments show that decreasing solution ionic strength could release small portion of plastic particles from both bare and biofilm-coated sand columns especially from the segments near to the column inlet (with slighter lower percentage from biofilm-coated columns based on the total mass of retained plastics). In contrast, increasing flow rate does not obviously detach the plastic particles that already deposited onto porous media. The results of this study clearly show that the presence of biofilm in natural environment could enhance the deposition and decrease the transport of plastic particles.

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# Pesticide bioaccumulation in epilithic biofilms as a biomarker of agricultural activities in a representative watershed

**Authors:** dos Santos DR, Lima JAMD, de Vargas JPR, Bastos MC, dos Santos MAS, Mondamert L, Labanowski J

**Source:** ENVIRONMENTAL MONITORING AND ASSESSMENT 192(6):381, 2020, DOI: 10.1007/s10661-020-08264-8

**Abstract:** Brazil is one of the largest consumers of pesticides in the world. The high rainfall rate and inadequate soil use and management promote the transfer of these compounds to the aquatic system. The aim of this study was to identify and quantify pesticides present in epilithic biofilms in order to evaluate the effectiveness of this matrix as a bioindicator able to discriminate areas and periods with different inputs of pesticides. Among the 25 pesticides analyzed in the biofilms, 20 compounds were detected. The epilithic biofilms picked up pesticides independent of their polarities, even in the period of lower use. The frequency and median concentration of five herbicides (2,4-D, atrazine, desethyl-atrazine, simazine, nicosulfuron), three fungicides (carbendazim,
epoxiconazole, tebuconazole), and one insecticide (imidacloprid) were highest in biofilms sampled in summer crops during the growing period. Biofilms collected in the upper region of the catchment, where genetically modified soybean and corn cultivated in a no-tillage system prevail, the highest frequency and median concentration of three herbicides (2,4-D, thifensulfuron, isoproturon), four fungicides (carbendazim, epoxiconazole, tebuconazole, metconazole), and one insecticide (imidacloprid) were observed. Despite the excessive amounts of pesticides used in the catchment, the median values of all pesticides in the epilithic biofilm were considered low. The lower diversity and concentration of pesticides observed in the autumn/winter season is representative of lower use of pesticides, barriers to pesticide transfer from soil to water, and the biofilm's resilience capacity to decompose pesticides.

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## Investigating the composition and distribution of microplastics surface biofilms in coral areas

**Authors:** Feng LM, He L, Jiang SQ, Chen JJ, Zhou CX, Qian ZJ, Hong PZ, Sun SL, Li CY

**Source:** CHEMOSPHERE 252:126565, 2020, DOI: 10.1016/j.chemosphere.2020.126565

**Abstract:** In recent years, global climate change and pollution of the marine environment have caused large-scale coral deaths and severe damages to coral reef ecosystems. Numerous studies have shown that coral diseases are closely related to microorganisms. And microplastics (MPs) are a potential threat to corals. In marine ecosystems, MPs are an emerging contaminant. MPs have a strong adsorption effect on pollutants in the water environment, and they are very easily colonized by microorganisms to form biofilms. Biofilms may accumulate many pathogens, increasing the probability of coral disease. However, there is no report about the composition of biofilms on the surface of microplastics in coral growth areas. In this study, nine kinds of MPs were chosen in the experiments, which are commonly found in the ocean. Four stakeout points were selected in the coral area. Biofilms were cultivated in natural environment. The composition and distribution

of biofilms on the surface of the MPs were analyzed by 16 S rRNA sequencing. The characteristics of biofilms were observed by scanning electron microscopy (SEM). The experimental results show that the species composition and abundance distribution of the biofilm on the MP surface are significantly different from the surrounding seawater. The type of MPs and the stake out point are important factors affecting the structure of the biofilm bacterial community. Compared to seawater samples, MPs are enriched with certain dominant bacteria such as Vibrionaceae, Rhodobacteraceae, Flavobacteraceae, Microtrichaceae and Sphingomonadaceae. Among them, Vibrionaceae, Rhodobacteraceae and Flavobacteraceae are closely related to the tissue damage of stony corals, and Vibrios are also the main pathogens of coral albinism. In addition, Pseudomonas and Bbellvibrio cholerae are also detected on the MPs biofilm. SEM graphs of the MPs after culture could clearly observe rodshaped bacteria and Streptococci. This study can provide a new direction for the study of coral toxicology by MPs and provide basic data for the toxicology research of MPs.

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## Do environmental concentrations of zinc oxide nanoparticle pose ecotoxicological risk to aquatic fungi associated with leaf litter decomposition?

**Authors:** Du JJ, Zhang YY, Yin YT, Zhang J, Ma H, Li K, Wan N

**Source:** WATER RESEARCH 178:115840, 2020, DOI: 10.1016/j.watres.2020.115840

**Abstract:** Ecotoxicological risk of ZnO nanoparticles at environmental levels is a key knowledge gap for predicting how freshwater ecosystems will respond to nanoparticle pollution. A microcosm experiment was conducted to explore the chronic effects of ZnO nanoparticle at environmental concentrations (30, 300, 3000 ng L-1) on aquatic fungi associated with the decomposing process of poplar leaf litter (45 days). ZnO nanoparticles led to 9-33% increases in fungal biomass after acute exposure (5 days), but 33-50% decreases
after chronic exposure (45 days), indicating that the hormetic effect of ZnO nanoparticles at the environmental level may occur during acute exposure. Besides, ZnO nanoparticles had negative effects on microbial enzyme activity, especially on day 10, when the activities of N-acetylglucosaminidase, glycine-aminopeptidase, aryl-sulfatase, polyphenol oxidase, and peroxidase were significantly inhibited. After chronic exposure, the fungal community structure was significantly impacted by ZnO nanoparticles at 300 ng L-1 due to the reduced proportion of Anguillospora, which eventually caused a significant decrease in litter decomposition rate. Therefore, ZnO nanoparticles may pose ecotoxicological effects on aquatic fungi even at a very low concentration and eventually negatively affect freshwater functioning.

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## Toxicity of ten herbicides to the tropical marine microalgae *Rhodomonas salina*

**Authors:** Thomas MC, Flores F, Kaserzon S, Fisher R, Negri, AP

**Source:** SCIENTIFIC REPORTS 10(1), 2020, DOI: 10.1038/s41598-020-64116-y

**Abstract:** Herbicide contamination of nearshore tropical marine ecosystems is widespread and persistent; however, risks posed by most 'alternative' herbicides to tropical marine microalgae remain poorly understood. Experimental exposures of the important but understudied microalgae *Rhodomonas salina* to seven individual Photosystem II (PSII) inhibitor herbicides (diuron, metribuzin, hexazinone, tebuthiuron, bromacil, simazine, propazine) led to inhibition of effective quantum yield (Delta F/F-m') and subsequent reductions in specific growth rates (SGR). The concentrations which reduced Delta F/F-m' by 50% (EC50) ranged from 1.71-59.2 µgL-1, while the EC50s for SGR were 4-times higher, ranging from 6.27-188 µgL-1. Inhibition of Delta F/F-m' indicated reduced photosynthetic capacity, and this correlated linearly with reduced SGR (R²=0.89), supporting the application of F/F-m' inhibition as a robust and sensitive indicator of sub-lethal toxicity of PSII inhibitors for this microalga. The three non-

PSII inhibitor herbicides (imazapic, haloxyfop and 2,4-Dichlorophenoxyacetic acid (2,4-D)) caused low or no toxic responses to the function of the PSII or growth at the highest concentrations tested suggesting these herbicides pose little risk to *R. salina*. This study highlights the suitability of including *R. salina* in future species sensitivity distributions (SSDs) to support water quality guideline development for the management of herbicide contamination in tropical marine ecosystems.

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## Effect of norfloxacin on performance, microbial enzymatic activity and microbial community of a sequencing batch reactor

**Authors:** Li SS, Ma BR, She ZL, Guo L, Zhao YG, Jin CJ, Gao MC

**Source:** ENVIRONMENTAL TECHNOLOGY & INNOVATION 18:100726, 2020, DOI: 10.1016/j.eti.2020.100726

**Abstract:** The performance, microbial community and enzymatic activity of a sequencing batch reactor have been assessed under norfloxacin stress. The COD removal was restrained at 5-30 mg/L norfloxacin, whereas there was a slight inhibition on the NH4+-N removal at 30 mg/L norfloxacin. The effluent NO3- kept an increasing trend under norfloxacin stress. The oxygen uptake rate, nitrifying rate and denitrifying rate of activated sludge maintained the decreasing trend with the increase of norfloxacin concentration from 0 to 30 mg/L. The variation tendencies of microbial enzymatic activity interrelated with nitrogen transformation was similar to the corresponding nitrifying rate and denitrifying rate under norfloxacin stress. The existence of norfloxacin promoted the extracellular polymeric substances (EPS) production, reactive oxygen species generation and lactate dehydrogenase release of microorganisms in activated sludge due to the potential biotoxicity of norfloxacin. The protein and polysaccharide contents of loosely bound EPS (LB-EPS) and tightly bound EPS (LB-EPS) maintained an increasing trend with the increase of norfloxacin concentration. The chemical composition of EPS was also impacted under
norfloxacin stress. The microbial diversity and richness displayed some distinct differences at different norfloxacin concentrations.

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# Dissolved organic matter does not promote glyphosate degradation in auto-heterotrophic aquatic microbial communities

Authors: Artigas J, Batisson I, Carles L

Source: ENVIRONMENTAL POLLUTION
259:113951, 2020, DOI: 10.1016/j.envpol.2020.113951

**Abstract:** Environmental dissolved organic matter (DOM) has been proved to increase microbial population sizes and stimulate the degradation of some pesticide molecules. Among these molecules, the present study investigated the biodegradation of the herbicide glyphosate depending on photoautotrophs DOM supply in a microbial consortium isolated from river biofilms. Degradation experiments in the laboratory were performed in dark and light conditions, as well as after antibiotic supply, in order to characterize the eventual interactions between photoautotrophs and heterotrophs activity during glyphosate degradation. Fifty percent of the initial concentration of glyphosate (0.6 mM) was transformed into aminomethyl phosphonic acid (AMPA) after 9 days in presence or absence of light. Accordingly, the photoautotrophic DOM supply was not stimulating glyphosate degradation by microbial heterotrophs. This lack of response was probably explained by the low net primary production values and weak dissolved organic carbon production recorded in light treatments. The supply of the antibiotic drastically stopped glyphosate transformation demonstrating the central role of bacteria in the biodegradation of the herbicide. Glyphosate also modified the structure of prokaryotes assemblages in the consortium by increasing the relative abundances of Alphaproteobacteria and slightly decreasing those of Gammaproteobacteria. The chemoorganotrophic bacteria Phenylobacterium sp. (Alphaproteobacteria) was related to the transformation of glyphosate in our microbial consortium. The present study highlights the

complexity of microbial interactions between photoautotrophs and heterotrophs in microbial assemblages that can contribute to the degradation of pesticides present in aquatic environments.

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# Impacts of organic matter on the toxicity of biosynthesized silver nanoparticles to green microalgae *Chlorella vulgaris*

Authors: Khoshnamvand M, Ashtiani S, Chen YS, Liu JF

Source: ENVIRONMENTAL RESEARCH 185:109433, 2020, DOI: 10.1016/j.envres.2020.109433

**Abstract:** The increasing production of eco-friendly nanoparticles like biosynthesized nanoparticles (BNPs) calls for study on their environmental and biological safety. Herein, the impact of natural organic matter on the toxicity of BNPs was studied. Using leaf extract of herbal plant *Allium fistulosum*, the *Allium fistulosum*-silver nanoparticles (AF-AgNPs) were synthesized with the yield of around 100% and used to explore the impacts of natural organic matter (Suwannee river humic acid) on their toxicity to green microalgae *Chlorella vulgaris*. The results showed that the as-prepared AF-AgNPs could decrease the end-points of biomass and chlorophyll a content of *C. vulgaris* in a dose-dependent manner. In addition, AF-AgNPs enhanced algal aggregation and decreased size of cells, especially at higher concentrations. However, organic matter showed an ameliorative effect on the toxicity of AF-AgNPs, and significant enhancement of biomass and chlorophyll a content (p < 0.05) were observed in media treated with higher contents of AF-AgNPs. Organic matter could also prevent more cellular aggregation and size reduction of *C. vulgaris*. Our results are helpful for understanding the effects of organic matter on the toxicity of BNPs to aquatic organisms.

