bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microbial enzyme activity and biomass relationships in soil ecotoxicology
Authors: Lanza Guy R. , Dougherty Joel M. 
Published: October 2006

AbstractMultispecies toxicity testing is emerging as a useful tool in ecotoxicological assessments. Understanding the relationship between soil microbial biomass levels and microbial enzyme activities (MEA) is basic to clarifying ecotoxicity effects and bioremediation potential in soil systems.Saturated subsurface soils were exposed to fluctuating concentrations of a mixture of 1‐choromethyl‐2‐methyl naphthalene, phenothiazine and 2,4,2′4′‐tetrachlorobiphenyl. An enzyme suite composed of dehydrogenase, amylase, esterase, alkaline phosphatase, and protease was monitored, along with simultaneous biomass estimates using total plate counts for facultative aerobes and anaerobes, acridine orange direct counts (AODC) for total bacteria, and endogenous protein. Results indicate that quantitative biomass levels (AODC) remained relatively constant. Mean log10 values of AODC biomass reached a plateau between 6.45 (±0.15) and 7.06 (±0.10) with coefficients of variation <3.0. AODC adjusted to biovolume carbon estimates indicated that bacterial organic carbon could represent 0.03 and 0.35% of the mean measured levels of total organic carbon depending on the number of cells and the volume of each cell in μm3. Multivariate statistical analyses identified significant correlations among some MEA, biomass measurements, and chemical pollutants. The general implications of these results to ecosystem function and bioremediation potential are discussed.
Tumor promotion and liver injury caused by oral consumption of cyanobacteria
Authors: Falconer Ian R. 
Published: October 2006

AbstractWater supply reservoirs in many countries are now affected by intermittent water blooms of cyanobacteria. During 1989 a significant number of domestic supply reservoirs in the United Kingdom developed copious blankets of Microcystis, and pet and sheep deaths were reported due to swimming in or drinking the water. In Australia there are annual blooms of Anabaena and Microcystis in natural lakes and supply reservoirs, many of which are toxic. Studies of epidemics and individual cases of gastroenteritis and hepatitis due to cyanobacterial blooms have been reported from North America, Africa, and Australia. Our studies of the effect of low‐concentration oral consumption of Microcystis on mice have shown progressive liver injury with leucocyte invasion and hepatocyte death. Measurements of liver injury in a human population exposed to Microcystis in the domestic water supply indicate similar damage. Recent research has concentrated on the possible tumor‐promoting activity of oral consumption of cyanobacterial extracts. A group of mice given dilute Microcystis for one year showed more spontaneous tumors at the highest concentration of cyanobacterial extract. Mice stimulated to grow skin tumors by topical application of dimethylbenzanthracene showed a significantly greater weight of tumors in one group given a Microcystis extract to drink. A comparable group given an Anabaena extract in their drinking water showed no stimulation of tumor growth.
Estimating the toxicity of chlorinated organic compounds using A multiparameter bacterial bioassay
Authors: Pill Kenneth G. , Kupillas Gregory E. , Picardal Flynn W. , Arnold Robert G. 
Published: October 2006

AbstractA battery of microbial tests that included contemporary measurement of specific growth rate, intracellular ATP level, and respiration rate proved capable of distinguishing among toxicants that acted primarily as (a) catabolic inhibitors, (b) uncouplers, and (c) inhibitors of biosynthetic processes. The concentration of chlorinated phenols and ethanes that produced a 50% reduction in specific growth rate (ECk50) provided the most useful single‐parameter indication of relative chemical toxicity generated within the test battery.Among the chlorinated ethanes tested, toxicity resulted from nonspecific chemical interactions with bacterial membranes, as indicated by correlation between toxicity (ECk50) and measures of lipophilicity. The ECk50 value for 1,2‐dichloroethane was 8.5 × 10−3M as compared to 1.7 × 10−4M for the more hydrophobic pentachloroethane. Intermediate ECk50 values were obtained for 1,1,1‐trichloroethane and 1,1,2,2‐tetrachloroethane. For a comparable degree of lipophilicity, the chlorinated phenols were about an order of magnitude more toxic than chlorinated ethanes. ECk50 values for Spirochaeta aurantia at pH 7 ranged from 1.3 × 10−3M for 2‐chlorophenol to 9.4 × 10−6M for penta‐chlorophenol. There was indirect evidence that the toxicity of chlorinated phenols arises from both specific and nonspecific chemical interactions with bacterial membranes.The test battery proved capable of distinguishing among the relative toxicities of the chemicals tested at least as well as other bioassay procedures including Microtox and Daphnia‐based tests. However, ECk50 was less sensitive than parametric measures of chemical toxicity generated via other procedures.
The evaluation of bacterial biosensors for screening of water pollutants
Authors: van Hoof François M. , de Jonghe Els G. , Briers Michael G. , Hansen Peter D. , Pluta Hans J. , Rawson David M. , Wilmer Allison J. 
Published: October 2006

