# Bulletin de veille du réseau d'écotoxicologie terrestre et aquatique N°47

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

Morin, Olivier Crouzet, Pascale Karmasyn-Veyrines

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## 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°47. 2020, 10.15454/6MQT-0H51. hal-03041889v2

HAL Id: hal-03041889

https://hal.inrae.fr/hal-03041889v2

Submitted on 13 Jul 2021

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

<figure><img src="image_3.png" /></figure>

N°47, Octobre 2020

Réalisé par l'équipe de veille sur la période du 1er septembre au 31 octobre 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

## Edito

Voici notre 47ème bulletin de veille, toujours riche en informations !

Nous vous rappelons le séminaire trisannuel de notre réseau Ecotox, qui se tiendra les lundi 16 novembre après midi, et la journée du mardi 17 en webinaire. Le thème retenu cette année est « L'écotoxicologie du continuum sol-eau, opportunités suite à la fusion INRA-Irstea ». Vous trouverez les informations utiles comme le receuil des résumés sur la page dédiée de notre site ECOTOX :
https://www6.inrae.fr/ecotox/Manifestations/Seminaires-du-reseau/2020

Nous vous proposons dans ce bulletin une tribune présentant PestiEcotox, une expertise scientifique collective relative aux effets non intentionnels des produits phytopharmaceutiques sur la biodiversité et les services écosystémiques. 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-29-octobre-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 une bonne lecture de ce bulletin !

Contact : veille-ecotox@inrae.fr
## SOMMAIRE

TRIBUNE LIBRE 12

ERA / PUBLICATIONS SCIENTIFIQUES 16

Ecotoxicology of strobilurin fungicides 16

ERA / PUBLICATIONS SCIENTIFIQUES / COMMUNAUTES MICROBIENNES AQUATIQUES. 16

The roles of phytohormones in metal stress regulation in microalgae 16

Physiological and morphological responses of green microalgae Chlorella vulgaris to silver nanoparticles 16

Short-term effect of cadmium on the motility of three flagellated algal species 17

Cytotoxicological evaluation of copper oxide nanoparticles on green algae, bacteria and crustacean systems 17

Responses to iron oxide and zinc oxide nanoparticles in echinoderm embryos and microalgae: uptake, growth, morphology, and transcriptomic analysis 18

Diatoms as indicators of environmental health on Korean islands 18

The effects of ionizing radiation on the structure and antioxidative and metal-binding capacity of the cell wall of microalga Chlorella sorokiniana 19

The "Plastisphere" of Biodegradable Plastics Is Characterized by Specific Microbial Taxa of Alpine and Arctic Soils 19

Plain polystyrene microplastics reduce the toxic effects of ZnO particles on marine microalgae Dunaliella salina 20

Shifts in photosynthetic parameters and lipid production of the freshwater microalga *Selenastrum gracile* (Chlorophyceae) under cadmium exposure 20

Assessing the Toxicity of Leachates From Weathered Plastics on Photosynthetic Marine Bacteria *Prochlorococcus* 21

Amelioration of copper toxicity to a tropical freshwater microalga: Effect of natural DOM source and season 22

Metabolomic modulations in a freshwater microbial community exposed to the fungicide azoxystrobin 22

Biochemical responses of the freshwater microalga *Dictyosphaerium* sp. upon exposure to three sulfonamides 23

Secondary Effects of Antibiotics on Microbial Biofilms 23

Tolerance Patterns in Stream Biofilms Link Complex Chemical Pollution to Ecological Impacts 24

The effects of bisphenol A, F and their mixture on algal and cyanobacterial growth: from additivity to antagonism 24

Unravelling the effects of multiple stressors on diatom and macroinvertebrate communities in European river basins using structural and functional approaches 25

Micro- and Nanoplastic Exposure Effects in Microalgae: A Meta-Analysis of Standard Growth Inhibition Tests 25

Pollution shapes the microbial communities in river water and sediments from the Olifants River catchment, South Africa 26

Size-dependent cellular internalization and effects of polystyrene microplastics in microalgae *P. helgolandica* var. tsingtaensis and *S. quadricauda* 26

Toxic effects of Fe2WO6 nanoparticles towards microalga Dunaliella salina: Sonochemical synthesis nanoparticles and investigate its impact on the growth 27

The interactions between microplastic polyvinyl chloride and marine diatoms: Physiological, morphological, and growth effects 28

Effect of Azamethiphos on enzymatic activity and metabolic fingerprints of marine microbial communities from the water column 28

Bacterial community colonization on tire microplastics in typical urban water environments and associated impacting factors 29

Differences in metal tolerance among strains, populations, and species of marine diatoms - Importance of exponential growth for quantification 29

The Fungicide Tebuconazole Confounds Concentrations of Molecular Biomarkers Estimating Fungal Biomass 30

Distinct Temporal Succession of Bacterial Communities in Early Marine Biofilms in a Portuguese Atlantic Port 30

The role of metal contamination in shaping microbial communities in heavily polluted marine sediments 31

Interactive effects of warming and copper toxicity on a tropical freshwater green microalga *Chloromonas augustae* (Chlorophyceae) 32

Characterization of the nano-bio interaction between metallic oxide nanomaterials and freshwater microalgae using flow cytometry 32

Effect of humic acids on the toxicity of pollutants to *Chlamydomonas reinhardtii*: Investigation by a microscale algal
<table><tr><td>growth inhibition test</td><td>33</td></tr><tr><td>Increased inheritance of structure and function of bacterial communities and pathogen propagation in plastisphere along a river with increasing antibiotics pollution gradient</td><td>33</td></tr><tr><td>Advances in characterizing microbial community change and resistance upon exposure to lead contamination: Implications for ecological risk assessment</td><td>34</td></tr><tr><td>Polystyrene nanoplastics cause growth inhibition, morphological damage and physiological disturbance in the marine microalga <i>Platymonas helgolandica</i></td><td>35</td></tr><tr><td>Effects of humic acids on biotoxicity of tetracycline to microalgae <i>Coelastrella sp.</i></td><td>35</td></tr></table>

<table><tr><td>ERA / PUBLICATIONS SCIENTIFIQUES / MICROBIOLOGIE ET CONTAMINANTS</td><td>35</td></tr><tr><td>Effects of co-contamination of heavy metals and total petroleum hydrocarbons on soil bacterial community and function network reconstitution</td><td>36</td></tr><tr><td>Molecular identification and phylogenetic analysis of chromium-resistant bacteria isolated from chromite mine area soil, Sukinda, India using 16S rRNA sequencing</td><td>36</td></tr><tr><td>Effects of dibutyl phthalate contamination on physiology, phytohormone homeostasis, rhizospheric and endophytic bacterial communities of Brassica rapa var. chinensis</td><td>37</td></tr><tr><td>Bioavailable metal(loid)s and physicochemical features co-mediating microbial communities at combined metal(loid) pollution sites</td><td>37</td></tr><tr><td>Temporal dynamics of heavy metal distribution and associated microbial community in ambient aerosols from vanadium smelter</td><td>38</td></tr><tr><td>Microbial Distribution and Diversity of Soil Around a Manganese Mine Area</td><td>38</td></tr><tr><td>Unraveling consequences of soil micro- and nano-plastic pollution on soil-plant system: Implications for nitrogen (N) cycling and soil microbial activity</td><td>39</td></tr><tr><td>Smectite clay minerals reduce the acute toxicity of quaternary alkylammonium compounds towards potentially pathogenic bacterial taxa present in manure and soil</td><td>39</td></tr><tr><td>Graphene oxide influences bacterial community and soil environments of Cd-polluted Haplic Cambisols in Northeast China</td><td>40</td></tr><tr><td>Spatial and Temporal Variation in Microbial Diversity and Community Structure in a Contaminated Mangrove Wetland</td><td>41</td></tr><tr><td>Fungal heavy metal adaptation through single nucleotide polymorphisms and copy-number variation</td><td>41</td></tr><tr><td>Selective pressures of heavy metals on microbial community determine microbial functional roles during composting: Sensitive, resistant and actor</td><td>42</td></tr><tr><td>Comparative study on the pollution status of organochlorine pesticides (OCPs) and bacterial community diversity and structure between plastic shed and open-field soils from northern China</td><td>42</td></tr><tr><td>Physicochemical properties, heavy metals, and metal-tolerant bacteria profiles of abandoned gold mine tailings in Krugersdorp, South Africa</td><td>43</td></tr><tr><td>Physicochemical and microbial properties of urban park soils of the cities of Marrakech, Morocco and Torun, Poland: Human health risk assessment of fecal coliforms and trace elements</td><td>43</td></tr><tr><td>Effect of heavy metals on soil microbial biomass, and nematode trophic groups of a paddy soil affected by long-runningpolymetallic mining activities in Guangdong, Southern China</td><td>44</td></tr><tr><td>Soil Microbial Community Changes in a Field Treatment with Chlorotoluron, Flufenacet and Diflufenican and Two Organic Amendments</td><td>44</td></tr><tr><td>Microbial responses to selected pharmaceuticals in agricultural soils: Microcosm study on the roles of soil, treatment and time</td><td>45</td></tr><tr><td>Impact assessment of heavy metals pollution in the air on bacterial microflora of elm trees</td><td>45</td></tr><tr><td>Metal-induced bacterial interactions promote diversity in river-sediment microbiomes</td><td>46</td></tr><tr><td>Responses of soil and earthworm gut bacterial communities to heavy metal contamination</td><td>46</td></tr><tr><td>Ecological Effects of Heavy Metal Pollution on Soil Microbial Community Structure and Diversity on Both Sides of a River around a Mining Area</td><td>47</td></tr><tr><td>The interaction of dissolved organic nitrogen removal and microbial abundance in iron-filings based green environmental media for stormwater treatment</td><td>47</td></tr><tr><td>The response of soil and phyllosphere microbial communities to repeated application of the fungicide iprodione: accelerated biodegradation or toxicity?</td><td>48</td></tr><tr><td>Effect of dibutyl phthalate on microbial function diversity and enzyme activity in wheat rhizosphere and non-
<table><tr><td>rhizosphere soils</td><td>48</td></tr><tr><td>Levels of heavy metal concentrations and their effect on net nitrification rates and nitrifying archaea/bacteria in paddy soils of Bangladesh</td><td>49</td></tr><tr><td>Soil bacterial community response to long-term land use conversion in Yellow River Delta</td><td>49</td></tr><tr><td>Elevated CO2 Affects the Soil Organic Carbon Fractions and Their Relation to Soil Microbial Properties in the Rhizosphere of Robinia pseudoacacia L. Seedlings in Cd-Contaminated Soils</td><td>50</td></tr><tr><td>A novel extracellular enzyme stoichiometry method to evaluate soil heavy metal contamination: Evidence derived from microbial metabolic limitation</td><td>50</td></tr><tr><td>Spatiotemporal vanadium distribution in soils with microbial community dynamics at vanadium smelting site</td><td>51</td></tr><tr><td>Analysis of Fungal Composition in Mine-Contaminated Soils in Hechi City</td><td>52</td></tr><tr><td>Microbial remediation of micro-nano plastics: Current knowledge and future trends</td><td>52</td></tr></table>

## ERA / PUBLICATIONS SCIENTIFIQUES / MICROBIOLOGIE ET CONTAMINANTS / ANTIBIOTIQUES ET ANTIBIORESISTANCES

<table><tr><td>Modeling transport of antibiotic resistant bacteria in aquatic environment using stochastic differential equations</td><td>52</td></tr><tr><td>Detection and Profiling of Antibiotic Resistance among Culturable Bacterial Isolates in Vended Food and Soil Samples</td><td>53</td></tr><tr><td>High levels of antibiotic resistance genes and opportunistic pathogenic bacteria indicators in urban wild bird feces</td><td>54</td></tr><tr><td>Bacteriophages as antibiotic resistance genes carriers in agro-food systems</td><td>54</td></tr><tr><td>Isolation of antibiotic-resistant bacteria in biogas digestate and their susceptibility to antibiotics</td><td>55</td></tr><tr><td>Antimicrobial resistance: more than 70 years of war between humans and bacteria</td><td>55</td></tr><tr><td>Seasonal variations in export of antibiotic resistance genes and bacteria in runoff from an agricultural watershed in Iowa</td><td>56</td></tr><tr><td>Linkage of antibiotic resistance genes, associated bacteria communities and metabolites in the wheat rhizosphere from chlorpyrifos-contaminated soil</td><td>56</td></tr><tr><td>The formation mechanism of antibiotic-resistance genes associated with bacterial communities during biological decomposition of household garbage</td><td>57</td></tr><tr><td>Untreated swine wastes changed antibiotic resistance and microbial community in the soils and impacted abundances of antibiotic resistance genes in the vegetables</td><td>57</td></tr><tr><td>Oxytetracycline, copper, and zinc effects on nitrification processes and microbial activity in two soil types</td><td>58</td></tr><tr><td>Effects of co-loading of polyethylene microplastics and ciprofloxacin on antibiotic degradation efficiency and microbial community structure soil</td><td>59</td></tr><tr><td>Antibiotic resistance gene abundance and bacterial community structure in soils altered by Ammonium and Nitrate Concentrations</td><td>59</td></tr><tr><td>Effect of Drug-Resistant Bacteria on Agriculture, Livestock, and Environment</td><td>60</td></tr><tr><td>Characteristics of microbial community of soil subjected to industrial production of antibiotics</td><td>60</td></tr><tr><td>Genetic Determinants for Metal Tolerance and Antimicrobial Resistance Detected in Bacteria Isolated from Soils of Olive Tree Farms</td><td>61</td></tr><tr><td>Antibiotic resistance genes, bacterial communities, and functions in constructed wetland-microbial fuel cells: Responses to the co-stresses of antibiotics and zinc</td><td>61</td></tr><tr><td>Detection of sul1 and sul2 genes in sulfonamide-resistant bacteria (SRB) from sewage, aquaculture sources, animal wastes and hospital wastewater in South-West Nigeria</td><td>62</td></tr><tr><td>The Effects of Tetracycline Residues on the Microbial Community Structure of Tobacco Soil in Pot Experiment</td><td>62</td></tr></table>

## ERA / PUBLICATIONS SCIENTIFIQUES / MICROBIOLOGIE ET CONTAMINANTS / BIOREMEDIATION

<table><tr><td>Bioremediation of Fluazifop-p-butyl herbicide by some soil bacteria isolated from various regions of Turkey in an artificial agricultural field</td><td>63</td></tr><tr><td>Combined use of municipal solid waste biochar and bacterial biosorbent synergistically decreases Cd(II) and Pb(II) concentration in edible tissue of forage maize irrigated with heavy metal-spiked water</td><td>64</td></tr><tr><td>Arsenic mobilization affected by extracellular polymeric substances (EPS) of the dissimilatory iron reducing bacteria isolated from high arsenic groundwater</td><td>64</td></tr><tr><td>Bioremediation potential of new cadmium, chromium, and nickel-resistant bacteria isolated from tropical</td><td>64</td></tr></table>
<table><tr><td>agricultural soil</td><td>65</td></tr><tr><td>Biochar-bacteria-plant partnerships: Eco-solutions for tackling heavy metal pollution</td><td>65</td></tr><tr><td>4-Nitrophenol biodegradation by an isolated and characterized microbial consortium and statistical optimization of physicochemical parameters by Taguchi Methodology</td><td>66</td></tr><tr><td>The "Plastisphere" of Biodegradable Plastics Is Characterized by Specific Microbial Taxa of Alpine and Arctic Soils</td><td>66</td></tr><tr><td>Novel metabolites of triazophos formed during degradation by bacterial strains <i>Pseudomonas kilonensis</i> MB490, <i>Pseudomonas kilonensis</i> MB498 and <i>Pseudomonas</i> sp. MB504 isolated from cotton fields</td><td>67</td></tr><tr><td>Inoculation of <i>Brassica napus</i> L. genotypes with endophytic bacteria promote growth and alleviate cadmium toxicity</td><td>68</td></tr><tr><td>Biodegradation of diesel oil by cold-adapted bacterial strains of <i>Arthrobacter</i> spp. from Antarctica</td><td>68</td></tr><tr><td>Xenobiotic thiencarbazone-methyl biotransformation investigation by bacteria <i>Streptococcus pneumoniae</i>, <i>Escherichia coli</i> and <i>Streptococcus pyogenes</i></td><td>69</td></tr><tr><td>Influence of Microbial Inoculation on Heavy Metals Absorption of Three Reforestation Species</td><td>69</td></tr><tr><td>Optimization of microbial assisted phytoremediation of soils contaminated with pesticides</td><td>70</td></tr><tr><td><i>Trifolium repens</i>-Associated Bacteria as a Potential Tool to Facilitate Phytostabilization of Zinc and Lead Polluted Waste Heaps</td><td>70</td></tr><tr><td>A Newly Discovered Humic-Reducing Bacterium, <i>Pseudomonas geniculata</i> PQ01, Isolated From Paddy Soil Promotes Paraquat Anaerobic Transformation</td><td>71</td></tr><tr><td>Biodegradation of organophosphorus pesticide chlorpyrifos by <i>Sphingobacterium</i> sp. C1B, a psychrotolerant bacterium isolated from apple orchard in Himachal Pradesh of India</td><td>71</td></tr><tr><td>Lead (Pb)-resistant bacteria inhibit Pb accumulation in dill (<i>Anethum graveolens</i> L.) by improving biochemical, physiological, and antioxidant enzyme response of plants</td><td>72</td></tr><tr><td>Efficient biodegradation of DEHP by CM9 consortium and shifts in the bacterial community structure during bioremediation of contaminated soil</td><td>72</td></tr><tr><td>Characterization of the Belowground Microbial Community in a Poplar-Phytoremediation Strategy of a Multi-Contaminated Soil</td><td>73</td></tr><tr><td>Potential Plant Growth-Promoting Bacteria with Heavy Metal Resistance</td><td>73</td></tr><tr><td>Biodegradation of Pesticides at the Limit: Kinetics and Microbial Substrate Use at Low Concentrations</td><td>74</td></tr><tr><td>Performance of microbial induced carbonate precipitation for immobilizing Cd in water and soil</td><td>75</td></tr><tr><td>Fungal bioremediation of soil co-contaminated with petroleum hydrocarbons and toxic metals</td><td>75</td></tr><tr><td>The Fate of Lead (Pb) in Multitrophic Interactions Among Bacteria, Fungi, and Bacterivorous Soil Nematodes</td><td>75</td></tr><tr><td>Accelerated Biodegradation of the Agrochemical Ametoctradin by Soil-Derived Microbial Consortia</td><td>76</td></tr><tr><td>Microbial Consortium of PGPR, Rhizobia and Arbuscular Mycorrhizal Fungus Makes Pea Mutant SGECd(t)</td><td>76</td></tr><tr><td>Comparable with Indian Mustard in Cadmium Tolerance and Accumulation</td><td>76</td></tr><tr><td>Bioremediation of toxic metals in mining site of Zamfara metropolis using resident bacteria (<i>Pantoea agglomerans</i>): A optimization approach</td><td>77</td></tr><tr><td>Remediation potential of immobilized bacterial strain with biochar as carrier in petroleum hydrocarbon and Ni co-contaminated soil</td><td>78</td></tr><tr><td>Effects of root endophytic fungus, <i>Microdochium bolleyi</i> on cadmium uptake, translocation and tolerance by <i>Hordeum vulgare</i> L.</td><td>78</td></tr><tr><td>Poly-gamma-glutamic acid-producing bacteria reduced Cd uptake and effected the rhizosphere microbial communities of lettuce</td><td>79</td></tr><tr><td>Impact of a synthetic fungicide (fosetyl-Al and propamocarb-hydrochloride) and a biopesticide (<i>Clonostachys rosea</i>) on soil bacterial, fungal, and protist communities</td><td>79</td></tr><tr><td>Responses of microbial communities and metabolic activities in the rhizosphere during phytoremediation of Cd-contaminated soil</td><td>80</td></tr><tr><td>Zinc tolerant plant growth promoting bacteria alleviates phytotoxic effects of zinc on maize through zinc immobilization</td><td>80</td></tr><tr><td>Responses of microbial communities and metabolic activities in the rhizosphere during phytoremediation of Cd-contaminated soil</td><td>81</td></tr><tr><td>Evaluation of organic carbon and microbial inoculum for bioremediation of acid mine drainage</td><td>82</td></tr><tr><td>Insight into plant-bacteria-fungi interactions to improve plant performance via remediation of heavy metals: an overview</td><td>82</td></tr><tr><td>Endophytic bacteria stimulate mercury phytoremediation by modulating its bioaccumulation and volatilization</td><td>82</td></tr></table>
<table><tr><td>Efficient fungal and bacterial facilitated remediation of thiencarbazone methyl in the environment</td><td>83</td></tr><tr><td>Phytomanagement Reduces Metal Availability and Microbial Metal Resistance in a Metal Contaminated Soil</td><td>83</td></tr><tr><td>Application of a simazine degrading bacterium, <i>Arthrobacter ureafaciens</i> XMJ-Z01 for bioremediation of simazine pollution</td><td>84</td></tr><tr><td>Characterization and bioremediation potential of nickel-resistant endophytic bacteria isolated from the wetland plant <i>Tamarix chinensis</i></td><td>84</td></tr><tr><td>A hyperaccumulator plant <i>Sedum alfredii</i> recruits Cd/Zn-tolerant but not Pb-tolerant endospheric bacterial communities from its rhizospheric soil</td><td>85</td></tr><tr><td>Bacterial bioaugmentation enhances hydrocarbon degradation, plant colonization and gene expression in diesel-contaminated soil</td><td>85</td></tr><tr><td>The modulation of sugarcane growth and nutritional profile under aluminum stress is dependent on beneficial endophytic bacteria and plantlet origin</td><td>86</td></tr><tr><td>Acclimatization of a newly isolated bacteria in monomer tere-phthalic acid (TPA) may enable it to attack the polymer poly-ethylene tere-phthalate (PET)</td><td>86</td></tr><tr><td>Structure of microbial communities in amended and unamended acid-generating mine wastes along gradients of soil amelioration and revegetation</td><td>87</td></tr><tr><td>Microbial approach for alleviation of potentially toxic elements in agricultural soils</td><td>88</td></tr><tr><td>Microbial insights into the biogeochemical features of thallium occurrence: A case study from polluted river sediments</td><td>88</td></tr><tr><td>The Immobilization of Soil Cadmium by the Combined Amendment of Bacteria and Hydroxyapatite</td><td>88</td></tr><tr><td>Diversity of Metal-Resistant and Tensoactive-Producing Culturable Heterotrophic Bacteria Isolated from a Copper Mine in Brazilian Amazonia</td><td>89</td></tr><tr><td>Responses of soil and earthworm gut bacterial communities to heavy metal contamination</td><td>89</td></tr><tr><td>Effect of biochar on Cd and pyrene removal and bacteria communities variations in soils with culturing ryegrass (<i>Lolium perenne</i> L.)</td><td>90</td></tr><tr><td><i>Bacillus aryabhattai</i> FACU: A promising bacterial strain capable of manipulate the glyphosate herbicide residues</td><td>90</td></tr><tr><td>Effects of liquid digestate on the valence state of vanadium in plant and soil and microbial community response</td><td>91</td></tr></table>