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# Biofilms Provide New Insight into Pesticide Occurrence in
# Streams and Links to Aquatic Ecological Communities

**Authors:** Mahler BJ, Schmidt TS, Nowell LH, Qi SL, Van Metre PC, Hladik ML, Carlisle DM, Munn MD, May J

ENVIRONMENTAL SCIENCE & TECHNOLOGY
54(9):5509-5519, 2020, DOI:
10.1021/acs.est.9b07430

**Abstract:** Streambed sediment is commonly analyzed to assess occurrence of hydrophobic pesticides and risks to aquatic communities. However, stream biofilms also have the potential to accumulate pesticides and may be consumed by aquatic organisms. To better characterize risks to aquatic life, the U.S. Geological Survey Regional Stream Quality Assessment measured 93 current-use and 3 legacy pesticides in bed sediment and biofilm from 54 small streams in California across a range of land-use settings. On average, 4 times as many current-use pesticides were detected in biofilm at a site (median of 2) as in sediment (median of 0.5). Of 31 current-use pesticides detected, 20 were detected more frequently in biofilm than in sediment and 10 with equal frequency. Pyrethroids as a class were the most potentially toxic to benthic invertebrates, and of the 9 pyrethroids detected, 7 occurred more frequently in biofilm than sediment. We constructed general additive models to investigate relations between pesticides and 6 metrics of benthic community structure. Pesticides in biofilm improved fit in 4 of the 6 models, and pesticides in sediment improved fit in 2. The results indicate that the sampling of stream biofilms can complement bed-sediment sampling by identification of more current-use pesticides present and better estimation of ecological risks.

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# Infrared spectroscopy as a tool to monitor interactions between nanoplastics and microalgae

**Authors:** Deniel M, Lagarde F, Caruso A, Errien N

**Source:** ANALYTICAL AND BIOANALYTICAL CHEMISTRY, Early Access, 2020, DOI: 10.1007/s00216-020-02683-9

**Abstract:** The unicellular photosynthetic organisms known as microalgae are becoming

one of the most important models for aquatic system studies. Among them, *Chlamydomonas reinhardtii* is widely used as a bioindicator of pollution or of different changes in the environment. Numerous pollutants are present in aquatic environments, particularly plastics and nanoplastics. Physiological variations after an environmental change highlight variation in the macromolecular composition of microalgae (proteins, nucleic acids, lipids and carbohydrates). Recently, Fourier transform infrared vibrational spectroscopy has been described as a reliable tool, sensitive and allowing rapid measurement of macromolecular composition of microalgae. Coupled with preprocessing and principal component analysis, it is well adapted to monitoring the effect of environmental stress on biochemical composition. In this study, infrared spectroscopy, combined with multivariate analysis, has been tested first on known environmental stresses such as light intensity variation and nitrogen limitation. Then, this technique has been applied to monitor the interaction and potential impacts of polystyrene nanoparticles on microalgae. The results showed slight variations on protein and carbohydrates bands in the presence of nanoplastics, suggesting that their presence led to modifications in the biochemical composition of the microalgae. To confirm the interaction between microalgae and nanoplastics, visualization by confocal microscopy and cytotoxicity measurement has been carried out. Results showed that polystyrene nanoparticles seemed to adsorb on microalgae surface, leading to a loss of plasma membrane integrity. The resulting chemical modifications, even if moderate, could be detected by infrared spectroscopy, showing that this tool could be very helpful in the understanding of nanoparticle-microalgae interaction mechanisms.

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# Effects of Bisphenol A on the microalga *Chlamydomonas reinhardtii* and the clam *Corbicula fluminea*

**Authors:** Esperanza M, Seoane M, Servia MJ, Cid A
**Source:** ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 197:110609, 2020, DOI: 10.1016/j.ecoenv.2020.110609

**Abstract:** Bisphenol A (BPA) is used throughout the world and it could enter aquatic ecosystems causing harmful effects on humans, animals and plants. The current study relies on the investigation of the toxicity of this emerging pollutant on two freshwater species from different trophic levels: the microalga *Chlamydomonas reinhardtii* and the clam *Corbicula fluminea*.

After 96 h of exposure to several concentrations of BPA, the growth of *C. reinhardtii* was affected, being the 96 h-EC50 value for growth 30 mg L-1. The toxicity and bioaccumulation of 30 mg L-1 BPA in microalgae after 24 h of exposure were studied. Several cytotoxicity biomarkers such as vitality, oxidative stress and cytoplasmic membrane potential were altered in exposed cells and microalgae accumulated 0.16 pg BPA cell(-1).

Regarding *C. fluminea*, four treatments were established: control without BPA (C); BPA in the food (microalgae pre-exposed for 24 h to 30 mg L-1) (M); BPA in the water (7.5 mg L-1) (W); BPA in both food and water (M + W). After one month of exposure, treated bivalves showed a significantly decrease in the filtration rate and increased lipid peroxidation levels, indicating fitness reduction and oxidative damage. Furthermore, the activities of catalase, glutathione reductase, Se-dependent and total glutathione peroxidase enzymes increased significantly in W and M + W treatments with respect to the control. Clams of the M + W treatment were the most affected, indicating that the little amount of BPA bioaccumulated by microalgae could increase the damage. Emerging contaminants may accumulate in several organisms, such as microalgae, and could have negative impacts on ecosystems.

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Evaluation of toxic effects of
platinum-based
antineoplastic drugs
(cisplatin, carboplatin and
oxaliplatin) on green alga
*Chlorella vulgaris*

**Authors:** Dehghanpour S, Pourzamani HR, Amin MM, Ebrahimpour K

**Source:** AQUATIC TOXICOLOGY 223:105495, 2020, DOI: 10.1016/j.aquatox.2020.105495

**Abstract:** Platinum-based antineoplastic drugs (PBADs) enter the environment via hospital and municipal wastes as reactive and highly toxic molecules. *Chlorella vulgaris* is a freshwater microalgae and is used as an excellent aquatic model for toxicity assessment. In the present study, the toxicity of PBADs to *C. vulgaris* was investigated for better understanding of PBADs environmental toxicity. The algae were cultured in Bold's Basal Medium (BBM) and exposed to different concentrations of PBAD5 for 48, 72 and 96 h. Then, cell proliferation, the synthesis of photosynthetic pigments, protein content, malondialdehyde (MDA) release and antioxidant potential were determined. IC(50)s of cisplatin, carboplatin and oxaliplatin for 96 h of exposure were 106.2, 124.3 and 153.9 mg/L respectively. Cell proliferation, synthesis of chlorophyll a, chlorophyll b and algal protein content significantly decreased in a time and dose-dependent manner. The release of MDA to culture media significantly increased and antioxidant potential decreased.

Cisplatin showed more toxic effects on *C. vulgaris* compared to carboplatin and oxaliplatin indicating its severe toxicity for marine organisms. PBADs induce their toxic effects in algal cells via the interaction with DNA, production of free radicals (such as reactive oxygen species), lipid peroxidation and cell wall damages. Due to these toxic effects of PBAD5 for various environmental organisms, there must be severe restriction on their release into the environment.

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Major Role of Surrounding Environment in Shaping Biofilm Community Composition on Marine Plastic Debris

**Authors:** Basili M, Quero GM, Giovannelli D, Manini E, Vignaroli C, Avio CG, De Marco R, Luna GM
**Source:** FRONTIERS IN MARINE SCIENCE 7:262, 2020, DOI: 10.3389/fmars.2020.00262

**Abstract:** Plastic debris in aquatic environments is colonized by microbes, yet factors influencing biofilm development and composition on plastics remain poorly understood. Here, we explored the microbial assemblages associated with different types of plastic debris collected from two coastal sites in the Mediterranean Sea. All plastic samples were heavily colonized by prokaryotes, with abundances up to 1.9 x 10(7) cells/cm². Microbial assemblages on plastics significantly differed between the two geographic areas but not between polymer types, suggesting a major role of the environment as source for the plastisphere composition. Nevertheless, plastic communities differed from those in the surrounding seawater and sediments, indicating a further selection of microbial taxa on the plastic substrates. The presence of potential pathogens on the plastic surface reflected the levels of microbial pollution in the surrounding environment, regardless of the polymer type, and confirmed the role of plastics as carriers for pathogenic microorganisms across the coastal ocean, deserving further investigations.

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## Lanthanum and Cerium Toxicity to the Freshwater Green Alga *Chlorella fusca*: Applicability of the Biotic Ligand Model

**Authors:** Aharchaou I, Beaubien C, Campbell PGC, Fortin C

**Source:** ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 39(5):996-1005, 2020, DOI: 10.1002/etc.4707

**Abstract:** The environmental risk assessment of rare earth elements (REEs) requires data on their potential toxicity. In the present study, the toxicity of lanthanum (La) and cerium (Ce) was studied in relation to metal speciation in solution. For both La and Ce, the use of organic ligands demonstrated that the calculated free ion concentration was a good indicator of toxicity. Whether in the absence or presence of organic ligands, when based on free ion concentrations, the obtained half-maximal

effective concentrations were similar. When all generated data were pooled, Ce and La showed identical toxicity thresholds after 120 h of exposure with free ion concentration-based median effective concentration values (95% confidence intervals) of 0.48 (0.38-0.60) µM and 0.47 (0.36-0.61) µM for La3+ and Ce3+, respectively. The inhibition of algal growth was also correlated with the intracellular lanthanide concentrations, regardless of the ligand used. Finally, increasing the ambient calcium concentration protected the test algae by reducing the amount of lanthanide internalized into the cells. These results suggest that, at constant pH (5.5), REE accumulation and toxicity are linked to the free ion concentration and ambient calcium concentration, as predicted by the biotic ligand model.

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## Cultivation substrata differentiate the properties of river biofilm EPS and their binding of heavy metals: A spectroscopic insight

**Authors:** Wang LF, Chen W, Song XC, Li Y, Zhang WL, Zhang HJ, Niu LH

**Source:** ENVIRONMENTAL RESEARCH 182:109052, 2020, DOI: 10.1016/j.envres.2019.109052

**Abstract:** River biofilms inevitably serve as recipients of heavy metals including copper (Cu) and cadmium (Cd) following their introduction in fluvial systems. Nevertheless, the effects of cultivation substrata on the characteristics of river biofilm extracellular polymeric substances (EPS) and the binding behaviors of heavy metals on biofilms remain unclear. Integrating spectroscopic methods with chemometric analyses, we explored the binding behaviors of Cu(II) and Cd(II) onto biofilm EPS cultivated from two representative substrata at the molecular level. Chemical analysis revealed that biofilm cultivated on polyethylene (PE) pieces contained more non-fluorescent protein fractions, whereas EPS from periphyton grown on mineral, i.e., cobblestones was richer in aromatic fractions and polysaccharides. Excitation-emmision matrix combined with parallel factor analysis suggested a stronger interaction between fluorophores in periphytic EPS with Cu(II) compared to
fluorophores in plastic biofilm EPS. Integrated use of infrared spectroscopy and two-dimensional correlation analyses revealed that, during the heavy metal binding processes, the amines and phenolics in plastic biofilm EPS gave the fastest responses to metal binding. While the amides and the aliphatic fractions in periphytic EPS showed a preferential binding to heavy metals. This study differentiates the effects of cultivation substrata on structuring the biofilm EPS characteristics and offers new insights into the environmental behaviors of heavy metal discharge into fluvial systems in river biofilm matrix.

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Reproductive cycle
progression arrest and
modification of cell
morphology (shape and
biovolume) in the alga
*Pseudokirchneriella*
*subcapitata* exposed to
metolachlor

Authors: Machado MD, Soares EV

Source: AQUATIC TOXICOLOGY 222:105449, 2020, DOI: 10.1016/j.aquatox.2020.105449

**Abstract:** Metolachlor (MET) is an herbicide widely used and frequently found (at µg L-1) in aquatic systems. This work aimed to study the modes of action of MET on the green microalga *Pseudokirchneriella subcapitata*. Algae exposed to 115 or 235 µg L-1 MET, for 48 or 72 h, presented a reduction of metabolic activity, chlorophyll a and b content and photosynthetic efficiency. The exposure to 115 or 235 µg L-1 MET also induced growth yield reduction, mean cell biovolume increase and alteration of the typical algae shape (cells lunate or helically twisted) t(o) "French croissant"-type; at these MET concentrations, algal population was mainly composed by multinucleated cells ( = 4 nuclei), which suggest that MET impairs the normal progression of the reproductive cycle but did not hinder nuclear division. The accumulation of multinucleated cells seems to be the consequence of the incapacity of the parent cell to release the autospores. In conclusion, MET disrupts the physiology of P. subcapitata cells;

the disturbance of the progression of the reproductive cycle should be in the origin of growth slowdown (or even its arrest), increase of mean cell biovolume and modification of algal shape. This work contributed to elucidate, in a systematically and integrated way, the toxic mechanism of MET on the non-target organism, the alga P. subcapitata.

