Two methods of measuring nitrification in soil bioassays were compared for their sensitivity in estimating toxic effects of endosulfan, a cyclodiene insecticide. Both technical grade endosulfan (95% pure) and endosulfan formulated as a commercial preparation (Thiodan 4EC) were tested in a sandy loam (pH 5.7), a silt loam (pH 5.0), and a clay loam (pH 4.9) soil. Nitrification was assayed using both soil perfusion and batch incubation techniques. There was a significant difference in the nitrification pattern evidenced by the three soils. In the sandy loam soil up to 90% of the added ammonium ion was converted into nitrate within 30 days, while the silt loam required 40 days to achieve similar nitrate levels. Activity in the clay loam was very slow and only 5% of the added ammonium ion was converted into nitrate within 70 days. The nitrification pattern for any given soil was similar when measured by both test methods. At insecticide levels of 10, 50, and 100 ppm of active ingredient, there was no significant difference in toxicity between the commercial preparation and technical endosulfan in 50% of the systems tested. In the remainder, the commercial formulation was usually more toxic. For concentrations of 500 and 1000 ppm of active ingredient, endosulfan supplied as the commercial preparation was consistently more toxic than the technical material when tested toward nitrification. There was also a significant difference between the two incubation methods in their sensitivity to endosulfan. The exact level of toxicity was dependent upon both the soil type and the incubation method used. Generally, endosulfan was more toxic with the batch incubation system and in the silt loam soil. The importance of these results in nitrification bioassays are discussed.
{"title":"Effects of the insecticide endosulfan on nitrification in low pH agricultural soils","authors":"G. Stratton","doi":"10.1002/TOX.2540050402","DOIUrl":"https://doi.org/10.1002/TOX.2540050402","url":null,"abstract":"Two methods of measuring nitrification in soil bioassays were compared for their sensitivity in estimating toxic effects of endosulfan, a cyclodiene insecticide. Both technical grade endosulfan (95% pure) and endosulfan formulated as a commercial preparation (Thiodan 4EC) were tested in a sandy loam (pH 5.7), a silt loam (pH 5.0), and a clay loam (pH 4.9) soil. Nitrification was assayed using both soil perfusion and batch incubation techniques. There was a significant difference in the nitrification pattern evidenced by the three soils. In the sandy loam soil up to 90% of the added ammonium ion was converted into nitrate within 30 days, while the silt loam required 40 days to achieve similar nitrate levels. Activity in the clay loam was very slow and only 5% of the added ammonium ion was converted into nitrate within 70 days. The nitrification pattern for any given soil was similar when measured by both test methods. At insecticide levels of 10, 50, and 100 ppm of active ingredient, there was no significant difference in toxicity between the commercial preparation and technical endosulfan in 50% of the systems tested. In the remainder, the commercial formulation was usually more toxic. For concentrations of 500 and 1000 ppm of active ingredient, endosulfan supplied as the commercial preparation was consistently more toxic than the technical material when tested toward nitrification. There was also a significant difference between the two incubation methods in their sensitivity to endosulfan. The exact level of toxicity was dependent upon both the soil type and the incubation method used. Generally, endosulfan was more toxic with the batch incubation system and in the silt loam soil. The importance of these results in nitrification bioassays are discussed.","PeriodicalId":11824,"journal":{"name":"Environmental Toxicology & Water Quality","volume":"11 1","pages":"319-336"},"PeriodicalIF":0.0,"publicationDate":"1990-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76286608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Devillers, R. Steiman, F. Seigle-Murandi, P. Prevot, C. André, J. Benoit-Guyod
The combination of 15 single-species laboratory tests (6 bacteria, 1 Dinoflagellate, 5 yeasts, 2 Crustacea, and 1 fish) was used for the assessment of the ecotoxicological effects of p-benzoquinone. Marked differences were observed in the susceptibility among the species since the toxicity values were ranged between 0.020 mg/L (Photobacterium phosphoreum) and >700 mg/L (Candida parapsilosis). These results support the philosophy that for assessing toxicity more thoroughly, a battery of several tests carried out with organisms occupying different trophic levels in the environment is required.