<table><tr><td>ERA / PUBLICATIONS SCIENTIFIQUES / PESTICIDES ET FAUNE SAUVAGE</td><td>92</td></tr><tr><td>Multiscale habitat mediates pest reduction by birds in an intensive agricultural region</td><td>92</td></tr><tr><td>Birds suppress pests in corn but release them in soybean crops within a mixed prairie/agriculture system</td><td>92</td></tr><tr><td>Yellow-legged gull eggs (<i>Larus michahellis</i>) as persistent organic pollutants and trace metal bioindicator for two nearby areas with different human impact</td><td>92</td></tr><tr><td>Glyphosate-based herbicides influence antioxidants, reproductive hormones and gut microbiome but not reproduction: A long-term experiment in an avian model</td><td>93</td></tr><tr><td>Exposure Impacts of Environmentally Relevant Concentrations of a Glufosinate Ammonium Herbicide Formulation on Larval Development and Thyroid Histology of <i>Xenopus laevis</i></td><td>93</td></tr><tr><td>Cypermethrin- and fipronil-based insecticides cause biochemical changes in <i>Physalaemus gracilistadpoles</i></td><td>93</td></tr><tr><td>Organochlorine pesticide residues in feathers of four bird species from western part of Turkey</td><td>94</td></tr><tr><td>A micronucleus assay detects genotoxic effects of herbicide exposure in a protected butterfly species</td><td>94</td></tr><tr><td>Legacy and Contaminants of Emerging Concern in Tree Swallows Along an Agricultural to Industrial Gradient: Maumee River, Ohio</td><td>94</td></tr><tr><td>Genotoxicity in American kestrels in an agricultural landscape in the Baja California peninsula, Mexico</td><td>94</td></tr></table>

<table><tr><td>ERA / PUBLICATIONS SCIENTIFIQUES / PESTICIDES / CLIMAT ET VDT / ENCHY</td><td>95</td></tr><tr><td>Ecotoxicology of strobilurin fungicides</td><td>95</td></tr><tr><td>Sub-Lethal Effects of Pesticides on the DNA of Soil Organisms as Early Ecotoxicological Biomarkers</td><td>95</td></tr><tr><td>A two years field experiment to assess the impact of two fungicides on earthworm communities and their recovery</td><td>95</td></tr><tr><td>A biological characteristic extrapolation of compound toxicity for different developmental stage species with toxicokinetic-toxicodynamic model</td><td>95</td></tr><tr><td>What are the effects of PFAS exposure at environmentally relevant concentrations?</td><td>96</td></tr><tr><td>Transcriptome, bioaccumulation and toxicity analyses of earthworms (<i>Eisenia fetida</i>) affected by trifloxystrobin and trifloxystrobin acid</td><td>96</td></tr></table>
<table><tr><td>Novel Pesticide Risk Indicators for Aquatic Organisms and Earthworms</td><td>96</td></tr><tr><td>Biochemical response, histopathological change and DNA damage in earthworm (Eisenia fetida) exposed to sulfentrazone herbicide</td><td>96</td></tr><tr><td>Sub-lethal effects of the pesticide imazalil on the earthworm Eisenia andrei: reproduction, cytotoxicity, and oxidative stress</td><td>96</td></tr><tr><td>Interactive effect of glyphosate-based herbicides and organic soil layer thickness on growth and reproduction of the tropical earthworm Pontoscolex corethrurus (Muller, 1857)</td><td>97</td></tr><tr><td>More frequent droughts slow down litter decomposition across European agroecosystems and increase the importance of earthworm functional diversity</td><td>97</td></tr></table>

<table><tr><td><strong>DROIT ET POLITIQUE DE L'ENVIRONNEMENT</strong></td><td><strong>97</strong></td></tr><tr><td>Drinking Water Directive</td><td>97</td></tr><tr><td>Reducing agricultural ammonia emissions: benefits and costs</td><td>98</td></tr><tr><td>Impact des polluants en mélange: un appel à projets de recherche est ouvert</td><td>98</td></tr><tr><td>Qualité de l'air: l'Ademe regroupe ses programmes de recherche dans l'appel à propositions unique Aqacia</td><td>98</td></tr></table>

<table><tr><td><strong>REGLEMENTATION / DROIT</strong></td><td><strong>99</strong></td></tr><tr><td>Limites maximales applicables aux résidus de 1,4diaminobutane, de 1méthylcyclopropène, d'acétate d'ammonium, de bifénazate, de chlorantraniliprole, de chlorméquat, de cyprodinil, de chaux, de mandipropamide, de poivre, de pyridaben, de la substance «répulsifs: farine de sang», d'extraits d'algues et de chlorhydrate de triméthylamine, présents dans ou sur certains produits</td><td>99</td></tr><tr><td>Limites maximales applicables aux résidus de bupirimate, de carfentrazone-éthyle, d'éthirimol et de pyriofénone présents dans ou sur certains produits</td><td>99</td></tr><tr><td>Démarches ou pratiques ayant des incidences favorables sur la réduction de l'usage et des impacts de produits phytopharmaceutiques</td><td>99</td></tr><tr><td>Activité « application en prestation de service de produits phytopharmaceutiques » : référentiel de certification</td><td>100</td></tr><tr><td>Distribution de produits phytopharmaceutiques à des utilisateurs non professionnels : référentiel de certification</td><td>100</td></tr><tr><td>Distribution de produits phytopharmaceutiques à des utilisateurs professionnels : référentiel de certification</td><td>100</td></tr><tr><td>Référentiel de certification pour l'activité « conseils stratégique et spécifique à l'utilisation de produits phytopharmaceutiques »</td><td>100</td></tr><tr><td>Prolongation de l'approbation des substances actives: amidosulfuron, bifénox, chlorotoluron, clofentézine, clomazone, cyperméthrine, daminozide, deltaméthrine, dicamba, difénoconazole, diflufénican, fenoxaprop-P, fenpropidine, fludioxonyl, flufénacet, fosthiazate, indoxacarbe, lénacile, MCPA, MCPB, nicosulfuron, huiles de paraffine, piclorame, prosulfocarbe, soufre, triflusulfuron et tritosulfuron</td><td>101</td></tr><tr><td>Mise sur le marché des produits phytopharmaceutiques: approbation de la substance active thiophanate-méthyl non renouvelée</td><td>101</td></tr><tr><td>Autorisation de l'Union pour la famille de produits biocides «Iodine based products - CID LINES NV»</td><td>101</td></tr><tr><td>Teneurs maximales en 3-monochloropropanediol (3-MCPD), en esters d'acides gras de 3-MCPD et en esters d'acides gras de glycidol dans certaines denrées alimentaires</td><td>102</td></tr><tr><td>Avis aux opérateurs sur les décrets biocides</td><td>102</td></tr><tr><td>Teneurs maximales en 3-monochloropropanediol (3-MCPD), en esters d'acides gras de 3-MCPD et en esters d'acides gras de glycidol dans certaines denrées alimentaires</td><td>102</td></tr><tr><td>Mise sur le marché des produits phytopharmaceutiques: approbation de la substance active «hydrogénocarbonate de sodium»</td><td>102</td></tr><tr><td>Non-renouvellement de l'approbation de la substance active fenamiphos</td><td>103</td></tr></table>

<table><tr><td><strong>PUBLICATIONS DU RESEAU ECOTOX</strong></td><td><strong>103</strong></td></tr><tr><td>Differential side-effects of Bacillus thuringiensis bioinsecticide on non-target Drosophila flies</td><td>103</td></tr><tr><td>Synergetic effect of antibiotic mixtures on soil bacterial N2O-reducing communities</td><td>103</td></tr><tr><td>Transfer and Transcriptomic Profiling in Liver and Brain of European Eels (Anguilla anguilla) After Diet-borne</td><td></td></tr></table>
<table><tr><td>Exposure to Gold Nanoparticles</td><td>104</td></tr><tr><td>A maternal effect influences sensitivity to chlorpyrifos pesticide in the pest moth <i>Spodoptera littoralis</i></td><td>104</td></tr><tr><td>Keep and promote biodiversity at polluted sites under phytomanagement</td><td>105</td></tr><tr><td>Behavior of metallurgical zinc contamination in coastal environments: A survey of Zn from electroplating wastes and partitioning in sediments</td><td>105</td></tr><tr><td>Reprint of: The effect of the Music Day event on community drug use</td><td>106</td></tr><tr><td>Multi-scale impact of chronic exposure to environmental concentrations of chlordecone in freshwater cnidarian, <i>Hydra circumcincta</i></td><td>106</td></tr><tr><td>Phytol, (E)-nerolidol and spathulenol from Stevia rebaudiana leaf essential oil as effective and eco-friendly botanical insecticides against <i>Metopolophium dirhodum</i></td><td>107</td></tr><tr><td>Contribution of chemical inputs on the trace elements concentrations of surface soils in urban allotment gardens</td><td>107</td></tr><tr><td>Emerging polar pollutants in groundwater: Potential impact of urban stormwater infiltration practices</td><td>108</td></tr><tr><td>Analysis of surface water reveals land pesticide contamination: an application for the determination of chlordecone-polluted areas in Guadeloupe, French West Indies</td><td>109</td></tr><tr><td>Impact of a synthetic fungicide (fosetyl-Al and propamocarb-hydrochloride) and a biopesticide (<i>Clonostachys rosea</i>) on soil bacterial, fungal, and protist communities</td><td>109</td></tr><tr><td>Do rainfall characteristics affect the export of copper, zinc and synthetic pesticides in surface runoff from headwater catchments?</td><td>110</td></tr><tr><td>Direct and indirect effects of multiple environmental stressors on fish health in human-altered rivers</td><td>110</td></tr><tr><td>Screening of potential uranium protein targets in fish ovaries after chronic waterborne exposure: Differences and similarities between roach and zebrafish</td><td>111</td></tr><tr><td>Microbiome-Aware Ecotoxicology of Organisms: Relevance, Pitfalls, and Challenges</td><td>111</td></tr><tr><td>Dose reconstruction supports the interpretation of decreased abundance of mammals in the Chernobyl Exclusion Zone</td><td>112</td></tr><tr><td>High-multiplexed monitoring of protein biomarkers in the sentinel <i>Gammarus fossarum</i> by targeted scot-MRM assay, a new vision for ecotoxicoproteomics</td><td>112</td></tr><tr><td>Sublethal exposure to deltamethrin impairs maternal egg care in the European earwig <i>Forficula auricularia</i></td><td>113</td></tr><tr><td>A two years field experiment to assess the impact of two fungicides on earthworm communities and their recovery</td><td>113</td></tr><tr><td>Quantification of spatial and temporal variations in trace element fluxes originating from urban areas at the catchment scale</td><td>114</td></tr><tr><td>Dietary bioaccumulation of persistent organic pollutants in the common sole <i>Solea solea</i> in the context of global change. Part 1: Revisiting parameterisation and calibration of a DEB model to consider inter-individual variability in experimental and natural conditions</td><td>115</td></tr><tr><td>Integration of ecosystem science into radioecology: A consensus perspective</td><td>115</td></tr><tr><td>Flubendiamide, the first phthalic acid diamide insecticide, impairs neuronal calcium signalling in the honey bee's antennae</td><td>116</td></tr><tr><td>Water and pesticide transfers in undisturbed soil columns sampled from a Stagnic Luvisol and a Vermic Umbrisol both cultivated under conventional and conservation agriculture</td><td>116</td></tr><tr><td>An active biomonitoring approach using three-spined stickleback (<i>Gasterosteus aculeatus</i>, L.) to assess the efficiency of a constructed wetland as tertiary treatment of wastewater</td><td>117</td></tr><tr><td>The Role of Legislation, Regulatory Initiatives and Guidelines on the Control of Plastic Pollution</td><td>118</td></tr><tr><td>Ecotoxicity of trace elements to chicken <i>Gallus gallus</i> domesticus exposed to a gradient of polymetallic-polluted sites</td><td>118</td></tr><tr><td>Characterization of the nano-bio interaction between metallic oxide nanomaterials and freshwater microalgae using flow cytometry</td><td>119</td></tr></table>

<table><tr><td>REVUE DE PRESSE / ALTERNATIVES / BIOPESTICIDES</td><td>119</td></tr><tr><td>Intercropping technique may improve agricultural sustainability and productivity</td><td>119</td></tr><tr><td>Info firmes Syngenta acquiert Valagro, leader dans la production de biostimulants</td><td>119</td></tr><tr><td>Betteraves - Programme Aker : Une diversité variétale élargie pour répondre aux défis de demain</td><td>120</td></tr><tr><td>Plant protein discovery could reduce need for fertilizer</td><td>120</td></tr></table>
<table><tr><td>REVUE DE PRESSE / ASSOCIATIONS</td><td>120</td></tr><tr><td>Politique agricole commune : La Pac rate son cap vert</td><td>120</td></tr><tr><td>Vote de la loi sur les néonicotinoïdes - Après les députés, les sénateurs et sénatrices manquent de vision et de courage en votant pour le retour des « insecticides tueurs d'abeilles »</td><td>121</td></tr><tr><td>New European Union Looks at Chemical Mixtures</td><td>121</td></tr><tr><td>Natural Areas Surrounding Farmland Critical to Reducing Pesticide Use</td><td>121</td></tr><tr><td>Captured by Extremist Pro-Pesticide Agenda, A Broken EPA Reregisters Several Toxic Pesticides</td><td>121</td></tr><tr><td>23 organisations demandent au sénat de ne pas entériner le retour des insecticides tueurs d'abeilles</td><td>122</td></tr><tr><td>Commission spéciale sur la Lutte contre le Cancer - Mes priorités en tant que coordinatrice pour le groupe Verts/ALE</td><td>122</td></tr><tr><td>Combination of Pesticide Exposure, Limited Food Lead to Wild Bee Declines</td><td>123</td></tr><tr><td>Switzerland to stop exporting banned pesticides</td><td>123</td></tr><tr><td>Scientists Warn of Another Pandemic If Officials Continue to Ignore Explosion of 'Antimicrobial Resistance'</td><td>123</td></tr><tr><td>Literature Review: Pesticides Exposure Highly Correlated with Respiratory Diseases</td><td>124</td></tr><tr><td>Insecticide Linked to Testicular Cancer, With Latinos Disproportionately Affected</td><td>124</td></tr><tr><td>Victoire juridique : La France était légitime pour prendre son interdiction des néonicotinoïdes en 2016</td><td>124</td></tr><tr><td>Plan de sortie du glyphosate : Un rapport qui sonne comme un renoncement à l'interdiction !</td><td>125</td></tr><tr><td>La PAC post-2020 face à l'urgence écologique</td><td>125</td></tr><tr><td>Alimentation : vers un indicateur environnemental des produits</td><td>125</td></tr><tr><td>Exclusif : des néonicotinoïdes dans nos assiettes !</td><td>126</td></tr><tr><td>What's on our food ? Sometimes, it's pesticides</td><td>126</td></tr><tr><td>EPA Dismisses Disproportionate Harm to Farmworker Children from Neurotoxic Insecticide Chlorpyrifos, Leaves in Food Supply, Rejects Scientific Method</td><td>126</td></tr><tr><td>Seed Keepers and Truth Tellers: From the Frontlines of GM Agriculture</td><td>127</td></tr><tr><td>New Insecticides Escalate Indiscriminate Harm to All Organisms</td><td>127</td></tr><tr><td>Common Fungicide Causes a Decrease in Antioxidant Responsible for Defense Against Diseases like COVID-19</td><td>127</td></tr><tr><td>Glyphosate : l'Anses restreint les usages agricoles de l'herbicide</td><td>128</td></tr><tr><td>Néonicotinoïdes : le projet de loi « n'oppose pas économie et écologie »</td><td>128</td></tr><tr><td>Néonicotinoïdes : Nicolas Hulot « appelle les députés à ne pas voter cette loi »</td><td>128</td></tr><tr><td>Webinaire "Pesticides interdits ici, mais exportés hors UE"</td><td>128</td></tr><tr><td>Neonicotinoid Insecticides Trigger Neurodegeneration and Can Blind Insects at Low Doses</td><td>129</td></tr><tr><td>Baver Coordinated with U.S. Government on Pressure Campaign to Stop Thailand from Banning Glyphosate</td><td>129</td></tr><tr><td>EPA Reapproves Toxic Weedkiller Atrazine with Fewer Protections for Children's Health</td><td>129</td></tr><tr><td>La HVE fait de l'ombre au bio, il faut l'éliminer</td><td>130</td></tr><tr><td>10 raisons de ne pas revenir sur l'interdiction des néonicotinoïdes</td><td>130</td></tr><tr><td>Épandage de pesticides : recul sur la protection des riverains</td><td>130</td></tr><tr><td>Fake news autour du glyphosate : François Veillerette frappe encore</td><td>131</td></tr><tr><td>Lettre ouverte d'un lecteur au député Matthieu Orphelin</td><td>131</td></tr><tr><td>Ré-autorisation des néonicotinoïdes : vraiment pas d'alternative ?</td><td>131</td></tr><tr><td>Reining in a dangerous tool</td><td>132</td></tr><tr><td>Yes, pesticides are still making us sick</td><td>132</td></tr><tr><td>Primates, Both Wild and Captive, Are Being Exposed to Toxic Pesticides and Flame Retardants</td><td>132</td></tr><tr><td>Pesticides and Heavy Metals Found in Blunt (Cigar) Wrappers, Cellulose-Based Rolling Papers, and other Plant-based Rolling Paper Products</td><td>132</td></tr><tr><td>Une association dénonce des résidus de pesticides dans des vins certifiés HVE</td><td>133</td></tr><tr><td>Pesticides : la maladie de Parkinson est plus facilement reconnue comme maladie professionnelle</td><td>133</td></tr><tr><td>Nouveau procès bâillon mené par des promoteurs de pesticides</td><td>133</td></tr><tr><td>Interview : Les Perturbateurs Endocriniens</td><td>133</td></tr><tr><td>Néonicotinoïdes : les parlementaires doivent dire NON !</td><td>134</td></tr><tr><td>Take Action by Sept. 13 : Tell Canada to Ban Horrifically Hazardous Wood Preservative Pentachlorophenol</td><td>134</td></tr><tr><td>Pesticide Drift from Greenhouses Adversely Affects Children Living Nearby</td><td>134</td></tr><tr><td>Work-Related Exposure to Pollutants Increases the Risk of Developing Heart Defects in among Hispanic/Latinx Communities</td><td>135</td></tr></table>
<table><tr><td>Ré-autorisation de pesticides interdits : l'UFC-Que Choisir dénonce une grave atteinte démocratique, environnementale et sanitaire</td><td>135</td></tr><tr><td>EU microplastics ban set to make a growing problem worse</td><td>135</td></tr><tr><td>Monarch massacre: hundreds of Monarch butterflies die after aerial mosquito spraying in North Dakota</td><td>136</td></tr></table>