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Resistant fungi isolated from
contaminated uranium mine
in Brazil shows a high
capacity to uptake uranium
from water

Authors: Coelho E, Reis TA, Cotrim M, Mullan TK, Correa, B

Source: CHEMOSPHERE 248:126068, 2020, DOI: 10.1016/j.chemosphere.2020.126068

**Abstract:** The Osamu Utsumi uranium mine occupies a 20 km² area in the city of Caldas, which is located in the state of Minas Gerais, Brazil. Since mining activities ended at Osamu Utsumi 24 years ago, the surrounding area has become contaminated by acid effluents containing high concentrations of uranium. Thus, the aim of this study was to assess the uranium bioremediation capacity of 57 fungi isolated from the mine area. In tolerance tests, 38% (22) of the fungal isolates were considered tolerant to uranium, including 10 Penicillium species. At a uranium concentration of 2000 mg L-1 48 fungi did not exhibit mycelial growth index inhibition. Minimal inhibitory concentration (MIC) analysis showed growth of 25 fungi above a uranium concentration of 8000 mg L-1. At high uranium concentrations, some fungi (i.e., *Talaromyces amestolkiae* and *Penicillium citrinum*) showed morphological changes and pigment (melanin) production. Among the fungal isolates, those considered to be more tolerant to uranium were isolated from soil and sediment samples containing higher concentrations of heavy metal. When comparing the results of resistance/tolerance tests with those for uranium biosorption capacity, we concluded that the fungi isolated from the Osamu Utsumi mine with the best potential for uranium bioremediation were Gongronella butleri, Penicillium piscarium, Penicillium citrinum,
Penicillium ludwigii, and Talaromyces amestolkiae. Biosorption tests with live fungal biomass showed that 11 species had a high potential for uranium uptake from contaminated water.

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Understanding the influence
of glyphosate on the
structure and function of
freshwater microbial
community in a microcosm

Authors: Lu T, Xu NH, Zhang Q, Zhang ZY, Debognies A, Zhou ZG, Sun LW, Qian HF

Source: ENVIRONMENTAL POLLUTION
260:114012, 2020, DOI:
10.1016/j.envpol.2020.114012

Abstract: Glyphosate, one of the most popular herbicides, has become a prominent aquatic contaminant because of its huge usage. The eco-safety of glyphosate is still in controversy, and it is inconclusive how glyphosate influences aquatic microbial communities. In the present study, the effects of glyphosate on the structure and function of microbial communities in a freshwater microcosm were investigated. 165/185 rRNA gene sequencing results showed that glyphosate treatment (2.5 mg L-1, 15 days) did not significantly alter the physical and chemical condition of the microcosm or the composition of the main species in the community, but metatranscriptomic analyses indicated that the transcriptions of some cyanobacteria were significantly influenced by glyphosate. The microbial community enhanced the gene expression in pathways related to translation, secondary metabolites biosynthesis, transport and catabolism to potentially withstand glyphosate contamination. In the low phosphorus (P) environment, a common cyanobacterium, Synechococcus, plays a special role by utilizing glyphosate as P source and thus reducing its toxicity to other microbes, such as Pseudanabaena. In general, addition of glyphosate in our artificial microcosms did not strongly affect the aquatic microbial community composition but did alter the community's transcription levels, which might be potentially explained by that some microbes could alleviate

glyphosate's toxicity by utilizing glyphosate as a
P source.

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Species-specific sensitivity of
three microalgae to sediment
elutriates

Abstract: Gallo A, Guida M, Armiento G, Siciliano A, Mormile N, Carraturo F, Pellegrini D, Morroni L, Tosti E, Ferrante MI, Montresor M, Molisso F, Sacchi M, Danovaro R, Lofrano G, Libralato G

Source: MARINE ENVIRONMENTAL RESEARCH
156:UNSP104901, 2020, DOI:
10.1016/j.marenvres.2020.104901

Abstract: Microalgae are considered good bioindicators of marine environmental quality. Frequently, they are used to investigate the toxicity of sediment elutriates, but their sensitivity is disputed. This paper compared the sensitivity of *Phaeodactylum tricornutum* (diatom), *Skeletonema costatum* (diatom), and *Dunaliella tertiolecta* (green alga), analyzing 257 samples of elutriates (1:4 sediment: water ratio), considering growth inhibition (72 h) as the reference endpoint and sediment chemical (metals, metalloids and polyaromatic hydrocarbons) and grain size. Results of the toxicity tests showed that the microalgae sensitivity was not correlated. The integration of chemical data did not allow to discriminate toxicity effects but contributed to highlight that *D. tertiolecta* was the most sensitive microalgae (no cell wall) followed by *P. tricornutum* and *S. costatum*. Further analysis, including lines of evidence and weight of evidence approaches to calculate risk quotients of elutriate samples, confirmed these results.

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Effects of oxytetracycline on
growth and chlorophyll a
fluorescence in green algae
(Chlorella vulgaris), diatom
(Phaeodactylum tricornutum)
and cyanobacteria
## (Microcystis aeruginosa and Nodularia spumigena)

**Authors:** Siedlewicz G, Zak A, Sharma L, Kosakowska A, Pazdro K

**Source:** OCEANOLOGIA 62(2):214-225, 2020, DOI: 10.1016/j.oceano.2019.12.002

**Abstract:** The study aimed at measuring the influence of a wide range of oxytetracycline concentrations, with particular attention to the low levels of the antibiotic on cyanobacteria *Microcystis aeruginosa* and *Nodularia spumigena*, diatom *Phaeodactylum tricornutum* and the model green algae *Chlorella vulgaris* by conducting prolonged toxicity tests (lasting 10 days). Standard measurements (cell number, optical density, chlorophyll a concentration) were combined with photosynthetic parameters measurements. The obtained results show that concentrations of oxytetracycline present in the environment can affect tested microorganisms. It was found to decrease photosystem II efficiency and disrupt the photosynthesis process. A careful interpretation of photosynthetic parameters allowed a better understanding of the mode of action of oxytetracycline in relation to non-target photoautotrophic organisms like cyanobacteria and microalgae. In conclusion, it would appear that the use of standard chronic toxicity tests (72 h) does not allow to accurately and reliably assess the chronic impact of bioactive compounds including drugs and their metabolites on water organisms. On this basis, we recommend the application of extended duration tests.

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## Ecotoxicological effects of alpha-cypermethrin on freshwater alga *Chlorella* sp.: Growth inhibition and oxidative stress studies

**Authors:** Baruah P, Chaurasia N

**Source:** ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 76:103347, 2020, DOI: 10.1016/j.etap.2020.103347

**Abstract:** Alpha-cypermethrin (ACy) is a synthetic pyrethroid insecticide commonly used in agricultural practices for controlling a broad

range of insect pests particularly belonging to the order Lepidoptera and Coleoptera. The present study aims to evaluate the toxic effect of ACy on microalgae by studying its influence on *Chlorella* sp. According to our knowledge, this is the first detailed study of ACy toxicity on microalgae. Significant growth inhibition of *Chlorella* sp. was observed at high ACy concentration (6-48 mg L-1) during the entire 96 h bioassay. The 96 h median effective concentration (EC50) of ACy was estimated to be 11.00 mg L-1. Flow cytometry analysis showed an enhanced generation of reactive oxygen species (ROS) and intracellular lipid accumulation after 96 h exposure to 11.00 mg L-1 of ACy. Further, the same ACy concentration showed a significant decrease in photosynthetic pigment content and an increase in antioxidant enzyme activity and malondialdehyde (MDA) content in *Chlorella* sp.

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## The potential assessment of green alga *Chlamydomonas reinhardtii* CC-503 in the biodegradation of benz(a)anthracene and the related mechanism analysis

**Authors:** Luo J, Deng JL, Cui LL, Chang P, Dai XZ, Yang CY, Li NN, Ren ZM, Zhang XH

**Source:** CHEMOSPHERE 249:126097, 2020, DOI: 10.1016/j.chemosphere.2020.126097

**Abstract:** Benz(a)anthracene (BaA) is a polycyclic aromatic hydrocarbons (PAHs), that belongs to a group of carcinogenic and mutagenic persistent organic pollutants found in a variety of ecological habitats. In this study, the efficient biodegradation of BaA by a green alga *Chlamydomonas reinhardtii* (C. reinhardtii) CC-503 was investigated. The results showed that the growth of C. reinhardtii was hardly affected with an initial concentration of 10 mg/L, but was inhibited significantly under higher concentrations of BaA (30 mg/L) (p < 0.05). We demonstrated that the relatively high concentration of 10 mg/L BaA was degraded completely in 11 days, which indicated that C. reinhardtii had an efficient degradation system. During the degradation, the intermediate metabolites were determined to be isomeric phenanthrene or anthracene, 2,6-
diisopropylnaphthalene, 1,3-
diisopropylnaphthalene, 1,7-
diisopropylnaphthalene, and cyclohexanol. The
enzymes involved in the degradation included
the homogentisate 1,2-dioxygenase (HGD), the
carboxymethylenebutenolidase, the ribulose 1,5-
bisphosphate carboxylase/oxygenase (Rubisco)
and the ubiquinol oxidase. The respective genes
encoding these proteins were significantly
upregulated ranging from 3.17 fold to 13.03 fold
and the activity of enzymes, such as HGD and
Rubisco, was significantly induced up to 4.53 and
1.46 fold (p &#60; 0.05), during the BaA
metabolism. This efficient degradation ability
suggests that the green alga *C. reinhardtii* CC-
503 may be a sustainable candidate for PAHs
remediation.

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Nanoplastics Promote
Microcystin Synthesis and
Release from Cyanobacterial
Microcystis aeruginosa

Authors: Feng LJ, Sun XD, Zhu FP, Feng Y, Duan JL, Xiao F, Li XY, Shi Y, Wang Q, Sun JW, Liu XY, Liu JQ, Zhou LL, Wang SG, Ding ZJ, Tian HY, Galloway TS, Yuan XZ

Source: ENVIRONMENTAL SCIENCE & TECHNOLOGY 54(6):3386-3394, 2020, DOI: 10.1021/acs.est.9b06085

**Abstract:** Although the fate of nanoplastics (<100 nm) in freshwater systems is increasingly well studied, much less is known about its potential threats to cyanobacterial blooms, the ultimate phenomenon of eutrophication occurrence worldwide. Previous studies have evaluated the consequences of nanoplastics increasing the membrane permeability of microbes, however, there is no direct evidence for interactions between nanoplastics and microcystin; intracellular hepatotoxins are produced by some genera of cyanobacteria. Here, we show that the amino-modified polystyrene nanoplastics (PS-NH2) promote microcystin synthesis and release from Microcystis aeruginosa, a dominant species causing cyanobacterial blooms, even without the change of coloration. We demonstrate that PS-NH2 inhibits photosystem II efficiency, reduces organic substance synthesis, and induces oxidative stress, enhancing the synthesis of

microcystin. Furthermore, PS-NH2 promotes the extracellular release of microcystin from M. aeruginosa via transporter protein upregulation and impaired cell membrane integrity. Our findings propose that the presence of nanoplastics in freshwater ecosystems might enhance the threat of eutrophication to aquatic ecology and human health.

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Biofilm alters tetracycline
and copper adsorption
behaviors onto polyethylene
microplastics

Authors: Wang Y, Wang XJ, Li Y, Li J, Wang F, Xia SQ, Zhao JF

Source: CHEMICAL ENGINEERING JOURNAL
392:123808, 2020, DOI:
10.1016/j.cej.2019.123808

**Abstract:** In this study, the adsorption properties of Cu(II) and tetracycline (TC) onto virgin and biofilm-developed polyethylene (PE) microplastics were investigated in batch sorption experiments. PE microplastics were placed at sewage outlets (Shanghai, China) for 20 days to develop biofilm on their surface. The adsorption and desorption isotherms of Cu(II) and TC were well fitted by the Freundlich model, and revealed that biofilm could enhance the adsorption and stabilization of Cu(II) and TC on microplastics. The linearity test of the film diffusion model in kinetic experiments suggested that the adsorption on virgin and biofilm-developed microplastics was dominated by intra-particle diffusion and film diffusion, respectively. Compared with the virgin microplastics, the adsorption of Cu(II) and TC on biofilm-developed microplastics was additionally affected by pH-dependent complexation interactions in the biofilm and competition interactions. Cu(II) pre-adsorbed on the biofilm could be released into solution because of competition effects of TC. Fourier transform infrared spectroscopy (FTIR) and density functional theory (DFT) further confirmed that the enhanced adsorption of TC on the biofilm could be attributed to the complexation of TC, Cu(II) and components in biofilm. This study illustrated that biofilms could enhance the role of microplastics in the Cu(II) and TC migration by
changing their adsorption properties on microplastics.