{"title":"Combination of single-species laboratory tests for the assessment of the ecotoxicity of p-Benzoquinone","authors":"J. Devillers, R. Steiman, F. Seigle-Murandi, P. Prevot, C. André, J. Benoit-Guyod","doi":"10.1002/TOX.2540050408","DOIUrl":"https://doi.org/10.1002/TOX.2540050408","url":null,"abstract":"The combination of 15 single-species laboratory tests (6 bacteria, 1 Dinoflagellate, 5 yeasts, 2 Crustacea, and 1 fish) was used for the assessment of the ecotoxicological effects of p-benzoquinone. Marked differences were observed in the susceptibility among the species since the toxicity values were ranged between 0.020 mg/L (Photobacterium phosphoreum) and >700 mg/L (Candida parapsilosis). These results support the philosophy that for assessing toxicity more thoroughly, a battery of several tests carried out with organisms occupying different trophic levels in the environment is required.","PeriodicalId":11824,"journal":{"name":"Environmental Toxicology & Water Quality","volume":"19 1","pages":"405-416"},"PeriodicalIF":0.0,"publicationDate":"1990-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79272638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Lampinen, M. Korpela, P. Saviranta, R. Kroneld, M. Karp
A method for evaluation of toxicity of aqueous solutions is described based on the use of genetically engineered Escherichia coli. The genes encoding bacterial luciferase have been cloned from Vibrio harveyi to a deep rough mutant of E. coli under the control of the lac promoter. Light production by this strain has been stabilized by optimizing several parameters having an effect on the gene expression. Toxicity measurements were performed for selected metals and organic solvents to determine the sensitivity of the test strain. Effective concentrations calculated from these measurements show that this method has a sensitivity equal to other normally used methods. The test can be performed using buffers with low ionic strength without any significant change in the stability of the light emitted. Moreover, the method does not necessitate the use of special equipment or skills.
{"title":"Use of Escherichia coli cloned with genes encoding bacterial luciferase for evaluation of chemical toxicity","authors":"J. Lampinen, M. Korpela, P. Saviranta, R. Kroneld, M. Karp","doi":"10.1002/TOX.2540050403","DOIUrl":"https://doi.org/10.1002/TOX.2540050403","url":null,"abstract":"A method for evaluation of toxicity of aqueous solutions is described based on the use of genetically engineered Escherichia coli. The genes encoding bacterial luciferase have been cloned from Vibrio harveyi to a deep rough mutant of E. coli under the control of the lac promoter. Light production by this strain has been stabilized by optimizing several parameters having an effect on the gene expression. Toxicity measurements were performed for selected metals and organic solvents to determine the sensitivity of the test strain. Effective concentrations calculated from these measurements show that this method has a sensitivity equal to other normally used methods. The test can be performed using buffers with low ionic strength without any significant change in the stability of the light emitted. Moreover, the method does not necessitate the use of special equipment or skills.","PeriodicalId":11824,"journal":{"name":"Environmental Toxicology & Water Quality","volume":"41 1","pages":"337-350"},"PeriodicalIF":0.0,"publicationDate":"1990-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81735349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aerobic and anaerobic biodegradation processes for 18 chlorophenols and 3 cresols were systematically evaluated under a controlled laboratory system, using an acclimatized mixed culture of pentachlorophenol-degrading bacteria. The biodegradation processes were characterized based on the lag time (time in hours required to observe 10% degradation of the added test chemical against the control), t90 (time in hours required to degrade 90% of the added test chemical). The results indicate that nonspecific generalizations such as the degree of a chemical's chlorination cannot be reliably used to predict the persistence of chemicals in the environment. On the other hand, a systematic analysis of the molecular structure of analogues and related chemicals, in particular the positions of chlorine substitution on the phenolic ring, appears to be the logical approach to provide useful information for predicting the environmental fate of existing and new chemicals. The substitution effect in dictating a chlorophenol's biodegradability appears to follow in the descending order of 2,4 > 4 > 3,5 > 2,6 > 3, or 5, or 2. Microbial acclimation was found to be a distinct feature associated with the biodegradation of toxic substances and thus having the potential to be utilized in characterizing the biodegradation process of such chemicals. Ignorance of this acclimation period in kinetics study could nullify the usefulness of using mathematical models in predicting the environmental fate of chemical compounds.