<table><tr><td>REVUE DE PRESSE / RECHERCHE ET MEDIAS</td><td>136</td></tr><tr><td>Reduction by reduction: Novel approach to mitigating chromium contamination in wastewater</td><td>136</td></tr><tr><td>New study reveals United States a top source of plastic pollution in coastal environments</td><td>136</td></tr><tr><td>Le biocontrôle et les variétés résistantes plébiscités pour obtenir des CEPP</td><td>137</td></tr><tr><td>Biosolutions : De Sangosse vise 17 millions d'hectares couverts en 2030</td><td>137</td></tr><tr><td>Filière betteravière : Feu vert du Sénat pour l'usage dérogatoire des néonicotinoïdes</td><td>137</td></tr><tr><td>Phytosanitaires : le retour des néonicotinoïdes au Sénat, en terre de droite</td><td>137</td></tr><tr><td>La pollution de l'air coûte cher aux villes européennes</td><td>138</td></tr><tr><td>Bisphénol A dans les vêtements : la Commission européenne lance une consultation publique</td><td>138</td></tr><tr><td>Néonicotinoïdes : le Sénat adopte le projet de loi contesté</td><td>138</td></tr><tr><td>Nitrates dans l'eau potable : la Commission européenne met la France en demeure</td><td>138</td></tr><tr><td>Pollution aux particules : la France traduite devant la Cour de justice européenne</td><td>139</td></tr><tr><td>Phytosanitaires : le fongicide mancozèbe sera interdit en Europe à partir de 2021</td><td>139</td></tr><tr><td>Consultation européenne sur la réglementation encadrant les substances chimiques</td><td>139</td></tr><tr><td>More than 200 million Americans could have toxic PFAS in their drinking water</td><td>139</td></tr><tr><td>Researchers step toward understanding how toxic PFAS chemicals spread from release sites</td><td>140</td></tr><tr><td>COVID-19 lockdowns averted tens of thousands of premature deaths related to air pollution</td><td>140</td></tr><tr><td>Researchers awarded over $11 million to study multi-drug resistant infection factors</td><td>140</td></tr><tr><td>Light pollution alters predator-prey interactions between cougars and mule deer in western US</td><td>141</td></tr><tr><td>Chemists create new crystal form of insecticide, boosting its ability to fight mosquitoes and malaria</td><td>141</td></tr><tr><td>Understanding how toxic PFAS chemicals spread from release sites</td><td>141</td></tr><tr><td>OECD, Experts Discuss Access to Information on Chemical Safety</td><td>142</td></tr><tr><td>Phytosanitaires : les contours du conseil aux utilisateurs professionnels sont définis</td><td>142</td></tr><tr><td>Sortie du glyphosate : les usages désormais interdits et... les autres</td><td>142</td></tr><tr><td>Can organic plant protection products damage crops ?</td><td>142</td></tr><tr><td>Pesticide Trade Group Wrote U.S. Government Policy to Undermine International Efforts to Combat Antibiotic Resistance</td><td>143</td></tr><tr><td>Denormandie veut les mêmes normes environnementales en agriculture pour l'Europe</td><td>143</td></tr><tr><td>Interdiction des néonicotinoïdes en 2018 : la justice européenne renvoie la balle au Conseil d'État</td><td>143</td></tr><tr><td>Néonicotinoïdes : les députés votent en faveur des dérogations</td><td>144</td></tr><tr><td>Je voterai contre le projet de loi néonicotinoïdes proposé par le Gouvernement</td><td>144</td></tr><tr><td>How a toxic chromium species could form in drinking water</td><td>144</td></tr><tr><td>URI grad student finds PFAS in seabirds from Narragansett Bay, Massachusetts Bay, Cape Fear</td><td>144</td></tr><tr><td>Two pesticides approved for use in US harmful to bees</td><td>145</td></tr><tr><td>In the arctic, extreme air pollution kills trees, limits growth by reducing sunlight</td><td>145</td></tr><tr><td>Insect Armageddon: low doses of the insecticide, Imidacloprid, cause blindness in insects</td><td>145</td></tr><tr><td>First evidence that air pollution particles and metals are reaching the placenta</td><td>146</td></tr><tr><td>UK lockdown and air pollution: Nitrogen dioxide halved but sulphur dioxide doubled</td><td>146</td></tr><tr><td>Premier feu vert sous conditions des députés, malgré la grogne</td><td>146</td></tr><tr><td>Synthetic clothing fibers contribute vast amounts of plastic pollution on land</td><td>147</td></tr><tr><td>Scientists sound alarm on plastic pollution</td><td>147</td></tr><tr><td>Pollution exposure linked to stroke risk in people with common heart rhythm disorder</td><td>147</td></tr><tr><td>Research explores factors influencing soybean injury by synthetic auxin herbicides</td><td>147</td></tr><tr><td>L'exposition au plomb pendant la grossesse réduit le poids des nouveau-nés</td><td>148</td></tr><tr><td>Pollution de l'air : le BEE cartographie les émissions des grandes installations de combustion européennes</td><td>148</td></tr><tr><td>Urbanization and agriculture are land uses that most affect Brazil's rivers</td><td>148</td></tr><tr><td>More chemicals can be assessed for endocrine disrupting effects</td><td>148</td></tr><tr><td>UBC scientists find clues to queen bee failure</td><td>149</td></tr><tr><td>Safe thresholds for antibiotics in sewage needed to help combat antibiotic resistance</td><td>149</td></tr></table>
<table><tr><td>Common sunscreen ingredients prove dangerous for freshwater ecosystems</td><td>149</td></tr><tr><td>Air pollution renders flower odors unattractive to moths</td><td>150</td></tr><tr><td>Researchers warn of food-web threats from common insecticides</td><td>150</td></tr><tr><td>Phytosanitaires : la majorité des départements ont une charte permettant de réduire les ZNT</td><td>150</td></tr><tr><td>Glyphosate « Plus de la moitié » des usages interdits en 2021, dit Barbara Pompili</td><td>151</td></tr><tr><td>Pollution au plomb : la ville de Carrières-sous-Poissy porte plainte</td><td>151</td></tr><tr><td>Néonicotinoïdes : le Gouvernement veut rassurer sur les conditions strictes d'application de la dérogation</td><td>151</td></tr><tr><td>Innovative approaches to evaluating the effects of insecticides on non-Apis bees</td><td>151</td></tr></table>
# Une expertise scientifique collective relative aux effets non intentionnels des produits phytopharmaceutiques sur la biodiversité et les services écosystémiques

Largement utilisés à des fins de protection des cultures et d'entretien des jardins, espaces végétalisés et infrastructures (JEVI), les produits phytopharmaceutiques sont retrouvés dans de nombreux compartiments de l'environnement allant des sols aux grands fonds océaniques en passant par les milieux aquatiques continentaux et côtiers, et dans le compartiment aérien. Au sein de ces différents milieux, les substances actives et leurs co-formulants peuvent avoir des effets à différents niveaux d'organisation biologique allant de perturbations moléculaires à des atteintes populationnelles voire écosystémiques. L'utilisation des produits phytopharmaceutiques, la contamination de l'environnement qui en découle et ses conséquences sur la biodiversité, les services écosystémiques associés, ainsi que sur la santé humaine, sont des sujets importants de préoccupation citoyenne dont les pouvoirs publics se sont saisis avec le Plan ECOPHYTO.

Mis en place en 2009 suite au Grenelle de l'Environnement, le Plan ECOPHYTO ambitionnait initialement de réduire le recours, les risques et les effets des produits phytopharmaceutiques. Son objectif phare consistait à réduire leur utilisation de 50% en 10 ans, soit entre 2008 et 2018. Publiée en 2018, la dernière version du Plan ECOPHYTO (ECOPHYTO 2+) renouvelle cette ambition en donnant une place plus importante à la recherche et à l'innovation. C'est dans ce contexte que les ministères respectivement en charge de la recherche, de l'environnement et de l'agriculture, ont confié à INRAE (Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement) et à Ifremer (Institut Français de Recherche pour l'Exploitation de la Mer) la réalisation d'une expertise scientifique collective (ESCO) traitant des effets des produits phytopharmaceutiques conventionnels et de biocontrôle sur la biodiversité et les services écosystémiques (Fig. 1). Cet exercice permettra d'établir un bilan des connaissances scientifiques disponibles sur cette thématique afin d'éclairer les politiques publiques en matière d'utilisation des produits phytopharmaceutiques et les besoins de recherche associés.

## Un périmètre large en réponse à un enjeu global

Cette ESCO n'est pas une première sur le sujet des produits phytopharmaceutiques et de leurs effets. Elle fait suite aux ESCO « Pesticides, Agriculture et Environnement » et « Agriculture et Biodiversité » réalisées en 2005 et 2008. Ce nouvel exercice propose toutefois un périmètre élargi afin de prendre en considération le développement important des questionnements et travaux scientifiques portant sur ces molécules et leurs effets sur la biodiversité et les services écosystémiques.

Ce périmètre élargi se traduit d'abord par la prise en compte du continuum terre-mer. En effet, si les produits phytopharmaceutiques sont utilisés en milieu terrestre, différents mécanismes de transfert vont conduire à la contamination des écosystèmes aquatiques continentaux, des eaux de transition (estuaires, mangroves), des zones littorales et in fine du milieu marin. La récente communication du Conseil National de la Mer et des Littoraux portant sur l'accélération de la stratégie maritime en faveur de la relance souligne d'ailleurs le besoin d'accompagner l'évolution vers de nouveaux modèles agricoles permettant de diminuer les intrants et donc de reconquérir la qualité des eaux côtières (CNML, 2020). L'utilisation des produits phytopharmaceutiques et la contamination des différents compartiments environnementaux n'étant pas limitées à la métropole, l'ESCO prendra en
compte les spécificités des départements et territoires ultra-marins qu'il s'agisse de molécules, de pratiques culturales ou d'utilisations spécifiques mais aussi de la contamination liée au transport atmosphérique à longue distance de certaines molécules ou à la migration des espèces.

<figure><img src="image_4.png" /><figcaption>Figure 1. Organisation de l'Expertise Scientifique Collective relative aux effets des produits phytopharmaceutiques sur la biodiversité et les services écosystémiques</figcaption></figure>

Le périmètre considéré en matière de substances est également large. Naturellement, il porte sur les produits phytopharmaceutiques conventionnels actuellement utilisés ainsi que sur leurs produits de dégradation car les évolutions analytiques permettent, pour certains, de les détecter dans des conditions environnementales et de les caractériser. Il porte également sur les substances désormais interdites mais dont les propriétés physico-chimiques intrinsèques et/ou les conditions environnementales conduisent à des phénomènes de persistance et donc à de potentiels effets. Enfin, ce périmètre inclut également les produits de biocontrôle. En plein essor, le biocontrôle s'appuie sur l'utilisation de substances naturelles d'origine végétale, animale ou minérale, de médiateurs chimiques (phéromones...) et de micro et macroorganismes dont la présence dans l'environnement et les effets potentiels sur la biodiversité doivent aussi être considérés pour une approche holistique de la question.

Parce que les produits phytopharmaceutiques ne sont pas utilisés uniquement dans un objectif de protection des cultures, cette ESCO intègrera les utilisations non agricoles (i.e. JEVI) notamment à des fins d'entretien des jardins, des espaces végétalisés (i.e. golfs et autres terrains de sports, cimetières) et des infrastructures de transports (i.e. routes, pistes cyclables, voies ferrées, infrastructures de transport de l'énergie et de l'information).

En matière d'effets à considérer, le périmètre est également élargi par rapport à celui des ESCO précédentes. Si les effets directs et indirects des produits phytopharmaceutiques sur la biodiversité non cible intra et inter spécifique seront abordés, cette ESCO traitera aussi des effets sur les
fonctions écologiques et les services écosystémiques. Les récents travaux conduits dans le cadre de l'évaluation française des écosystèmes et des services écosystémiques (EFESE) ont en effet mis en évidence les fortes interactions entre l'agriculture et les services écosystémiques, décrits comme des avantages socio-économiques retirés par l'homme de son utilisation durable des fonctions écologiques des écosystèmes (Tibi et Thérond, 2017). Il est donc apparu comme particulièrement pertinent de traiter, dans ce travail, les effets que les produits phytopharmaceutiques pourraient avoir sur ces services écosystémiques en considérant aussi bien les aspects monétaires que non monétaires.

## Du diagnostic à la surveillance et à la réduction des effets non intentionnels

Si la première question posée porte sur l'état des lieux de la contamination de l'environnement par les produits phytopharmaceutiques, des risques associés et des effets sur la biodiversité, les fonctions écologiques et les services écosystémiques qui en découlent, cette ESCO propose d'aller au-delà de ce diagnostic. Ainsi, elle questionne également les méthodes courantes et innovantes pouvant conduire à une amélioration de la surveillance et de la réduction de cette contamination et de ses effets.

Les procédures réglementaires dans ce domaine s'appuient sur un nombre limité de tests connus pour leur robustesse et leur normalisation, tandis que la recherche académique développe de nombreux outils permettant d'évaluer, souvent dans des conditions propres à chaque laboratoire, les effets de substances ou de mélanges de substances sur une cible donnée. L'ESCO interrogera le périmètre de validité scientifique de ces différentes tests physico-chimiques et écotoxicologiques ainsi que des outils de modélisation dont le développement est de plus en plus important, porté par les exigences de réduction de l'expérimentation animale.

Par ailleurs, elle se penchera aussi sur les méthodes et innovations qui permettent de maîtriser et de réduire l'utilisation, la dispersion et les effets des produits phytopharmaceutiques. En effet, il peut s'agir de leviers mis en œuvre au niveau de l'application, de pratiques culturales innovantes, de gestion paysagère, ou de voies de remédiation face à des contaminations persistantes, qui conduit au développement de nombreuses recherches dont l'ESCO devra réaliser un bilan au regard de leur efficacité dans des conditions réelles.

Ce second volet de l'ESCO doit donc apporter un éclairage aux pouvoirs publics et aux instances d'évaluation des risques et de gestion environnementale pouvant contribuer à l'amélioration continue des processus d'homologation et de suivi des produits ainsi qu'à la préservation de la qualité chimique et écologique des milieux qui y sont exposés. Comme pour la partie relative à l'état de la contamination et des effets, ce second volet devra aussi prendre en considération les spécificités des départements et territoires ultra-marins.

## Méthode de travail et enjeux

Lancée début 2020 pour 2 ans, cette ESCO est animée par une équipe projet composée d'une chef de projet, de 3 pilotes scientifiques et de 3 documentalistes issus d'INRAE et d'Ifremer. Elle s'appuie sur un collectif pluridisciplinaire de plus de 40 experts francophones (nationaux et internationaux) permettant de couvrir les nombreuses disciplines nécessaires à cette expertise (Fig. 1). Ecotoxicologues, physiologistes, agronomes, chimistes et physico-chimistes, modélisateurs, évaluateurs du risque mais aussi économistes et sociologues sont ainsi répartis en 13 groupes de travail couvrant les différentes questions posées par les commanditaires (i.e. ministères en charge de la recherche, de l'environnement et de l'agriculture) dans la lettre de saisine.

Tout au long du travail, un comité de suivi permet de garder le lien avec les commanditaires afin d'échanger sur l'avancement du travail, leurs attentes et les ajustements nécessaires au regard du
travail réalisé par le collectif d'experts, en accord avec les directions scientifiques d'INRAE et d'Ifremer. De plus, en lien avec la préoccupation plus globale d'ouverture de l'expertise à la société, un comité consultatif d'acteurs est mis en place. Composé de structures à l'interface recherche/société (e.g. comité français de l'Union Internationale pour la Conservation de la Nature (UICN), Fondation pour la Recherche sur la Biodiversité (FRB)), de représentants des utilisateurs de produits phytopharmaceutiques ou de certaines filières professionnelles, d'associations environnementales et de consommateurs ainsi que d'acteurs des territoires, cette instance vise à recueillir les préoccupations et attentes des acteurs mais aussi à échanger autour des conclusions de l'expertise attendues au premier trimestre 2022.

## Contacts

Sophie Leenhardt<fnref n="1" />, Laure Mamy<fnref n="2" />, Stéphane Pesce<fnref n="3" />, Wilfried Sanchez<fnref n="4" />

INRAE
la science pour la vie, l'humain, la terre

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

## Pour en savoir plus

Plan ECOPHYTO 2+ : http://www.consultation-ecophyto2plus.gouv.fr/IMG/pdf/plan-ecophyto_2_bat.pdf

EFESE : http://www.ecologie.gouv.fr/levaluation-francaise-des-ecosystemes-et-des-services-ecosystemiques

## Bibliographie citée

CNML (Conseil National de la Mer et des Littoraux), 2020. Recommandations pour une accélération de la stratégie maritime en faveur de la relance mer et littoral. 20p.

Tibi, A., Thé rond, O., 2017. Evaluation des services écosystémiques rendus par les écosystèmes agricoles. Une contribution au programme EFESE. Synthèse du rapport d'étude. Inra (France).

<footnote n="1">¹ INRAE, Direction de l'expertise scientifique collective, de la prospective et des études, 75338 Paris cedex 07</footnote>

<footnote n="2">² UMR ECOSYS, INRAE, AgroParisTech, Université Paris-Saclay, 78850 Thiverval-Grignon</footnote>

<footnote n="3">³ INRAE, UR RiverLy, 69625 Villeurbanne</footnote>

<footnote n="4">⁴ Institut Français de Recherche pour L'Exploitation de la Mer (Ifremer), Direction Scientifique, Station de Sète, 34200 Sète</footnote>
ERA / PUBLICATIONS

SCIENTIFIQUES

Ecotoxicology of strobilurin fungicides

**Authors:** Zhang C, Zhou T, Xu Y, et al.

**Sources:** Science of The Total Environment, 742, 2020, DOI: 10.1016/j.scitotenv.2020.140611

**Abstract:** The toxicities of strobilurins to terrestrial and aquatic biota were summarized. The residue, fate, and transportation of strobilurin fungicides were summarized. Strobilurin fungicides are highly toxic to aquatic and soil organisms...but current toxicology studies are more focused on acute or chronic toxicity, but the underlying mechanisms are still unclear and require further analysis. Future studies may focus on more toxicological mechanisms of strobilurin fungicides. The analysis methods are needed to compare the toxicity difference of strobilurins.

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ERA / PUBLICATIONS

SCIENTIFIQUES /

COMMUNAUTES

MICROBIENNES

AQUATIQUES

The roles of phytohormones in metal stress regulation in microalgae

**Authors:** Nguyen HN, Kisiala AB, Emery RJN

**Source:** JOURNAL OF APPLIED PHYCOLOGY Early access, 2020, DOI: 10.1007/s10811-020-02271-5

**Abstract:** The constant spread of heavy metal contamination creates an increasing global environmental issue that results in considerable deterioration of land and water ecosystems leading to a decline in the health of plants, animals and humans. Novel, algal-based filtration technologies have been gaining a great deal of attention given their eco-friendly, effective and easy to implement processes. This review focuses on the potential roles that phytohormones can play in heavy metal stress response in microalgae. It emphasizes phytohormone efficiency and proposes the use of these signaling molecules for enhanced metal stress alleviation in microalgae. Furthermore, future implications for algal-based filtration technologies involving modifications of phytohormone metabolism towards improved heavy metal biodegradation rates are presented.

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Physiological and morphological responses of green microalgae *Chlorella vulgaris* to silver nanoparticles

**Authors:** Romero N, Visentini FF, Marquez VE, Santiago LG, Castro GR, Gagneten AM

**Source:** ENVIRONMENTAL RESEARCH 189:109857, 2020, DOI:10.1016/j.envres.2020.109857

**Abstract:** The toxic effects of silver nanoparticles (AgNPs) on the physiology and morphology of the green microalga *Chlorella*
vulgaris were studied. AgNPs were characterized by particle size distribution, zeta potential measurement, and atomic force microscopy (AFM). *Chlorella vulgaris* was exposed to 90-1440 µg/L of AgNPs range in Bold's Basal Medium for 96 h. The inhibition of algae growth rate and changes in the concentrations of chlorophyll-a, chlorophyll-b, pheophytin, and carotenoids was determined at the beginning and end of the trial. Cell diameter and volume, carbohydrate, total lipids, and protein content were also determined. Our data strongly suggest that the toxic effects of the AgNPs resulted in concentration and time-dependent. AgNPs altered *C. vulgaris* growth kinetics and cell metabolism expressed in photosynthetic pigments and biochemical composition. Our study confirmed the cytotoxicity of AgNPs through the algal growth inhibition with an EC50 value of 110 µg/L. Also, changes of chlorophyll-a, chlorophyll-b, pheophytin, and carotenoids concentrations were observed associated with a color shift from green to pale brown of algae cultures exposed to AgNPs for 96 h. Furthermore, algae cell concentration, diameter, and volume, plus total lipid, protein, and carbohydrates contents in the presence of AgNPs, were significantly altered compared to untreated cells. In synthesis, this study highlighted AgNPs toxic effects on morphological and physiological traits of *C. vulgaris* and warns about possible impacts on energy flow and aquatic food web structure, and on the transfer efficiency of energy to higher trophic levels.

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## Short-term effect of cadmium on the motility of three flagellated algal species

**Authors:** Novosel N, Kasum D, Zutinic P, Legovic T, DeNardis NI

**Source:** JOURNAL OF APPLIED PHYCOLOGY Early Access, 2020, DOI: 10.1007/s10811-020-02283-1

**Abstract:** The present work aims to develop a fast and reliable procedure for motility analysis of a short-term effect of heavy metal cadmium on the algal cell response in laboratory conditions. Three unicellular motile species similar in cell length, while differing in the cell wall and the flagellar system are used as model algae. We quantitatively characterise motility in terms of swimming speed and search radius following addition of 1 mg Cd L-1. Both swimming speed and search radius determined in control algal cultures reflect morphological features of the corresponding flagellated system. After 1 h of cell exposure to a toxic concentration of cadmium, a statistically significant decrease in swimming speed is determined with predominant erratic cell movement on the spot in all examined cultures. After 3 h of cell exposure to cadmium, swimming speed in most of the examined cell cultures recovered close to the control value, indicating quick cell adaptation to elevated cadmium concentration. The results support the implementation of swimming speed and search radius as motility parameters for direct screening of cell physiological state, which is applicable to ecotoxicological studies providing insight into the mechanism of cell adaptation under stress, as well as a better understanding of the spatial distribution of algal cells in aquatic systems.

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## Cytotoxicological evaluation of copper oxide nanoparticles on green algae, bacteria and crustacean systems

**Authors:** Janani B, Al Farraj DA, Raju LL, Elshikh MS, Alkubaisi NA, Thomas AM, Das A, Khan SS

**Source:** JOURNAL OF ENVIRONMENTAL HEALTH SCIENCE AND ENGINEERING Early Access, 2020, DOI: 10.1007/s40201-020-00561-1

**Abstract:** Copper oxide (CuO) nanoparticles (NPs) have been utilized in several industries
including textile, consumer products, medical, automobiles etc. The discharge of industrial effluents in environment increased the probability of CuO NPs contamination in the ecosystem. The present investigation used CuO NPs to determine the toxic effect on Lyngbyaspecies, fresh water algae isolated from natural pond, bacterial species Pseudomonas aeruginosa and *Staphylococcus aureus* and a crustacean species *Daphnia magna*. The NPs average diameter and zeta potential was estimated to be 45 +/- 3 nm and 29 +/- 1.78 mV respectively. The results showed that 0.1 mg/mL CuO NPs showed the growth inhibition of 47 +/- 2% on *Lyngbya* sp. after 5 days of incubation. The CuO NPs also showed toxic effect to bacterial systems such as P. aeruginosa and S. aureus and crustacean system D. magna. Further, there was an increased lipid peroxidation and generation of reactive oxygen species (ROS) in algal cells observed up on NPs exposure. The exposure of NPs suppressed the antioxidant defense system. The amount of glutathione was reduced after the exposure of NPs. The study suggested the role of ROS in toxicity of algal and bacterial systems. The present study pointed out the potent toxicity of CuO NPs to the organisms present in the aquatic environment.

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## Responses to iron oxide and zinc oxide nanoparticles in echinoderm embryos and microalgae: uptake, growth, morphology, and transcriptomic analysis

**Authors:** Geneviere AM, Derelle E, Escande ML, Grimsley N, Klopp C, Menager C, Michel A, Moreau H

**Source:** NANOTOXICOLOGY Early Access, 2020, DOI: 10.1080/17435390.2020.1827074

**Abstract:** We investigated the toxicity of Iron oxide and Zinc oxide engineered nanoparticles

(ENPs) on *Paracentrotus lividus* sea urchin embryos and three species of microalgae. Morphological responses, internalization, and potential impacts of Fe (2)O (3)and ZnO ENPs on physiology and metabolism were assessed. Both types of ENPs affected P. lividus larval development, but ZnO ENPs had a much stronger effect. While growth of the alga Micromonas commoda was severely impaired by both ENPs, *Ostreococcus tauri* or *Nannochloris* sp. were unaffected. Transmission electron microscopy showed the internalization of ENPs in sea urchin embryonic cells while only nanoparticle interaction with external membranes was evidenced in microalgae, suggesting that marine organisms react in diverse ways to ENPs. Transcriptome-wide analysis in *P. lividus* and *M. commoda* showed that many different physiological pathways were affected, some of which were common to both species, giving insights about the mechanisms underpinning toxic responses.