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## Metabolomic, functional, and ecologic responses of the common freshwater fungus *Neonectria lugdunensis* to mine drainage stress

Authors: Seena S, Sobral O, Cano A

Source: SCIENCE OF THE TOTAL ENVIRONMENT
718:137359, 2020, DOI:
10.1016/j.scitotenv.2020.137359

**Abstract:** Metal contamination of watersheds is a global problem. Here, we conducted litter decomposition studies with *Neonectria lugdunensis*, a cosmopolitan aquatic fungus. Fungal isolates from four reference (non-impacted) and six metal-contaminated streams (due to mine drainage) were exposed to mine drainage and reference stream waters in Central Portugal. Impact of mine drainage waters on *N. lugdunensis* hyphae was investigated by performing metabolomic profiling of 200 lipids and 25 amino acids (M) with ultra-high performance liquid chromatography-mass spectrometry. In parallel, functional response of *N. lugdunensis* isolates was assessed through expression profiles of a functional gene, cellobiohydrolase I (Cbhl). Ecological performance via leaf mass loss was also determined. Exposure to mine drainage waters altered the concentration of numerous AA and lipids. Most strikingly, a gradual increase in the concentration of the triacylglycerols (TAG) with shorter acyl chains and lesser unsaturation was observed after the exposure to mine drainage waters. In addition, the changes in the concentration of numerous TAG, lysophosphatidylcholines, and AA were more significant in the isolates from the metal-contaminated streams after exposure to mine drainage water. Cbhl gene of the isolates from reference streams was down-regulated by metal stress, while those from metal-contaminated streams remained unaffected. Finally, leaf mass loss was influenced by both exposure to mine drainage waters and the origin of isolates. Overall, our study demonstrates unique functional signatures displayed by fungi under

metal stress and the relevant role that fungal AA and lipids play to cope with metal toxicity.

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## Resistance of cyanobacteria *Microcystis aeruginosa* to erythromycin with multiple exposure

Authors: Wu YX, Wan L, Zhang WH, Ding HJ, Yang WF

Source: CHEMOSPHERE 249:126147, 2020, DOI:
10.1016/j.chemosphere.2020.126147

**Abstract:** Here we report a set of experiments in which water blooming cyanobacteria *Microcystis aeruginosa* was repeatedly exposed to erythromycin. Growth inhibition increased with increasing erythromycin concentration (1-150 µg/L) upon first exposure. Maximum inhibition rate (76.06%), occurred under 150 µg/L erythromycin. Moreover, 96-h 50% effective concentration (EC50) was 22.97 µg/L, indicating that the growth of M. aeruginosa was affected by erythromycin under common environmental concentrations. Photosynthesis was hindered by chlorophyll and photosystem II limitations. Malondialdehyde, reactive oxygen species, and superoxide dismutase contents increased significantly under certain concentrations of erythromycin, but superoxide dismutase was suppressed by 150 µg/L erythromycin. Synthesis of intracellular and extracellular microcystins was promoted by 10-60 and by 20-60 µg/L erythromycin, respectively, but both were inhibited by 100-150 µg/L. Principal component analysis and Pearson's correlation revealed the accumulation of reactive oxygen species as the dominant mechanism of erythromycin toxicity to cells. M. aeruginosa repeatedly subjected to erythromycin exposure showed obvious resistance against the antibiotic, especially when treated twice with 60 µg/L erythromycin. The 96-h EC50 was 81.29 µg/L. As compared to the first exposure to erythromycin, photosynthetic and antioxidant activities increased, while growth inhibition and oxidation stress decreased upon multiple exposures. Production and release of microcystins were enhanced by repeated exposure to the antibiotic. Thus, erythromycin persistence in water should be examined, as repeated exposure may lead to serious environmental and human health hazards.
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Interaction of Cyanobacteria
with Nanometer and Micron
Sized Polystyrene Particles in
Marine and Fresh Water

Authors: de Oliveira TTS, Andreu I, Machado MC, Vimbela G, Tripathi A, Bose A

Source: LANGMUIR 36(14):3963-3969, 2020, DOI: 10.1021/acs.langmuir.9b03644

**Abstract:** Microplastics and nanoplastics are emerging pollutants, widespread both in marine and in freshwater environments. Cyanobacteria are also ubiquitous in water and play a vital role in natural ecosystems, using photosynthesis to produce oxygen. Using photography, fluorescence microscopy and cryogenic and scanning electron microscopy (cryo-SEM, SEM) we investigated the physicochemical response of one of the most predominant seawater cyanobacteria (Synechococcus elongatus, PCC 7002) and freshwater cyanobacteria (S. elongatus Nageli PCC 7942) when exposed to 10 µm diameter polystyrene (microPS) and 100 nm diameter polystyrene (nanoPS) particles. Marine and freshwater cyanobacteria formed aggregates with the nanoPS, bound together by extracellular polymeric substances (EPS), and these aggregates sedimented. The aggregates were larger, and the sedimentation was more rapid for the marine system. Aggregate morphologies were qualitatively different for the microPS samples, with the bacteria linking up a small number of particles, all held together by EPS. There was no sedimentation in these samples. The cyanobacteria remained alive after exposure to the particles. The particle size- and salt concentration-dependent response of cyanobacteria to these anthropogenic stressors is an important factor to consider for a proper understanding of the fate of the particles as well as the bacteria.

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Mechanism of lead
bioaccumulation by
freshwater algae in the
presence of organic acids

Authors: Que WY, Wang BH, Li FL, Chen XJ, Jin H, Jin ZF

Source: CHEMICAL GEOLOGY 540:UNSP 119565, 2020, DOI:10.1016/j.chemgeo.2020.119565

**Abstract:** The accumulation of heavy metals by freshwater algae becomes more complex in the presence of dissolved organic matter but it is unclear how and to what extent. In this study, we comparatively assessed the effects of malic acid and citric acid on the bioaccumulation of Pb by Chlorella pyrenoidosa. A 6 h exposure experiment showed that adding organic acid (OA) to an algae-Pb binary system prolonged the adsorption equilibrium time and that the extended time was related to the concentration and number of carboxyl groups of the OA. A pseudo-second-order model fit the kinetic data well in the presence of OAs. The normality of carboxyl groups was negatively correlated with the bioaccumulation rate, k(2), but positively correlated with the maximum bioaccumulation capacity, q(max), of Pb following a linear equation, Y = 121.3x + 52.2, R² = 0.9877. Neither the Freundlich model nor the Langmuir model could fit the isotherm data in the presence of OA, suggesting that a new mechanism might exist. The quantitative relationship between bioaccumulated Pb and carboxyl group of OA indicated a stoichiometric relationship, which seemed to support the theory of a ternary complex of Pb, OA, and algal surface. Our results have added clarity to the current understanding of the accumulation of heavy metals by algae in freshwater ecosystems.

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Age-related physicochemical
differences in ZnO
nanoparticles in the seawater
and their bacterial
interaction

Authors: Baysal A, Saygin H, Ustabasi GS

Source: ENVIRONMENTAL MONITORING AND ASSESSMENT 192(5): 276, 2020, DOI:10.1007/s10661-020-08254-w

**Abstract:** To assess the fate and behavior of engineered nanoparticles in the environment, it is important to examine the physicochemical and toxicological transformation of nanoparticles as
they age in seawater. In this study, we investigated how aging and seawater conditions altered the physiochemical structure of nanoparticles and affected their interactions with bacteria. For this purpose, zinc oxide nanoparticles were aged under different seawater conditions by keeping them in 1%, 10%, and 100% seawater for 1 day and 20 days. The main physicochemical parameters (surface chemistry, chemical composition, particle size, and zeta potential) and toxicity of aged nanoparticles towards gram-negative Pseudomonas aeruginosa and gram-positive Staphylococcus aureus were examined. The results indicated that aged zinc oxide nanoparticles in various concentrations of seawater changed their surface chemistry, chemical composition, particle size, and zeta potentials. Growth inhibition results were observed in that the inhibition of gram-negative (Pseudomonas aeruginosa) bacteria was higher compared with the gram-positive (Staphylococcus aureus) bacteria, and Staphylococcus aureus activated with the aged zinc oxide nanoparticles. Also, the results showed that the key biochemical factors affected by the aging and seawater concentration.

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## Biofilms grown in aquatic microcosms affect mercury and selenium accumulation in Daphnia

**Authors:** Issa S, Ciesielski TM, Mikkelsen Ø, Einum S, Jaspers VLB

**Source:** ECOTOXICOLOGY 29: 485-492, 2020, DOI: 10.1007/s10646-020-02194-4

**Abstract:** Experiments examining mercury (Hg) toxicity in *Daphnia* are usually conducted in highly standardized conditions that prevent the formation of biofilm. Although such standardization has many advantages, extrapolation of results to natural conditions and inference of ecological effects is challenging. This is especially true since biofilms can accumulate metals/metalloids and play a key role in their transfer to higher trophic level organisms. In this study, we experimentally tested the effects of spontaneously appearing

biofilm in Daphnia cultures on accumulation of Hg and its natural antagonist selenium (Se) in Daphnia magna. We added Hg (in the form of mercury (II) chloride) at two concentrations (0.2 µg/L and 2 µg/L) to experimental microcosms and measured the uptake of Hg and Se by D. magna in the presence and absence of biofilm. To test for consistent and replicable results, we ran two identical experimental sets one week apart. Biofilm presence significantly reduced the accumulation of Hg, while increasing the tissue Se content in *D. magna*, and these findings were reproducible across experimental sets. These findings indicate that highly standardized tests may not be adequate to predict the bioaccumulation and potential toxicity of metals/metalloids under natural conditions.

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## Portable Microalgal Biosensor for Herbicide Monitoring

**Authors:** Boron I, Juarez A, Battaglini F

**Source:** CHEMELECTROCHEM 7(7):1623-1630, 2020, DOI: 10.1002/celc.202000210

**Abstract:** The need for in-situ and real-time tools to monitor the fate of pesticides in extensive areas is of great concern to preserve the environment in countries where agroindustry represents an essential part of its economy. In this work, we present the construction of a portable system based on the reversible photosynthesis inhibition produced by herbicides on microalgae, using atrazine as a model compound. The decrease in oxygen production due to the photosynthesis inhibition is electrochemically detected using an automated flow system. The system presented here involves the immobilization of microalgae in a polyelectrolyte-surfactant-carbon nanotube self-assembled material cast on a screen-printed graphite electrode; these components contribute to the stability and sensitivity of the whole device. The system presents a limit of detection of 0.11 µM, showing an excellent performance in river samples. The sensor maintains its integrity after five months immersed in a freshwater algae medium at room temperature. These features are key to install this system along the course of a river at a low cost, allowing early detection of polluted areas and long term environmental studies.

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# Enhanced production of laccase from gamma irradiated endophytic fungus: A study on biotransformation kinetics of aniline blue and textile effluent decolourisation

Authors: Navada KK, Kulal A

Source: JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING 8(2):UNSP 103550, 2020, DOI: 10.1016/j.jece.2019.103550

**Abstract:** Managing triphenylmethane class of dyes such as aniline blue present in the effluents is a nightmare for the industries and environmentalists. There are physical and chemical approaches available for degrading these recalcitrant dyes. However, these methods become expensive process and also degraded products are not ecofriendly in nature. Laccase from white rot fungi had been used for biotransformation of triphenylmethane class of dyes except for aniline blue. This study focussed on laccase from gamma irradiated endophytic fungus (*Phomopsis* sp.) and its enhanced activity in degrading aniline blue as well as textile dye effluent. Laccase production was increased in 1.2 kGy gamma irradiated endophytic fungus (2 fold) and hence dye degradation was enhanced when compared to the non-irradiated (wild) fungus. The laccase activity exhibited appreciable stability for metal ions (Zn2+, Cu2+, Cr2+ and Ca2+) up to 10 mM concentration. The highest laccase activity and dye decolourisation rate was observed around 30 degrees C temperature at pH 5. The degraded intermediates were identified and a mechanism of degradation was proposed based on UV-vis, FTIR and LC-MS analysis. The aniline blue degradation kinetics strictly followed Michaelis-Menten model. The degraded aniline blue dye samples had reduced COD and were non-toxic to plants and microorganisms. To substantiate the industrial application, textile effluent was treated with laccase from the endophytic fungus and found 99 % decolourisation within 2.5 h. There was a 67 % reduction in COD and a 47 % reduction in BOD in laccase mediated textile effluent treatment.