{"title":"A systematic study of the aerobic and anaerobic biodegradation of 18 chlorophenols and 3 cresols","authors":"Dickson L. S. Liu, G. Pacepavicius","doi":"10.1002/TOX.2540050405","DOIUrl":"https://doi.org/10.1002/TOX.2540050405","url":null,"abstract":"Aerobic and anaerobic biodegradation processes for 18 chlorophenols and 3 cresols were systematically evaluated under a controlled laboratory system, using an acclimatized mixed culture of pentachlorophenol-degrading bacteria. The biodegradation processes were characterized based on the lag time (time in hours required to observe 10% degradation of the added test chemical against the control), t90 (time in hours required to degrade 90% of the added test chemical). The results indicate that nonspecific generalizations such as the degree of a chemical's chlorination cannot be reliably used to predict the persistence of chemicals in the environment. On the other hand, a systematic analysis of the molecular structure of analogues and related chemicals, in particular the positions of chlorine substitution on the phenolic ring, appears to be the logical approach to provide useful information for predicting the environmental fate of existing and new chemicals. The substitution effect in dictating a chlorophenol's biodegradability appears to follow in the descending order of 2,4 > 4 > 3,5 > 2,6 > 3, or 5, or 2. Microbial acclimation was found to be a distinct feature associated with the biodegradation of toxic substances and thus having the potential to be utilized in characterizing the biodegradation process of such chemicals. Ignorance of this acclimation period in kinetics study could nullify the usefulness of using mathematical models in predicting the environmental fate of chemical compounds.","PeriodicalId":11824,"journal":{"name":"Environmental Toxicology & Water Quality","volume":"1 1","pages":"367-387"},"PeriodicalIF":0.0,"publicationDate":"1990-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89648918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Three simple sediment extraction procedures, using Milli-Q water, DMSO, and methanol, were applied to 16 sediment samples collected from the Thames River, Ontario, Canada. The three extracts were tested for the presence of toxicity and genotoxicity using the Microtox,® Toxi-Chromotest,® and Mutatox® (with and without S9) procedures. Results of the study indicated that the Mutatox genotoxicity screening test was an extremely sensitive procedure responding to chemicals in all three types of extracts. Methanol was found to be more efficient than DMSO in extracting toxic and genotoxic chemicals from these sediments. Procedural details and results are discussed.
{"title":"Simple two‐step sediment extraction procedure for use in genotoxicity and toxicity bioassays","authors":"K. Kwan, B. Dutka","doi":"10.1002/TOX.2540050407","DOIUrl":"https://doi.org/10.1002/TOX.2540050407","url":null,"abstract":"Three simple sediment extraction procedures, using Milli-Q water, DMSO, and methanol, were applied to 16 sediment samples collected from the Thames River, Ontario, Canada. The three extracts were tested for the presence of toxicity and genotoxicity using the Microtox,® Toxi-Chromotest,® and Mutatox® (with and without S9) procedures. Results of the study indicated that the Mutatox genotoxicity screening test was an extremely sensitive procedure responding to chemicals in all three types of extracts. Methanol was found to be more efficient than DMSO in extracting toxic and genotoxic chemicals from these sediments. Procedural details and results are discussed.","PeriodicalId":11824,"journal":{"name":"Environmental Toxicology & Water Quality","volume":"1 1","pages":"395-404"},"PeriodicalIF":0.0,"publicationDate":"1990-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75730017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Arabian Gulf offers a suitable location for investigating the potential impact of toxic chemicals on marine life, because it is a semienclosed, relatively shallow, small body of water. This study was carried out to evaluate the relative sensitivity, precision, and accuracy of three published microbial bioassay procedures to ascertain their ability to detect toxicity in the marine environment of Kuwait. The bioassay procedures used were dissolved oxygen depletion (DOD), viable plate count (VPC), and optical density (OD). Mixed marine bacteria isolated from the local seawater of Kuwait was used, and test samples (pollutants) investigated include mercuric chloride (HgCl2), lindane, and a wastewater samples. The DOD technique was evaluated as best for sensitivity of testing toxicity. In both brief and extended exposures, activity quotient values given by this technique were much lower than the LC50 and IC50 values given by the VPC and OD techniques. However, both VPC and OD techniques showed better reproducibility than the DOD technique, as indicated by lower coefficient of variation (CV) values. When evaluating complexity, the OD assay would be considered the least complex, then the DOD, and last would be the VPC. Although both VPC and OD assays showed better reproducibility than the DOD technique, as indicated by lower CV values, the DOD demonstrated a higher sensitivity in detecting toxicity, and showed several other advantages such as rapidity and lower expenditure of routine assay requirements. However, the initiation of short-term bioassay in Kuwait for predicting effect of pollutants in the marine environment is of necessity and importance.