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## Diatoms as indicators of environmental health on Korean islands

**Authors:** Park J, Bergey EA, Han T, Pandey LK

**Source:** AQUATIC TOXICOLOGY 227:105594, 2020, DOI: 10.1016/j.aquatox.2020.105594

**Abstract:** Diatoms are highly sensitive to perturbations in their environment and are thus useful as bioindicators for anthropogenic impacts such as pollution. However, there is no consensus about what aspects of diatom populations to measure (e.g., diversity, physiology, or morphology) and efficient and reliable survey protocols are lacking. Here, we evaluated the ecological status of diatom communities using both traditional and relatively novel methods on two islands (Deokjeok island and Daeijak island) affected by anthropogenic activities due to extensive agricultural practices and exploitation and that are under consideration for representative touristic sites in South Korea.
Dissolved concentrations of metals and metalloid (As, Cu, Cr, Cd, Ni, Hg, Pb, and Zn) were below the ecological screening and toxicity reference values in water fractions but were above these values for sediment, particularly at one island, Deokjeok. The tested methods were generally consistent in finding little evidence for disruption of diatom communities, with dominance by *Navicula* and *Gyrosigma*, relatively high diversity, and typical abundance of lipid bodies and morphological deformities. However, analysis of lipid bodies and morphological deformities suggested greater potential anthropogenic disturbance at one site in Deokjeok. Future planning is required to ensure the maintenance of the near-pristine environments present on these islands.

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## The effects of ionizing radiation on the structure and antioxidative and metal-binding capacity of the cell wall of microalga *Chlorella sorokiniana*

**Authors:** Vojvodic S, Lukovic JD, Zechmann B, Jevtovic M, Pristov JB, Stanic M, Lizzul AM, Pittman JK, Spasojevic I

**Source:** CHEMOSPHERE 260:127553, 2020, DOI: 10.1016/j.chemosphere.2020.127553

**Abstract:** The impact of ionizing radiation on microorganisms such as microalgae is a topic of increasing importance for understanding the dynamics of aquatic ecosystems in response to environmental radiation, and for the development of efficient approaches for bioremediation of mining and nuclear power plants wastewaters. Currently, nothing is known about the effects of ionizing radiation on the microalgal cell wall, which represents the first line of defence against chemical and physical environmental stresses. Using various microscopy, spectroscopy and biochemical techniques we show that the unicellular alga

*Chlorella sorokiniana* elicits a fast response to ionizing radiation. Within one day after irradiation with doses of 1-5 Gy, the fibrilar layer of the cell wall became thicker, the fraction of uronic acids was higher, and the capacity to remove the main reactive product of water radiolysis increased. In addition, the isolated cell wall fraction showed significant binding capacity for Cu2+, Mn2+, and Cr3+. The irradiation further increased the binding capacity for Cu2+, which appears to be mainly bound to glucosamine moieties within a chitosan-like polymer in the outer rigid layer of the wall. These results imply that the cell wall represents a dynamic structure that is involved in the protective response of microalgae to ionizing radiation. It appears that microalgae may exhibit a significant control of metal mobility in aquatic ecosystems via biosorption by the cell wall matrix.

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## The "Plastisphere" of Biodegradable Plastics Is Characterized by Specific Microbial Taxa of Alpine and Arctic Soils

**Authors:** Ruthi J, Bolsterli D, Pardi-Comensoli L, Brunner I, Frey B

**Source:** FRONTIERS IN ENVIRONMENTAL SCIENCE 8:562263, 2020, DOI:10.3389/fenvs.2020.562263

**Abstract:** Plastic pollution poses a threat to terrestrial ecosystems, even impacting soils from remote alpine and arctic areas. Biodegradable plastics are a promising solution to prevent long-term accumulation of plastic litter. However, little is known about the decomposition of biodegradable plastics in soils from alpine and polar ecosystems or the microorganisms involved in the process. Plastics in aquatic environments have previously been shown to form a microbial community on the surface of the plastic distinct from that in the surrounding water, constituting the so-called "plastisphere." Comparable studies in terrestrial environments are scarce. Here, we
aimed to characterize the plastisphere microbiome of three types of plastics differing in their biodegradability in soil using DNA metabarcoding. Polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), and polyethylene (PE) were buried in two different soils, from the Swiss Alps and from Northern Greenland, at 15 degrees C for 8 weeks. While physico-chemical characteristics of the polymers only showed minor (PLA, PBAT) or no (PE) changes after incubation, a considerably lower alpha-diversity was observed on the plastic surfaces and prominent shifts occurred in the bacterial and fungal community structures between the plastisphere and the adjacent bulk soil not affected by the plastic. Effects on the plastisphere microbiome increased with greater biodegradability of the plastics, from PE to PLA. Copiotrophic taxa within the phyla Proteobacteria and Actinobacteria benefitted the most from plastic input. Especially taxa with a known potential to degrade xenobiotics, including Burkholderiales, Caulobacterales, Pseudomonas, Rhodococcus, and Streptomyces, thrived in the plastisphere of the Alpine and Arctic soils. In addition, Saccharimonadales (superphylum Patescibacteria) was identified as a key taxon associated with PLA. The association of Saccharibacteria with plastic has not been reported before, and pursuing this finding further may shed light on the lifestyle of this obscure candidate phylum. Plastic addition affected fungal taxa to a lesser extent since only few fungal genera such as Phlebia and Alternaria were increased on the plastisphere. Our findings suggest that the soil microbiome can be strongly influenced by plastic pollution in terrestrial cryoenvironments. Further research is required to fully understand microbial colonization on plastic surfaces and the biodegradation of plastic in soils.

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Plain polystyrene
microplastics reduce the
toxic effects of ZnO particles

on marine microalgae
*Dunaliella salina*

**Authors:** Gunasekaran D, Chandrasekaran N, Jenkins D, Mukherjee A

**Source:** JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING 8:104250, 2020, DOI: 10.1016/j.jece.2020.104250

**Abstract:** A critical literature survey on marine ecotoxicology reveals a lack of comprehensive studies to assess the impact of microplastics on the toxicity of engineered nanomaterials at environmentally relevant doses. Though ZnO and microplastics both are well known to be marine pollutants, the combined toxicity of ZnO particles with plain polystyrene (PS) microplastics are yet to be studied. Preliminary characterization of ZnO particles included examining particle size, morphology, and surface area. The amount of nominal and dissolved ions in the suspensions containing nano-sized ZnO particles was determined. The toxicity of bulk and nano-sized ZnO particles in combination with plain PS microplastics at low concentration (1 mg/L) was assessed towards marine algae *Dunaliella salina* at three exposure concentrations 1.22, 12.28 and 122.88 µM under UV-A and dark exposure conditions. As expected, a dose-dependent increment in the toxicity, ROS (extracellular & intracellular) generation and lipid peroxidation were noted for both bulk and nano-sized ZnO particles. The harmful effects of bulk and nano-sized ZnO particles were considerably reduced in the presence of plain PS microplastics. This study opens up new dimensions regarding the positive impact of microplastics at low concentration, where they lessen the toxic effects of co-pollutants in the marine ecosystem.

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Shifts in photosynthetic
parameters and lipid
production of the freshwater
microalga *Selenastrum*
## gracile (Chlorophyceae) under cadmium exposure

**Authors:** Rocha GS, Parrish CC, Espindola ELG

**Source:** JOURNAL OF APPLIED PHYCOLOGY Early Access, 2020, DOI: 10.1007/s10811-020-02255-5

**Abstract:** The amount of metals released into the environment can increase with anthropogenic activities and different trophic levels can be affected. In the present study, we evaluated the changes in growth, chlorophyll content, photosynthetic parameters, and lipid and fatty acid (FA) contents of the freshwater microalga *Selenastrum gracile* (Chlorophyceae) exposed to sublethal concentrations of cadmium for 72 h. Our results show that Cd negatively affected algal growth and chlorophyllaincreased per cell under Cd exposure. Photosynthetic parameters (maximum and operational yield, as well as quenching) were affected under Cd exposure, indicating damage to the photosynthetic apparatus. The amount of lipids and fatty acids increased with the increase of Cd in the medium. The most affected lipid classes under metal exposure were aliphatic hydrocarbon (HC), acetone mobile polar lipid (AMPL), and phospholipid (PL). Based on our results, we suggest that the production of algal lipids and fatty acids changed as a response to the amount of metal in the medium, avoiding photosynthetic damage at the lowest Cd concentration with the increase of polyunsaturated fatty acids (PUFA). However, at higher concentrations, the maintenance of the high values of PUFA was not observed and there was a decrease in the unsaturation of FA, resulting in higher amounts of MUFA. In addition, the percentage of structural lipids (sterol-ST-and PL) also decreased at the highest concentration. This, in combination with the decreased unsaturation of FA, suggests changes in membrane conformation and, consequently, damage to the photosynthetic machinery in the presence of Cd.

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## Assessing the Toxicity of Leachates From Weathered Plastics on Photosynthetic Marine Bacteria *Prochlorococcus*

**Authors:** Sarker I, Moore LR, Paulsen IT, Tetu SG

**Source:** FRONTIERS IN MARINE SCIENCE 7:571929, 2020, DOI: 10.3389/fmars.2020.571929

**Abstract:** Marine plastic pollution is a well-recognized, global problem. Research addressing plastic pollution has largely focused on investigating impacts on macroorganisms, with few studies investigating effects on marine microbes. We previously showed that marine *Prochlorococcus*, which are important contributors to oceanic primary production, suffer declines in growth and photosynthetic activity following exposure to leachates from new plastic bags (HDPE) and plastic matting (PVC). However, as such plastics reside in the environment they will be subject to weathering processes, so it is also important to consider how these may alter the composition and amounts of substances available to leach. Here we report on how plastic leachate toxicity is affected by environmental weathering (17- and 112-days in estuarine water) of these common plastic materials. We found that while toxicity was reduced by weathering, materials weathered for up to 112-days continued to leach substances that negatively affected *Prochlorococcus* growth, photophysiology and membrane integrity. Weathered plastics were found to continue to leach zinc, even after up to 112-days in the environment. The two *Prochlorococcus* strains tested, NATL2A and MIT9312, showed differences in the sensitivity and timing of their responses, indicating that exposure to leachate from weathered plastics may affect even closely related strains to different degrees. As many marine regions inhabited by *Prochlorococcus* are likely to be subject to continued accumulation of plastic pollution, our findings highlight the potential for ongoing impacts on these important primary producers.
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# Amelioration of copper toxicity to a tropical freshwater microalga: Effect of natural DOM source and season

**Authors:** Macoustra GK, Jolley DF, Stauber J, Koppel DJ, Holland A

**Source:** ENVIRONMENTAL POLLUTION
266:115141, 2020, DOI:
10.1016/j.envpol.2020.115141

**Abstract:** Australian tropical freshwaters can experience extreme seasonal variability in rainfall and run off, particularly due to pulse events such as storms and cyclones. This study investigated how seasonal variability in dissolved organic matter (DOM) quality impacted the chronic toxicity of copper to a tropical green alga (Chlorella sp.) in the presence of two concentrations of DOM (low: similar to 2 mg C/L; high: similar to 10 mg C/L) collected from three tropical waters. Copper speciation and lability were explored using diffusive gradients in thin-films (DGT) and modelled maximum dynamic concentrations (c(max)(dyn)) using data derived from the Windermere Humic Aqueous Model (WHAM VII). Relationships between copper lability and copper toxicity were assessed as potential tools for predicting toxicity. Copper toxicity varied significantly with DOM concentration, source and season. Copper toxicity decreased with increasing concentrations of DOM, with 50% growth inhibition effect concentrations (EC50) increasing from 1.9 mg Cu/L in synthetic test waters with no added DOM (0.34 mg C/L) up to 63 mg Cu/L at DOM concentrations of 9.9 mg C/L. Copper toxicity varied by up to 2-fold between the three DOM sources and EC50 values were generally lower in the presence of wet season DOM compared to dry season DOM. Linear relationships between DGT-labile copper and dissolved copper were significantly different between DOM source, but

not concentration or season. Modelled c(max)(dyn) consistently under-predicted labile copper in high DOM treatments compared to DGT measurements but performed better in low DOM treatments, indicating that this method is DOM-concentration dependent. Neither speciation method was a good surrogate for copper toxicity in the presence of different sources of natural DOM. Our findings show that DOM source and season, not just DOM concentration, affect copper toxicity to freshwater biota. Therefore, DOM quality should be considered as a toxicity-modifying factor for future derivation of bioavailability-based site-specific water quality guideline values.

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# Metabolomic modulations in a freshwater microbial community exposed to the fungicide azoxystrobin

**Authors:** Zhang MW, Liu WY, Qu Q, Ke MJ, Zhang ZY, Zhou ZG, Lu T, Qian HF

**Source:** JOURNAL OF ENVIRONMENTAL SCIENCES
97:2-102-109, 2020, DOI:
10.1016/j.jes.2020.04.013

**Abstract:** An effective broad-spectrum fungicide, azoxystrobin (AZ), has been widely detected in aquatic ecosystems, potentially affecting the growth of aquatic microorganisms. In the present study, the eukaryotic alga *Monoraphidium* sp. and the cyanobacterium *Pseudanabaena* sp. were exposed to AZ for 7 days. Our results showed that 0.2-0.5 mg/L concentrations of AZ slightly inhibited the growth of *Monoraphidium* sp. but stimulated *Pseudanabaena* sp. growth. Meanwhile, AZ treatment effectively increased the secretion of total organic carbon (TOC) in the culture media of the two species, and this phenomenon was also found in a freshwater microcosm experiment (containing the natural microbial community). We attempted to assess the effect of AZ on the function of aquatic microbial communities through metabolomic analysis and further explore the potential risks of
this compound. The metabonomic profiles of the microcosm indicated that the most varied metabolites after AZ treatment were related to the citrate cycle (TCA), fatty acid biosynthesis and purine metabolism. We thereby inferred that the microbial community increased extracellular secretions by adjusting metabolic pathways, which might be a stress response to reduce AZ toxicity. Our results provide an important theoretical basis for further study of fungicide stress responses in aquatic microcosm microbial communities, as well as a good start for further explorations of AZ detoxification mechanisms, which will be valuable for the evaluation of AZ environmental risk.

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## Biochemical responses of the freshwater microalga Dictyosphaerium sp. upon exposure to three sulfonamides

**Authors:** Chen S, Li JY, Feng WB, Yuan MZ, Zhang W, Xu HT, Zheng XY, Wang LQ

**Source:** JOURNAL OF ENVIRONMENTAL SCIENCES
97:141-148, 2020, DOI: 10.1016/j.jes.2020.05.018

**Abstract:** Sulfonamides (SAs) are common antimicrobial drugs, which are frequently detected in surface water systems, and are difficult to degrade, posing a potential threat to the aquatic environment. However, little is known about the potential adverse effects of SAs on nontarget organisms (e.g., microalgae) in the aquatic ecosystem. In this study, the effect of SAs (sulfadiazine (SD), sulfamerazine (SM1), and sulfamethazine (SM2) at 1, 5, 20, and 50 mg/L concentrations, respectively) on the freshwater microalga Dictyosphaerium sp. was investigated, with respect to changes of biomass and chlorophyll a content and induction of extracellular polymer substances (EPS), including protein and polysaccharide contents. At the same time, the residue of SAs was determined.

The results showed that Dictyosphaerium sp. was tolerant to the three SAs, and the chlorophyll a content in Dictyosphaerium sp. significantly decreased on day 7, followed by a "compensation phenomena". The increase in protein and polysaccharide contents played a defensive role in Dictyosphaerium sp. against antibiotic stress, and there was a strong positive correlation between polysaccharide contents and antibiotic concentrations. Dictyosphaerium sp. exhibited 35%-45%, 30%-42%, and 26%-51% removal of SD, SM1, and SM2, respectively. This study is helpful to understand the changes of EPS in the defense process of microalgae under the action of antibiotics, and provides a new insight for the ecological removal of antibiotic pollution in natural surface water system.

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## Secondary Effects of Antibiotics on Microbial Biofilms

**Authors:** Penesyan A, Paulsen IT, Gillings MR, Kjelleberg S, Manefield MJ

**Source:** FRONTIERS IN MICROBIOLOGY 11:2109, 2020, DOI: 10.3389/fmicb.2020.02109

**Abstract:** Biofilms are assemblages of microorganisms attached to each other, or to a surface, and encased in a protective, self-produced matrix. Such associations are now recognized as the predominant microbial growth mode. The physiology of cells in biofilms differs from that of the planktonic cells on which most research has been conducted. Consequently, there are significant gaps in our knowledge of the biofilm lifestyle. Filling this gap is particularly important, given that biofilm cells may respond differently to antibiotics than do planktonic cells of the same species. Understanding the effects of antibiotics on biofilms is of paramount importance for clinical practice due to the increased levels of antibiotic resistance and resistance dissemination in biofilms. From a wider environmental perspective antibiotic exposure can alter the
ecology of biofilms in nature, and hence disrupt ecosystems. Biofilm cells display increased resilience toward antibiotics. This resilience is often explained by mechanisms and traits such as decreased antibiotic penetration, metabolically inactive persister cells, and intrinsic resistance by members of the biofilm community. Together, these factors suggest that cells in biofilms are often exposed to subinhibitory concentrations of antimicrobial agents. Here we discuss how cells in biofilms are affected by the presence of antibiotics at subinhibitory concentrations, and the possible ramifications of such secondary effects for healthcare and the environment.

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# Tolerance Patterns in Stream Biofilms Link Complex Chemical Pollution to Ecological Impacts

**Authors:** Tlili A, Corcoll N, Arrhenius A, Backhaus T, Hollender J, Creusot N, Wagner B, Behra R

**Source:** ENVIRONMENTAL SCIENCE & TECHNOLOGY 54:10735-10743, 2020, DOI: 10.1021/acs.est.0c02975

**Abstract:** Preventing and remedying fresh waters from chemical pollution is a fundamental societal and scientific challenge. With other nonchemical stressors potentially co-occurring, assessing the ecological consequences of reducing chemical loads in the environment is arduous. In this case study, we comparatively assessed the community structure, functions, and tolerance of stream biofilms to micropollutant mixtures extracted from deployed passive samplers at wastewater treatment plant effluents. These biofilms were growing up- and downstream of one upgraded and two nonupgraded wastewater treatment plants before being sampled for analyses. Our results showed a substantial decrease in micropollutant concentrations by 85%, as the result of upgrading the wastewater treatment plant at one of the sampling sites with activated carbon filtration. This decrease was positively correlated with a

loss of community tolerance to micropollutants and the recovery of the community structure downstream of the effluent. On the other hand, downstream biofilms at the nonupgraded sites displayed higher tolerance to the extracts than the upstream biofilms. The observed higher tolerance was positively linked to micropollutant levels both in stream water and in biofilm samples, and to shifts in the community structure. Although more investigations of upgraded sites are needed, our findings point toward the suitability of using community tolerance for the retrospective assessment of the risks posed by micropollutants, to assess community recovery, and to relate effects to causes in complex environmental conditions.

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# The effects of bisphenol A, F and their mixture on algal and cyanobacterial growth: from additivity to antagonism

**Authors:** Elersek T, Notersberg T, Kovacic A, Heath E, Filipic M

**Source:** ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH Early Access, 2020, DOI: 10.1007/s11356-020-10329-7

**Abstract:** Bisphenol A (BPA) is, due to its widespread use including the production of plastic materials, an ubiquitous pollutant in the aquatic environment. Due to evidence of adverse BPA effects on the environment and human health, its use has been restricted and replaced by analogues such as bisphenol F (BPF). This study examined the toxicity of BPA, BPF and their mixture towards primary producers, the eukaryotic green alga *Pseudokirchneriella subcapitata* and the prokaryotic cyanobacterium *Synechococcus leopoliensis*. The results demonstrated that *S. leopoliensis* is more sensitive than *P. subcapitata*, whereas toxic potential of the two BPs is comparable and represents comparable hazard for phytoplankton. The toxicity of the binary mixture was predicted by different models (concentration addition,
independent action, combination index and the isobologram method) and compared to experimental data. Additive effect was observed in *P. subcapitata* over the whole effect concentration range (EC5-EC90), whereas in *S. leopoliensis*, no pronounced combined effect was observed. The environmental risk characterisation based on the comparison of reported concentrations of BPA and BPF in surface waters to the predicted no-effect concentration values obtained in this study showed that at certain industrial areas, BPA represents environmental risk, whereas BPF does not. However, BPF concentrations in aquatic environment are expected to increase in the future. To enable environmental risk assessment of BP analogues, more data on the toxicity to aquatic species, including combined effect, as well as data on their occurrence in the aquatic environment are needed.

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Unravelling the effects of
multiple stressors on diatom
and macroinvertebrate
communities in European
river basins using structural
and functional approaches

**Authors:** De Castro-Catala N, Doledec S, Kalogianni E, Skoulikidis NT, Paunovic M, Vasiljevic B, Sabater S, Tornes E, Munoz I

**Source:** SCIENCE OF THE TOTAL ENVIRONMENT
742:140543, 2020, DOI:
10.1016/j.scitotenv.2020.140543

**Abstract:** Rivers suffer from more severe decreases in species diversity compared to other aquatic and terrestrial ecosystems due to a variety of pressures related to human activities. Species provide different roles in the functioning of the ecosystem, and their loss may reduce the capacity of the ecosystems to respond to multiple stressors. The effects on diversity will differ based on the type, combination and severity of stressors, as well as on the

characteristics of the community composition and tolerance. Multiple trait-based approaches (MTBAs) can help to unravel the effects of multiple stressors on communities, providing a mechanistic interpretation, and, thus, complementing traditional biodiversity assessments using community structure. We studied the relationships between diversity indexes and trait composition of macroinvertebrate and diatom communities, as well as environmental variables... and toxic pollution (pesticides and pharmaceuticals) of three different European river basins: the Adige, the Sava, and the Evrotas. These river basins can be considered representative cases of different situations in European freshwater systems. Hydrological variables were the main drivers determining the community structure and function in the rivers, for both diatoms and macroinvertebrates. For diatom communities, pharmaceutical active compound (PhAC) toxic units were also identified as a my important driver of diversity changes, explaining up to 57% of the variance in taxonomic richness. For macroinvertebrates, river geomorphology was an important driver of structural changes, particularly affecting Plecoptera richness. In addition, PhAC and pesticide toxic units were also identified as stressors for macroinvertebrate communities. MTBA provided a detailed picture of the effects of the stressors on the communities and confirmed the importance of hydrological variables in shaping the functional attributes of the communities.