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# The combined toxicity influence of microplastics and nonylphenol on microalgae *Chlorella pyrenoidosa*

Authors: Yang WF, Gao XX, Wu YX, Wan L, Tan LC, Yuan SM, Ding HJ, Zhang WH

Source: ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 195:110484, 2020, DOI: 10.1016/j.ecenv.2020.110484

**Abstract:** Microplastics and nonylphenol (NP) are considered as emerging pollutant and have attracted wide attention, while their combined toxicity on aquatic organisms is barely researched. Therefore, the combined toxicity influence of NP with three types of microplastics containing polyethylene (PE1000, 13 µm and PE, 150 µm), polyamide (PA1000, 13 µm and PA, 150 µm) polystyrene (PS, 150 µm) on microalgae *Chlorella pyrenoidosa* was analyzed. Both growth inhibition, chlorophyll fluorescence, superoxide dismutase (SOD), malondialdehyde (MDA), and catalase (CAT) were determined. We found that single microplastics and NP both inhibited algal growth, thereby causing oxidative stress. The order of inhibition effect in single microplastics experiment was PE1000 > PA1000 > PE approximate to PS > PA. The combined toxicity experiment results indicated that the presence of microplastics had positive effect in terms of alleviating NP toxicity to *C. pyrenoidosa*, and the microplastics adsorption capacity to NP was the dominant contributing factor for this effect. According to the independent action model, the combined toxicity was antagonistic. Because the negative effect of smaller size microplastics on algal growth was aggravated with prolonged exposure time, the optimum effect of microplastics alleviated NP toxicity was PA1000 at 48 h, while this effect was substituted by PA at 96 h during combined toxicity. Thus, the toxicity of smaller size microplastics has a nonnegligible influence on combined toxicity. This study confirms that microplastics significantly affected the toxicity of organic pollutants on microalgae. Further research on the combined toxicity of smaller size microplastics with pollutants in chronic toxicity is needed.

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# Insights Into the Biodegradation of Lindane (gamma-Hexachlorocyclohexane) Using a Microbial System

**Authors:** Zhang WP, Lin ZQ, Pang SM, Bhatt P, Chen SH

**Source:** FRONTIERS IN MICROBIOLOGY 11:522, 2020, DOI: 10.3389/fmicb.2020.00522

**Abstract:** Lindane (gamma-hexachlorocyclohexane) is an organochlorine pesticide that has been widely used in agriculture over the last seven decades. The increasing residues of lindane in soil and water environments are toxic to humans and other organisms. Large-scale applications and residual toxicity in the environment require urgent lindane removal. Microbes, particularly Gram-negative bacteria, can transform lindane into non-toxic and environmentally safe metabolites. Aerobic and anaerobic microorganisms follow different metabolic pathways to degrade lindane. A variety of enzymes participate in lindane degradation pathways, including dehydrochlorinase (LinA), dehalogenase (LinB), dehydrogenase (LinC), and reductive dechlorinase (LinD). However, a limited number of reviews have been published regarding the biodegradation and bioremediation of lindane. This review summarizes the current knowledge regarding lindane-degrading microbes along with biodegradation mechanisms, metabolic pathways, and the microbial remediation of lindane-contaminated environments. The prospects of novel bioremediation technologies to provide insight between laboratory cultures and large-scale applications are also discussed. This review provides a theoretical foundation and practical basis to use lindane-degrading microorganisms for bioremediation.

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# Comparison of the Level and Mechanisms of Toxicity of Carbon Nanotubes, Carbon Nanofibers, and Silicon

# Nanotubes in Bioassay with Four Marine Microalgae

**Authors:** Pikula K, Chaika V, Zakharenko A, Markina Z, Vedyagin A, Kuznetsov V, Gusev A, Park S, Golokhvast K

**Source:** NANOMATERIALS 10(3):485, 2020, DOI: 10.3390/nano10030485

**Abstract:** Nanoparticles (NPs) have various applications in medicine, cosmetics, optics, catalysis, environmental purification, and other areas nowadays. With an increasing annual production of NPs, the risks of their harmful influence to the environment and human health is rising. Currently, our knowledge about the mechanisms of interaction between NPs and living organisms is limited. Additionally, poor understanding of how physical and chemical characteristic and different conditions influence the toxicity of NPs restrict our attempts to develop the standards and regulations which might allow us to maintain safe living conditions. The marine species and their habitat environment are under continuous stress due to anthropogenic activities which result in the appearance of NPs in the aquatic environment. Our study aimed to evaluate and compare biochemical effects caused by the influence of different types of carbon nanotubes, carbon nanofibers, and silica nanotubes on four marine microalgae species. We evaluated the changes in growth-rate, esterase activity, membrane polarization, and size changes of microalgae cells using flow cytometry method. Our results demonstrated that toxic effects caused by the carbon nanotubes strongly correlated with the content of heavy metal impurities in the NPs. More hydrophobic carbon NPs with less ordered structure had a higher impact on the red microalgae P. purpureum because of higher adherence between the particles and mucous covering of the algae. Silica NPs caused significant inhibition of microalgae growth-rate predominantly produced by mechanical influence.

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# Co-metabolism of sulfamethoxazole by a freshwater microalga *Chlorella pyrenoidosa*
**Authors:** Xiong Q, Liu YS, Hu LX, Shi ZQ, Cai WW, He LY, Ying GG

**Source:** WATER RESEARCH 175:115656, 2020, DOI: 10.1016/j.watres.2020.115656

**Abstract:** Microalgae-mediated biodegradation of antibiotics has recently gained increased attention from international scientific community. However, limited information is available regarding microalgae-mediated biodegradation of SMX in a co-metabolic system. Here we investigated the biodegradation of sulfamethoxazole (SMX) by five algal species (*Pseudokirchneriella subcapitata*, *Scenedesmus quadricauda*, *Scenedesmus obliquus*, *Scenedesmus acuminatus* and *Chlorella pyrenoidosa*), and its transformation pathways by *C. pyrenoidosa* in a sodium acetate (3 mM) co-metabolic system. The results showed that the highest SMX dissipation (14.9%) was detected by *C. pyrenoidosa* after 11 days of cultivation among the five tested algal species in the absence of other carbon sources. The addition of sodium acetate (0-8 mM) significantly enhanced the dissipation efficiency of SMX (0.4 µM) from 6.05% to 99.3% by *C. pyrenoidosa* after 5 days of cultivation, and the dissipation of SMX followed the first-order kinetic model with apparent rate constants (k) ranging from 0.0107 to 0.9811 d⁻¹. Based on the results of mass balance analysis, biodegradation by *C. pyrenoidosa* was the main mechanism for the dissipation of SMX in the culture medium. Fifteen phase I and phase II metabolites were identified, and subsequently the transformation pathway was proposed, including oxidation, hydroxylation, formylation and side chain breakdown, as well as pterin-related conjugation. The majority of metabolites of SMX were only observed in the culture medium and varied with cultivation time. The findings of the present study showed effective co-metabolism of a sulfonamide by microalgae, and it may be applied in the aquatic environment remediation and wastewater treatment in the future.

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Treatment enhances the prevalence of antibiotic-resistant bacteria and antibiotic resistance genes in

the wastewater of Sri Lanka, and India

**Authors:** Kumar M, Ram B, Sewwandi H, Sulfikar, Honda R, Chaminda T

**Source:** ENVIRONMENTAL RESEARCH 183:109179, 2020, DOI: 10.1016/j.envres.2020.109179

**Abstract:** Wastewater treatment plants (WWTPs) are being debated for being the hot spots for the development of antibiotic resistance in pathogenic microbial communities. We observed the prevalence of antibiotic-resistant bacteria (ARB), antibiotic resistance genes (ARG), and multidrug resistance (MDR) in two municipal WWTPs and one hospital WWTP in Western and Southern Sri Lanka, and compared the results with particular reference to Indian and the World scenario to trace the imprints of treatment on ARB and ARG. Result suggests that although wastewater treatment resulted in higher than 1.06 log Escherichia coli (*E. coli*) reduction at all WWTPs, yet the percent of E. coli resistant to most of the antibiotics increased from influent to effluent. Higher prevalence of ARB, ARG, and MDR were noted in hospital WWTP owing to the higher antibiotic concentrations used and excreted by the patients. With reference to India, the WWTPs in Sri Lanka showed more ARB and a consistent increase in its percentages after the treatment but were less resistant to Fluoroquinolone (FQ). *E. coli* strains isolated from each location of both countries showed multidrug resistance, which has increased after the treatment and was strongly correlated with FQ in every WWTP. Resistant genes for Fluoroquinolone (FQ) (aac(6')-1b-cr, qnrB, qnrS), beta-lactams (ampC), and sulphonamides (sul1) were common in all the wastewaters except additional parC gene in the hospital effluent of Sri Lanka, implying much higher resistance for quinolones, especially for Ciprofloxacin. Multivariate statistical treatments suggest that effluent showed higher loadings and association for MDR/ARB, where pH change and more extensive interaction with metals during the treatment processes seem to have profound effects.

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ERA / PUBLICATIONS
SCIENTIFIQUES /
MICROBIOLOGIE ET
CONTAMINANTS

Alleviation of Cd phytotoxicity and enhancement of rape seedling growth by plant growth-promoting bacterium Enterobacter sp. Zm-123

Authors: Zhang M, Jin ZH, Zhang X, and more...

Source: ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH, 2020, DOI: 10.1007/s11356-020-09558-7

**Abstract:** The present study aims to investigate the impact of a metal-tolerant bacterium on metal detoxification and rape seedling growth promotion under Cd stress. The results showed that the isolated bacterium *Enterobacter* sp. Zm-123 has capability to resist Cd (200 mg/L), produce IAA (26.67 mg/L) and siderophores (82.34%), and solubilize phosphate (137.5 mg/L), etc. Zm-123 inoculation significantly enhanced the fresh weight of rape seedlings from 9.47 to 19.98% and the root length from 10.42 to 57.05% compared with non-inoculation group under different concentrations of Cd (0, 0.5, 1, 3, 5 mg/L) (p < 0.05). It also significantly increased the content of chlorophyll, soluble sugar, soluble protein, and proline (p &60; 0.05) in rape seedlings. Moreover, a significant elevation in catalase (CAT) and peroxidase (POD) activities and a significant reduction in malondialdehyde (MDA), electrolyte leakage (EL), and Cd content in rape seedlings were detected owing to Zm-123 inoculation (p < 0.05). The combined results imply that strain Zm-123 can alleviate the Cd phytotoxicity and promote the rape seedling growth by improving the physiological activity and antioxidant level, which can be potentially applied to protect plants from Cd toxicity.

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Evaluating the protection of
bacteria from extreme Cd (II)
stress by P-enriched biochar

Authors: Chen HM, Tang LY, Wang ZJ, and more...

Source: ENVIRONMENTAL POLLUTION 263, A, 2020, DOI: 10.1016/j.envpol.2020.114483

**Abstract:** Cadmium cations (Cd2thorn) are extremely toxic to organisms, which limits the remediation of Cd by microorganisms. This study investigated the feasibility of applying biochar to protect bacteria from extreme Cd2thorn stress (1000 mg/L). An alkaline biochar (RB) and a slightly acidic biochar (SB) were selected. SB revealed a higher Cd2thorn removal than RB (15.5% vs. 4.8%) due to its high surface area. Addition of Enterobacter sp. induced formation of Cd phosphate and carbonate on both SB and RB surface. However, Cd2thorn removal by RB enhanced more evidently than SB (78.9% vs. 30.2%) due to the substantial microbial regulation and surficial alkalinity. Thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and geochemical modeling (GWB) all confirmed that the formation of stable Cd phosphate on RB was superior to that in SB. These biomineralization, together with biochar pore structure, protect bacterial cells from Cd stress. Moreover, the alkalinity of biochar promoted the formation of carbonate, which strengthened the decline of Cd2thorn toxicity. The protection by RB was also confirmed by the intense microbial respiration and biomass (PLFA). Furthermore, this protection induced a positive feedback between P-abundant biochar and Enterobacter sp.: biochar provides P source (the most common limiting nutrient) to support microbial growth; bacteria secrete more organic acids to drive P release. This study therefore elucidated the protection of bacteria by P-enriched biochar based on both physic-chemical and microbial insights.

