摘要:

AbstractPesticides—a serious problem especially for drinking water quality—frequently are potent inhibitors of enzymes in their target organisms. As the established chemical analyses of pesticides are time‐consuming, complicated, and expensive, so‐called screening methods are urgently needed. For this purpose the sensitivity of 13 different enzymes was testedin vitroby inhibiting their kinetic rates and/or substrate conversions by 16 pesticides (herbicides and fungicides). Because of the stabilization and resulting low sensitivity of enzymes commercially available—especially in test kits—it was necessary to vary the test conditions and to develop special methods for detecting enzymatic inhibitions. It was shown that the sensitivity to pesticides of the different enzymes varies in a wide range, partly in irrelevant high concentrations. Four enzymes seem to be suitable for inhibition tests, but need to be checked before practical application. The enzyme aldehyde dehydrogenase (AlDh), isolated from yeasts, was very sensitive to ethendithiocarbamates. Therefore an inhibition test could be developed to detect this class of pesticides in a range of some μg/L. The AlDh inhibition test is the first part of an enzymatic screening system for pesticide pollution in water. © 1992 John Wi

ISSN:1053-4725    

DOI:10.1002/tox.2530070402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractMetPADTM, a bioassay kit designed for the specific determination of heavy metal toxicity in environmental samples, was evaluated for toxicity assessment of sediment elutriates from hazardous waste sites in Florida. MetPAD, when run concurrently with Microtox® was useful in pinpointing sediments with heavy metal toxicity. MetPAD results were confirmed by heavy metal analysis of the samples. The MetPAD bioassay for the specific detection of the presence of bioavailable heavy metals should be included in test batteries for toxicity assessment of sediments. © 1992 John Wiley&sons, In

ISSN:1053-4725    

DOI:10.1002/tox.2530070403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractTwo procedures for extracting hydrophobic contaminants from sediment samples collected from various sites in Florida were compared. The sediments, which varied in nature and degree of chemical contamination, were extracted with dichloromethane by shaking (24 h) and sonication (15 min). The dichloromethane extracts obtained were solvent exchanged into either methanol or dimethyl sulfoxide (DMSO). The efficiency of each procedure was evaluated based on the response ofPhotobacterium phosphoreumin the Microtox assay to the solvent extracts. The 24‐h shaking procedure produced significantly higher toxicity than the 15‐min sonication procedure for 8 of the 10 sediment samples tested. Comparisons of methanol and DMSO as exchange solvents revealed that there was generally no significant difference between these solvents in terms of toxic

ISSN:1053-4725    

DOI:10.1002/tox.2530070404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractUse of the EDTA chelation test in conjunction with microbioassays for general toxicity (Microtox) and heavy metal toxicity (β‐galactosidase activity) allowed us to identify the presence of heavy metal toxicity, and to distinguish between cases in which toxicity was due solely to either heavy metals, organic compounds, or a mixture of these chemicals. The technique is effective over a wide range of water hardness and pH. Screening of industrial wastewater samples by the EDTA‐microbioassay technique gave results that were consistent with chemical analysis of samples by atomic absorption. © 1992 John Wiley&sons

ISSN:1053-4725    

DOI:10.1002/tox.2530070405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractFermentor studies were conducted to examine the microbial degradation of polycyclic aromatic hydrocarbons (PAHs; naphthalene, phenanthrene, anthracene) and a polycyclic aromatic nitrogen heterocyclic (quinoline) using a mixed bacterial culture capable of utilizing these compounds as the sole carbon and energy source for growth. Half‐lives for the three PAHs in the cyclone fermentor system ranged from 1 day for naphthalene to 4 days for anthracene. Several major metabolites during the biodegradation of PAHs were also identified. These included 2‐hydroxybenzoic acid and 1‐naphthalenol (for naphthalene); 1‐phenanthrenol and 1‐hydroxy‐2‐naphthalenecarboxylic acid (for phenanthrene); and 3‐hydroxy‐2‐naphthalenecarboxylic acid (for anthracene). Thus our bacterial culture biodegraded the three PAHs by initial hydroxylation of the molecule followed by the eventual cleavage of the ring to yield the ortho‐ or meta‐cleavage intermediates, which would be further metabolized via conventional metabolic pathways. However, biodegradation of the nitrogen‐containing polycyclic aromatic hydrocarbon compound quinoline by our culture resulted in the accumulation of 4–5 metabolites, one of which has been identified as 2‐quinolinol. Work is in progress to identify the other metabolites from quinoline degradation

ISSN:1053-4725    

DOI:10.1002/tox.2530070406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThirty‐eight organic extracts of sediment samples collected from 28 sites in three Great Lakes priority areas (Grand Calumet River, Buffalo River, and Saginaw River) were evaluated with the new activated Mutatox Genotoxicity Assay. Thisin vitroprocaryotic assay used rat hepatic S9 for exogenous metabolic activation and a dark mutant strain of the luminescent bacteriumPhotobacterium phosphoreumfor detection of environmental DNA‐damaging substances (genotoxins). A genotoxic response was indicated when the test chemical restored the luminescent state in bacteria; the degree of light increase identified the relative genotoxicity of the sample. Within the three priority areas sampled, 27 sites showed evidence of genotoxins, 23 of 28 sites (82%) were designated genotoxic; 4 were suspect (14%), and 1 was negative (3%). Assay sensitivity to known progenotoxins arylamines (2‐aminoanthracene and 2‐aminofluorene) and polycyclic arylhydrocarbons [benzo(α)pyrene and pyrene] in complex sediment mixtures was ⩾1 μg per cuvette. The activated Mutatox Assay was a sensitive, specific, predictive, and short‐term test for detecting the presence of genotoxins in complex environmen

ISSN:1053-4725    

DOI:10.1002/tox.2530070407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

ISSN:1053-4725    

DOI:10.1002/tox.2530070408

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

ISSN:1053-4725    

DOI:10.1002/tox.2530070401

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY