bluuebunny/crossref_metadata_2025 huggingface dataset:
Desulfovibrio desulfuricans growth kinetics
Authors: Herrera L. , Hernández J. , Ruiz P. , Gantenbein S.
Published: October 2006

Growth kinetics of Desulfovibrio desulfuricans, strain NCIMB 9467, was studied in laboratory scale, under well‐controlled batch conditions. This research is oriented toward the practical, industrial removal of sulfate and metal ions from mine water. Growth of the microorganism in such waters was verified.

From 290 experimental observations of sulfate and lactate (obtained from 145 culture tubes of 20 mL) the parameters of a Monod model were estimated. Inoculum mass was not measured but it was incorporated as another model parameter. Hydrogen sulfide was removed by addition of ferrous iron, which rapidly formed iron sulfide and precipitated toward the bottom of the culture tube. Parameters were estimated by a nonlinear least squares parameter minimizer. The growth‐limiting substrate was the sulfate concentration. Under these conditions the growth of Desulfovibrio desulfuricans was characterized by a maximum growth rate of 25 · 10−3 h−1, a sulfate affinity constant of 850 mg L, and a reduced sulfate yield of 6.2 · 10−3 (biomass per sulfate mass). Inoculum was 1.97 mg of bacteria/L and the consumption of lactate was characterized by a yield of 2.5 · 10−2 (biomass per lactate mass). Sulfate was reduced at a rate of 400 mg/L/day while lactate was oxidized at a rate of 1100 mg/L/day.

Mine wastewater was used as sulfate source and complemented with lactate as the carbon source. Under these conditions the strain growth was similar to that obtained with the controlled media. It was concluded that no inhibitory effects exist. The reduction velocity obtained, 200 mg/L/day, was lower than before, probably due to inoculum size or strain adaptation.

A novel process is proposed to produce solid sulfur from sulfate and sulfur oxides.
Characterization of aerobic heterotrophic bacteria isolated from marshes
Authors: Horsnell G. E. , Young M. , Pagel J. E. , Desjardins R. M. , Seyfried P. L.
Published: October 2006

An organized approach, requiring a minimum number of tests, is presented for the relatively rapid identification of a wide range of aerobic heterotrophic bacteria found in freshwater. Bacterial isolates were identified to the genus level and many strains could be identified to the species level with the appropriate use of commercially available bacterial identification panels.

Bacteria were separated into four groups based on gram reaction, motility, cell shape and arrangement, spore and pigment production, catalase, oxidase, and O/F glucose tests. Further identification was based on selected tests for each group.

Over 95% of the 800 aerobic heterotrophic bacteria isolated from Ontario marshes were identified using the procedures outlined.
Regulatory influence of light and temperature on petroleum toxicity to Anabaena doliolum
Authors: Gaur J. P. , Singh A. K.
Published: October 2006

Effects of light and temperature, the most important variables in natural environments, on the toxicity of Assam crude oil extract were examined. Illumination of oil extract increased the degree of inhibition of growth, photosynthesis, and respiration of Anabaena doliolum. Higher light intensities were more effective in inhibiting the test organism. This may result from the formation of highly toxic photooxidation products. The toxicity of oil extract also showed an increase with increase in temperature, even though it might be envisioned that elevated temperature would facilitate the loss of highly toxic volatile fractions. It is possible, therefore, that the toxic effects of petroleum might be more severe in tropical than in temperate climates.
Ecological effects testing under the Toxic Substances Control Act: Acrylamide
Authors: Walker John D.
Published: October 2006

Analysis of acrylamide aquatic toxicity data submitted under section 4 of the Toxic Substances Control Act revealed that for acute toxicity studies with bluegill, fathead minnow, and rainbow trout, concentrations of acrylamide necessary to produce 50% mortality decreased by 50‐70% as a function of increasing exposure from 1 to 4 days. Analysis of acute toxicity data for Mysidopsis bahia suggested that increases in mortality with increased exposure to acrylamide might also be observed in saltwater organisms. Ratios of acute (4‐day) LC50 values to chronic (28‐day) maximum acceptable toxic concentrations for this saltwater invertebrate were 26 for parent and offspring survival, 115 for female dry weights, and 975 for male dry weights. These ratios illustrate that long‐term acrylamide exposure to sensitive life stages of M. bahia produced adverse effects on reproduction and growth at acrylamide concentrations significantly lower than those suggested by acute LC50 or EC50 values.
Microtesting appraisal of ATP and cell recovery toxicity end points after acute exposure of Selenastrum capricornutum to selected chemicals
Authors: Hickey C. W. , Blaise C. , Costan G.
Published: October 2006