AbstractBacterial biosensors incorporating the cyanobacterium Synechoccus as the biocatalyst have been evaluated by three laboratories as potential biomonitors for detecting water pollutants. The biosensors were capable of detecting at low concentrations herbicides that interact with photosynthetic electron transfer chains. Statistical evaluation of the interlaboratory comparison results for linuron and atrazine indicated that these compounds can be detected rapidly at 50 μg/L concentrations.
Comparative assessment of herbicide phytotoxicity to Selenastrum capricornutum using microplate and flask bioassay procedures
Authors: St‐Laurent D. , Blaise C. , Macquarrie P. , Scroggins R. , Trottier B. 
Published: October 2006

AbstractFour reference toxicants (Cr6+, Cu2+, Zn2+, phenol) and 9 herbicides (imazamethabenz, 2,4‐dichlorophenoxyacetic acid, picloram, glyphosate, bromoxynil, metolachlor, diquat dibromide, hexazinone, cyanazine) were appraised using both the microplate and flask assay Ninety‐six hour EC50s determined with Selenastrum capricornutum as the indicator species essentially demonstrated good intermethodological data concordance for all chemicals, with the exception of diquat dibromide, whose phytotoxicity in the microplate assay (EC50 = 4.9 μg · L−1) was nearly 7 times that of the flask assay (EC50 = 34.2 μg · L−1). Comparisons with other data in the scientific literature relating to similar herbicides with the same or different green algal indicator species appeared to corroborate the overall data obtained in our study. More than 4 orders of magnitude separated the most toxic (cyanazine, flask, and microplate EC50s of 17.6 and 16.9 μg · L−1, respectively) and the least toxic (imazamethabenz, flask, and microplate EC50s of 89.1 and 91.1 mg · L−1, respectively) herbicides. The biprocedural phytotoxicity comparison described in this work suggests that the simpler algal microplate assay can be an appropriate alternative to the flask technique to evaluate the algal growth inhibition effects of herbicides.
The effects of bayluscide and malathion on the mortality and infectivity of Schistosoma mansoni cercariae
Authors: Tchounwou P. B. , Englande A. J. , Malek E. A. , Greer G. J. , Anderson A. C. 
Published: October 2006

AbstractLaboratory experiments were conducted to assess the effects of bayluscide and malathion on the mortality and infectivity of Schistosoma mansoni cercariae. Mortality of cercariae varied with time of exposure and concentration of tested chemicals. The LC5, LC50, and LC95 for bayluscide were 0.04, 0.07, and 0.10 ppm after 2 h of exposure; 0.03, 0.04, and 0.06 ppm after 4 h of exposure; and 0.02, 0.03, and 0.05 ppm after 6 h of exposure, respectively. Malathion gave LC5, LC50, and LC95 values of 59.16, 107.07, and 193.78 ppm after 2 h of exposure; and 39.79, 69.36, and 120.89 ppm after 4 h of exposure, respectively. Sublethal concentrations of bayluscide and malathion significantly reduced the rate of infection of laboratory mice by S. mansoni cercariae (p < 0.01). Approximately 1.50 and 0.00% of adult worms were recovered by autopsy of mice whose cercariae were preexposed for only 1 h to 0.04 ppm of bayluscide and 50.00 ppm of malathion, respectively. These results clearly show that bayluscide is much more toxic to cercariae than to snail intermediate hosts cited in the literature, and that malathion possesses some cercaricidal properties at concentrations expected to be achieved in the field.
Precision of the nitocra spinipes acute toxicity test and the effect of salinity on toxicity of the reference toxicant potassium bichromate
Authors: Dave GÖRan , Björnestad Estelle , Efraimsen Harry , Tarkpea Maria 
Published: October 2006