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Micro- and Nanoplastic Exposure Effects in Microalgae: A Meta-Analysis of Standard Growth Inhibition Tests

**Authors:** Reichelt S, Gorokhova E

**Source:** FRONTIERS IN ENVIRONMENTAL SCIENCE
8:131, 2020, DOI:10.3389/fenvs.2020.00131
**Abstract:** Ecological impacts of micro- and nanoplastics particles (MNP) are among the most discussed environmental concerns. In algae, MNP are commonly hypothesized to reduce growth, which is a standard ecotoxicological endpoint. However, the reported test outcomes vary, with both growth inhibition and stimulation being observed. Due to this conflict of information, a data synthesis for MNP potential to cause growth inhibition in toxicity testing is needed. We performed a meta-analysis study to assess the effect of MNP exposure on algal growth. Twenty studies published between 2010 and 2020 and representing 16 algal species and five polymer materials administered as particles in size range 0.04-3,000 µm were included in this meta-analysis. A random-effect model was used to estimate the effect size in three datasets: (1)Low concentration range (< 100 mg/L), (2)High concentration range ≥ 100 mg/L), and (3)Full range model (0.004-1,100 mg/L), which encompassed all studies using the combination of experimental settings (test species, MNP concentration, polymer material, and particle size) yielding the highest effect size within a study. The exposure to MNP was not significantly associated with growth inhibition in any of the models tested. However, a high heterogeneity between the studies was found in all three models. Neither MNP concentration nor polymer material contributed significantly to the heterogeneity, whereas polymer density had a significant moderating effect, with a higher risk of growth inhibition at lower densities. We also identified a publication bias, with small studies that reported significant inhibition being overrepresented in our dataset. The meta-analysis found limited evidence for MNP effect on microalgal growth in the standard algal growth inhibition test. The heterogeneity and varying methodological quality of studies limited the interpretation and the confidence in the findings. For hazard assessment, standardization and controlled exposure are needed as well as more sensitive endpoints that can inform us about the effect mechanisms. Finally, using particle-free controls in such tests cannot account for the presence of inert particulates in the test system, and, hence, does not allow to attribute observed effects to the test polymers.

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# Pollution shapes the microbial communities in river water and sediments from the Olifants River catchment, South Africa

**Authors:** Valverde A, Cason ED, Gomez-Arias A, Bozkale D, Govender D, Riddell E, Cowan D

**Source:** ARCHIVES OF MICROBIOLOGY, Early Access, 2020, DOI: 10.1007/s00203-020-02035-2

**Abstract:** Human activities such as agriculture and mining are leading causes of water pollution worldwide. Individual contaminants are known to negatively affect microbial communities. However, the effect of multifaceted pollution on these communities is less well understood. We investigated, using next-generation sequencing of the 16S rRNA genes, the effects of multisource (i.e., fertilizer industry and mining) chronic pollution on bacterial and archaeal communities in water and sediments from the Olifants River catchment, South Africa. Water samples showed less microbial species diversity than sediments and both habitats displayed different microbial communities. Within each of these habitats, pollution had no effect on alpha diversity but shaped the microbial composition and taxonomy-based predicted functions. Certain prokaryotic taxa and functional groups were indicative of different degrees of pollution. Heterotrophic taxa (e.g., *Flavobacterium* sp.) and sulphur-oxidizing bacteria (i.e., *Thiobacillus* sp.) were indicators of pollution in water and sediments, respectively. Ultimately, this information could be used to develop microbial indicators of water quality degradation.

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# Size-dependent cellular internalization and effects of
polystyrene microplastics in
microalgae *P. helgolandica*
var. tsingtaoensis and *S.
quadricauda*

**Authors:** Chen YX, Ling Y, Li XY, Hu JN, Cao CJ, He DF

**Source:** JOURNAL OF HAZARDOUS MATERIALS
399:123092, 2020, DOI:
10.1016/j.jhazmat.2020.123092

**Abstract:** Microplastics (MPs) are persistent contaminants in aquatic environments. Microalgae, as the main phytoplankton and primary producers, usually co-exist with MPs. Despite previous studies that have proved the interaction of MPs and microalgae, it is largely unknown whether MPs can be uptake into cells of microalgae. In this study, both marine *P. helgolandica* var. tsingtaoensis and freshwater microalgae *S. quadricauda* were respectively exposed to 10 mg/L polystyrene microbeads with five diameter sizes: 1.0, 2.0, 3.0, 4.0, and 5.0 μm. Confocal laser scanning and 3D image analysis showed that mean 24.0 % or 11.3 % cells of *P. helgolandica* var. tsingtaoensis contained 1.0 μm or 2.0 μm MPs after 72 h exposure. While mean 43.3 % or 15.3 % of *S. quadricauda* individuals engulfed 1.0 μm or 2.0 μm MPs within cells. But, none of 3.0-5.0 μm MPs were observed within algal cells. These results demonstrate the size-dependent cellular internalization of MPs in microalgae. Exposure to 1.0-2.0 μm PS MPs caused a significant reduction in the density of microalgae and influenced photosynthesis, which suggests cellular internalization of MPs can influence algal fertility and growth. This discovery first confirms cellular internalization of MPs in phytoplankton, of significance for the fate and eco-toxicity of MPs in the aquatic ecosystem.

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Toxic effects of Fe2WO6
nanoparticles towards

microalga *Dunaliella salina*:
Sonochemical synthesis
nanoparticles and investigate
its impact on the growth

**Authors:** Hassanpour M, Tafreshi SAH, Amiri O, Hamadanian M, Salavati-Niasari M

**Source:** CHEMOSPHERE 258:127348, 2020, DOI: 10.1016/j.chemosphere.2020.127348

**Abstract:** In this work, Fe2WO6 nanoparticles were synthesized by the ultrasound-assisted precipitation method. Various conditions were applied, including the change of the pH factor and reaction time for the synthesis of nanoparticles. After confirming the synthesis of the nanoparticles by various analyzes and evaluating their size and morphology, one of the conditions for the synthesis of the nanoparticles were selected as the optimum condition. The samples were added to the growth medium of a well-known microalga, *Dunaliella salina* at three concentrations of 20, 40 and 80 ppm to evaluate the effect of nanoparticles on biological systems. After 10 days different biological parameters were measured and compared with those of the control sample. According to the results, at concentration of 20 ppm the number of cells, the amount of chlorophyll a, and b, and biomass increased compared to the control samples. The Carotenoid level was higher in the treatment with 40 ppm of nanoparticles than that in the control samples. Compared to the control sample, the level of lipid peroxidation and the ratio of carbohydrate to amide II showed to be higher under 80 ppm treatment of particles. According to HCA analysis, both the evaluated parameters and concentrations of nanoparticles were divided into two general categories. Overall results showed that the effect of Fe2WO6 nanoparticles on microalgae could be a dose-dependent phenomenon, so that the addition of 20 ppm nanoparticles in the culture media helped the growth and the physiological status of algae. On the other hand, the application of a higher concentration of nanoparticles negatively affects algal biology. The results showed that the algae could be successfully used to precise
screen of various nanoparticles in terms of safety especially in aquatic environments and also biotechnological applications.

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# The interactions between microplastic polyvinyl chloride and marine diatoms: Physiological, morphological, and growth effects

**Authors:** Wang S, Wang Y, Liang Y, Cao W, Sun CJ, Ju P, Zheng L

**Source:** ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 203:111000, 2020, DOI: 10.1016/j.ecoenv.2020.111000

**Abstract:** Microplastics are identified as a great threat to marine environments. However, knowledge of their impacts on phytoplankton, especially for the diatoms is scarce. Herein, the effects of different polyvinyl chloride (PVC) microplastic concentrations and contact times (24, 48, 72 and 96 h) on the F-v/F-m and cell density of *Phaeodactylum tricornutum* (B255), *Chaetoceros gracilis* (B13) and *Thalassiosira* sp. (B280) were investigated to evaluate the toxic effects of micoplastics on marine diatoms. The effects of PVC microplastics on the morphology of the diatoms was observed by SEM. The order of sensitivity to 1 µm PVC microplastics among three marine diatoms was B13 B280 B255, showing that the toxic effects varied with different microalgae species. Furthermore, the presence of a siliceous cell wall played a minimal role in protecting cells from the physical attack of PVC microplastics, with no significant difference from the common cell wall. PVC microplastics caused dosedependent adverse effects on three marine diatoms. High PVC concentrations (200 mg/L) reduced the chlorophyll content, inhibited F-v/F-m, and affected the photosynthesis of three marine diatoms. The PVC micoplastics adsorbed and caused physical damage on the structure of algal cells. Interactions between PVC microplastics

and diatoms may be the probable reason for the negative effects of PVC on diatoms.

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# Effect of Azamethiphos on enzymatic activity and metabolic fingerprints of marine microbial communities from the water column

**Authors:** Garces DV, Fuentes ME, Quinones RA

**Source:** AQUACULTURE 529:735650, 2020, DOI: 10.1016/j.aquaculture.2020.735650

**Abstract:** Salmon production in Chile has increased significantly since the 1990s. However, there have been significant economic losses owing to outbreaks of *Caligus rogercresseyi*. Pesticides, among them Azamethiphos, are used to mitigate the impact of this sea louse. Azamethiphos can affect non-target species living near salmon farms such as microbial plankton, although there is little information about this. The general objective of this study was to determine the effect of different concentrations of the pesticide Azamethiphos on the metabolism of microbial plankton communities (< 100 µm) in two contrasting zones, one without salmon farming and the other with a high level of aquaculture activity. Several methodological approaches were used, including the enzymatic activity of j3-glucosidase and malate dehydrogenase (MDH), fingerprinting techniques (EcoPlates for bacteria and FF microplate for marine fungi) and the estimation of microbial aerobic respiration. We found greater de gradation of the pesticide Azamethiphos in the salmon culture zone (-72.4%) than in an area not previously used in salmon production (-26.1%). The response of microbial beta-glucosidase activity to Azamethiphos is highly variable, but there is a tendency toward more activity in the smaller size fractions (5-25 µm and 0.22-3 µm) when exposed to high Azamethiphos concentrations.
We also detected a highly variable response in microbial MDH activity. The most widely used carbon substrates by bacterioplankton and marine fungi are those related to carbohydrate metabolism. We also found increased use of carboxylic acids and amino acids in the treatments with higher concentrations of Azamethiphos. Enzyme activity, together with metabolic fingerprints, could be used as an indicator of perturbations in marine microbial communities.

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## Bacterial community colonization on tire microplastics in typical urban water environments and associated impacting factors

**Authors:** Wang LY, Luo ZX, Zhen Z, Yan Y, Yan CZ, Ma XF, Sun L, Wang M, Zhou XY, Hu AY

**Source:** ENVIRONMENTAL POLLUTION
265:114922, 2020, DOI: 10.1016/j.envpol.2020.114922

**Abstract:** Only limited information is available on bacterial communities' dynamics on tire microplastics in urban water environments. This study exploited 16S rDNA high-throughput sequencing to characterize bacterial communities on tire microplastics, using three different tire brands and tire sizes, in two typical urban water environments, including an influent pond of constructed wetland (CW) and its subsequent effluent into a landscape river (LR) during three different periods, namely, 1 month, 3 and 6 months. Results showed that the abundance of bacterial colonization on tire microplastics will increase over time. Proteobacteria, Bacteroidetes were the dominant bacteria at a phylum level, although they exhibited dynamic changes. At a genus level, the identifiable bacteria found in tire microplastics was generally the common bacteria in wastewater discharge, such as Aquabacterium and Denitratisoma. Additionally, alpha diversity

showed no significant differences in bacterial communities at the same locations. While beta diversity showed that the bacterial communities on the tire microplastics in the two locations was different. BugBase revealed that tire microplastics could support pathogenic bacteria in urban water environments. PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) indicated that the abundance of microorganisms associated with metabolism and degradation increased with time. Moreover, the ambient environmental factors were the main influencing factors of bacterial communities on tire microplastics. Herein, the contribution rate of nutrient salts (NO2-N, NO3-N, NH4-N, CODcr) was approximately 63%, and that of environmental physical factors of T and pH was 50%. While physicochemical factors, including particle size, contact angle, element content only had a slight impact. Accordingly, tire microplastics, as an emerging environmental pollutant, can act as carriers for bacterial colonization and propagation, particularly harmful microorganisms. Therefore, the obtained findings can provide new insight into potential risks of harmful microorganisms that colonize tire microplastics in urban water environments.

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## Differences in metal tolerance among strains, populations, and species of marine diatoms - Importance of exponential growth for quantification

**Authors:** Andersson B, Godhe A, Filipsson HL, Rengefors K, Berglund O

**Source:** AQUATIC TOXICOLOGY 226:105551, 2020, DOI: 10.1016/j.aquatox.2020.105551
**Abstract:** Strains of microalgae vary in traits between species and populations due to adaptation or stochastic processes. Traits of individual strains may also vary depending on the acclimatization state and external forces, such as abiotic stress. In this study we tested how metal tolerance differs among marine diatoms at three organizational levels: species, populations, and strains. At the species level we compared two pelagic Baltic Sea diatoms (*Skeletonema marinoi* and *Thalassiosira baltica*). We found that the between-species differences in tolerance (EC50) to the biologically active metals (Cu, Co, Ni, and Zn) was similar to that within-species. In contrast, the two species differed significantly in tolerance towards the non-essential metals, Ag (three-fold higher in *T. baltica*), Pb and Cd (two and three-fold higher in S. marinoi). At the population level, we found evidence that increased tolerance against Cu and Co (17 and 41 % higher EC50 on average, respectively) had evolved in a S. marinoi population subjected to historical mining activity. On a strain level we demonstrate how the growth phase of cultures (i.e., cellular densities above exponential growth) modulated dose-response relationships to Ag, Cd, Co, Cu, and Zn. Specifically, the EC50's were reduced by 10-60 % in non-exponentially growing S. marinoi (strain RO5AC), depending on metal. For the essential metals these differences were often larger than the average differences between the two species and populations. Consequently, without careful experimental design, interactions between nutrient limitation and metal stress may interfere with detection of small, but evolutionary and ecologically important, differences in tolerance between microalgae. To avoid such artifacts, we outline a semi-continuous cultivation approach that maintains, and empirically tests, that exponential growth is achieved. We argue that such an approach is essential to enable comparison of population or strain differences in tolerance using dose-response tests on cultures of microalgae.

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# The Fungicide Tebuconazole Confounds Concentrations of Molecular Biomarkers Estimating Fungal Biomass

**Authors:** Baudy P, Konschak M, Sakpal H, Baschien C, Schulz R, Bundschuh M, Zubrod JP

**Source:** BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY Early Access, 2020, DOI: 10.1007/s00128-020-02977-9

**Abstract:** Due to their ecological importance, fungi are suitable indicator organisms for anthropogenic stress. To estimate fungal biomass, the fungal membrane molecule ergosterol is often quantified as a proxy. Estimates based on ergosterol may, however, be distorted by exposure to demethylase inhibiting (DMI) fungicides, interfering with sterol synthesis. To test this hypothesis, we exposed ten fungal species to the DMI fungicide tebuconazole and measured concentrations of ergosterol and DNA per unit dry mass of the fungal hyphae. The latter served as alternative biomass proxy that is not specifically targeted by tebuconazole. Effects of tebuconazole on ergosterol concentrations were species-specific, while concentrations were on average reduced by 13%. In contrast, DNA concentrations were on average increased by 13%. We demonstrate that DMI fungicides - at close to field relevant levels - can distort fungal biomass estimation, complicating the use of this endpoint for environmental management.

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# Distinct Temporal Succession of Bacterial Communities in Early Marine Biofilms in a Portuguese Atlantic Port

**Authors:** Antunes JT, Sousa AGG, Azevedo J, Rego A, Leao PN, Vasconcelos V
**Source:** FRONTIERS IN MICROBIOLOGY 11:1938, 2020, DOI: 10.3389/fmicb.2020.01938

**Abstract:** Marine biofilms are known to influence the corrosion of metal surfaces in the marine environment. Despite some recent research, the succession of bacterial communities colonizing artificial surfaces remains uncharacterized in some temporal settings. More specifically, it is not fully known if bacterial colonizers of artificial surfaces are similar or distinct in the different seasons of the year. In particular the study of early biofilms, in which the bacterial cells communities first adhere to artificial surfaces, are crucial for the development of the subsequent biofilm communities. In this work, we used amplicon-based NGS (next-generation sequencing) and universal 16S rRNA bacterial primers to characterize the early biofilm bacterial communities growing on 316 L stainless steel surfaces in a Northern Portugal port. Sampling spanned 30-day periods in two distinct seasons (spring and winter). Biofilm communities growing in steel surfaces covered with an anti-corrosion paint and planktonic communities from the same location were also characterized. Our results demonstrated that distinct temporal patterns were observed in the sampled seasons. Specifically, a significantly higher abundance of Gammaproteobacteria and Mollicutes was found on the first days of biofilm growth in spring (day 1 to day 4) and a higher abundance of Alphaproteobacteria during the same days of biofilm growth in winter. In the last sampled day (day 30), the spring biofilms significantly shifted toward a dominance of photoautotrophic groups (mostly diatoms) and were also colonized by some macrofouling communities, something not observed during the winter sampling. Our results revealed that bacterial composition in the biofilms was particularly affected by the sampled day of the specific season, more so than the overall effect of the season or overall sampling day of both seasons. Additionally, the application of a non-fouling-release anti-corrosion paint in the steel plates resulted in a significantly lower diversity compared with plates without paint, but this was only observed during spring. We suggest that temporal succession of marine biofilm communities should be taken in

consideration for future antifouling/anti-biofilm applications.

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The role of metal contamination in shaping microbial communities in heavily polluted marine sediments

**Authors:** Di Cesare A, Pjevac P, Eckert E, Curkov N, Sparica MM, Corno G, Orlic S

**Source:** ENVIRONMENTAL POLLUTION
265:114823, 2020, DOI: 10.1016/j.envpol.2020.114823

**Abstract:** Microorganisms in coastal sediments are fundamental for ecosystem functioning, and regulate processes relevant in global biogeochemical cycles. Still, our understanding of the effects anthropogenic perturbation and pollution can have on microbial communities in marine sediments is limited. We surveyed the microbial diversity, and the occurrence and abundance of metal and antibiotic resistance genes is sediments collected from the Pula Bay (Croatia), one of the most significantly polluted sites along the Croatian coast. With a collection of 14 samples from the bay area, we were able to generate a detailed status quo picture of a site that only recently started a cleaning and remediation process (closing of sewage pipes and reduction of industrial activity). The concentrations of heavy metals in Pula Bay sediments are significantly higher than in pristine sediments from the Adriatic Sea, and in some cases, manifold exceed international sediment quality guidelines. While the sedimentary concentrations of heavy metals did significantly influence the abundance of the tested metal resistance genes, no strong effect of heavy metal pollution on the overall microbial community composition was observed. Like in many other marine sediments, Gammaproteobacteria, Bacteroidota and Desulfobacterota dominated the microbial community composition in most
samples, and community assembly was primarily
driven by water column depth and nutrient
(carbon and nitrogen) availability, regardless of
the degree of heavy metal pollution.

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Interactive effects of
warming and copper toxicity
on a tropical freshwater
green microalga *Chloromonas
augustae* (Chlorophyceae)

**Authors:** Yong WK, Sim KS, Poong SW, Wei D, Phang SM, Lim PE

**Source:** JOURNAL OF APPLIED PHYCOLOGY Early Access, 2020, DOI: 10.1007/s10811-020-02087-3

**Abstract:** Microalgae, the primary producers in aquatic ecosystems, are highly susceptible to heavy metal contamination. In this study, the interactive effects of warming and copper (Cu) toxicity on the physiology (cell density, photosynthetic efficiency, reactive oxygen species (ROS) production, and metal uptake in the biomass) and biochemistry (metabolite) of a freshwater green microalga, *Chloromonas augustae* (UMACC246), were elucidated. The microalgae were exposed to culture media supplemented with copper (II) sulfate pentahydrate (CuSO4·5H(2)O) at different concentrations (50, 150, 250 µM) at two temperatures, 25 degrees C (control) and 30 degrees C (sub-optimal), for 24 h. The results indicated that *C. augustae* exhibited a concentration- and temperature-dependent decrease in the cell density. Copper greatly affected the photosynthetic efficiency of *C.augustae* by reducing the maximum rate of relative electron transport (rETR(m)), light harvesting efficiency (alpha), and saturation irradiance (E-k). Warming increased ROS production remarkably in the microalga. Untargeted metabolomics indicated that temperature contributed to the most significant variations in the cultures (p < 0.05) in comparison with Cu toxicity or both factors

combined. Compounds such as amino acids and
amines were significantly dysregulated in
response to warming and Cu toxicity. Pathway
analyses showed that the glutathione
metabolism, sulfur metabolism, and mechanisms
in the amino acid metabolism were regulated,
suggesting that the microalga underwent primary
metabolism restructuring for survival and
adaptation. Overall, the data showed that
warming enhanced Cu toxicity in the cultures.
This implied that increasing water temperature
and metal toxicity due to global warming and
anthropogenic activities will probably exacerbate
existing threats to the primary producers.