{"title":"Toxicity assessment of pollutants in the marine environment of Kuwait using Microbial bioassay","authors":"M. Salama, A. Salem","doi":"10.1002/TOX.2540050304","DOIUrl":"https://doi.org/10.1002/TOX.2540050304","url":null,"abstract":"The Arabian Gulf offers a suitable location for investigating the potential impact of toxic chemicals on marine life, because it is a semienclosed, relatively shallow, small body of water. This study was carried out to evaluate the relative sensitivity, precision, and accuracy of three published microbial bioassay procedures to ascertain their ability to detect toxicity in the marine environment of Kuwait. \u0000 \u0000 \u0000 \u0000The bioassay procedures used were dissolved oxygen depletion (DOD), viable plate count (VPC), and optical density (OD). Mixed marine bacteria isolated from the local seawater of Kuwait was used, and test samples (pollutants) investigated include mercuric chloride (HgCl2), lindane, and a wastewater samples. \u0000 \u0000 \u0000 \u0000The DOD technique was evaluated as best for sensitivity of testing toxicity. In both brief and extended exposures, activity quotient values given by this technique were much lower than the LC50 and IC50 values given by the VPC and OD techniques. However, both VPC and OD techniques showed better reproducibility than the DOD technique, as indicated by lower coefficient of variation (CV) values. When evaluating complexity, the OD assay would be considered the least complex, then the DOD, and last would be the VPC. \u0000 \u0000 \u0000 \u0000Although both VPC and OD assays showed better reproducibility than the DOD technique, as indicated by lower CV values, the DOD demonstrated a higher sensitivity in detecting toxicity, and showed several other advantages such as rapidity and lower expenditure of routine assay requirements. However, the initiation of short-term bioassay in Kuwait for predicting effect of pollutants in the marine environment is of necessity and importance.","PeriodicalId":11824,"journal":{"name":"Environmental Toxicology & Water Quality","volume":"79 1","pages":"237-252"},"PeriodicalIF":0.0,"publicationDate":"1990-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84072347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ecological effects of selenium (as sodium selenite) on naturally derived microbial communities were evaluated in laboratory microcosms and in outdoor experimental streams at the U.S. Environmental Protection Agency (U.S. EPA) Monticello Ecological Research Station (MERS). Microcosms were continuously dosed for 21 days at selenium concentrations ranging from 0 to 160μg Se/L. Outdoor streams were continuously dosed at 0, 10, and 30 μg Se/L, the highest concentration approximating the current U.S. EPA water quality criterion. In laboratory microcosms, protozoan species richness was reduced by 20%, and chlorophyll and hexosamine levels were reduced by 40% at μ80 μg Se/L. Total biomass and carbohydrate levels decreased with increasing Se, but these effects were not significant. Selenium had no effect on microcosm production to respiration ratios. In outdoor streams, microbial community biomass collected on artificial substrata was 2–3 times greater than in the laboratory. In general, adverse effects were not observed, confirming laboratory estimates of no adverse effects at <80 μg Se/L. However, low doses (10μg Se/L) consistently stimulated microbial biomass (protein, chlorophyll, hexosamine) and elevated production to biomass (P/B), consistent with reports of Se stimulation of algal growth. The highest Se dose (30 μg/L) caused decreased primary production and decreased P/B compared to controls. Experiments showed that ecological responses of laboratory microcosms and outdoor experimental ecosystems are similar, and are at least as sensitive as standard toxicological responses.