AbstractThe precision of the 96‐h LC50 test with the eurohaline copepod Nitocra spinipes was evaluated from a data set containing 85 tests with the reference toxicant potassium bichromate conducted at 12 laboratories during a 12‐year period. The overall mean was 30 mg/L as K2Cr2O7 with a coefficient of variation (CV) of 47% (N = 85). Since salinity differed between tests (7–33 o/oo), it explained part of the variation (ca. 25%; Pearson two‐tailed test r = 0.49; p = 0.0000; N = 85). The effect of salinity on Cr(VI) toxicity was confirmed in an experiment with 4 salinities (3.4, 6.8, 14.6, and 27 o/oo) and was explained to 99% by the equation 96‐h LC50 (mg/L) = 2.58 + 1.79 × salinity (o/oo). Intralaboratory CVs for corresponding salinities ranged from 8 to 35% (repeatability). Interlaboratory CVs at two salinities were 42% (N = 11) at 7–9 o/oo and 47% (N = 4) at 15–16 o/oo. © 1993 John Wiley & Sons, Inc.
Toxicity potential of a textile dye toward the diazotrophic cyanobacterium Nostoc muscorum ISU
Authors: Shukla S. P. , Gupta G. S. 
Published: October 2006

AbstractThe impact of graded concentrations (5, 10, 15, and 20 mg L−1) of Omega Chrome Red ME, a common dye used in woollen, carpet, and textile industries, on protein production, pigment content, and photosynthetic oxygen evolution in a diazotrophic cyanobacterium Nostoc muscorum ISU, was studied. All concentrations were found to be inhibitory, with lower concentrations (5 mg L−1) producing a negligible effect, while higher concentrations produced a dramatic decrease in the parameters observed. The highest concentration of dye tested (20 mg L−1) resulted in a decrease in protein, chlorophyll a, phycocyanin, and carotenoid content of 82.20, 82.69, 46.20 and 41% of control, respectively. Photosynthetic oxygen evolution was decreased by 83.50% of control at the highest dye concentration. © 1994 by John Wiley & Sons, Inc..
Comparative studies on cytotoxicity of micropollutants in water: Principle of cytotoxicity matrix
Authors: Utsumi Hideo , Kiyoshige Koji , Shimbara Satoko , Hamada Akira 
Published: October 2006

AbstractCytotoxicities were investigated with chemicals including pesticides, industrial materials, and chlorination by‐products using colony formation inhibition of L‐929 cells and membrane damage of “liposomes” to develop the simple bioassays for estimation of human hazardous micropollutants in water. Some chemicals including pesticides and chlorination by‐products strongly inhibited colony formation of L‐929 cells, and the inhibition was dose dependent. But most cytotoxic substances did not increase membrane permeability of liposomes, suggesting that Cytotoxicity of these chemicals does not arise from direct damage of cell membranes. The IC10 and IC50,10 and 50% inhibition concentrations, were obtained from the dose‐response curve of colony formation. The IC10 showed good correlation (r = 0.75) to LD50 of rat by intraperitoneal administration but not to those by oral administration.The results were compared to those with viability of HL‐60 cells, phagocytic activity of mice peritoneal macrophages, glycogenolysis, and LDH release of rat liver hepatocytes. The susceptibilities were largely different among these Cytotoxicity tests, and the colony formation inhibition test gave similar results to the viability of HL‐60 cells. The principle of “cytotcxicity matrix” was developed from the comparison of cytotoxicities for each chemical. The characteristic relation was found between the chemical structure and the pattern of the Cytotoxicity matrix, indicating that the Cytotoxicity matrix may be useful for predicting the origin and nature of micropollutants. © 1994 by John Wiley & Sons, Inc..
Persistence of cyclic peptide toxins in dried Microcystis aeruginosa crusts from lake Mokoan, Australia
Authors: Jones Gary J. , Falconer Ian R. , Wilkins Richard M. 
Published: October 2006