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Self-cleaning of very heavily
oil-polluted sites proceeds
even under heavy-metal
stress while involved
bacteria exhibit bizarre
pleomorphism

Authors: Ali N, Khanafer M, Al-Awadhi H, Radwan S
**Source:** ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 200, 2020, DOI: 10.1016/j.ecoenv.2020.110717

**Abstract:** Two substrates saturated with crude oil, a desert soil sample (17.3% oil) and an olive-pomace (plant-based oil sorbent) sample (41% oil) showed effective self-cleaning via their own native microorganisms. The oil in such systems did not gather in one compact layer as it may be expected, but became dispensed as vesicles of varying dimensions connected together with narrow tunnels. Bacteria colonized the oil vesicles but only at the borders between the oil and the watery substrates. Through this architectural arrangement, the cells were capable of absorbing oil through their oil-contact surfaces and oxygen, water and water soluble nutrients through their substrate-contact surfaces. The cells involved were those of indigenous hydrocarbonoclastic bacterial communities. Many of those bacteria also tolerated and removed the amended heavy-metals, Hg2+, Cd2+, Pb2+, AsO43- and AsO33-. In the presence of heavy-metals, some of the bacterial species particularly of the pseudomonads exhibited bizarre pleomorphic cell-forms. It was concluded that even environments toxified with extremely high oil concentrations and heavy-metals can be remediated rather effectively via their already existing native microorganisms.

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## Isolation and Identification of Endosulfan Degrading Native Bacterial Consortium from Agricultural Soils

**Authors:** Bilgin A, Sanin SL

**Source:** WASTE AND BIOMASS VALORIZATION 11, 7: 3303-3313, 2020, DOI: 10.1007/s12649-019-00662-5

**Abstract:** The environmental impact of chlorinated pesticides, including endosulfan, is not only caused by their persistency in the ecosystem but also from their toxic effects on off-target living organisms. In this study, three different strains of microorganisms, namely *Afipia genosp*, *Sphingomonas yanoikuyae* Q1 and *Methylobacterium rhodesianum* that are capable of biodegrading endosulfan at low concentrations (100 µg g/L) from a tea cultivation field were

reported. The isolated microbial consortium biodegraded 59% of the total endosulfan (63% alpha-endosulfan, 57% beta-endosulfan) at pH 6.5. The same consortium biodegraded 98% of the total endosulfan (96% of alpha-endosulfan, 97% of beta-endosulfan) at pH 8.4. All endosulfan removal performances were observed for a period of 25 days and the experiments were conducted at 25 degrees C, which was a relatively lower temperature compared to other endosulfan biodegradation studies in the literature. Additional carbon source did not change the overall endosulfan removal. No endosulfan sulfate production was observed during the study.

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## A beneficial role of arbuscular mycorrhizal fungi in influencing the effects of silver nanoparticles on plant-microbe systems in a soil matrix

**Authors:** Cao JL, Feng YZ, Lin XG, Wang JH

**Source:** ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH 27(11), 2020, DOI: 10.1007/s11356-020-07781-w

**Abstract:** Silver nanoparticles (AgNPs) are considered to be emerging contaminant for plant-soil systems. AM arbuscular mycorrhizal (AM) fungi can alleviate the negative effects of a variety of pollutants on their hosts, but its potential roles in influencing the toxicity of AgNPs and the underlying mechanisms are still an open question. This study investigated the responses of maize (Zea mays L.) inoculated with or without AM fungi and soil microorganisms to different concentrations of AgNPs (0, 0.025, 0.25, and 2.5 mg kg(-1)). The inoculation of AM fungi helps to alleviate the AgNP-induced phytotoxicity. Compared to the non-AM fungal inoculated treatments, AM fungal inoculation significantly increased the mycorrhizal colonization, biomass and phosphorus (P)
acquisitions of maize, with an upregulation of P transporter gene expression under AgNP treatments. AM fungal inoculation decreased Ag content in plant shoots and roots, downregulated expression levels of genes involved in Ag transport and gene encoding a metallothionein involved in metal homeostasis. The beneficial role of AM fungi extended to soil microbes. Compared to the non-AM fungal inoculated treatments, AM fungal inoculation decreased the toxicity of AgNPs to soil microbial activities and bacterial abundance. AM fungal inoculation increased the bacterial diversity and induced changes in the soil bacterial community composition. Altogether, the present study revealed that AM fungal symbiosis can play beneficial roles in mediating the negative effects exposed by AgNPs on plants probably through changing the expressions of potential Ag transporters and cooperating with soil bacterial community.

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## Pesticide bioremediation in liquid media using a microbial consortium and bacteria-pure strains isolated from a biomixture used in agricultural areas

**Authors:** Gongora-Echeverria VR, Garcia-Escalante R, Rojas-Herrera R., and more...

**Source:** ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 200, 2020, DOI: 10.1016/j.ecoenv.2020.110734

**Abstract:** Microorganisms' role in pesticide degradation has been studied widely. Insitu treatments of effluents containing pesticides such as biological beds (biobeds) are efficient biological systems where biomixture (mixture of substrates) and microorganisms are the keys in pesticide treatment; however, microbial activity has been studied poorly, and its potential beyond biobeds has not been widely explored. In this study, the capacity of microbial consortium and bacteria-pure strains isolated from a biomixture (soil-straw; 1:1, v/v) used to treat agricultural effluents under real conditions were evaluated during a bioremediation process of five pesticides commonly used Yucatan Mexico. Atrazine, carbofuran, and glyphosate had the

highest degradations (> 90%) using the microbial consortium; 2,4-D and diazinon were the most persistent (DT50 = 8.64 and 6.63 days). From the 21 identified bacteria species in the microbial consortium, Pseudomonas nitroreducens was the most abundant (52%) according to identified sequences. For the pure strains evaluation 2,4-D (DT50 = 9.87 days), carbofuran (DT50 = 8.27 days), diazinon (DT50 = 8.80 days) and glyphosate (DT50 = 8.59 days) were less persistent in the presence of the mixed consortium (Ochrobactrum sp. DGG-1-3, Ochrobactrum sp. Ge-14, Ochrobactrum sp. B18 and *Pseudomonas citronellolis* strain ADA-23B). Time, pesticide, and strain type were significant (P < 0.05) in pesticide degradation, so this process is multifactorial. Microbial consortium and pure strains can be used to increase the biobed efficiency by inoculation, even in the remediation of soil contaminated by pesticides in agricultural areas.

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## Interactions of microplastics and cadmium on plant growth and arbuscular mycorrhizal fungal communities in an agricultural soil

**Authors:** Wang FY, Zhang XQ, Zhang SQ, and more...

**Source:** CHEMOSPHERE 254, 2020, DOI: 10.1016/j.chemosphere.2020.126791

**Abstract:** Microplastics (MPs) as emerging contaminants have attracted attention worldwide, but little is known on their interactions with metallic contaminants in soil-plant systems. Here, we investigated the interactions between MPs, i.e., polyethylene (PE) and polylactic acid (PLA), and cadmium (Cd) on plant performance and arbuscular mycorrhizal fungal community in an agricultural soil. PE showed no noticeable phytotoxicity, while 10% PLA decreased maize biomass and chlorophyll content in leaves. A significant interaction on root biomass occurred between PE and Cd, but not between PLA and Cd. Both PE and PLA caused increase in soil pH and DTPA-extractable Cd concentrations, but no alterations in Cd accumulation in plant tissues. Different numbers
of endemic and total OTUs were observed in various treatments. The relative abundance of arbuscular mycorrhizal fungi (AMF) genera highly varied with MPs and Cd. MPs altered AMF community structure and diversity, depending on their type and dose. Coexisting Cd produced slight but significant interactions with MPs on the dominant AMF genera. Overall, plant growth and AMF community varied with MPs type and dose, Cd, and their interactions, and the high dose of PLA produced stronger phytotoxicity. In conclusion, coexisting MPs and Cd can jointly drive shifts in plant performance and root symbiosis, thereby posing additional risks for agroecosystems and soil biodiversity.

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# Insights Into the Microbial Degradation and Biochemical Mechanisms of Neonicotinoids

**Authors:** Pang SM, Lin ZQ, Zhang WP, and more...

**Source:** FRONTIERS IN MICROBIOLOGY 11, 2020, DOI: 10.3389/fmicb.2020.00868

**Abstract:** Neonicotinoids are derivatives of synthetic nicotinoids with better insecticidal capabilities, including imidacloprid, nitenpyram, acetamiprid, thiacloprid, thiamethoxam, clothianidin, and dinotefuran. These are mainly used to control harmful insects and pests to protect crops. Their main targets are nicotinic acetylcholine receptors. In the past two decades, the environmental residues of neonicotinoids have enormously increased due to large-scale applications. More and more neonicotinoids remain in the environment and pose severe toxicity to humans and animals. An increase in toxicological and hazardous pollution due to the introduction of neonicotinoids into the environment causes problems; thus, the systematic remediation of neonicotinoids is essential and in demand. Various technologies have been developed to remove insecticidal residues from soil and water environments. Compared with non-bioremediation methods, bioremediation is a cost-effective and eco-friendly approach for the treatment of pesticide-polluted environments. Certain neonicotinoid-degrading microorganisms, including Bacillus, Mycobacterium, Pseudoxanthomonas, Rhizobium,

Rhodococcus, Actinomycetes, and Stenotrophomonas, have been isolated and characterized. These microbes can degrade neonicotinoids under laboratory and field conditions. The microbial degradation pathways of neonicotinoids and the fate of several metabolites have been investigated in the literature. In addition, the neonicotinoid-degrading enzymes and the correlated genes in organisms have been explored. However, few reviews have focused on the neonicotinoid-degrading microorganisms along with metabolic pathways and degradation mechanisms. Therefore, this review aimed to summarize the microbial degradation and biochemical mechanisms of neonicotinoids. The potentials of neonicotinoid-degrading microbes for the bioremediation of contaminated sites were also discussed.

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# Long-term effects of copper exposure to agricultural soil function and microbial community structure at a controlled and experimental field site

**Authors:** Shaw JLA, Ernakovich JG, Judy JD, and more...

**Source:** ENVIRONMENTAL POLLUTION 263, A, 2020, DOI: 10.1016/j.envpol.2020.114411

**Abstract:** The long-term effect of heavy metals on soil microbial communities and their function is relatively unknown and little work has been done in field settings. To address this gap, we revisited a field-based experiment, 12 years after the application of copper (Cu) to agricultural soils, with treatment concentrations ranging from 0 to 3310 mg Cu kg(-1) soil. We measured the long-term effects of Cu exposure to soils using multiple functionality assessments and environmental DNA-based community analyses. The assessment results revealed that soils that received moderate to high Cu doses had still not recovered functionality 12-years post exposure. However, plots that received doses of 200 mg kg(-1) Cu or less appeared to have a functionality index not dissimilar to control plots. Environmental DNA analyses of the microbial communities revealed a high level of beta diversity in low Cu treatment plots,
whereas communities within high Cu treatment plots had similar community structures to one another (low beta diversity), indicating that specific Cu-tolerant or dormant taxa are selected for in high-Cu environments. Interestingly, high Cu plots had higher within-sample taxa counts (alpha diversity) compared with controls and low Cu plots. We hypothesise that taxa in high Cu plots activated dormancy mechanisms, such that their genetic signal remained present, whilst the functionality of the soil was reduced. Many species identified in high Cu plots are known to have associated dormancy mechanisms and survive in high stress environments. Understanding how these mechanisms collectively contribute to contaminant outcomes is of great importance for the goals of predicting and managing microbial communities and their function. As we found that Cu concentrations above 200 mg kg(-1) can cause significant functionality loss and a selective pressure on microbial communities, it is recommended that Cu concentrations above 200 mg kg(-1) are avoided in agricultural soils.

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Antimony-oxidizing bacteria
alleviate Sb stress in
Arabidopsis by attenuating Sb
toxicity and reducing Sb
uptake

Authors: Gu TY, Yu H, Li F, and more...