{"title":"Effect of selenium on microbial communities in laboratory microcosms and outdoor streams","authors":"J. Pratt, N. Bowers","doi":"10.1002/TOX.2540050308","DOIUrl":"https://doi.org/10.1002/TOX.2540050308","url":null,"abstract":"Ecological effects of selenium (as sodium selenite) on naturally derived microbial communities were evaluated in laboratory microcosms and in outdoor experimental streams at the U.S. Environmental Protection Agency (U.S. EPA) Monticello Ecological Research Station (MERS). Microcosms were continuously dosed for 21 days at selenium concentrations ranging from 0 to 160μg Se/L. Outdoor streams were continuously dosed at 0, 10, and 30 μg Se/L, the highest concentration approximating the current U.S. EPA water quality criterion. In laboratory microcosms, protozoan species richness was reduced by 20%, and chlorophyll and hexosamine levels were reduced by 40% at μ80 μg Se/L. Total biomass and carbohydrate levels decreased with increasing Se, but these effects were not significant. Selenium had no effect on microcosm production to respiration ratios. In outdoor streams, microbial community biomass collected on artificial substrata was 2–3 times greater than in the laboratory. In general, adverse effects were not observed, confirming laboratory estimates of no adverse effects at <80 μg Se/L. However, low doses (10μg Se/L) consistently stimulated microbial biomass (protein, chlorophyll, hexosamine) and elevated production to biomass (P/B), consistent with reports of Se stimulation of algal growth. The highest Se dose (30 μg/L) caused decreased primary production and decreased P/B compared to controls. Experiments showed that ecological responses of laboratory microcosms and outdoor experimental ecosystems are similar, and are at least as sensitive as standard toxicological responses.","PeriodicalId":11824,"journal":{"name":"Environmental Toxicology & Water Quality","volume":"131 1","pages":"293-307"},"PeriodicalIF":0.0,"publicationDate":"1990-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79203491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The use of bacteria as test organisms in rapid ecotoxicity assays is under investigation in several laboratories worldwide. However, little attention has been given to the question of permeability of the outer membrane of gram-negative bacteria to toxicants of environmental interest. We have investigated the effect of physical, chemical, and genetic alterations on the sensitivity of Escherichia coli to environmental toxicants, as measured via inhibition of β-galactosidase biosynthesis. Polymyxin treatment (2 mg/L) was the most promising treatment tested, significantly increasing the sensitivity of wild-type E. coli to pentachlorophenol and sodium dodecyl sulfate. A mutant strain of E. coli (EW1b), with an outer membrane protein alteration (tol C gene), was found to be the most sensitive to hydrophobic compounds and to detergent. EW1b, further sensitized via polymyxin treatment, appears to be a sensitive microorganism for toxicant assay.
{"title":"Inhibition of β‐galactosidase biosynthesis in Escherichia coli: Effect of alterations of the outer membrane permeability on sensitivity to environmental toxicants","authors":"Ronald J. Dutton, G. Bitton, B. Koopman, O. Agami","doi":"10.1002/TOX.2540050305","DOIUrl":"https://doi.org/10.1002/TOX.2540050305","url":null,"abstract":"The use of bacteria as test organisms in rapid ecotoxicity assays is under investigation in several laboratories worldwide. However, little attention has been given to the question of permeability of the outer membrane of gram-negative bacteria to toxicants of environmental interest. We have investigated the effect of physical, chemical, and genetic alterations on the sensitivity of Escherichia coli to environmental toxicants, as measured via inhibition of β-galactosidase biosynthesis. Polymyxin treatment (2 mg/L) was the most promising treatment tested, significantly increasing the sensitivity of wild-type E. coli to pentachlorophenol and sodium dodecyl sulfate. A mutant strain of E. coli (EW1b), with an outer membrane protein alteration (tol C gene), was found to be the most sensitive to hydrophobic compounds and to detergent. EW1b, further sensitized via polymyxin treatment, appears to be a sensitive microorganism for toxicant assay.","PeriodicalId":11824,"journal":{"name":"Environmental Toxicology & Water Quality","volume":"22 1","pages":"253-264"},"PeriodicalIF":0.0,"publicationDate":"1990-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91194296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effects of copper, nickel, and iron on survival, growth, nutrient uptake (NH, NO, and PO), carbon fixation, nitrate reductase, nitrogenase (CH2 reduction assay), glutamine synthetase (transferase), and alkaline phophatase activities of Anabaena doliolum were studied. About 50% survival of the test alga was scored at 8.0 × 10−3, 8.6 × 10−3, and 0.36 mM of Cu, Ni, and Fe, respectively. However 45, 59, and 57% reductions in final yield were scored, respectively, at LD50 concentrations of Cu, Ni, and Fe. On the basis of the LD50 of the test metals, Ni was the most inhibitory for nutrient uptake. However, the LD50 concentrations of Cu, Ni, and Fe showed different levels of inhibition for different processes. Although metal concentrations higher than LD50 were found to be more inhibitory, 0.54 mM iron generated maximum inhibitory effect as compared to Cu and Ni. The present study demonstrates that the test cyanobacterium exhibits metal and dose-specific responses toward different physiological and biochemical processes.