Employing microtesting procedures, intracellular ATP and cell recovery (96‐h cell count determinations) were appraised as toxicity end‐point responses after acute (4‐h) exposure of the green alga Selenastrum capricornutum to metals (Cu2+, Co2+, Cd2‐, Cr3+, Cr6+, Ni2+, Hg2+, Zn2+, B3+), sodium azide, and 4 organic compounds (sodium dodecyl sulphate, 2,4‐dichlorophenol, phenol, tebuthiuron). Except for B3‐, both end points were able to measure acute metal phytotoxicity effects at concentrations of 5 mg · L−1 or lower. The algal recovery test showed better metal toxicity discrimination than the ATP test on the basis of dose—response slope steepness and elevation differences. Both tests, however, supplied useful complementary information. While the ATP test reacted rapidly to chemical aggression, the recovery test offered pertinent insight into actual long‐term consequences of acute exposure. With the nonmetals, both end‐point responses were mitigated (sodium azide, sodium dodecyl sulphate, 2,4‐dichlorophenol) or insensitive (phenol, tebuthiuron), suggesting low acute exposure risk to algae by these chemicals. Based on 4‐h (ATP and cell recovery) EC50 to standard 96‐h EC50 ratio values, the algal indicator was shown to have low tolerance to 6 chemicals (Cr3+, Cr6+, Hg2‐, Cu2+, sodium dodecyl sulphate, 2,4‐dichlorophenol). When compared to acute exposure bacterial assays, the acute exposure ATP and cell recovery microtests competed well in terms of overall sensitivity to a selection of chemicals. In general, this work demonstrates the utility that short‐term algal exposure tests can provide for chemical toxicity investigations.
Acute toxicity of Phytolacca dodecandra (Endod‐S) and Niclosamide to snails, Schistosoma mansoni cercaria, Tilapia fish, and soil microorganisms
Authors: Monkiedje Adolphe , Anderson Ann C. , Englande A. J.
Published: October 2006

The acute toxicity of two molluscicides, the extract of the plant Phytolacca dodecandra (Endod‐S) and Niclosamide, was determined using the following test species: The snails Biomphalaria glabrata (albino) and Biomphalaria pfeifferi, Schistosoma mansoni cercaria, and Tilapia nilotica fish. Endod‐S showed a 24‐h LC50 of 2.57 and 5.37 mg/L for B. glabrata (albino) and B. pfeifferi respectively. Niclosamide produced a 24‐h LC50 of 0.063 mg/L and 0.049 mg/L for B. glabrata (albino) and B. pfeifferi, respectively. The 4‐h LC50 for S. mansoni cercaria was 2.92 mg/L for Endod‐S and 0.0008 mg/L for Niclosamide. The 24‐h LC50 for Tilapia nilotica was 1.82 mg/L for Endod‐S and 0.21 mg/L for Niclosamide. The toxicity of Endod‐S and Niclosamide to a mixed population of soil microorganisms was measured using oxygen uptake and growth as measured by turbidity. Endod‐S was not toxic to the microorganisms. The average Niclosamide toxic end point (IC50) for these bacteria was 450 mg/L.
Wastewater upgrading as measured by coliphage
Authors: Kott Yehuda
Published: October 2006

Bacterial viruses are prevalent in nature. The coliphage counts in any wastewater sample might show very significant diversity in numbers, due to use of various Escherichia coli strains. In this study coliphage (E. coli B host) coliform, fecal coliform, and fecal streptococci densities were estimated from chlorinated secondary effluent being carried in a 30‐km long pipeline. Comparison of die‐off of the various indicators was performed between controlled and uncontrolled chlorination at slow and fast flow in the pipe. In addition, a swab technique was applied from which a rough estimation of the ratios of coliphage to the other indicators could be made, as well as coliphage to salmonella ratio. The results showed that there was a decrease in coliphage number at higher levels of chlorine residual, and wherever aftergrowth of coliform occurred, the number of coliphage did not change.
Genotoxicity of hazardous leachates from solid wastes evaluated for environmental impact with the ames test
Authors: Bessi H. , Ferard J. F. , Vasseur P. , Colin F. , Belkhadir E.
Published: October 2006

Fourteen series of toxic wastes from various origins (metallurgy, chemical industries, incinerators, industrial treatment plants, etc.) have been studied for their genotoxic properties with the Salmonella reversion assay. To consider realism of environmental impact, a strategy is proposed to assess genotoxicity of the water‐soluble fraction of the wastes. Water‐extractable micropollutants were further concentrated by liquid–liquid extraction or lyophilization prior to genotoxicity testing.

None of the 14 crude aqueous fractions was shown to be mutagenic. On the contrary, positive responses were registered on the concentrated phases of two solid wastes derived from one chemical industry and from the treatment of organophosphorus wastewaters. Chemical analysis did not reveal the presence of known mutagens in the positive extracts. Interacting effects between micropollutants is thus hypothesized to explain genotoxicity.
Biodegradation of pentachlorophenol by micromycetes. I. Zygomycetes
Authors: Seigle‐Murandi Francoise , Steiman Regine , Benoit‐Guyod Jean‐Louis , Guiraud Pascale
Published: October 2006

A study of the biodegradation of pentachlorophenol (PCP) (100 mg/L) by 70 strains of Zygomycetes cultivated in liquid synthetic medium showed that most strains were able to degrade it extensively, except some from the genera Circinella, Mortierella, Mucor, and Spinellus. The most consistently effective genera were Absidia (degradation 69–88%) and Cunninghamella (degradation 62–90%). Much more scattered results were found with the genera Mortierella (degradation 0–67%), Mucor (degradation 18–86%), and Rhizopus (degradation 45–91%). The production of extracellular phenoloxidases was examined on solid media. Most of the strains were devoid of any phenoloxidase activity. The biodegradation of PCP did not depend on the presence of phenoloxidases since strains with a high level of phenoloxidases did not degrade PCP and the best degradation was obtained with strains devoid of phenoloxidases. Another mechanism must be proposed to explain the high biodegradation potential of Zygomycetes for PCP.
Effect of test conditions and interfering factors on sensitivity of bacterial tests based on inhibition of growth and motility
Authors: Süssmuth R. , Lenz P. , Müller D.
Published: October 2006