AbstractDried Microcystis aeruginosa Kuetzing emend. Elenkin crusts estimated to be 5–6 months old from the shore of Lake Mokoan were toxic by mouse bioassay (LD100 100–140 mg dry wt/kg mouse). Fresh bloom material from the lake was also highly toxic (LD100 25–35 mg dry wt/kg mouse). Microcystin high performance liquid chromatography (HPLC) profiles of the crust and fresh material were very similar, with 24 compounds having UV spectra consistent with microcystin LR. Five of the major microcystins were purified and analysed by electrospray/mass spectrometry. The molecular weights of these microcystins [910, 924, 982, 982 (two compounds), and 986] do not correspond with known microcystins. All five compounds were hepatotoxic to mice with LD100 values ranging from 85 to 140 μg microcystin/kg mouse). Total microcystin contents (expressed as microcystin LR aquivalents) determined by HPLC correlated with the mouse bioassay analyses (crust 2.1 μg microcystin/mg dry wt; fresh 4.1 μg microcystin/mg dry wt). These results suggest that microcystin is protected from degradation while encapsulated within the dried Microcystis crusts. Leaching experiments demonstrated that re‐wetting of the crust material leads to rapid release of microcystins into the surrounding water. These observations have important management implications for lakes and reservoirs where crusts of cyanobacterial material form on the shoreline. © by John Wiley & Sons, Inc.
Comparison of gram positive and gram negative bacterial strains cloned with different types of luciferase genes in bioluminescence cytotoxicity tests
Authors: Lampinen Jorma , Virta Marko , Karp Matti 
Published: October 2006

AbstractThe bacterial bioluminescence assay is widely used to estimate chemical cytotoxicity. This assay is performed most often by using luminescent bacteria Vibrio fisheri NRRL‐B‐11177 (earlier cited as Photobacterium phosphoreum NRRL‐B‐11177) as a test organism. In this work we have used cloned gram(+) and gram(−) bacterial strains for the evaluation of chemical toxicity. Two types of luciferase genes were used as reporter genes, one of which was ATP‐dependent eukaryotic luciferase from Pyrophorus plagiophthalamus and the other was FMN‐dependent bacterial luciferase from Vibrio harveyi. These cloned strains were used to evaluate the effects of differences in cell wall structures in the bioluminescence cytotoxicity test using small molecular weight toxic chemicals as model compounds. The strains were found to have remarkably similar behavior and sensitivity toward test toxicants regardless of rather different kinds of membrane structure. However, the eukaryotic luciferase was found in every aspect more useful in toxicity tests than bacterial luciferase mainly because of increased sensitivity and ease of operation. The general behavior of the light emission is described and several aspects affecting the usefulness of the strains are discussed. © by John Wiley & Sons, Inc.
Assessment of water quality problems due to microbial growth in drinking water distribution systems
Authors: Augoustinos M. T. , Venter S. N. , Kfir R. 
Published: October 2006

AbstractThe microbiological quality of water in the potable water distribution system of a major South African metropolitan area was studied. Water samples were collected from private houses, apartment buildings, and public institutions over a period of two years. Total coliform bacteria were isolated from 33% of the water samples, of which 10% exceeded the South African recommended guidelines. Fecal coliform bacteria were isolated from 10% of the samples tested. Twenty‐five different fungal cultures were isolated. The dominant bacteria found were of the genus Bacillus. Other organisms were Staphylococcus, Micrococcus, Acinetobacter, Flavobacterium, Aeromonas, Klebsiella, Citrobacter, and Escherichia coli. Legionella bacteria were isolated occasionally. Higher bacterial counts were found in apartment buildings than in private houses. The age of the plumbing system was also found to result in potable water of a poorer microbial quality. © by John Wiley & Sons, Inc.
Assessment of genotoxic potential of pulp mill effluent and an effluent fraction using ames mutagenicity and Umu‐C genotoxicity assays
Authors: Rao Salem S. , Burnison B. Kent , Efler S. , Wittekindt Elisabeth , Hansen Peter D. , Rokosh David A. 
Published: October 2006