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Characterization of the nano-bio interaction between metallic oxide nanomaterials and freshwater microalgae using flow cytometry

**Authors:** Arze AR, Manier N, Chatel A, Mouneyrac C

**Source:** NANOTOXICOLOGY Early Access, 2020, DOI: 10.1080/17435390.2020.1808106

**Abstract:** Since nanomaterials (NMs) are particulate contaminants, their first contact with organisms is a physical encounter ruled by physic-chemical processes that can determinate the potential NMs accumulation, toxicity, and trophic transfer. Freshwater ecosystems often become a final depository for NMs, so they can get in contact with the biota, especially primary organisms as algae. There are almost none comparative studies of this interaction using various NMs in the same conditions. This work identifies, analyzes, and compares the algae-NMs interaction by flow cytometry after a short-term contact test in which three freshwater algae (*Raphidocelis subcapitata*, *Desmodesmus subspicatus*, and *Chlorella vulgaris*) interact individually with a set of twelve metallic oxide NMs. Dose-response profiles and differences in the algae-NMs interaction were found according
to each algae species (C. vulgaris had the most affinity, starting the interaction from 0.5 mg/L and D. subspicatus had the less affinity starting at 5 mg/L). Flow cytometry results were confirmed by optical microscopy. Some NMs characteristics were identified as key-factors that govern the algae-NMs interaction: NMs composition (no interaction for SiO2NMs), surface electric charge (higher interaction for the positively charged NMs and lower interaction for the negatively charged ones) and crystalline form (for TiO2NMs). The presented method can be useful for a rapid determination of the interaction between free cells organisms as microalgae and (nano)particulate substances.

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Effect of humic acids on the
toxicity of pollutants to
Chlamydomonas reinhardtii:
Investigation by a microscale
algal growth inhibition test

**Authors:** Nanayama Y, Sazawa K, Yustiawati Y, Syawal MS, Fukushima M, Kuramitz H

**Source:** ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH Early Access, 2020, DOI: 10.1007/s11356-020-10425-8

**Abstract:** Dissolved humic substances (DHSs) are the major components of organic matter in the aquatic environment. DHSs are well known to considerably affect the speciation, solubility, and toxicity of a wide variety of pollutants in the aquatic environment. In this study, the effects of the toxicity of heavy metals and hydrophobic organic pollutants (HOPs) on Chlamydomonas reinhardtii in the presence of humic acid (HA) were examined by a microscale algal growth inhibition (mu-AGI) test based on spectrophotometric detection. To clarify the relationship between the chemical properties of HAs and the toxicity change of pollutants, eight HAs from different sources were prepared and used. HAs were responsible for mitigating the toxicity of Hg, Cu, pesticides (gamma-HCH, 2,4-

D, and DDT), and polycyclic aromatic hydrocarbons (PAHs) such as naphthalene (Nap), anthracene (Ant), and benzo[a]pyrene (BaP). In particular, an approximately 100-fold decrease in the toxicity of BaP was observed in the presence of 10 ppm HAs extracted from tropical peat. The results indicated that the carboxylic group content and the HA molecular weight are correlated to the changes in the heavy metal toxicity. For HOPs, the aromaticity and polarity of HAs are crucial for mitigating their toxicity. Furthermore, it was clearly shown that the lake water including a high concentration of DHSs collected from Central Kalimantan, Indonesia, reduced the toxicity of Hg and gamma-HCH on Chlamydomonas reinhardtii.

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Increased inheritance of
structure and function of
bacterial communities and
pathogen propagation in
plastisphere along a river
with increasing antibiotics
pollution gradient

**Authors:** Xue NN, Wang LY, Li WF, Wang SS, Pan XL, Zhang DY

**Source:** ENVIRONMENTAL POLLUTION
265:114641, 2020, DOI:
10.1016/j.envpol.2020.114641
**Abstract:** Plastic debris provides a stable substrate and novel ecological niche for microorganisms in the aquatic environment, which was referred to as "Plastisphere". Little is known about distribution patterns and responses of ecological function and structure of microbial communities in the plastisphere along rivers which usually have antibiotics pollution gradient. In this study, the differences in the community structure between the plastisphere and the planktonic bacteria, and their spatial variation of the community structure and function along a river with increased antibiotics pollution gradient was investigated at the watershed scale. The diversity of bacteria colonized on most plastic debris was higher than in surrounding water. Plastic debris could accumulate a higher abundance of some potential pathogens than surrounding water even at high antibiotics concentrations. The source tracking results showed that downstream plastisphere inherited much higher proportions of bacterial taxa from upstream than planktonic bacteria. About 92.3-99.7% of bacteria communities in downstream water were not from upstream but from the input of downstream human activities. On the contrary, high proportions of bacterial taxa in downstream plastisphere were closely connected to upstream. The plastisphere possesses higher ecological functional diversity than the planktonic bacteria. Seventy nine functional groups across plastisphere were predicted using functional annotation of prokaryotic taxa and only 65 functional groups were found in the planktonic bacteria. Plastisphere also acts as hotspot for biogeochemical cycling of nutrients such as N and S. Intensive human activities of urban and downstream agriculture and aquaculture had great effects on microbial community structure and functional groups of the Urumqi River. Pastisphere communities are much more resistant to human disturbance than planktonic bacteria. Compared to surrounding water, plastisphere increased inheritance from upstream microbial structure and function and also increased survival and propagation of pathogens in the downstream water with high concentrations of antibiotics.

Advances in characterizing
microbial community change
and resistance upon
exposure to lead
contamination: Implications
for ecological risk assessment

**Authors:** George SE, Wan YS

**Source:** CRITICAL REVIEWS IN ENVIRONMENTAL SCIENCE AND TECHNOLOGY 50:2223-2270, 2020, DOI: 10.1080/10643389.2019.1698260

**Abstract:** Recent advancement in molecular techniques has spurred numerous studies on responses of microorganisms to lead exposure, leveraging detailed phylogenetic analyses and functional gene identification to discern the effects of lead toxicity on microbial communities. A comprehensive review of recent research is provided on (1) lead resistance mechanisms of microorganisms; (2) microbial community changes in contaminated aquatic sediments and terrestrial soils; and (3) lead resistance genes applied to lead biosensor development. Ample evidence in the literature, including both in vitro and in situ studies, indicates that exposure to lead inhibits microbial activities (such as respiration and metabolism), reduces biomass and alters microbial community structure. Even at sites where microbial communities do not vary compositionally with contaminant levels, functional differences between microbial communities are evident. The main mechanisms of lead resistance involve extracellular and intracellular biosorption, precipitation, complexation, and/or efflux pumps. The suites of genes associated with lead resistance mechanisms can serve, when considered with phylogenetic information, as indicators of lead contamination. This holds potential for development of next generation lead biosensors. To promote applications of advanced knowledge, molecular techniques, and lead biosensor technology, perspectives on using
microbial indicators for site ecological
assessment are presented.

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Polystyrene nanoplastics cause growth inhibition, morphological damage and physiological disturbance in the marine microalga *Platymonas helgolandica*

**Authors:** Wang SY, Liu MH, Wang JM, Huang JS, Wang J

**Source:** MARINE POLLUTION BULLETIN
158:111403, 2020, DOI: 10.1016/j.marpolbul.2020.111403

**Abstract:** Effects of nanoplastics at low level on the marine primary producer are largely unclear. To assess the potential risk of nanoplastic pollution, this study exposed marine green microalgae *Platymonas helgolandica* to 20, 200, and 2000 µg/L 70-nm polystyrene nanoplastics for 6 days. Nanoplastics significantly inhibited the growth of *P. helgolandica* during the first 4 days of exposure, and elevated heterocyst frequency was observed in 200 and 2000 µg/L exposure groups in the early exposure stage. Exposure to 200 and 2000 µg/L nanoplastics for 4 days increased the membrane permeability and mitochondrial membrane potential, and decreased light energy used in photochemical processes of microalgae. Moreover, clear morphological changes, including surface folds, fragmentation, aggregation cluster, and rupture, in the microalgae exposed to nanoplastics were observed under scanning electron microscope and transmission electron microscope. These results demonstrate that nanoplastics could reduce the microalgal vitality by the damage on cell morphology and organelle function.

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Effects of humic acids on
biotoxicity of tetracycline to
microalgae *Coelastrella* sp.

**Authors:** Tong MY, Li X, Luo Q, Yang CP, Lou W, Liu HY, Du C, Nie LJ, Zhong YY

**Source:** ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS 50:101962, 2020, DOI: 10.1016/j.algal.2020.101962

**Abstract:** The release of antibiotics into aquatic environments would induce adverse effects on organisms, so the environmental impact and fate of antibiotics must be paid close attention. In this paper, the effects of tetracycline on the growth of microalgae *Coelastrella* sp. in the presence of humic acids were investigated at various tetracycline concentrations ranging from 0.5 to 10 mg/L in Blue-Green medium, and the underlying mechanisms were also discussed. Results revealed that the microalgae growth showed a hormesis dose-response phenomenon under tetracycline stress with stimulation at low levels ≤ 2 mg/L) while inhibition at higher levels (2 mg/L). More importantly, tetracycline biotoxicity to *Coelastrella* sp. decreased significantly due to the increase in humic acids concentration, as evidenced by the increased biomass, chlorophyll-a and total proteins contents, as well as the reduced oxidative stress response in *Coelastrella* sp. cells. The strong complexation between tetracycline and humic acids was responsible for the reduced tetracycline biotoxicity. These findings are helpful for better understanding the environmental risk of antibiotics in eutrophic waters.

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ERA / PUBLICATIONS

SCIENTIFIQUES /
MICROBIOLOGIE ET
CONTAMINANTS

Effects of co-contamination
of heavy metals and total
petroleum hydrocarbons on
soil bacterial community and
function network
reconstitution

Authors: Li Q, You Pi, Hu Q, Leng BF, and more
...

Source: ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 204, 2020, DOI: 10.1016/j.ecoenv.2020.111083

**Abstract:** Due to the accumulation of heavy metals in soil ecosystems, the response of soil microorganisms to the disturbance of heavy metals were widely studied. However, little was known about the interactions among microorganisms in heavy metals and total petroleum hydrocarbons (TPH) co-contaminated soils. In the present study, the microbiota shifts of 2 different contamination types of heavy metal-TPH polluted soils were investigated. NGS sequencing approach was adopted to illustrate the microbial community structure and to predict community function. Networks were established to reveal the interactions between microbes and environmental pollutants. Results showed that the alpha diversity and OTUs number of soil microbiota were reduced under heavy metals and TPH pollutants. TPH was the major pollutant in HT1 group, in which Proteobacteria phylum increased significantly, including Arenimonas genus, Sphingomonadaceae family and Burkholderiaceae family. Moreover, the function structures based on the KEGG database of HT1 group was enriched in the benzene matter metabolism and bacterial motoricity in microbiota. In contrast, severe Cr-Pb-TPH co-pollutants in HT2 increased the abundance of Firmicutes. In details, the relative abundance of Streptococcus genus and Bacilli

class raised sharply. The DNA replication
functions in microbiota were enriched under
severely contaminated soil as a result of high
concentrations of heavy metals and TPH
pollutants' damage to bacteria. Furthermore,
according to the correlation analysis between
microbes and the pollutants, Streptococcus,
Neisseria, Aeromonas, Porphyromonas and
Acinetobacter were suggested as the
bioremediation bacteria for Cr and Pb polluted
soils, while Syntrophaceae spp. and
Immundisoli bacter were suggested as the
bioremediation bacteria for TPH polluted soil.
The study took a survey on the microbiota shifts
of the heavy metals and TPH polluted soils, and
the microbe's biomarkers provided new insights
for the candidate strains of biodegradation,
while further researches are required to verify
the biodegradation mechanism of these
biomarkers.

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Molecular identification and
phylogenetic analysis of
chromium-resistant bacteria
isolated from chromite mine
area soil, Sukinda, India using
16S rRNA sequencing

Authors: Pradhan SK, Singh NR, Das S, Thatoi H

Source: SOIL & SEDIMENT CONTAMINATION 29, 8: 805-822, 2020, DOI: 10.1080/15320383.2020.1771272
**Abstract:** The present study was undertaken to characterize the Cr(VI)-resistant bacteria isolated from the chromite mine area of Sukinda, Odisha through 16S rRNA sequencing technique followed by homology search, secondary structure analysis. The 16S rRNA sequencing resulted in varied bacterial sequence lengths. Characterization of these isolated sequences showed the dominance of the members of the genera Bacillus, Lysinibacillus, and Staphylococcus followed by the members of other distinct genera such as Enterobacter, Curtobacterium, Kocuria, and Stenotrophomonas. Cr(VI)-tolerant study of these bacterial isolates exhibited comparatively higher resistance toward Cr(VI) at 500 mg L(-1) concentration. Secondary-structural diversity among isolated sequences obtained from mfold prediction server varied with sequence-based diversity with some conserved pattern observed among the few Bacillus groups and Staphylococcus groups, but in other genera, the structural similarity is not observed. Multiple sequence alignment of all 16S rRNA sequences showed monomorphic and polymorphic sites in most of the sequences, whereas parsimony-informative sites were identified in a few bacterial isolates. Further, phylogenetic analysis of the isolated chromium-resistant 16S rRNA bacterial sequences along with the sequences retrieved from NCBI's ENTREZ database was performed to study their divergence. Phylogenetic analysis revealed that chromate-resistant sequences were clustered into two distinct clades in maximum parsimony-based phylogenetic tree construction.

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Effects of dibutyl phthalate contamination on physiology, phytohormone homeostasis, rhizospheric and endophytic bacterial communities of Brassica rapa var. chinensis

Authors: Ge J, Cheng JJ, Li Y, and more ...

Source: ENVIRONMENTAL RESEARCH 189, 2020, DOI: 10.1016/j.envres.2020.109953

**Abstract:** Phthalates are plasticizers and are ubiquitously detected in the environment, frequently at mg/kg levels. The present study aimed to evaluate the effects of dibutyl phthalate (DBP) on germination, growth, enzyme activity, phytohormone homeostasis and bacterial communities of two cultivars of Brassica rapa var. chinensis. The germination rate was decreased up to 20% compared to the control, and the growth of the vegetables was severely inhibited at the early stage when exposed to DBP at 20 mg/kg. Antioxidant defense enzyme activities and malondialdehyde (MDA) content increased upon exposure to DBP. A dose-response of auxin (IAA) was observed after a 2 d exposure. Gibberellin (GA3) and abscisic acid (ABA) responded at day 10 under DBP stress. GA3 did not show a clear dose-response effect and ABA increased about 3 times as the DBP concentration increased from 2 to 20 mg/L. Microbial population shifts were observed, especially in rhizosphere soil and roots. No obvious change occurred for the diversity of rhizospheric bacteria among different treatments. Chaol, Shannon and Simpson indices of the root endophytic bacteria showed a decreasing trend with increasing DBP supplementation, while all the indices increased in shoot endophytic bacteria in comparison to the control. The results indicated that exposure to DBP may compromise the fitness of the leafy vagetables and alter the endophytic and rhizospheric bacteria, which might further affect the nutrients of the vegetables and alter ecosystem functions.

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Bioavailable metal(loid)s and physicochemical features co-mediating microbial communities at combined metal(loid) pollution sites
**Authors:** Wang JW, Liu T, Sun WL, Chen Q

**Source:** CHEMOSPHERE 260, 2020, DOI: 10.1016/j.chemosphere.2020.127619

**Abstract:** Heavy metal contamination poses considerable threats to various ecosystems, yet little is known about the assembly and adaptation of microbial communities at sites with combined heavy metal(loid) pollution. Here, we examined metal(loid) pollutants and bacterial communities in three zones (Zones I, II, and III) of an abandoned sewage reservoir with different usage years. The contamination level of multiple metal(loid)s was higher in Zone I than in the other zones, and arsenic (As), zinc (Zn), selenium (Se), copper (Cu), tin (Sn), molybdenum (Mo), antimony (Sb), cadmium (Cd), lead (Pb), thallium (Tl), and nickel (Ni) were the major contaminants (pollution load index &#62; 1). Bioavailable forms of titanium (Ti), chromium (Cr), Sn, and cobalt (Co) played essential roles in shaping the microbial structure, and physicochemical properties, especially organic matter (OM) and pH, also mediated the microbial diversity and composition in the metal(loid) contaminated zones. Metal-microbe interactions and heatmap analysis revealed that the bioavailability of metal(loid)s promoted the niche partitioning of microbial species. Metal-resistant species were abundant in Zone I that had the highest metal-contaminated level, whereas metal-sensitive species prevailed in Zone III that had the lowest pollution level. The bioavailable metal(loid)s rather than physicochemical and spatial variables explained a larger portion of the variance in the microbial community, and the homogeneous selection was the dominant ecological process driving the assembly of the microbial community. Overall, our study highlighted the importance of metal(loid) bioavailability in shaping microbial structure, future bioremediation, and environmental management of metal(loid) contaminated sites.

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Temporal dynamics of heavy metal distribution and

associated microbial community in ambient aerosols from vanadium smelter

**Authors:** Wang YN, Zhang BG, Wang S and more ...

**Source:** SCIENCE OF THE TOTAL ENVIRONMENT 735, 2020, DOI: 10.1016/j.scitotenv.2020.139360

**Abstract:** Heavy metals (HMs) such as vanadium (V), zinc (Zn), arsenic (As), chromium (Cr), copper (Cu) and nickel (Ni) are released into atmosphere during V smelting activities, resulting in their co-existence with airborne microbes. However, little is known about HMs distributions and associated microbes in aerosols from such industrial districts. This study reveals seasonal dynamics of HMs and microbes in ambient aerosols from V smelter in Panzhihua, China. Multiple HMs were detected, while V concentration was the highest, maximizing at 228.0 +/- 10.3 ng/m(3) in Spring. Health risks displayed similar trends to HMs distributions, and children were posed much higher risks than adults due to their more sensitivity to HMs. V and As contributed dramatically to total health risks among all examined HMs. High-throughput 16S rRNA gene sequencing analysis revealed microbes tolerant to V, Zn, As, Cr, Cu and Ni. Acinetobacter widely existed with function of detoxifying V(V) and more species as Bacillus, Gobacter and Thauera tolerating V, Zn, As, Cr, Cu and Ni appeared in Summer. These findings shed light on understandings of HMs dynamics and associated microbial community in aerosols from smelting regions.

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Microbial Distribution and Diversity of Soil Around a Manganese Mine Area

**Authors:** Xiang YW, Dong YiQ, Zhao SY, and more ...
**Source:** WATER AIR AND SOIL POLLUTION 231, 10, 2020, DOI: 10.1007/s11270-020-04878-3

**Abstract:** From 12 mining areas surrounding a manganese mining area in Guangxi, soil samples were collected at different distances from the center of the mining area and different sampling points at the same distance. 16S rRNA gene sequencing was used in extracting and amplifying DNA in the soil samples, and double-terminal gene sequence library comparison was performed. Through OUT clustering, species community, species diversity, and inter-group difference analyses, the composition of microbial community and biological diversity in the mining soil was evaluated. Results showed that the soil around the mining area was affected by heavy metals, and species complexity was positively correlated with distance. Proteobacteria, Firmicutes, Bacteroidetes, and Acidobacteria were the dominant species with high abundance in some soil samples because of their pollution tolerance. The samples closer to the center were more disturbed by mining activities, and species diversity sequencing based on observed species index and Shannon index was consistent with that of cluster analysis. Differences among the sample groups at 2 km from the center were the smallest, and species diversity had the highest similarity. Differences among the sample groups at 1 km from the center were the largest, and species composition significantly varied. Microorganism distribution is an important indicator of soil ecological characteristics, and the analysis of species and diversity of soil microorganisms is important to the assessment of the impact of mining activities and the extent of soil contamination.

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Unraveling consequences of
soil micro- and nano-plastic
pollution on soil-plant
system: Implications for
nitrogen (N) cycling and soil
microbial activity

Authors: Iqbal S, Xu JC, Allen SD and more ...

**Source:** CHEMOSPHERE 260, 2020, DOI: 10.1016/j.chemosphere.2020.127578

**Abstract:** Micro- and nano-plastics have widely been recognized as major global environmental problem due to its widespread use and inadequate waste management. The emergence of these plastic pollutants in agroecosystem is a legitimate ecotoxicological concerns for food web exchanges. In agriculture, micro/ nano plastics are originated from a variety of different agricultural management practices, such as the use of compost, sewage sludge and mulching. A range of soil properties and plant traits are affected by their presence. With the increase of plastic debris, these pollutant materials have now begun to demonstrate serious implications for key soil ecosystem functions, such as soil microbial activity and nutrient cycling. Nitrogen (N) cycle is key predictor of ecological stability and management in terrestrial ecosystem. In this review, we evaluate ecological risks associated with micro-nano plastic for soil-plant system. We also discuss the consequence of plastic pollutants, either positive or negative, on soil microbial activities. In addition, we systematically summarize both direct and hypothesized implications for N cycling in agroecosystem. We conclude that soil N transformation had showed varied effects resulting from different types and sizes of plastic polymers present in soil. While mixed effects of microplastic pollution on plant growth and yield have been observed, biodegradable plastics have appeared to pose greater risk for plant growth compared to chemical plastic polymers.

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Smectite clay minerals
reduce the acute toxicity of
quaternary alkylammonium
compounds towards
potentially pathogenic
## bacterial taxa present in manure and soil

**Authors:** Heyde BJ, Glaeser SP, Bisping L and more ...

**Source:** SCIENTIFIC REPORTS 10, 1, 2020, DOI: 10.1038/s41598-020-71720-5

**Abstract:** Quaternary alkylammonium compounds (QAACs) are a group of cationic surfactants which are disinfectants with numerous industrial and agricultural applications and frequently released into the environment. One recent hypothesis is that bacteria present in soil will be protected from acute toxic effects of QAACs in the presence of expandable layer silicates due to interlayer sorption. We therefore studied bacterial growth kinetics with high temporal resolution and determined minimal inhibitory concentrations (MICs) of two QAACs, benzyldimethyldodecylammonium chloride (BAC-C12) and didecyldimethylammonium chlorid (DADMAC-C10), for eight strains of different bacterial taxa (Escherichia coli, Acinetobacter, Enterococcus faecium, Enterococcus faecalis, and Pseudomonas fluorescens) in relation to QAAC sorption to smectite and kaolinite. The MICs of BAC-C12 and DADMAC-C10 were in the absence of smectite and kaolinite in the order of 10 to 30 µg mL(-1) and 1.0 to 3.5 µg mL(-1) for all strains except the more sensitive Acinetobacter strain. For all tested strains and both tested QAACs, the presence of smectite increased apparent MIC values while kaolinite had no effect on MICs. Sorption curves without bacteria showed that smectite sorbed larger amounts of QAACs than kaolinite. Correcting nominal QAAC concentrations employed in toxicity tests for QAAC sorption using the sorption curves explained well the observed shifts in apparent MICs. Transmission electron microscopy (TEM) demonstrated that the interlayer space of smectite expanded from 13.7 +/- 1 angstrom to 19.9 +/- 1.5 angstrom after addition of BAC-C12. This study provides first evidence that low charge 2:1 expandable layer silicates can play an important role for buffering QAAC toxicity in soils.