The effect of test conditions on the sensitivity of the swarming activity of Proteus mirabilis and Azospirillum brasilense, of the cup plate assay (Bacillus thuringiensis), and of a cell counting assay in liquid medium using a Coulter Counter (B. thuringiensis) was studied. Tested substances were pesticides, mycotoxins, lactones, and anhydrides. Sensitivity was increased by cell counting (up to 1000‐fold), by variation of nutrient concentration and pH in the culture medium, by density of inoculum, by preincubation at 4 or 44°C, by incubation with a detergent, and by the use of sensitive mutants. Interferences were exerted by certain substances and toxin mixtures. They included synergistic and antagonistic effects as well as oscillations, e.g., concentration‐dependent activation and inactivation. © 1992 John Wiley & sons, Inc.
Resistance to antibiotics and heavy metals in escherichia coli from marine fish
Authors: Alves De Lima E Silva Agostinho , Hofer Ernesto
Published: October 2006

Escherichia coli isolated from the intestinal tract of marine fish captured along polluted beaches of the city of Rio de Janeiro, Brazil, were investigated in terms of resistance to seven antibiotics and to four heavy metals. Approximately 40% of the strains were resistant to one or more antibiotics, with predominance of mono‐ and biresistance. Overall resistance to heavy metals was 70.7%, and exclusive resistance to these elements was more elevated than resistance to antibiotics only. Resistance to mercury was closely associated with resistance to antibiotics and with multiple resistance in particular. Most of the strains analyzed transferred resistance determinants to standard receptor strains during conjugation, the phenomenon being particularly outstanding for the transfer of the copper marker. The epidemiological and ecological aspects of the results obtained are discussed. © 1993 John Wiley & Sons, Inc.
Virulence characteristics of heterotrophic bacteria commonly isolated from potable water
Authors: Lye Dennis J. , Dufour Alfred P.
Published: October 2006

Heterotrophic bacteria isolated from drinking water distribution systems were examined to determine if they possessed putative virulence factors such as hemolysins, proteases, or cytotoxins. Representative samples of colonies from several different distribution systems indicated that the median percentage of heterotrophic bacteria having at least one putative virulence characteristic was about 11% and all of the samples contained bacteria expressing at least one putative virulence characteristic. The overall frequency of bacteria from drinking water distribution samples expressing more than one putative virulence factor ranged from 0 to 8%. The eukaryotic cell culture cytotoxicity test appeared to be the most reliable indicator of those bacteria expressing multiple virulence factors. The results also indicated that the expression of putative virulence factors was highly dependent upon the type of isolation medium used. Although slow‐growing heterotrophic bacteria occurred at high densities in certain systems, they expressed very few of the putative virulence factors observed in this study. © 1993 John Wiley & Sons, Inc.
Sensitivity of planktonic photosynthesis to various toxicants in the river rhine
Authors: Tubbing Diny M. J. , De Ruyter Van Steveninck Erik D. , Admiraal Wim
Published: October 2006

Natural populations of phytoplankton from the lower River Rhine were exposed to selected pollutants in order to estimate their sensitivity to chemical pollution. The photosynthesis, measured as 14C incorporation, was inhibited by 50% when circa 100 μg · L−1 copper or atrazine was added. Potassium dichromate (K2Cr2O7) and an anionic detergent (tetrapropylbenzenesulphonate) affected the photosynthesis of Rhine phytoplankton only at concentrations of about 3 and 40 mg L−1, respectively. A tenfold concentrate of the organic compounds from river water, harvested on XAD resin, inhibited the photosynthesis by 50%. Comparison of the results of this study with literature data indicate that the algal populations in the River Rhine are as sensitive and not more tolerant than several algae from less polluted habitats. These observations on the Rhine plankton also indicate that the pollution level in the River Rhine is likely to affect the photosynthesis of phytoplankton. This supports the request for a further reduction in toxicant input in the River Rhine. © 1993 John Wiley & Sons, Inc.
Potential ecotoxic effects probe (PEEP): A novel index to assess and compare the toxic potential of industrial effluents
Authors: Costan G. , Bermingham N. , Blaise C. , Ferard J. F.
Published: October 2006

An index allowing the assessment and comparison of the toxic potential of industrial effluents is described. Integrating the results of practical small‐scale screening bioassays (Photobacterium phosphoreum Microtox® test. Selenastrum capricornutum growth inhibition microtest, Ceriodaphnia dubia lethality and reproduction inhibition tests, Escherichia coli genotoxicity SOS Chromotest), this index takes into account persistence of toxicity, (multi) specificity of toxic impact, as well as effluent flow. The resulting Potential Ecotoxic Effects Probe (PEEP) index number is reflected by a log10 value that varies from 0 to infinity but normally will not surpass a value of 10. The structure of the mathematical formula generating PEEP values is simple and “user friendly” in that it can accommodate numbers and types of bioassays to fit particular needs. Thirty‐seven effluents from 8 industrial sectors (pulp and paper, petroleum refining, inorganic/organic chemical production, mining, metallurgy, metal plating, textile production) were appraised and compared with the proposed PEEP scale. The pulp and paper sector effluents (n = 15) markedly stood out from the others owing to their greater toxicity and higher discharge volume, with reported PEEP values lying between 4.4 and 7.5. For most of these effluents, toxicity was found to be persistent, multitrophic (i.e., affecting our bacterial, algal, and crustacean bioindicators), and it expressed itself at all levels of assessment (i.e., lethal, acute sublethal, chronic sublethal, and genotoxic levels). The usefulness of the PEEP index in the environmental management of industrial effluent toxicity is discussed herein. © 1993 John Wiley & Sons, Inc.
Biological and chemical aspects of differences in sensitivity of natural populations of aquatic bacterial communities exposed to copper
Authors: Tubbing Diny M. J. , Santhagens Linda‐Rose , Admiraal Wim , Van Beelen Patrick
Published: October 2006