AbstractThe Ames Mutagenicity Fluctuation and the Umu‐C genotoxicity bioassays were applied to assess the genotoxic potential in pulp mill effluents and their fractions. Mutagenicity was measured in the filtered effluents and the methanol extract of the diethyl‐amino‐ethyl cellulose. (DEAE) adsorbed materials by the Ames Fluctuation assay. The Umu‐C genotoxicity assay was applied only to the methanol extract of the DEAE adsorbed materials. Data indicate that the majority of the mutagenic substances from the filtered effluent were adsorbed by the DEAE cellulose and were effectively recovered with methanol. Approximately 1/3n to 1/6 of the materials in the effluent passed through the DEAE cellulose. The responses of the test organisms to genotoxic substances in the methanol extract fractions were comparable, suggesting that either one of these two bioassays could be used in screening pulp and paper effluents for genotoxicity. © by John Wiley & Sons, Inc.
Antibiotic resistance of Pseudomonas from German mineral waters
Authors: Rosenberg F. A. , Duquino H. Hernandez 
Published: October 2006

AbstractEighty‐seven different mineral waters available for purchase in the Federal Republic of Germany were tested for the presence of heterotrophic bacteria and, specifically, antibiotic‐resistant Pseudomonas species. Waters lacking carbon dioxide and Heilwasser (waters often prescribed for a variety of ailments) tended to show the highest numbers of bacteria. Eighty‐one isolates of Pseudomonas were obtained from 39 samples of mineral water. Of the 9 species found, P. cepacia and P. maltophilia, most commonly associated with nosocomial infections, made up 13. 6% of the isolates. These 2 species also showed the highest resistance to the ten antibiotics used in the study. A comparison of antibiotic resistance patterns between mineral water and clinical isolates from the Medizinische Hochschule, Hannover, shows a higher similarity than that between mineral water and Massachusetts General Hospital (Boston) isolates. With the exception of P. pseudoalcaligenes, all mineral water isolates showed basically 100% resistance to cefoxitin and were highly resistant to ampicillin. Only 1 of 81 isolates (1. 2%) was resistant to tobramycin, although 2 isolates of P. cepacia showed intermediate resistance to this drug. Though no P. aeruginosa were found in any of the samples, the presence of species associated with nosocomial infections and highly resistant to commonly used antibiotics suggests that careful thought be given to the routine ingestion of mineral water by compromised individuals and those with underlying disease.
Kinetics and effect of moisture content and preincubation on the decomposition of 14C‐labeled herbicides in soil
Authors: Stenström John 
Published: October 2006

AbstractThe kinetics and the influence of soil moisture content (MC) on the mineralization of 14C‐labeled linuron were investigated at 15 different MCs in the range from air‐dried soil to 100% of the water‐holding capacity (WHC). For all MCs used, the data on the liberated amount of 14C (x) were initially described by Eq. (1) x = k1t + a—after which the data were described by Eq. (2) x = k2t1/2 + b—where t is time, k1 and k2 are rate constants, and a and b are constants. The rate constants k1 and k2 for MCs < 100% of WHC were mathematically described by the equation k = l + m. MC12, where k is either of the rate constants, l is a constant that can account for a threshold value of MC below which no decomposition occurs, and m is a constant. The validity of this equation for first‐order rate constants was tested by using data from the literature. The kinetics of mineralization of 14C‐labeled glyphosate were investigated by adding glyphosate after different times of preincubation (tp) of a previously frozen soil. An initial phase of 11 days linear with t [Eq. (1)] was obtained when the herbicide was added immediately after the thawing, after which a phase linear with t1/2 [Eq. (2)] ensued. The length of the initial phase decreased and k1 increased with increasing tp, and for tp ≥ 8 days the initial phase could not be confirmed. The following phase was almost unaffected by the preincubation. Thus, the phases represented by Eqs. (1) and (2) are separate, since they can be affected independently of each other. It is suggested that the initial phase is an induction phase, or lag phase, which reflects the disturbances introduced by handling the soil, and that the second phase is the steady state.
Use of Escherichia coli cloned with genes encoding bacterial luciferase for evaluation of chemical toxicity
Authors: Lampinen Jorma , Korpela Matti , Saviranta Petri , Kroneld Rolf , Karp Matti 
Published: October 2006

AbstractA 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.
Combination of single‐species laboratory tests for the assessment of the ecotoxicity of p‐Benzoquinone
Authors: Devillers J. , Steiman R. , Seigle‐Murandi F. , Prévot P. , André C. , Benoit‐Guyod J. L. 
Published: October 2006

AbstractThe 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.