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## Graphene oxide influences bacterial community and soil environments of Cd-polluted Haplic Cambisols in Northeast China

**Authors:** Ru JX, Chen GY, Liu Y, Sang Y, Song JF

**Source:** JOURNAL OF FORESTRY RESEARCH, 2020, DOI: 10.1007/s11676-020-01217-4

**Abstract:** Graphene oxide (GO), a carbon nanomaterial that is widely used in the environment and other industries, may pose potential risks to ecosystems, especially the soil ecosystem. Some soils in Northeast China are frequently polluted with cadmium (Cd) metal. However, there is no study on the influence of GO on the Cd-contaminated soil microbial community and soil chemical properties. In this study, Cd (100 mg kg(-1))-polluted soils were treated with different concentrations of GO (0, 25, 50, 150, 250, and 500 mg L-1, expressed as T1, T2, T3, T4, T5, and T6, respectively) for 40 days. The treatment without Cd pollution and GO served as the control (CK). Then, we investigated the influence of the GO concentrations on the bacterial community and chemical properties of Cd-polluted Haplic Cambisols, the zonal soil in Northeast China. After GO addition, the richness and diversity indexes of the bacterial community in Cd-contaminated Haplic Cambisols initially increased by 0.05-33.92% at 25 mg L-1, then decreased by 0.07-2.37% at 50 mg L-1, and then increased by 0.01-24.37% within 500 mg L(-1) again. The species and abundance of bacteria varied with GO concentration, and GO significantly increased bacterial growth at 25 and 250 mg L-1. GO treatments influenced the bacterial community structure, and the order of similarity of the bacterial community structure was as follows: T4 = T5 > T1 = T6 > T2 > T3 > CK. Proteobacteria and Acidobacteria were the dominant bacteria, accounting for 36.0% and 26.2%, respectively, of soil bacteria. Different GO treatments also significantly affected the metabolic function of bacteria and further
influenced the diversity of the bacterial
community structure by affecting several key soil
chemical properties: soil pH, organic matter and
available potassium, phosphorus, and cadmium.
Our results provide a theoretical basis for
scientific and comprehensive evaluation of the
environmental impacts of GO on the zonal forest
soils of Northeast China.

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Spatial and Temporal
Variation in Microbial
Diversity and Community
Structure in a Contaminated
Mangrove Wetland

Authors: Ma J, Zhou T, Xu C, and more ...

Source: APPLIED SCIENCES-BASEL 10, 17, 2020, DOI: 10.3390/app10175850

**Abstract:** Field and laboratory investigations were conducted to characterize bacterial diversity and community structure in a badly contaminated mangrove wetland adjacent to the metropolitan area of a megacity in subtropical China. Next-generation sequencing technique was used for sequencing the V4-V5 region of the 16s rRNA gene on the Illumina system. Collectively, Proteobacteria, Chloroflexi, Planctomycetes, Actinobacteria and Bacteroidetes were the predominant phyla identified in the investigated soils. A significant spatial variation in bacterial diversity and community structure was observed for the investigated mangrove soils. Heavy metal pollution played a key role in reducing the bacterial diversity. The spatial variation in soil-borne heavy metals shaped the spatial variation in bacterial diversity and community structure in the study area. Other environmental factors such as total carbon and total nitrogen in the soils that are affected by seasonal change in temperature could also influence the bacterial abundance, diversity and community structure though the temporal variation was relatively weaker, as compared to spatial variation. The

bacterial diversity index was lower in the
investigated site than in the comparable
reference site with less contaminated status.
The community structure in mangrove soils at
the current study site was, to a remarkable
extent, different from those in the tropical
mangrove wetlands around the world.

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Fungal heavy metal
adaptation through single
nucleotide polymorphisms
and copy-number variation

Authors: Bazzicalupo AL, Ruytinx J, Ke YH, and more ...

Source: MOLECULAR ECOLOGY, 2020, DOI: 10.1111/mec.15618

**Abstract:** Human-altered environments can shape the evolution of organisms. Fungi are no exception, although little is known about how they withstand anthropogenic pollution. Here, we document adaptation in the mycorrhizal fungus Suillus luteus driven by soil heavy metal contamination. Genome scans across individuals from recently polluted and nearby unpolluted soils in Belgium revealed low divergence across isolates and no evidence of population structure based on soil type. However, we detected single nucleotide polymorphism divergence and gene copy-number variation, with different genetic combinations potentially conferring the ability to persist in contaminated soils. Variants were shared across the population but found to be under selection in isolates exposed to pollution and located across the genome, including in genes involved in metal exclusion, storage, immobilization and reactive oxygen species detoxification. Together, our results point to S. luteus undergoing the initial steps of adaptive divergence and contribute to understanding the processes underlying local adaptation under strong environmental selection.

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Selective pressures of heavy metals on microbial community determine microbial functional roles during composting: Sensitive, resistant and actor

**Authors:** Chen XM, Zhao Y, Zhao XY and more ...

**Source:** JOURNAL OF HAZARDOUS MATERIALS 398, 2020, DOI: 10.1016/j.jhazmat.2020.122858

**Abstract:** Heavy metals (HM) pollution exerts an effect on microbial community composition and structure during composting, the way how microbial community responses to HM pressure is remain poorly understood though. The aim of this study was to explore functional roles of microorganisms based on selective pressures of HM (Cu, Zn and Cd). The results of microbial resistance showed that the toxicity of metals to microorganisms were Cu > Zn > Cd during composting. Cu and Zn were more toxic for microorganisms during composting when compared with Cd. However, microorganisms had a longer lag period to grow under Zn stress through microbial tolerance determination. In addition, the microbial catalase activity generally decreased and protease activity generally increased, thus microorganisms became more adaptable to HM stress during composting. The experimental results confirmed the existence of sensitive, resistant and actor microorganisms during beef cattle and chicken manures composting. Ultimately, the resistant, sensitive and actor microorganisms at genus level were distinguished under HM pressure based on the network analysis and structural equation models, including 85 resistant microorganisms, 5 sensitive microorganisms and 6 actor microorganisms. This would be helpful to understand the microbial succession process under HM stress and identify functional strains of HM remediation.

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Comparative study on the pollution status of organochlorine pesticides (OCPs) and bacterial community diversity and structure between plastic shed and open-field soils from northern China

**Authors:** Sun Y, Chang XP, Zhao LX, and more ...

**Source:** SCIENCE OF THE TOTAL ENVIRONMENT 741, 2020, DOI: 10.1016/j.scitotenv.2020.139620

**Abstract:** The pollution status of organochlorine pesticides (OCPs) and microbial community in plastic shed and open-field soils may be different due to the significant variations in environmental factors between the two cultivation modes. However, the differences remain unclear. We conducted a regional-scale survey to investigate the pollution level, distribution, and sources of 20 OCPs, and to evaluate the soil physicochemical properties and bacterial community in soils from plastic shed and open-field locating the north areas of China. We found that levels of total OCPs in the plastic shed soils were significantly higher than those in the nearby open-field soils. Most of these OCPs were attributed to historical application, except for dichlorodiphenyltrichloroethanes (DDTs) due to the fresh input along with dicofol application. Soil pH (for both cultivation modes) and total organic carbon (TOC) content (only for plastic sheds) were significantly correlated with the total OCP concentrations. Additionally, microbial diversity and richness were generally lower in plastic shed soils than in nearby open-field soils for each region. The bacterial community variation among different regions might be principally determined by the soil type. Soil pH had the greatest impact on the microbial community across all plastic shed and open-field samples. These results provide a better understanding of the environmental impact and ecological risk of OCPs in soils with different cultivation modes.
# Physicochemical properties, heavy metals, and metal-tolerant bacteria profiles of abandoned gold mine tailings in Krugersdorp, South Africa

**Authors:** Fashola MO, Ngole-Jeme VM, Babalola OO

**Source:** CANADIAN JOURNAL OF SOIL SCIENCE 100 3: 217-233, 2020, DOI: 10.1139/cjss-2018-0161

**Abstract:** Mine tailings are a potential source of heavy metals (HM) that can be toxic to microbes, plants, and animals in aquatic and terrestrial ecosystems. Bacteria have evolved several mechanisms to tolerate the uptake of HM ions. This study aimed to assess the physicochemical properties, concentrations of selected HM and metalloids [arsenic (As), nickel (Ni), lead (Pb), zinc (Zn), cadmium (Cd), and cobalt (Co)], and isolate potential metal-tolerant bacteria present at three abandoned gold mining sites with a view of understanding how tailings characteristics vary and the implications on microbial activities in tailings dumps. Heavy-metal-tolerant bacteria were isolated from the samples using minimum inhibitory and maximum tolerable concentrations of the Ni, Pb, Zn, Cd, and Co. The substrates of the studied sites were acidic and deficient in nutrients. High metals and metalloid concentrations in the order Zn > Ni > Co > As > Pb > Cd were recorded in some of the studied sites and its adjacent soil which exceeded South African recommended values for soil and sediments. Heavy-metal-tolerant bacteria that showed multiple tolerances to Ni, Pb, and Zn were isolated and putatively identified using biochemical tests as belonging to the phyla Proteobacteria, Actinobacteria, and Firmicutes. Gold mine tailings enriched the soil with HM and also affect soil physicochemical properties. Proper management of mine wastes must be ensured to prevent their adverse effects on the diversity, composition, and activity of soil

microorganisms that help in maintenance of the ecosystem.

# Physicochemical and microbial properties of urban park soils of the cities of Marrakech, Morocco and Torun, Poland: Human health risk assessment of fecal coliforms and trace elements

**Authors:** Beroigui M, Naylo A, Walczak M. and more ...

**Source:** CATENA 194, 2020, DOI: 10.1016/j.catena.2020.104673

**Abstract:** The public green space (PGS) in urban areas presents an image of nature and its animal and plant biodiversity in the city. Due to intense urbanization in the world, pollutants such as trace elements (FE) or pathogenic microorganisms are continually emitted into the environment and pose a threat to ecosystems. The aim of this work was to assess the soil quality of PGS in the cities of Marrakech (Morocco) and Torun (Poland) through physicochemical and microbiological approaches and to assess related health risks. Eighteen soils from the most visited historic parks in Marrakech and Torun were sampled and analyzed. The results showed that content of Total Organic Carbon (TOC) in Torun urban soils is about three times higher than that measured in Marrakech urban park soils. These differences are related to the naturally higher content of organic matter in the soils of temperate climate regions than in Mediterranean soils. The concentrations of trace element (FE) showed a similar trend in both cities, except for Pb in one Marrakech site, which exhibited a high concentration (400 mg Pb Kg(-1) in Bab Rab Park). Soil enzymes present a high sensitivity to anthropogenic disturbances and can be used as tool to evaluate early disturbance of urban soils. The alkaline
phosphatase (APHa) and urease (URa) activities are less affected by anthropogenic pressure than dehydrogenase (DHa). Slight sensitivity to TE was observed in the microbial community in the order fungi &#60;; actinomycetes &#60;; bacteria. Total and fecal coliforms (TC, FC) were present in all soil samples, with higher concentrations in Marrakech sites. Based on estimated FC risk, the highest percentage did not exceed 11% of the guideline limit set by International Commission on Microbiological Specifications for Foods. Hazard index showed no health risk for adults caused by studied TE concentrations in the park soils of Marrakech and Torun, but potential adverse non-cancer health effects for children. Their safety depends on their own behavior and the ways by adults supervise them.

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Effect of heavy metals on soil microbial biomass, and nematode trophic groups of a paddy soil affected by long-running polymetallic mining activities in Guangdong, Southern China

Authors: Zeng QP, Zhu LA, Wang JZ and more ...

**Source:** APPLIED ECOLOGY AND ENVIRONMENTAL RESEARCH 18(4):4915-4927, 2020, DOI: 10.15666/aeer/1804_49154927

**Abstract:** While the effects of heavy metals on soil organisms are relatively well-documented, the effects of heavy metals caused by long-term sewage irrigation are poorly understood. Therefore, we collected two kinds of soil samples from a paddy field which was irrigated with sewage for more than 20 years (SIA) and the adjacent non-sewage irrigated land as control (NSIA) in Shaoguan, southern China, to assess the

long-term effects of multiple metal mining activities on soil microbial biomass, nematode assemblages. The available Cu and Zn, and the total Cu, Zn, Pb and As contents in SIA were higher than those in NSIA area by 13.60, 7.69, 8.56, 2.35, 2.96 and 3.11 times on average. Heavy metals stimulated microbial biomass and nematode biomass consumption, which caused a shift in nematode groups, and the mean content of soil microbial biomass carbon (C) and nitrogen (N) in SIA drops by 25.76%, 11.10% compared to the NSIA. Organics showed a positive effect on soil microbial biomass C and N, with the same response for all types of nematodes, Available Cu and Zn, and the total Cu, Zn, Pb and As content in soils exhibited a negative effect on soil microbial biomass C and N, and each group of nematodes, which reveal that the microbial/nematode activities had been disrupted by the heavy metals.

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Soil Microbial Community Changes in a Field Treatment with Chlorotoluron, Flufenacet and Diflufenican and Two Organic Amendments

**Authors:** Carpio MJ, Garcia-Delgado C, Marin-Benito JM, and more ...

**Source:** AGRONOMY-BASEL 10, 8, 2020, DOI: 10.3390/agronomy10081166

**Abstract:** The soil microbial activity, biomass and structure were evaluated in an unamended (S) and organically amended soil treated with two commercial formulations of the herbicides chlorotoluron (Erturon(R)) and flufenacet plus diflufenican (Herold(R)) under field conditions. Soils were amended with spent mushroom substrate (SMS) or green compost (GC). Soil microbial dehydrogenase activity (DHA), biomass and structure determined by the phospholipid fatty acid (PLFA) profiles were recorded at 0, 45, 145, 229 and 339 days after herbicide treatment.
The soil DHA values steadily decreased over time in the unamended soil treated with the herbicides, while microbial activity was constant in the amended soils. The amended soils recorded higher values of concentrations of PLFAs. Total soil microbial biomass decreased over time regardless of the organic amendment or the herbicide. Herbicide application sharply decreased the microbial population, with a significant modification of the microbial structure in the unamended soil. In contrast, no significant differences in microbial biomass and structure were detected in S + SMS and S + GC, untreated or treated with herbicides. The application of SMS and GC led to a significant shift in the soil microbial community regardless of the herbicides. The use of SMS and GC as organic amendments had a certain buffer effect on soil DHA and microbial biomass and structure after herbicide application due to the higher adsorption capacity of herbicides by the amended soils.

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## Microbial responses to selected pharmaceuticals in agricultural soils: Microcosm study on the roles of soil, treatment and time

**Authors:** Frkova Z, Vystavna Y, Koubova A

**Source:** SOIL BIOLOGY & BIOCHEMISTRY 149, 2020, DOI: 10.1016/j.soilbio.2020.107924

**Abstract:** Evaluating microbial responses to pharmaceuticals in agricultural soils is essential to improve our fundamental understanding of the fate of micropollutants and their potential implications for the environment and human health. In this study, we focused on the immediate (1 d), short- (13 d) and long-term effects (61 d) of pharmaceutical amendment on microbial communities in seven soils differing in physical chemical properties. Basal respiration was used to indicate microbial activity, while phospholipid fatty acids were used to determine

microbial biomass and community structure. We identified four microbial responses to pharmaceutical amendment: stimulation, inhibition, stress and dormancy, which were highly significant in the short-term. The largest stimulatory effect accompanied by shifts in the microbial community structure towards fungi and G- bacteria was detected for sulfamethoxazole. The inhibitory effect was mainly observed for citalopram, irbesartan and pharmaceutical mixture in Cambisol Dystric with minor alterations in microbial community structure compare to a non-amended control. The stress effect was detected for all pharmaceuticals in Arenosol and Cambisol Haplic. While the dormancy effect was mainly observed in Chernozem Siltic for most of the pharmaceuticals. Microbial responses were highly dependent on the soil type, pharmaceutical compound and time, highlighting the importance to consider these parameters including a resilience of soil microbial communities to micropollutants within a long-term agricultural soil management.

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## Impact assessment of heavy metals pollution in the air on bacterial microflora of elm trees

**Authors:** Sabourmoghaddam N, Shakery M

**Source:** CARPATHIAN JOURNAL OF EARTH AND ENVIRONMENTAL SCIENCES 15(1):87-92, 2020, DOI: 10.26471/cjees/2020/015/111

**Abstract:** Heavy metals are one of the most important environmental pollutants in all over the world. Heavy metals not only are seen in the soil and water but also can be found in the air. In recent years, the concentration of these metals has been increased in the atmosphere of many cities due to human activities. Examining the qualitative and quantitative changes of the endophyte microorganisms is one of the best markers to investigate the long-term impacts of these pollutants. This research was conducted in
order to identify the effect of cadmium, lead and mercury on the population of the endophyte bacteria inside the elm trees in Tabriz. The plant samples including leaf and stem were collected during two years (2015-2016) in two different regions of the city randomly and their endophyte bacteria were isolated. One of the selected sampling site was the central region of the city with the highest pollution and the other one was marginal with less pollution in Tabriz. The experiments showed that there was a significant difference between the bacterial micro flora in these two regions. While, in the elm trees of the marginal region with less pollution the dominated bacteria were Gram negative bacteria, mostly from Pseudomonas genus, though in the polluted area, Gram positive bacteria, particularly Actinomyces and Bacillus were dominated.

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Metal-induced bacterial
interactions promote
diversity in river-sediment
microbiomes

Authors: Cyriaque V, Geron A, Billon G and more
...

Source: FEMS MICROBIOLOGY ECOLOGY 96, 6, 2020, DOI: 10.1093/femsec/fiaa076

**Abstract:** Anthropogenic metal contamination results in long-term environmental selective pressure with unclear impacts on bacterial communities, which comprise key players in ecosystem functioning. Since metal contamination poses serious toxicity and bioaccumulation issues, assessing their impact on environmental microbiomes is important to respond to current environmental and health issues. Despite elevated metal concentrations, the river sedimentary microbiome near the MetalEurop foundry (France) shows unexpected higher diversity compared with the upstream control site. In this work, a follow-up of the microbial community assembly during a metal contamination event was performed in microcosms with periodic renewal of the

supernatant river water. Sediments of the control site were gradually exposed to a mixture of metals (Cd, Cu, Pb and Zn) in order to reach similar concentrations to MetalEurop sediments. Illumina sequencing of 16S rRNA gene amplicons was performed. Metal-resistant genes, czcA and pbrA, as well as IncP plasmid content, were assessed by quantitative PCR. The outcomes of this study support previous in situ observations showing that metals act as community assembly managers, increasing diversity. This work revealed progressive adaptation of the sediment microbiome through the selection of different metal-resistant mechanisms and cross-species interactions involving public good-providing bacteria co-occurring with the rest of the community.

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Responses of soil and
earthworm gut bacterial
communities to heavy metal
contamination

Authors: Liu P, Yang Y, Li M.

Source: ENVIRONMENTAL POLLUTION 265, B, 2020, DOI: 10.1016/j.envpol.2020.114921

**Abstract:** The large accumulation of heavy metals in the soil surrounding steel factories has become a severe environmental problem. However, few studies have focused on how the earthworm gut microbiota responds to heavy metals in the soil. This study used research sites at a steel factory in Nanjing, China, to investigate how the soil bacterial community and earthworm gut microbiota respond differently to heavy metal contamination using Illumina high-throughput sequencing targeting 16S rRNA genes. The bacterial community of earthworm guts showed a distinct structure compared with that of the soil, featuring a higher relative abundance of Proteobacteria (45.7%) and Bacteroidetes (18.8%). The bacterial community in the earthworm gut appeared more susceptible to heavy metal contamination compared with the soil community. For example, we identified 38
OTUs (Operational taxonomic units) significantly influenced by contamination among 186 abundant OTUs in the soil, whereas 63 out of the 127 abundant OTUs in the earthworm gut were altered significantly under contamination. This susceptibility may be partly explained by the lower alpha diversity and distinct microbial interactions in the gut. In addition, the accumulation of heavy metals also stimulated the growth of potential plant growth promoting bacteria (PGPB) in the earthworm gut, especially those related to indole-3-acetic acid (IAA) and 1-aminocyclopropane-1-carboxylic acid deaminase (ACCD) production, which may potentially benefit the phyto-remediation of heavy metals. These results contribute to our understanding of the soil biota and its interactions under heavy metal contamination and may provide further insights into the phytoremediation of metal-contaminated soil.

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# Ecological Effects of Heavy Metal Pollution on Soil Microbial Community Structure and Diversity on Both Sides of a River around a Mining Area

**Authors:** Zhao XQ, Huang J, Zhu XY and more ...

**Source:** INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 17, 16, 2020, DOI: 10.3390/ijerph17165680

**Abstract:** The objectives of this study were to understand the characteristics of heavy metal pollution caused by mining activities on the two sides of the Shun'an river and the response of soil microorganisms to the habitats by different contamination levels and vegetation. This paper selected soil samples from the banks of the Shun'an River near the Shizishan mining area, which is at the left of the river, in Tongling, Anhui Province, China. Using Illumina MiSeq 2500 technology, we analyzed the relationship between environmental factors and microbial

communities. As the distance from the mining area increased, the heavy metal comprehensive pollution and potential risk value decreased. Additionally, the pollution severity and risk value of the left bank, where the mining area lies, were generally higher than those of the right bank. Because the symmetric sampling points on both banks of the river had similar planting types, their environmental factors and microbial community structure were similar and clustered. However, under different vegetation, the paddy soils tended to have a higher nutrient content and community richness and diversity than the vegetable fields or the abandoned land. It was found that soil microbial communities in this area were mostly affected by pH and Nemerow pollution index (P-N). The pH significantly affected the abundance and structure of most microorganisms. In addition, Proteobacteria, Acidobacteria, and Bacteroidetes had significant tolerance to Zn, Pb, and Cd. By exploring the potential use of these tolerant microorganisms, we seek to provide strains and the theoretical basis for the bioremediation of areas contaminated by heavy metal.