Bacterial populations from the main stream of the River Rhine and its plume in the North Sea, the lower course of the rivers Meuse and Scheldt, and various stagnant waters in the Netherlands were exposed to additions of copper in order to analyze differences in sensitivity. Growth rate, measured as thymidine incorporation rate, was generally more sensitive to copper (EC50: 25–310 μg · L−1) than extracellular phosphatase activity, measured as hydrolysis of methylumbelliferin phosphate (EC50: 179–3000 μgl−1). The EC50 value for copper‐inhibited growth was correlated with the ambient total copper concentration, but such a correlation was not evident for copper‐inhibited enzymatic activity. Differences in capacity of the waters to chelate an addition of 1000 μg L·−1 of copper were estimated by measuring the inhibition of Photobacterium phosphoreum in the Microtox test. The growth rate of bacteria in the upper, middle, and lower courses of the Rhine showed an increasing tolerance to copper, concurrent with increased input of copper and increasing concentrations of suspended matter in the river. It is indicated in this study that part of the differences in sensitivity of bacterial communities is caused by the chemical conditions (i.e., by complexation), but biological differences in tolerance to copper, possibly induced by pollution, were also indicated. © 1993 John Wiley & Sons, Inc.
Direct toxicity assessment of solid phase samples using the toxi‐chromotest kit
Authors: Kwan K. K.
Published: October 2006

Toxicity screening of sediments, suspended sediments, soils, and solid wastes is becoming increasingly important in environmental studies. To date toxicity testing of sediments, suspended sediments, soils, and solid wastes has almost always been performed on exudates, water, and/or solvent extracts. These procedures are often complicated, labor intensive, and expensive. This report describes a simple, quick, inexpensive qualitative/ semiquantitative direct sediment/solid phase toxicity testing procedure (DSTTP) using the Toxi‐Chromotest kit. This procedure only requires the use of a balance, vortex mixer, and a 37°C incubator, and can easily be used under field conditions. The DSTTP measures the available toxicants of the test sediments, suspended sediments, soils, and any other solid wastes without altering the original characteristics of the samples as occurs in extraction and concentration procedures. © 1993 John Wiley & Sons, Inc.
Water quality of the river nile. III. Toxicity assessment of six industrial effluents polluting the river nile
Authors: Abdel‐Hamid Mohammad I. , Shaaban‐Dessouki Sami A. , Skulberg Olav M.
Published: October 2006

Six different industrial effluents were chemically and physically characterized. Their toxicity was evaluated using biotests with Selenastrum capricornutum strain NIVA‐CHL1. The growth of the test alga showed either inhibition or stimulation. Two of the effluents were highly inhibitory with EC50 values ranging between 1 and 10% (v/v) effluent concentrations. Others showed low growth inhibitory effects (50% < EC50 < 100%). EC50 values derived from the growth parameters, algal dry weight, cell count, growth rate, and area under the growth curve were almost similar for those two effluents exhibiting highly inhibitory effects. The toxicity values, calculated from algal dry weight and cell count showed, a strong positive linear relationship (r = 0.97 at p < 0.0001). The potential toxicity of some effluents was partly related to their high content of heavy metals. Changes in mean cell volume of the test alga may be used as an indicator for the potential effects of toxic effluents on the overall cellular activities. The results emphasized the indispensable role of algal bioassays among the basis of relevant and quantitative information about the biological impacts of the investigated effluents on the receiving waters. © 1993 John Wiley & Sons, Inc.
Interactive toxic effect and bioconcentration between cadmium and chromium using continuous algal culture
Authors: Aoyama Isao , Okamura Hideo
Published: October 2006

Numerous studies have been conducted on the effects of toxic chemicals using algal batch culture. On the other hand, continuous culture research has the advantage of allowing optimal cell growth. Few studies on the interactive toxic effect between chemicals have been carried out either with batch culture or with continuous culture. The purpose of this study is to find the relationship between interactive toxic effects and the bioconcentration of heavy metals using continuous algal culture. The green alga Chlorella ellipsoidea was used as a test organism. As test substances cadmium and chromium were used.