{"title":"Effects of heavy metals on the biology of a N2‐fixing cyanobacterium Anabaena doliolum","authors":"N. Mallick, L. Rai","doi":"10.1002/TOX.2540050302","DOIUrl":"https://doi.org/10.1002/TOX.2540050302","url":null,"abstract":"The effects of copper, nickel, and iron on survival, growth, nutrient uptake (NH, NO, and PO), carbon fixation, nitrate reductase, nitrogenase (CH2 reduction assay), glutamine synthetase (transferase), and alkaline phophatase activities of Anabaena doliolum were studied. About 50% survival of the test alga was scored at 8.0 × 10−3, 8.6 × 10−3, and 0.36 mM of Cu, Ni, and Fe, respectively. However 45, 59, and 57% reductions in final yield were scored, respectively, at LD50 concentrations of Cu, Ni, and Fe. On the basis of the LD50 of the test metals, Ni was the most inhibitory for nutrient uptake. However, the LD50 concentrations of Cu, Ni, and Fe showed different levels of inhibition for different processes. Although metal concentrations higher than LD50 were found to be more inhibitory, 0.54 mM iron generated maximum inhibitory effect as compared to Cu and Ni. The present study demonstrates that the test cyanobacterium exhibits metal and dose-specific responses toward different physiological and biochemical processes.","PeriodicalId":11824,"journal":{"name":"Environmental Toxicology & Water Quality","volume":"29 1","pages":"207-219"},"PeriodicalIF":0.0,"publicationDate":"1990-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79593603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. N. Mazidji, B. Koopman, G. Bitton, G. Voiland, C. Logue
Collection system and nonchlorinated secondary effluent samples from a large municipal wastewater system were fractionated using a scheme that included filration, EDTA treatment, C18 solid-phase extraction columns, and air stripping. Microtox required less time than Ceriodaphnia dubia bioassay 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 of C. dubia, were nontoxic to Microtox. Diazinon was tentatively identified as one of the causative toxicants present. Its LC50 to C. dubia (0.5 μg/L) is within the range of concentrations detected (0.1–0.6 μg/L), whereas the EC50 of diazinon to Microtox is much higher (> 18,000 μg/L).
{"title":"Use of Microtox® and Ceriodaphnia bioassays in wastewater fractionation","authors":"C. N. Mazidji, B. Koopman, G. Bitton, G. Voiland, C. Logue","doi":"10.1002/TOX.2540050306","DOIUrl":"https://doi.org/10.1002/TOX.2540050306","url":null,"abstract":"Collection system and nonchlorinated secondary effluent samples from a large municipal wastewater system were fractionated using a scheme that included filration, EDTA treatment, C18 solid-phase extraction columns, and air stripping. Microtox required less time than Ceriodaphnia dubia bioassay 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 of C. dubia, were nontoxic to Microtox. Diazinon was tentatively identified as one of the causative toxicants present. Its LC50 to C. dubia (0.5 μg/L) is within the range of concentrations detected (0.1–0.6 μg/L), whereas the EC50 of diazinon to Microtox is much higher (> 18,000 μg/L).","PeriodicalId":11824,"journal":{"name":"Environmental Toxicology & Water Quality","volume":"33 1","pages":"265-277"},"PeriodicalIF":0.0,"publicationDate":"1990-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82573367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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