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# The interaction of dissolved organic nitrogen removal and microbial abundance in iron-filings based green environmental media for stormwater treatment

**Authors:** Valencia A, Ordonez D, Wen D and more ...

**Source:** ENVIRONMENTAL RESEARCH 188, DOI: 10.1016/j.envres.2020.109815

**Abstract:** Nonpoint sources pollution from agricultural crop fields and urbanized regions oftentimes have elevated concentrations of dissolved organic nitrogen (DON) in stormwater runoff, which are difficult for microbial communities to decompose. The impact of elevated DON can be circumvented through the
use of green sorption media, such as Biosorption Activated Media (BAM) and Iron-Filing Green Environmental Media (IFGEM), which, as integral parts of microbial ecology, can contribute to the decomposition of DON. To compare the fate, transport, and transformation of DON in green sorption media relative to natural soil (control), a series of fixed-bed columns, which contain natural soil, BAM, and two types of IFGEM, respectively, were constructed to compare nutrient removal efficiency under three distinct stormwater influent conditions containing nitrogen and phosphorus. The interactions among six microbial species, including ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, complete ammonia oxidation (comammox) bacteria, anaerobic ammonium oxidation (anammox) bacteria, dissimilatory nitrate reduction to ammonium bacteria, and iron-reducing bacteria, were further analyzed from microbial ecology perspectives to determine the DON impact on nutrient removal in BAM and IFGEM. Natural soil was only able to achieve adequate DON transformation at the influent condition of lower nutrient concentration. However, the two types of IFGEM showed satisfactory nutrient removals and achieved greater transformation of DON relative to BAM when treating stormwater in all three influent conditions.

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## The response of soil and phyllosphere microbial communities to repeated application of the fungicide iprodione: accelerated biodegradation or toxicity?

**Authors:** Katsoula A, Vasileiadis S, Sapountzi M, Karpouzas DG

**Source:** FEMS MICROBIOLOGY ECOLOGY 96, 6, 2020, DOI: 10.1093/femsec/fiaa056

**Abstract:** Pesticides interact with microorganisms in various ways with the outcome

being negative or positive for the soil microbiota. Pesticides' effects on soil microorganisms have been studied extensively in soil but not in other pesticides-exposed microbial habitats like the phyllosphere. We tested the hypothesis that soil and phyllosphere support distinct microbial communities, but exhibit a similar response (accelerated biodegradation or toxicity) to repeated exposure to the fungicide iprodione. Pepper plants received four repeated foliage or soil applications of iprodione, which accelerated its degradation in soil (DT50_1st = 1.23 and DT50_4th = 0.48 days) and on plant leaves (DT50_1st &#62; 365 and DT50_4th = 5.95 days). The composition of the epiphytic and soil bacterial and fungal communities, determined by amplicon sequencing, was significantly altered by iprodione. The archaeal epiphytic and soil communities responded differently; the former showed no response to iprodione. Three iprodione-degrading Paenarthrobacter strains were isolated from soil and phyllosphere. They hydrolyzed iprodione to 3,5-dichloraniline via the formation of 3,5-dichlorophenyl-carboxiamide and 3,5-dichlorophenylurea-acetate, a pathway shared by other soil-derived arthrobacters implying a phylogenetic specialization in iprodione biotransformation. Our results suggest that iprodione-repeated application could affect soil and epiphytic microbial communities with implications for the homeostasis of the plant-soil system and agricultural production.

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## Effect of dibutyl phthalate on microbial function diversity and enzyme activity in wheat rhizosphere and non-rhizosphere soils

**Authors:** Gao ML, Dong YM, Zhang Z, Song ZG

**Source:** ENVIRONMENTAL POLLUTION 265, B, 2020, DOI: 10.1016/j.envpol.2020.114800

**Abstract:** The pollution of farm soils by the plasticizer dibutyl phthalate (DBP) should be
researched owing to the extensive use of plastic film. We investigated the influence of DBP on microbial communities and enzyme activities in rhizosphere and non-rhizosphere soil during the different growth stages of wheat and determined the response through simulations. The results indicated that protease, polyphenol oxidase, and beta-glucosidase activity in soil decreased with increasing DBP dosage, while dehydrogenase, urease, and acid phosphatase activities increased. Moreover, the effects of DBP on soil enzyme activity gradually weakened with DBP degradation. Dibutyl phthalate has a certain inhibitory effect on the activity, diversity, and heterogeneity of microorganisms in soil. In addition, DBP can increase the utilization of amines and carboxylic acids and decrease the utilization of carbohydrates and amino acids by soil microorganisms. According to the Gaussian and molecular docking analysis, we considered that monobutyl phthalate and DBP could affect the utilization of amino acids by Proteobacteria. The enzyme activity, microbial activity, and heterogeneity of rhizosphere soil were higher than those of non-rhizosphere soil. Microbial carbon source utilization in rhizosphere and non-rhizosphere soils depends on wheat growth, soil type, and DBP dosage. Owing to the widespread presence of DBP in agriculture, negative effects of phthalic acid esters should be considered in relation to soil quality and food safety in future.

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Levels of heavy metal concentrations and their effect on net nitrification rates and nitrifying archaea/bacteria in paddy soils of Bangladesh

**Authors:** Nahar K, Ali MM, Khanom A and more
...

**Source:** APPLIED SOIL ECOLOGY 156, 2020, DOI: 10.1016/j.apsoil.2020.103697

**Abstract:** Heavy metal concentrations (HMCs) may alter nitrification activity in soil. However, the levels of HMCs in paddy soil and the relations among HMCs, net nitrification rates, and nitrifying archaea/bacteria in paddy soils of Bangladesh remain unknown. The goal of this study was to determine the effect of HMCs on net nitrification rates and ammonia-oxidizing archaea (AOA) and bacteria (AOB), and nitrite-oxidizing bacteria (NOB) in paddy soils. HMCs and net nitrification rates were assayed through an atomic absorption spectrophotometer (AAS) and mass spectrophotometer (MS), respectively, and the abundance of AOA, AOB, and NOB was quantified by q-PCR. According to the contamination factor (C-f), concentrations of Cd were found to be a very severe pollutant in all soils. On the other hand, concentrations of Fe and Cu were found to be moderately contaminated and slightly polluted in paddy soils as compared to control soils. The net nitrification rates (8.67 to 12.75 mg kg(-1)h(-1)) and the abundance of AOA, AOB, and NOB were significantly higher (p &#60; 0.05) in the paddy soils than in the control soils. AOB, AOA, and NOB were correlated positively with net nitrification rates. The relations between net nitrification rates and HMCs (Fe, Pb, and Zn) were correlated significantly and positively (p &#60; 0.05), but the concentration of Cu was correlated negatively with net nitrification rates. To the best of our knowledge, this is the first report that has investigated the effects of HMCs on nitrifying bacteria in paddy soils, which will change the scenario of nitrification in Bangladesh greatly.

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Soil bacterial community response to long-term land use conversion in Yellow River Delta

**Authors:** He H, Miao YJ, Gan YD and more ...

**Source:** APPLIED SOIL ECOLOGY 156, 2020, DOI: 10.1016/j.apsoil.2020.103709
**Abstract:** Yellow River Delta undergoes intensive conversion from natural wetland to agricultural fields and artificial woodland. In this study, we analysed how the conversion affects bacterial community diversity and composition by Illumina Miseq sequencing combined with functional prediction. Compared to natural wetland, arable land and woodland were featured with higher soil organic matter, total nitrogen and bacterial diversity, but lower electrical conductivity. The bacteria Gemmatimonadetes related to soil organic matter and total nitrogen, was enriched in arable land, while salt-resistant bacteria (e.g. phylum Chloroflexi and its class Ardingicatenia) were abundant in natural wetland. Moreover, the relative abundances of the nitrifying bacteria Nitrospira and Nitrosospira were significantly higher in arable land and woodland than in natural wetland, suggesting that land use changes significantly affect the bacterial processes involved in nitrogen cycling. Redundancy analysis (RDA) showed that the differences in bacterial community were attributed to soil nutrient-related properties (i.e., total nitrogen and soil organic matter), soil salinity (i.e., electrical conductivity), and heavy metals (i.e. Cu and Cr). PICRUSt results revealed that land use conversion from natural wetland to arable land increased soil functions, e.g., biosynthesis process and oxidative phosphorylation. The data help us elucidate how land use changes affect terrestrial ecosystem function, and advise local farmers to apply the suitable land-use strategies and keep agricultural sustainable development.

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Elevated CO2 Affects the Soil Organic Carbon Fractions and Their Relation to Soil Microbial Properties in the Rhizosphere of *Robinia pseudoacacia* L. Seedlings in Cd-Contaminated Soils

Auithors: Huang SP, Huang XS, Fang B

Source: JOURNAL OF SOIL SCIENCE AND PLANT NUTRITION, 2020, DOI: 10.1007/s42729-020-00205-1

**Abstract:** As the global climates change, elevated CO2and soil contamination by heavy metal co-occur in natural ecosystems, which are anticipated to affect soil organic carbon fractions (SOC) and their relation to soil microbial activities, but this issue has not been extensively examined. We investigated the response of SOC and their relation with soil microorganisms and enzyme activities in rhizosphere soils ofRobinia pseudoacaciaL. seedlings to elevated CO2 plus cadmium (Cd) contamination. We found that elevated CO2 significantly (p < 0.05) stimulated total organic carbon (TOC) (8.6%), dissolved organic carbon (DOC) (32.6%), microbial biomass carbon (MBC) (13.5%), bacteria (11.6%), fungi (20.9%), actinomycetes (15.3%), urease (20.1%), dehydrogenase (15.8%), invertase (11.1%), and beta-glucosidase (11.9%), and DOC, MBC, bacteria, actinomycetes, urease, and invertase presented smaller growth trend in the range of 500-700 µmol mol(-1)CO2 than in the range of 385-500 µmol mol(-1)CO2. Cd decreased DOC (30.1%), MBC (24.9%), bacteria (21.5%), actinomycetes (15.9%), and enzyme activities. Elevated CO2 offsets the negative effect of Cd on SOC and microbial activities (except for TOC and L-asparaginase). Procrustes rotation test was used to determine the drivers (elevated CO2, Cd, and CO2 + Cd) of the relation between SOC and microbial activities, revealing the correlations between SOC, soil microorganisms, and enzyme activities were higher under elevated CO2 than under elevated CO2 + Cd. Our results suggest elevated CO2 could stimulate soil fertility and microecological cycle in the rhizosphere microenvironment exposed to heavy metal by affecting the relationship between SOC and soil microbial properties.

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A novel extracellular enzyme stoichiometry method to
evaluate soil heavy metal
contamination: Evidence
derived from microbial
metabolic limitation

Authors: Wang X, Cui YX, Zhang XC and more ...

Source: SCIENCE OF THE TOTAL ENVIRONMENT
738, 2020, DOI: 10.1016/j.scitotenv.2020.139709

**Abstract:** Heavy metal contaminates have become a significant threat to soil ecosystems due to their chronicity and universality in soil. Soil microbial metabolism plays a vital role in biogeochemical cycles and soil functions. However, the response of microbial metabolism to heavy metal contamination in soil remains elusive despite potentially offering important insight into the health and ecological consequences of soil ecosystems under such contamination. This study used extracellular enzyme stoichiometry models to identify the response of microbial metabolism to various heavy metal contaminants, while also revealing potential implications of heavy metal contaminates in soil ecosystems. Results showed that microbial metabolism was restricted by soil carbon (C) and phosphorus (P) within a heavy metal polluted area in Northwest China. Heavy metal stress significantly increased microbial C limitation while decreasing microbial P limitation. However, microbial C and P limitations both responded consistently to different heavy metals (i.e., Cd, Pb, Zn, and Cu). Heavy metals had the greatest effect on microbial C limitation (i.e., 0.720 of the total effects) compared to other soil properties, and soil with the lowest heavy metal concentration exhibited the lowest microbial C limitation, and vice versa. These results indicated that microbial metabolic limitation can robustly and sensitively reflect the degree of heavy metals pollution in soil. Additionally, increased microbial C limitation caused by heavy metal contaminants could potentially escalate C release by promoting soil C decomposition as well as increasing investments in enzyme production and the maintenance of metabolic processes. Consequently, potential C loss induced by heavy

metal pollution on soil eco-systems may be
extensive and significant. Generally, our results
suggest the usefulness of extracellular enzyme
stoichiometry as a new method from which to
evaluate heavy metal soil pollution, while
microbial metabolic limitation could potentially
be a promising indicator.

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Spatiotemporal vanadium
distribution in soils with
microbial community
 dynamics at vanadium
smelting site

Authors: Zhang H, Zhang BG, Wang S and more...

Source: ENVIRONMENTAL POLLUTION 265, PT A, A, 2020, DOI: 10.1016/j.envpol.2020.114782

**Abstract:** Whereas the adverse effects of vanadium released from smelting activities on soil microbial ecology have been widely recognized, little is known about spatiotemporal vanadium distribution and microbial community dynamics in typical contaminated sites. This study describes vanadium contents associated with health risk and microbial responses in both topsoil and subsoil during four consecutive seasons around an ongoing-production smelter in Panzhihua, China. Higher levels of vanadium concentration exceeding soil background value in China (82 mg/kg) were found close to the smelter. Vanadium concentrations decreased generally with the increase in distance to the smelter and depth below surface, as soil vanadium pollution is induced mainly by atmospheric deposition of vanadium bearing dust during smelting. Residual fraction was the predominated vanadium form in soils, with pronounced increase in bioavailable vanadium during rainfall period due to frequent drought-rewetting process. Topsoil close to the smelter exhibited significant contamination, inducing high probability of adverse health effects. Spatiotemporal vanadium distribution creates
filtering effects on soil microorganisms, promoting metal tolerant genera in topsoil (e.g. Microvirga) and subsoil (e.g. Bacillus, Geobacter), which is the key in maintaining the community structure by promoting cooperative relation with other taxa. Our results reveal spatiotemporal vanadium distribution in soils at site scale with potential health risk and microbial responses, which is helpful in identifying severe contamination and implementing bioremediation.

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# Analysis of Fungal Composition in Mine-Contaminated Soils in Hechi City

**Authors:** Ye FC, Gong DF, Pang CP and more ...

**Source:** CURRENT MICROBIOLOGY, 2020, DOI: 10.1007/s00284-020-02044-w

**Abstract:** Fungi play an important role in bioremediation of contaminated soil. However, the diversity of fungal populations in four mine-contaminated soils located in Hechi City has remained unexplored. In this study, high-throughput sequencing of ITS was performed to investigate the diversity and abundance of fungal communities in four mine-contaminated soils in Hechi city. Phylogenetic taxonomy showed that the fungal communities included five phyla. Ascomycota and Basidiomycotina were the most abundant phyla in four samples. The most abundant fungi included Agaricomycetes, Nectriaceae, Eurotiomycetes, Mortierellaceae, Incertae sedis, Trichocomaceae, Sordariomycetes, and Fusarium. Various fungi with the potential of bioremediation and industrial application were discussed. The results of fungal composition will provide a clue for isolation of new fungi with the potential of bioremediation and industrial application. Furthermore, this study will lay a good foundation for modifying the indigenous fungi by genetic engineering in the future.

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## Microbial remediation of micro-nano plastics: Current knowledge and future trends

**Authors:** Tiwari N., Santhiya D., Sharma J.G., 2020

**Sources:** Environmental Pollution 265, 2020, DOI: 10.1016/j.envpol.2020.115044

**Abstract:** An alarming rise of micro-nano plastics (MNPs) in environment is currently causing the biggest threat to biotic and abiotic components around the globe. These pollutants, apart from being formed through fragmentation of larger plastic pieces and are also manufactured for commercial usage. MNPs enter agro-ecosystem, wildlife, and human body through the food chain, ...

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ERA / PUBLICATIONS

SCIENTIFIQUES /

MICROBIOLOGIE ET

CONTAMINANTS /

Antibiotiques et
antibiorésistances

Modeling transport of
antibiotic resistant bacteria
in aquatic environment using
stochastic differential
equations

Authors: Gothwal R, Thatikonda S

Source: SCIENTIFIC REPORTS 10, 1, 2020, DOI: 10.1038/s41598-020-72106-3

**Abstract:** Contaminated sites are recognized as the "hotspot" for the development and spread of antibiotic resistance in environmental bacteria. It is very challenging to understand mechanism of development of antibiotic resistance in polluted environment in the presence of different anthropogenic pollutants. Uncertainties in the environmental processes adds complexity to the development of resistance. This study attempts to develop mathematical model by using stochastic partial differential equations for the transport of fluoroquinolone and its resistant bacteria in riverine environment. Poisson's process is assumed for the diffusion approximation in the stochastic partial differential equations (SPDE). Sensitive analysis is performed to evaluate the parameters and variables for their influence over the model outcome. Based on their sensitivity, the model parameters and variables are chosen and classified into environmental, demographic, and anthropogenic categories to investigate the sources of stochasticity. Stochastic partial differential equations are formulated for the state variables in the model. This SPDE model is then applied to the 100 km stretch of river Musi (South India) and simulations are carried out to assess the impact of stochasticity in model variables on the resistant bacteria population in sediments. By employing the stochasticity in model variables and parameters we came to know that environmental and anthropogenic variations are not able to affect the resistance dynamics at all. Demographic variations are able to affect the distribution of resistant bacteria population uniformly with standard deviation between 0.087 and 0.084, however, is not significant to have any biological relevance to it. ... This study is an ongoing effort to improve the model for the transport of antibiotics and transport of antibiotic resistant bacteria in

polluted river. There is a wide gap between the knowledge of stochastic resistant bacterial growth dynamics and the knowledge of transport of antibiotic resistance in polluted aquatic environment, this study is one step towards filling up that gap.

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Detection and Profiling of
Antibiotic Resistance among
Culturable Bacterial Isolates
in Vended Food and Soil
Samples

Authors: Muriuki SW, Neondo JO, Budambula NLM

Source: INTERNATIONAL JOURNAL OF MICROBIOLOGY, 2020, DOI: 10.1155/2020/6572693

**Abstract:** The emergence and persistence of antibiotic resistance remain formidable health challenges. This study aimed at detecting and profiling antibiotic resistance of bacterial contaminants in vended food and the environment. Seventy antibiotic-resistant bacterial isolates were isolated from fried fish, African sausages, roasted meat, smokies, samosa, chips (potato fries), vegetable salads, and soil samples collected from Embu Town and Kangaru Market in Embu County, Kenya. The antibiotic susceptibility test, morphological and biochemical characterization, antibiosis assay, polymerase chain reaction-based detection of antibiotic resistance genes, and sequencing of the 16S rRNA gene were done. Analysis of variance on all measured data was done, and Tukey's honest test was used to compare and separate mean diameters of zones inhibition. Resistance of bacterial isolates to antibiotics was chloramphenicol (90%), cefotaxime (84.29%), nalidixic acid (81.43%), tetracycline (77.14%), amoxicillin (72.86%), gentamycin (48.57%), streptomycin (32.86%), and trimethoprim + sulphamethoxazole (30%). Isolate KMP337, Salmonella spp., exhibited highly significant
antibiosis against S. aureus recording a mean inhibition diameter and standard error (SE) of 16.33 +/- 0.88 mm, respectively, at P = 0.001. The 70 bacterial isolates belonged to Bacillus, Paraclostridium, Lysinibacillus, Virgibacillus, and Serratia genera. The study isolated Bacillus wiedmannii (KC75) which is a risk group 2 as well as Serratia marcescens (KMP95) and Bacillus anthracis (KS606) which are risk group 3 organisms. +e presence of antibiotic resistance genes Tet A, (TEM)-T-Bla, StrB, Dfr A, Amp, and FloR genes was confirmed by a polymerase chain reaction. Samples from Kangaru Market recorded a higher (88.57%) proportion of resistant isolates as compared to isolates from Embu Town (11.43%). The study confirmed the presence of antibiotic-resistant bacteria in vended fast food and the soil in Embu Town and Kangaru Market. This study calls for continuous monitoring of bacterial status and hygienic handling of vended food.

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## High levels of antibiotic resistance genes and opportunistic pathogenic bacteria indicators in urban wild bird feces

**Authors:** Zhao HR, Sun RN, Yu PF, Alvarez PJ

**Source:** ENVIRONMENTAL POLLUTION 266, 2, 2020, DOI: 10.1016/j.envpol.2020.115200

**Abstract:** This study analyzed fresh feces from three common bird species that live in urban environments and interact with human communities. Antibiotic resistance genes (ARGs) encoding resistance to three major classes of antibiotics (i.e., tetracyclines, (beta-lactams, and sulfonamides) and the mobile genetic element integrase gene (intl1) were abundant (up to 10(9), 10(8), 10(9), and 10(10) copies/g dry feces for tetW, bla(TEM), sul1, andurpose, respectively), with relative concentrations surprisingly comparable to that in poultry and livestock that are occasionally fed antibiotics.

Biomarkers for opportunistic pathogens were also abundant (up to 10(7) copies/g dry feces) and the dominant isolates (i.e., Enterococcus spp. and Pseudomonas aeruginosa) harbored both ARGs and virulence genes. ARGs in bird feces followed first-order attenuation with half-lives ranging from 1.3 to 11.1 days in impacted soil. Although residual antibiotics were detected in the feces, no significant correlation was observed between fecal antibiotic concentrations and ARG relative abundance. Thus, other unaccounted factors likely contributed selective pressure for ARG maintenance. These findings highlight the contribution of wild urban bird feces to the maintenance and dissemination of ARGs, and the associated health risks.

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## Bacteriophages as antibiotic resistance genes carriers in agro-food systems

**Authors:** Jebri S, Rahmani F, Hmaied F

**Source:** JOURNAL OF APPLIED MICROBIOLOGY, 2020, DOI: 10.1111/jam.14851

**Abstract:** Antibiotic resistance genes (ARGs) are a global health concern. Antibiotic resistance occurs naturally, but misuse of antibiotics in humans and animals is accelerating the process of antibiotic resistance emergency, which has been aggravated by exposure to molecules of antibiotics present in clinical and agricultural settings and the engagement of many countries in water reuse especially in Middle East and North Africa region. Bacteriophages have the potential to be significant actors in ARGs transmission through the transduction process. These viruses have been detected along with ARGs in non impacted habitats and in anthropogenic impacted environments like wastewater, reclaimed water and manure amended soil as well as minimally processed food and ready to eat vegetables. The ubiquity of bacteriophages and their persistence in the environment raises concern about their involvement in ARGs transmission among