The amount of heavy metals both in algae and in the medium was determined after the cells had been exposed to heavy metals for 10 days. The amount of Cd taken up in the cells and the growth inhibition rates caused by Cd increased as the concentration of Cd in the medium became higher. The inhibition rates rose drastically but the amount of Cd in the cells remained at almost the same level even if Cr was added. The bioconcentration factors of Cd were ca. 10,000 in all the cases tested, regardless of the presence of Cr. The amount of Cr in the cell exposed to Cr was low, while that amount and the growth inhibition rates for all the concentrations tested increased when Cd was added to the medium containing Cr. The bioconcentration factors of Cr reached 156,000 as the concentration of Cd in the medium increased. It seems that the toxicity of Cr was enhanced because the presence of Cd in the medium raised the amount of Cr in the cell. © 1993 John Wiley & Sons, Inc.
Biodegradation of pentachlorophenol by micromycetes. II. Ascomycetes, basidiomycetes, and yeasts
Authors: Steiman Regine , Benoit‐Guyod Jean‐Louis , Seigle‐Murandi Françoise , Sage Lucile , Toe Adama
Published: October 2006

Following a previous study on the biodegradation of pentachlorophenol (PCP) (100 mg L−1) by Zygomycetes, other taxonomic groups (Ascomycetes, Basidiomycetes, and Yeasts) have been investigated in relation to their ability to produce extracellular phenoloxidases. Ascomycetes gave heterogeneous results since disappearance of PCP occurred both in phenoloxidases‐producing and non‐producing strains. Basidiomycetes were high producers of phenoloxidases and showed a moderate depletion of PCP. Yeasts degraded PCP very poorly and did not produce phenoloxidases. No correlation was found between phenoloxidases production and PCP depletion. © 1994 by John Wiley & Sons, Inc..
Semiautomated fluorometric analysis of nucleic acids in tissue homogenates
Authors: Nacci Diane , Cheer Sue , Jackim Eugene , Juinio Annette
Published: October 2006

This report describes a technique that was developed to provide an efficient and accurate estimation of RNA:DNA ratios. These ratios have been used as an instantaneous measure of recent growth of individual aquatic organisms where morphometrics are not appropriate (e.g., field‐collected species) or insufficiently sensitive (e.g., small life stages or species). In this semiautomated, sensitive method, ethidium bromide fluorescence was used to quantitate total nucleic acids in crude homogenates. Individual concentrations of RNA and DNA were determined by differences in fluorescence before and after elimination of RNA by digestion with RNase. Efficiency of the procedure was enhanced using a computer‐driven multiwell plate scanning system (CYTOFLUOR, Millipore Corporation

Reference to trade names does not imply endorsement.

) to measure fluorescence at timed intervals and perform data manipulations. Routinely, detection limits of 0.1 μg DNA and 0.4 μg RNA were achieved, allowing the analysis of small, individual organisms. Fluorescence results of split samples were comparable with those obtained using a standard spectro‐photometric method to quantitate nucleic acids. Coefficients of variation for replicate samples within an assay (1.6%) and for samples within replicate assays (5.6%) indicated good test reproducibility. Quantitative recoveries of nucleic acid standards spiked into tissue homogenates were generally high, averaging 91.0% for DNA and 119.0% for RNA. Factors affecting the fluorescence of ethidium bromide stained nucleic acids—e.g., nucleic acid source, crude homogenate components, and buffer composition—are discussed relative to assay performance. This method provides a rapid and reliable assessment of individual growth, an important sublethal toxicological end point, that is suitable for both laboratory and field studies. © 1994 by John Wiley & Sons, Inc..
Cytotoxicity of metals toward rainbow trout R1 cell line
Authors: Segner Helmut , Lenz Dietmar , Hanke Wilfried , Schüürmann Gerrit
Published: October 2006

Cultured fish cells are of potential use in the initial screening of the adverse effects of aquatic pollutants. In the present study, R1 cells, a fibroblast‐like cell line derived from liver tissue of rainbow trout (Oncorhynchus mykiss), were exposed to 13 metal salts. Cytotoxicity was assessed by the neutral red uptake inhibition test. The rank order of cytotoxicity for the cationic metals was silver > mercury > cadmium > zinc > copper > nickel > lead; for the anionic metal complexes it was arsenite > dichromate > chromate > arsenate > selenite > permanganate > selenate. Metal cytotoxicity toward R1 cells showed close correlation with the cytotoxicity values of metals toward the BF‐2 cell line from bluegill sunfish (r = 0.98). For the divalent cations, cytotoxicity correlated well with the physicochemical softness parameter σp (r = 0.93). Correlation coefficients between the in vitro toxicity of cationic metals and their in vivo LC50 data varied for different fish species, with r values from r = 0.64 to r = 0.92. The in vitro cytotoxicity of anionic metal complexes was not related with their acute in vivo toxicity. © 1994 by John Wiley & Sons, Inc..
Aquatic field studies in ecotoxicological assessment of hazardous substances
Authors: Kussatz Carola
Published: October 2006

The role of field tests for chemical management must not be overestimated. Results obtained from multi species tests in the field indisputably give valuable information on the fate of a substance that facilitates the assessment of results from laboratory tests provided the test design is orientated on the appropriate formulation of question.

If those investigations are available, they are included in the assessment of substances. These may increase the uncertainty factor, but this can only be a critical case‐by‐case decision.

The investigations, however, have to satisfy certain minimum requirements:

—examination of several test concentrations and untreated controls, proof of a dose–effect relationship, ability to derive the NOEC;

—exposure of several taxonomic groups over a longer period;

—analytical control of the test concentration during the experiment;

—equivalent development of controls, ability to repeat the experiments under different starting conditions; and

—use of aquatic ecological parameters as toxicological end points.