Source: PLANT AND SOIL, 2020, DOI: 10.1007/s11104-020-04569-2

**Abstract:** Aims Antimony (Sb)-oxidizing bacteria play an important role in Sb biogeochemical cycle in soil, but the benefits of microbial oxidation for plants have not been well documented. The aim of this study was to explore the contribution of Sb(III)-oxidizing bacteria to alleviate the Sb toxicity in plants. Methods The plant growth-promoting (PGP) characteristics of Sb(III)-oxidizing bacterium Bacillus sp. S3 and the effects of bacterial inoculation on Arabidopsis plants were evaluated under controlled and Sb stressed conditions. Results Indole acetic acid (IAA) production and 1-aminocyclopropane-1-carboxylate-deaminase (ACC-deaminase) activity were the only two PGP strategies that Bacillus sp. S3 possessed, despite

the production level of IAA and the activity of
ACC deaminase sharply decreased under Sb
stress. Bacillus sp. S3 inoculation significantly
increased the plant biomass and chlorophyll
content, alleviated the peroxidation of
membrane lipids, decreased the activities of the
antioxidant enzymes, and reduced the
transcription of Sb transporters and reactive
oxygen species (ROS)-related enzymes in
Arabidopsis. Noteworthily, inoculation of Bacillus
sp. S3 not only significantly decreased the Sb
accumulation but also reduced the percentage of
Sb(III) of total Sb in Arabidopsis. Conclusions This
study indicates that the Sb(III)-oxidizing strain of
Bacillus sp. S3 is a promising inoculant used for
bacteria-assisted phytoremediation on Sb-
contaminated sites.

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Deciphering metal toxicity
responses of flax (Linum
usitatissimum L.) with
exopolysaccharide and ACC-
deaminase producing
bacteria in industrially
contaminated soils

Authors: Zainab N, Amna, Din BU, Javed MT, and more...

Source: PLANT PHYSIOLOGY AND BIOCHEMISTRY
152:90-99, 2020, DOI:
10.1016/j.plaphy.2020.04.039

**Abstract:** Rapid industrialization is the main reason of heavy metals contamination of soil colloids and water reservoirs. Heavy metals are persistent inorganic pollutants; deleterious to plants, animals and human beings because of accumulation in food chain. The aim of the current work was to evaluate the role of indole acetic acid (IAA), exopolysaccharide (EPS) and ACC-deaminase producing plant growth promoting rhizobacteria (PGPR) i.e .B. gibsonii PM11 and B. xiamenensis PM14 in metal phytoremediation of metals, their survival and plant growth promotion potential in metal polluted environment as well as alterations in physio-biochemical responses of inoculated L. usitatissimum plants towards heavy metal toxicity. Two bacterial strains Bacillus gibsonii (PM11) and Bacillus xiamenensis (PM14),
previously isolated from sugarcane's rhizosphere, were screened for metal tolerance (50 mg/l to 1000 mg/l) and plant growth promoting traits like IAA, ACC-deaminase, EPS production and nitrogen fixing ability under metal stress. The response of flax plant (Linum usitatissimum L.) was analyzed in a pot experiment containing both industrially contaminated and non-contaminated soils. Experiment was comprised of six different treatments, each with three replicates. At the end of the experiment, role of metal tolerant plant growth promoting bacterial inoculation was elucidated by analyzing the plant growth parameters, chlorophyll contents, antioxidative enzymes, and metal uptake both under standard and metal contaminated rhizospheres. Results revealed that root and shoot length, plant's fresh and dry weight, proline content, chlorophyll content, antioxidant enzymatic activity was increased in plants inoculated with plant growth promoting bacteria as compared to non-inoculated ones both in non-contaminated and industrial contaminated soils. In current study, inoculation of IAA, EPS and ACC-deaminase producing bacteria enhances plant growth and nutrient availability by minimizing metal-induced stressed conditions. Moreover, elevated phytoextraction of multi-metals from industrial contaminated soils by PGPR inoculated L. usitatissimum plants reveal that these strains could be used as sweepers in heavy metals polluted environment.

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Can Toxicities Induced by Insecticide Methomyl be Remediated Via Soil Bacteria *Ochrobactrum thiophenivorans* and *Sphingomonas melonis?*

**Authors:** Tatar S, Yildirim NC, Serdar O, Erguven GQ

**Source:** CURRENT MICROBIOLOGY 77(7):1301-1307, 2020, DOI: 10.1007/s00284-020-02042-y

**Abstract:** The research study was about revealing the biochemical response of Gammarus pulex related to insecticide methomyl before and after bioremediation by two soil bacteria species, *Ochrobactrum thiophenivorans* and *Sphingomonas melonis*. Catalase (CAT),

glutathione S-transferase (GST), cytochrome. P4501A1 (CYP1A1) activities in *G. Pulex* related to methomyl solution were investigated in 24 h and 96 h. ELISA method was used for test studies. CAT enzyme was decreased in Gammarus pulex that was exposed to methomyl after all exposure period (P < 0.05). CAT activities were returned to control results after bioremediation assays. GST enzyme activity was decreased depending on methomyl exposure during 24 h but increased during 4 days (P < 0.05). After 8 days of bioremediation period, GST activity increased again during 24 h while decreased during 4 days (P < 0.05). CYP1A1 activity increased in Gammarus pulex that was exposed to methomyl after all exposure period (P < 0.05). After bioremediation, statistically significant changes were not revealed in CYP1A1 activities (P < 0.05). According to the results of our study, CYP1A1, CAT, and GST activities in *G. pulex* sanctioned the capability of *Ochrobactrum thiophenivorans* and *Sphingomonas melonis* in methomyl bioremediation. Isolated and enriched *Ochrobactrum thiophenivorans* and *Sphingomonas melonis* that were added to 2.5 ppb concentrations of methomyl for 8 days. Each day, chemical oxygen demand (COD) and biochemical oxygen demand (BOD5), pH and dissolved oxygen parameters were monitored. At the final phase of the bioremediation step, it was determined that these bacteria have efficient methomyl bioremediation properties in a mixed consortia at a rate of 86%. These results show that these bacteria can be used for bioremediate the receiving environments that are polluted by these kinds of insecticides.

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Bioremediation potency of multi metal tolerant native bacteria *Bacillus cereus* isolated from bauxite mines, kolli hills, Tamilnadu - A lab to land approach

**Auhors:** Anusha P, Natarajan D

**Source:** BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 25, 2020, DOI: 10.1016/j.bcab.2020.101581

**Abstract:** Bioremediation approaches by native microorganisms are an effective and best
resolution for treating metal contaminated area. The aim of the study was to determine the metal remediation efficiency of native bacteria B.cereus in lab and field remediation study. Minimum inhibitory concentration of metals show, the isolate was highly resistant to lead ions followed by other test metals and also highly resistant to multiple antibiotics. The optimum pH (pH 7) and temperature (35 degrees C) for bacterial growth was determined. Bioremediation efficiency of batch culture method by the strain was found to be 91.98% (Cu), 79.9% (Cr), 97.17% (Pb), 77.44% (Zn), 81.6% (Fe), 62.8% (Mn) and 60.92% (Mg) respectively. FT-IR analysis, resulted N-H primary amine, C-C stretch and N-O aliphatic nitro compounds present in the lead treated by B. cereus. We noticed some functional groups may be altered in the treated sample than control (-C C- alkyne and C-N amine groups). The novelty of the work is the simplest trail for field based metal remediation by the multi metal tolerant bacteria in bauxite mined waste soil. The strain shows notable percentage of in-situ remediation over eight weeks of experiments i.e 71.8% (Pb), 53% (Cu) and 41.4% (Cr). The outcome of In-situ remediation results suggest that B.cereus have a noticeable remediation capacity to all the metals particularly lead, so it could be served as a potential strain for In-situ field based bioremediation and in future it can be used for soil reclamation of toxic soil into nontoxic soil.

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## Cd heavy metal and plants, rather than soil nutrient conditions, affect soil arbuscular mycorrhizal fungal diversity in green spaces during urbanization

**Authors:** Lin LT, Chen Y, Qu LY, and more...

**Source:** SCIENCE OF THE TOTAL ENVIRONMENT 726, 2020, DOI: 10.1016/j.scitotenv.2020.138594

**Abstract:** Urbanization accelerates pollution and habitat fragmentation, and the mechanism that shapes the arbuscular mycorrhizal (AM) fungal community in urban ecosystem still remains poorly understood. In this study, soil samples from 23 sites (from rural to urban), belonging to 4 green space types (country park, Co; urban park, Pa; roadside green space1, RoP1; and

roadside green space2, RoP2), were collected to assess the effects of the urbanization on the AM fungal diversity.

Using 454 pyrosequencing, a total of 79 AM fungal OTUs were uncovered. We found that urbanization showed a neutral effect on Shannon diversity, Simpson diversity, Pielou diversity, and community composition of the AM fungi. Within urban areas, the composition of AM fungal community was significantly different between RoP1 and RoP2. The db-RDA analysis of RoP1 and RoP2 revealed that the soil Cd accounted for the largest community composition variation, with an explanation rate of 20.5%, followed by the SOC (15.1%).

Across 23 sites, Cd may have an obvious ecological toxicity on AM fungi, with significantly negative correlations between the soil Cd content and the AM fungal species richness and evenness. The AM fungal community also indicated significantly Mantel correlation with the soil Cd contents. Additionally, high herbaceous richness promoted rich AM fungi. The herbaceous composition, not the richness, has a significant impact on the AM fungal community composition. This study suggests that the toxicity of Cd from traffic should receive more attention during urban green space construction and management, and reasonable plant configuration contributed to the maintenance of the AM fungal community.

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## Effects of lead (Pb) in stormwater runoff on the microbial characteristics and organics removal in bioretention systems

**Authors:** Liu C, Lu Ji, Liu JQ, and more...

**Source:** CHEMOSPHERE 253, 2020, DOI: 10.1016/j.chemosphere.2020.126721

**Abstract:** Bioretention systems have been proved to be a natural approach for effectively reducing stormwater runoff pollution loads. However, the effects of heavy metals in stormwater runoff on microbial characteristics and organics removal in bioretention systems are unclear. In this study, two lab scale bioretention columns including the control and lead (Pb) treatment with the soil and
filler layer were established. The changes of organic matter and lead in the effluent water and the soil (or fillers) were monitored during 121 operation days. The soil (or fillers) microbial characteristics were also analyzed. The results showed that most of Pb was intercepted by soil, while a small amount accumulated in fillers after 121 days. The long-term Pb accumulation in the bioretention system negatively affected the microbial biomass and microbial activity, while positively affected the community diversity. Pb accumulation killed some microorganisms, but simultaneously stimulated the growth of some Pb-tolerance microorganisms. The abundance of bacteria with COD degradation function in soil layer decreased, while that in fillers increased, indicating the effect of Pb on the community structure of these two layers was different. The COD removal in the soil and filler layer was promoted and inhibited by Pb contamination respectively. Moreover, Pb affected the removal of organic matter by chelating organic matters and changing their composition. The results suggested that the long-term accumulation of heavy metals in bioretention system would affect microbial degradation function and pollutants removal, causing our concern for the long-term maintenance of the bioretention system.

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## Geo-distribution pattern of microbial carbon cycling genes responsive to petroleum contamination in continental horizontal oilfields

**Authors:** Li AY, Li GH, Yang JJ, and more...

**Source:** SCIENCE OF THE TOTAL ENVIRONMENT 731, 2020, DOI: 10.1016/j.scitotenv.2020.139188

**Abstract:** Contamination significantly affects soil microbial community structures, and the metabolisms of organic contaminants might particularly alter soil carbon cycling by shaping microbial carbon cycling genes. Although numerous studies have discussed the impacts of petroleum contamination on soil bacterial communities and relevant degrading genes, there is no work addressing how soil carbon cycling genes are affected by petroleum contamination. In this study, 77 soil samples were collected from

five typical oilfields horizontally located in China to explore the influence of environmental variables and petroleum contamination on microbial carbon cycling genes. Results from Geochip suggested a geographic-determined distribution of carbon cycling genes. Although no significant correlation was observed between carbon cycling genes and soil physio-chemical properties for all soils, some relationships were identified in specific oilfield. Principle component analysis indicated that soil physiochemical properties, rather than petroleum contamination disturbance, are the key factors determining the degree of sample dispersion, whereas environmental variables predominantly control the degree of sample aggregation. Co-occurrence ecological network analysis revealed a more complex interactions of all functional genes in petroleum-contaminated soils, and carbon cycling genes were grouped with nitrogen related genes in petroleum-contaminated communities. Soil moisture and heterogeneity were identified as the main drivers for the abundance and diversity of carbon cycling genes, particularly in petroleum-contaminated soils. These results are attributing to the fewer impacts of petroleum contamination on the diversity of carbon cycling genes than soil physio-chemical properties, and soil carbon cycling genes are mainly driven by geographic location and petroleum contamination together. Our findings provide deeper insight into the influence of petroleum contamination in soil microbial functions related to carbon cycling.