Independently of these requirements, the necessity of validation does in principle exist. © 1994 by John Wiley & Sons, Inc..
Inhibition of the biological self‐purification by chlorophenols, sodium dodecyl sulfate, and the complexing agents ethylenediaminetetraacetic acid and nitrilotriacetic acid
Authors: Weßler Adelheid , Obst Ursula
Published: October 2006

The determination of enzymatic activities in surface water allows the control of the biological selfpurification as well as being an indicator for microbial degradation of xenobiotics. As for this matter it is a good instrument for controlling alterations in the ecosystem. Inhibition of enzymatic activities (esterases, β‐glucosidases, and alanin‐aminopeptidases) were analyzed using linear dilution of the water under test, then correlating the resulting enzyme activities of each dilution step and the concentration of the sample. Because of the complex matrix of surface water, chemical analysis of inhibiting substances has been and still is very difficult. A characterization of these substances is therefore only possible by pretreatment of the samples. In order to simulate definite inhibition effects, surface water was spiked with 2‐chlorophenol and 4‐chlorophenol, as well as with the surfactant sodium dodecyl sulfate and the complex agents ethylenediaminetetraacetic acid and nitrilotriacetic acid. The simulated inhibition effects on the enzyme activities were characterized closely by an additional pretreatment of the water under test. The elimination of the inhibiting substances by adsorption on water‐insoluble polyvinylpyrrolidone or activated carbon and the reduction of the inhibitory effect on the enzyme activities were investigated. The oxidation of inhibiting chemicals using stripping or treatment with H2O2 was also found to be a reliable method to diminish the inhibitory effects on the enzymatic activities. © 1994 by John Wiley & Sons, Inc..
Comparison of standard most probable number method with three alternate tests for detection of bacteriological water quality indicators
Authors: Ramteke Pramod W.
Published: October 2006

The standard most probable number (MPN) method for the detection of total and fecal coliforms was compared with three simple microbial tests: H2S paper strip test, Presence‐absence (P‐A) test for coliforms using MacConkey broth (PA‐TC), and P‐A test for fecal streptococci using KF streptococcal broth (PA‐FS) in 187 samples of water from three districts of Indian state of Jammu and Kashmir: Doda, Udhampur, and Jammu. All three tests were comparable with the standard MPN method. However, the PA‐FS and H2S tests were found more sensitive in the detection of indicator organisms. Four hundred and fifty eight cultures obtained from positive tests were identified in order to evaluate the specificities of tests used in detection of coliform indicators. The low incidence of recovery of Escherichia coli (16–34%) for the standard MPN method places doubt on the validity of its application in tropical areas. In view of this, the need for relaxed standards of water quality in tropical areas is discussed. From the results reported here it appears that the combination of the PA‐FS and H2S test could be used as a suitable multiple test to assess the microbiological quality of drinking water in India and other tropical countries. © by John Wiley & Sons, Inc.
Coliphages as a rapid indicator of sequencing batch reactor (SBR) treatment performance
Authors: Sim T. S. , Ng W. J. , Ong S. L. , Ng K. Y. , Ramasamy M. , Tan K. N.
Published: October 2006

Generally, conventional tests for total and fecal coliforms take from 1 to 4 days before the results are available. In contrast, the coliphage method is a simple, rapid, economical, and reliable method that has been used as an additional indicator of potential pathogens whereby coliform numbers present in natural waters can be estimated within 6–24 h. In this pilot‐scale study, besides demonstrating that the 6‐h coliphage test may be used to evaluate sequencing batch reactor (SBR) treatment efficiency (up to 99% removal), predictions of coliform numbers were made by enumeration of the coliphages. Coliform–coliphage correlationships similar to that for natural water (as proposed by the American Public Health Association's Standard Methods, 1989) and SBR treated domestic sewage have been developed for SBR treated combined sewage:

where TC is total coliforms/100 mL and P is the coliphages/100 mL, and

where FC is fecal coliforms/100 mL and P is coliphages/100 mL. Comparison between the logarithm of coliphages after 24 h incubation with the logarithm of coliphages after 6 h incubation yielded correlation coefficients of at least 0.91 suggesting that the 6 h coliphage detection test is sufficient for use as a rapid test and may be correlated to coliform numbers in sewage. © by John Wiley & Sons, Inc.
Cyst‐based toxicity tests. IX. The potential of Thamnocephalus platyurus as test species in comparison with Streptocephalus proboscideus (crustacea: Branchiopoda: Anostraca)
Authors: Centeno Maria Dulce F. , Persoone Guido , Goyvaerts Marie Pierre
Published: October 2006

The potential of the larvae of the freshwater anostracan crustacean Thamnocephalus platyurus has been evaluated as an alternative to those of the related species Streptocephalus proboscideus, used so far as the test organism in the standard Streptoxkit F test. In line with the former cyst‐based toxicity test method, the hatching of dried T. platyurus eggs, the molting of larvae, and the sensitivity of the latter to toxicants were assessed. The acute toxicity of 10 pure chemicals, 4 solid waste leachates, and 5 sediment pore waters to T. platyurus nauplii was determined according to the standard Streptoxkit F test protocol. Hatching success and reliability of T. platyurus cysts proved better than that of S. proboscideus cysts after 20 h incubation in standard conditions; the hatching percentage after 24 h was slightly improved by diluting the Environmental Protection Agency medium to 1:8 with deionized water. The sensitivity of T. platyurus nauplii to pure toxicants and wastes was at least equal to, and in many cases even higher than, that of S. proboscideus larvae. Generally, precision of the toxicity tests with T. platyurus was better than that of the S. proboscideus assay, especially for the pure chemicals tested. Consequently, the standard operational testing protocol of the Streptoxkit F has been slightly modified with replacement of S. proboscideus by T. platyurus as a test species. The Streptoxkit F has consequently been renamed to Thamnotoxkit F for use in cost‐effective routine acute toxicity testing of chemicals and wastes. © by John Wiley & Sons, Inc.
Use of four microbial tests to assess the ecotoxicological hazard of contaminated sediments
Authors: Ross Philippe E. , Henebry Michael S.
Published: October 2006

Three single‐species bioassays (Microtox, Selenastrum capricornutum, and Panagrellus redivivus) and a test using microbial communities developed on artificial substrates were used in a series of in situ and laboratory tests evaluating the ecotoxicological hazard of contaminated sediments at two sites on Lake Michigan: Waukegan (Illinois) Harbor and The Chicago Area Confined Disposal Facility Study. In the single‐species tests, exposure to elutriates of contaminated sediments significantly inhibited bacterial luminescence, algal photosynthesis, and nematode survival and growth at polluted stations, while elutriates from control stations did not. The battery of three tests is a promising screening tool for in‐place pollutants.

Protozoan species richness and protozoan phototroph abundance were inhibited by elutriates from contaminated sites, but the abundance of heterotrophic protozoans was enhanced by sediment elutriates from some stations. Microbial community photosynthesis was significantly inhibited by most sediment elutriates, while community respiration was often stimulated; thus, functional responses paralleled the structural changes. Overall, the results of the microbial community tests were consistent with expected patterns of toxicity at the two sites on Lake Michigan.

In general, single‐species test results agreed with the community bioassays. Although community tests may be more realistic than single‐species bioassays in predicting the impact of sediment contamination on actual ecosystems, caution must be exercised in interpreting the results.
Statistical concerns in the design and analysis of multispecies microcosm and mesocosm experiments
Authors: Smith Eric P. , Mercante Donald
Published: October 2006

Microcosm and mesocosm experiments are useful in the environmental analysis of the effects of toxicants on ecological communities. While there has been much interest in the biological approaches to microcosm design, there seems to have been little thought given to statistical issues in the design of these experiments. Here, some statistical design issues are considered. Some criteria are proposed, and optimal or near optimal designs suggested. Of particular interest is the choice of doses in the experiment, choices that allow for tests with high power and also provide good estimates of effect levels and other parameters. Also, some analytical techniques recently suggested for the analysis of community data are criticized and alternate methods suggested.
Relationships among the biological properties, distribution, and regulation of production by planktonic cyanobacteria
Authors: Reynolds C. S.
Published: October 2006

Interrelationships between the morphological and physiological properties of selected cyanobacterial species distinguished in the laboratory are used to simulate their population dynamics against realistic scales of environmental variability. Differences in performances are shown to correlate well with the ambient conditions found in the various types of lakes in which cyanobacteria are typically distributed.
Bacterial indicators to estimate the health hazards associated with the use of swimming pools
Authors: Seyfried Patricia L.
Published: October 2006

A total of 200 swimming pools, including one wading pool, were monitored for specific bacteria to select the most appropriate water quality indicators for a proposed prospective epidemiological survey of swimming pools. The organisms included in the study were fecal coliforms, fecal streptococci, Pseudomonas aeruginosa, Staphylococcus aureus, Acinetobacter spp., and total plate counts of aerobic heterotrophic bacteria. The results indicated that fecal coliforms, fecal streptococci, and Acinetobacter spp. have limited use as water quality parameters because of their naturally low densities in pools. Total plate counts, P. aeruginosa, and S. aureus appeared to be the indicators of choice because they were either present in large numbers, were opportunistic pathogens, or had a varied susceptibility to chlorine. The study showed that P. aeruginosa has an added advantage as an indicator because it can be typed using serological and genotyping methods.
Acute toxicity of six metals to the Rotifer Brachionus calyciflorus, with comparisons to other freshwater organisms
Authors: Couillard Yves , Ross Philippe , Pinel‐Alloul Bernadette
Published: October 2006

There are several advantages to the use of planktonic rotifers as freshwater bioassay organisms, yet few studies report toxicological data for these taxa. The goal of the present study was to evaluate the 24‐h acute toxicity responses of Brachionus calycifiorus to six heavy metals, and to compare metal tolerance of this species to published results for other aquatic organisms. Metal toxicity to B. calyciflorus, in decreasing order, was Hg > Cu > Cd > Zn > Fe > Mn. This order follows the theoretical ranking by affinity for anionic radicals based on Lewis acid‐base classification. While not quite as sensitive as Daphnia magna, B. calyciflorus is potentially useful as a bioassay species because it is easy to culture and manipulate, and is widely distributed in alkaline waters of eastern North America.
Genotoxicity of 22 pesticides in microtitration SOS chromotest
Authors: Xu Hao H. , Schurr Karl M.
Published: October 2006

The authors adapted microtitration techniques to the SOS Chromotest, and thereby established a simple and reliable modified genotoxicity test: the Microtitration SOS Chromotest. This test employs microtitration techniques and photometric analysis with numerical readout. These data are integrated into the computerized data processing program Statistical Analysis System to obtain genotoxicity and toxicity results of a chemical or chemical mixture within 16 h.