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## Effects on soil microbial community after exposure to neonicotinoid insecticides thiamethoxam and dinotefuran

**Authors:** Yu B, Chen ZY, Lu XX, and more...

**Source:** SCIENCE OF THE TOTAL ENVIRONMENT 725, 2020, DOI: 10.1016/j.scitotenv.2020.138328

**Abstract:** The wide application of neonicotinoid insecticides in soil may affect soil microbial community, yet the information is limited. This study first reports the effects of thiamethoxam and dinotefuranon on soil microbial community. Soil from a forest land was collected and spiked
with different nominal levels (0.02 mg kg(-1), 0.2 mg kg(-1) and 2.0 mg kg(-1)) of thiamethoxam and dinotefuran, respectively, and cultivated for 112 days. During the study, concentrations of the two neonicotinoids and their potential degradation products were monitored by LC-MS/MS. At day 112, the soils were analyzed for genetic profile by high-throughput sequencing and carbon metabolic profile by Biolog-ECO plate. The results showed that thiamethoxam and dinotefuran were both attenuated during the study with rate constants being 0.008-0.017 d(-1) and 0.024-0.032 d(-1), respectively, and biodegradation played an important role. As compared to the blank control, the exposure to the studied two neonicotinoids changed the microbial community, and the changes were influenced by both the type of neonicotinoid and the level of exposure. As compared to the blank control, the relative abundances of phyla Gemmatimonadetes and OD1 decreased under most exposed conditions, while the relative abundances of Chloroflexi and Nitrospirae increased under most exposed conditions. The community transition changed the functional potential, particularly carbon metabolism (mostly decreased) and nitrogen metabolism (mostly increased). As compared to the blank control, the utilization of total 31 carbon sources (including six categories) was increased under low exposure to thiamethoxam, but was decreased under all other exposed conditions. Low exposure to dinotefuran stimulated the utilization of three categories of carbon sources (amines, carbohydrates and phenolic compounds). Low exposure to both neonicotinoids increased the community diversity, while middle and high exposure to both neonicotinoids decreased the community diversity. These findings provide new insights into the effects of neonicotinoids on microbial community in soil.

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Distribution pattern of
antibiotic resistance genes
and bacterial community in
agricultural soil samples of
Wuliangsuhai watershed.
China

Authors: Shi W, Liu Y, Li JJ, and more...

Source: AGRICULTURE ECOSYSTEMS & ENVIRONMENT 295, 2020, DOI: 10.1016/j.agee.2020.106884

**Abstract:** The occurrence and dissemination of antibiotic resistance genes (ARGs) constitute a major concern worldwide, and pose crucial threats to public health. The current study focused on this issue in the agricultural soils of Wuliangsuhai watershed in China. A total of 33 ARGs, belonging to 8 major types, were identified in the soil samples, mexF, bla(TEM), vanD, sell, sullI, and oprJ being the predominant ones. The abundance of ARGs ranged from 2.18 x 10(-6)-1.9 x 10(-2) copies/16S rRNA gene copies. Results of correlation analyses confirmed that intI1 significantly correlated with ARGs (aadA1, aadA2, mphA, adl, and sullI), indicating the potential horizontal transfer capability of these genes in soil. Based on the proximity of different sampling sites with urban areas, we found the abundance of bacterial community and ARGs to significantly increase in the sites proximal to urban area, which indicated the agricultural activities and industrial pollution might alter the bacterial community structure and spatial distribution of ARGs. In addition, the correlation between ARGs and environmental factors confirmed the association of microbial community distribution with environmental factors, such as soil organic matter (SOM), available phosphorus (AP), and total nitrogen (TN). The co-occurrence pattern of ARGs and bacterial taxa indicated the succession of Firmicutes and Proteobacteria to possibly be the potential driver for variation in ARGs in the different sampling sites examined. These findings are expected to improve the current understanding of ARG distribution and their relationship with microbial community succession.

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Lignin degradation and
nutrient cycling by white rot
fungi under the influence of
pesticides

Authors: Wali A, Gupta M, Gupta S, and more...

Source: BIOTECH 10, 6, 2020, DOI: 10.1007/s13205-020-02251-z

**Abstract:** The production of enzymes involved in lignin degradation (laccase, ligninase), carbon
cycling (beta-glucosidase), and phosphorous cycling (phosphomonoesterase) by white rot fungi (*Pleurotus sajor-caju*) was studied. In the presence of chlorpyrifos, carbofuran, and their mixture, laccase activity was highest on the 7th day, i.e., 192.5 +/- 0.31 U ml(-1), 213.6 +/- 0.31 U ml(-1), and 164.6 +/- 0.31 U ml(-1), respectively, compared to the control which produced maximum laccase on the 14th day (126.9 +/- 0.15 U ml(-1)). Phosphomonoesterase activity in the presence of chlorpyrifos, carbofuran, and their mixture was 31.5 +/- 0.25, 24.1 +/- 0.15, and 29.2 +/- 0.35 µg PNP min(-1) ml(-1), respectively, which was more than the control on the 21st day (11.63 +/- 0.21 mg PNP min(-1) ml(-1)). beta-Glucosidase production increased with the days of incubation in the presence of pesticides than in the control. beta-Glucosidase activity on the 21st day in the presence of chlorpyrifos, carbofuran, and their mixture was 32.4 +/- 0.1, 24.2 +/- 0.3, and 28.4 +/- 0.25 µg PNP min(-1) ml(-1), respectively, as compared to control (15.3 +/- 0.6 µg PNP min(-1) ml(-1)). Thus, chlorpyrifos, carbofuran, and their mixture were found to have a positive effect on the production of laccase, beta-glucosidase, and phosphomonoesterase by *P. sajor-caju*, which can use these pesticides as a source of their nutrition, thereby improving the health of pesticide-polluted soils.

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## Fungi and Arsenic: Tolerance and Bioaccumulation by Soil Saprotrophic Species

**Authors:** Ceci A, Spinelli V, Massimi L, and more...

**Source:** APPLIED SCIENCES-BASEL 10, 9, 2020, DOI: 10.3390/app10093218

**Abstract:** Increasing arsenic environmental concentrations are raising worldwide concern for its impacts on human health and ecosystem functionality. In order to cope with arsenic contamination, bioremediation using fungi can represent an efficient, sustainable, and cost-effective technological solution. Fungi can mitigate arsenic contamination through different mechanisms including bioaccumulation. In this work, four soil saprotrophic fungi *Absidia spinosa*, *Purpureocillium lilacinum*, *Metarhizium marquandii*, and *Cephalotrichum nanum*, isolated from soils with naturally high arsenic

concentrations, were tested for their ability to tolerate different sodium arsenite concentrations and accumulate As in different cultural conditions. pH medium after fungal growth was measured to study pH variation and metabolic responses. Arsenic bioaccumulation and its influence on the uptake of other elements were investigated through multi-elemental analysis using hydride generation atomic fluorescence spectrometry (HG-AFS), inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectroscopy (ICP-OES). Considering the increasing interest in siderophore application for metal bioremediation, the production of siderophores and their affinity for both Fe and As were also evaluated. All species were able to tolerate and accumulate As in their biomass in all of the tested conditions and produced siderophores with different affinities for Fe and As. The results suggest that the tested fungi are attractive potential candidates for the bioremediation of As contaminated soil and worthy of further investigation.

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## Co-selection of antibiotic-resistant bacteria in a paddy soil exposed to As (III) contamination with an emphasis on potential pathogens

**Authors:** Cao JY, Yang GQ, Mai QJ, and more...

**Source:** SCIENCE OF THE TOTAL ENVIRONMENT 725, 2020, DOI: 10.1016/j.scitotenv.2020.138367

**Abstract:** The increased acquisition of antibiotic resistance by pathogens is a global health concern. The environmental selection of antibiotic resistance can be caused by either antibiotic residues or co-selecting agents such as toxic metal(loid)s. This study explored the potential role of As(III) as a co-selecting driver in the spread of antibiotic resistance in paddy soils. By applying high-throughput sequencing, we found that the diversity and composition of soil microbial communities was significantly altered by As(III) exposure, resulting in an increased proportion of potential pathogens (9.9%) compared to the control soil (0.1%). Meanwhile, a total of 46 As(III)-resistant isolates were
obtained from As(III)-exposure soil, among which potential pathogens accounted for 54.3%. These As(III)-resistant bacteria showed a high incidence of resistance to sulfanilamide (100%) and streptomycin (88-93%). The association between antibiotic and As(III) resistances was further investigated in a potentially pathogenic isolate by whole-genome sequencing and a transcription assay. The results showed that As(III) and antibiotic resistance genes might co-occur in a mobile genomic island and be co-regulated by As(III), implying that antibiotic resistance could be co-selected by As(III) via co-resistance and co-regulationmechanisms. Overall, these results suggest that As(III) exposure provides a strong selective pressure for the expansion of soil bacterial resistome.

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Purification and
characterization of
salvianolic acid B from
*Streptomyces* sp. M4
possessing antifungal activity
against fungal
phytopathogens

Authors: Sharma M, Manhas RK

Source: MICROBIOLOGICAL RESEARCH 237, 2020, DOI: 10.1016/j.micres.2020.126478

**Abstract:** The emergence of resistance among fungal phytopathogens poses a biggest threat across the world. Streptomyces are a group of spore-forming Gram + ve bacteria and prolific producers of secondary bioactive metabolites which have been used as biocontrol agents against phytopathogens and also known for plant growth promotion. The current study identified a potent isolate M4 from soil with broad spectrum antifungal activity against different fungal phytopathogens. The isolate was identified as a Streptomyces sp. on the basis of cultural, morphological, physiological, biochemical and phylogenetic characteristics. 16S rRNA gene sequence of M4 showed 100 % similarity with three *Streptomyces* spp. i.e. *Streptomyces plicatus* NBRC 13071 T (AB184291), *Streptomyces rochei* NBRC 12908 T AB184237 and *Streptomyces enissocaesilis* NRRL-B-16365 T (DQ026641). However, phenotypic and phylogenetic analysis

concluded that M4 represents a novel sp. within the genus Streptomyces. One of the two antifungal compounds purified from Streptomyces M4 was identified as salvianolic acid B. To our knowledge, the present study is the first work reporting purification and characterization of salvianolic acid B from Streptomyces and its broad spectrum antifungal activity against different fungal phytopathogens viz. *Alternaria* spp., *Fusarium* spp., *Colletotrichum* spp., *Cladosporium herbarum* and *Botrytis cinerea*. Salvianolic acid B was found to be photostable, thermostable (up to 70 degrees C) and non-mutagenic in nature and might be developed as safe biofungicide to control phytopathogens.

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Potential risks of antibiotic resistant bacteria and genes in bioremediation of petroleum hydrocarbon contaminated soils

Authors: Cunningham Colin J, Kuyukina Maria S, Ivshina Irena B, and more...

Source: ENVIRONMENTAL SCIENCE-PROCESSES & IMPACTS 22(5):1110-1124, 2020, DOI: 10.1039/c9em00606k

**Abstract:** Bioremediation represents a sustainable approach to remediating petroleum hydrocarbon contaminated soils. One aspect of sustainability includes the sourcing of nutrients used to stimulate hydrocarbon-degrading microbial populations. Organic nutrients such as animal manure and sewage sludge may be perceived as more sustainable than conventional inorganic fertilizers. However, organic nutrients often contain antibiotic residues and resistant bacteria (along with resistance genes and mobile genetic elements). This is further exacerbated since antibiotic resistant bacteria may become more abundant in contaminated soils due to co-selection pressures from pollutants such as metals and hydrocarbons. We review the issues surrounding bioremediation of petroleum-hydrocarbon contaminated soils, as an example, and consider the potential human-health risks from antibiotic resistant bacteria. While awareness is coming to light, the relationship between contaminated land and antibiotic