In order to test the applicability of the new system, the genotoxicity and toxicity of 22 pesticides were studied. A two‐sample t test was employed to determine the level of significance (p < 0.05). Nine of the pesticides were found to induce the SOS response in Escherichia coli cells. Their relative degrees of induction based on SOS inducing potency values are as follows: captafol > captan > folpet > dinoseb > ferbam > linuron > alachlor > phosmet > cacodylic acid. The addition of rat liver S9 mix does not transform the nongenotoxic pesticides tested into genotoxic forms but significantly decreases the inducing ability of most positive pesticides.

The Microtitration SOS Chromotest is rapid and efficient in providing evidence for decision‐making related to cleanup of chemical spills and discharges where time is a critical factor. This method maintains its high accuracy and sensitivity compared with conventionally used assays. The studies of pesticide genotoxicity using this test confirm the applicability, reliability, and sensitivity of the Microtitration SOS Chromotest as a simple, efficient, and rapid genotoxicity prescreening system as well as an excellent research tool for genotoxic mechanism studies.
Use of Microtox® andCeriodaphniabioassays in wastewater fractionation
Authors: Mazidji C. N. , Koopman B. , Bitton G. , Voiland G. , Logue C.
Published: October 2006

Collection system and nonchlorinated secondary effluent samples from a large municipal wastewater system were fractionated using a scheme that included filration, EDTA treatment, C18solid‐phase extraction columns, and air stripping. Microtox required less time thanCeriodaphnia dubiabioassay for determining the toxicity of the numerous test samples generated by the fractionation procedure. Its usefulness was limited to collection system samples, however. Secondary effluent samples, which caused significant mortality ofC. dubia, were nontoxic to Microtox. Diazinon was tentatively identified as one of the causative toxicants present. Its LC50toC. dubia(0.5 μg/L) is within the range of concentrations detected (0.1–0.6 μg/L), whereas the EC50of diazinon to Microtox is much higher (> 18,000 μg/L).
Development of a protozoan chemoattraction bioassay for evaluating toxicity of aquatic pollutants
Authors: Roberts Robert O. , Berk Sharon G.
Published: October 2006

A microcapillary assay technique was developed to assess effects of pollutants on the chemoattraction of the ciliate, Tetrahymena pyriformis. Parameters in the protocol such as starvation period, exposure period, and trough design were standardized in an effort to obtain consistent results.

Cadmium, phenol, and naphthalene were tested for effects on ciliates' chemoattraction to 0.15% yeast extract. All three toxicants inhibited chemoattraction; cadmium had the greatest effect, followed by naphthalene and phenol, respectively. The percent inhibition of chemoattraction for each concentration was used to determine EC50 values for both 1 and 5 h exposures.

Results show that the chemoattraction assay may provide a rapid, inexpensive, and sensitive asessment of aquatic toxicity. Inclusion of a protozoan assay fills the existing taxonomic gap in the routine battery of toxicity tests used for many hazard evaluations.
Composition of dehydrated attiéké powder
Authors: Yao KJ , Koffi RA , Aboua F
Published: October 2006

Fresh attiéké contained 76.7% starch, 1.5% protein and 1.25 mg/100 g of hydrocyanic acid (HCN). The powder obtained as a by‐product from drying had similar starch and protein contents but only 0.4 mg/100 ml of HCN, below the safe level, so it could be used in food products. Copyright © 2006 John Wiley & Sons, Ltd
Methane oxidation rates in forest soils and their controlling variables: a review and a case study in Korea
Authors: Jang Inyoung , Lee Seunghoon , Hong Ji‐Hyung , Kang Hojeong
Published: October 2006

Methane is one of the strongest of the greenhouse gases, being 30‐fold more radiatively active than carbon dioxide on a molar basis. In addition, its atmospheric concentrations have increased by 1% per year since the Industrial Revolution. As such, the dynamics of methane is of great importance for the prediction of global climatic changes caused by increasing concentrations of greenhouse gases in the atmosphere. One of the most important biological sinks for methane is forest soils, where methanotrophic bacteria oxidize methane to carbon dioxide. Based on data mined from a review of the literature, we determined that the mean methane oxidation rate was 1.90 mg CH4m−2day−1and that the main variables controlling this rate were soil water content and inorganic nitrogen in the soils. In contrast, the effects of temperature and pH are minimal. In addition to reviewing the literature, we monitored methane oxidation rates in a temperate forest soil in Korea on a monthly basis for a year, using a static chamber method. The mean oxidation rate was 1.96 mg CH4m−2day−1and was positively correlated with nitrate concentration in the soil.
Development, potentials, and challenges of the International Long‐Term Ecological Research (ILTER) Network
Authors: Kim Eun‐Shik
Published: October 2006

In order to review the development, the potentials, and the challenges of the International Long‐Term Ecological Research (ILTER) Network, the necessity for the development of the ILTER Network, the development of ILTER activities in the world, and the body structures of ILTER Network are described. As an example for showing the potentials of ILTER activities, exemplary results of tree growth studies carried out by the author utilizing long‐term daily weather data at the Hubbard Brook Experimental Forest, New Hampshire, USA are presented and future potentials are discussed. At this time, as the ILTER Network is situated at a critical point, challenges for the ILTER Network are discussed with regard to its further development. In this review, the author tries to maintain that as the long‐term ecological research, whose results can secure comparability in the dimension of time and space, can provide us with a fundamental basis for sound understanding and management of ecosystems, we can publicize the activities and findings from the ILTER Network to the public, on from local to international levels, to continue further efforts around the world for our sustainable future.