bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coliphages as alternate indicators of fecal contamination in tropical waters
Authors: Hernández‐Delgado E. A. , Sierra M. L. , Toranzos G. A. 
Published: October 2006

AbstractStrong evidence has recently been found against the use of fecal coliforms as indicator organisms of fecal contamination in tropical waters due to their indigenous nature in pristine waters. There is a great need for the development of more rapid, accurate, and low‐cost techniques for determining bacteriological water quality. Coliphages seem to be an excellent alternative. We have developed a method to analyze large volumes of pristine water, which we compared to a commonly used direct method. It involves the filtration of water through positively charged filters and a virus‐elution step. The eluent is then mixed with culture medium, a host bacterium, and incubated. We sampled pristine tropical rivers, water collected from bromeliads (epiphytic vegetation), sewage‐contaminated waters, and marine waters. Concentrations of indicator bacteria were higher than recommended levels for recreational waters, including bromeliad waters. Indicators levels were higher in bromeliad waters than in sewage‐contaminated rivers. Phages were isolated only from waters being used for recreational purposes and from sites known to be contaminated with domestic sewage, but not from pristine or bromeliad waters. These results suggest that there is a correlation between the presence of coliphages and fecal contamination. This further suggests that coliphages may be reliable indicators of fecal contamination in the environment.
Shellfish and marine water microbiological quality
Authors: Sato M. I. Z. , Monteiro C. K. , Stoppe N. C. , Sanchez P. S. , Ostini S. , Matté G. R. 
Published: October 2006

AbstractSewage discharge to the marine environment constitutes an important problem faced by public health and environmental managers, and exerts great economic and social impact on shellfish‐producing areas. This study aims at characterizing the water quality and shellfish sanitary conditions of different growing areas on the northern coast of the São Paulo State. Seventy‐two samples of water and shellfish were enumerated for total and fecal coliforms, and were analyzed for the presence ofSalmonella. The most probable number ofVibrio parahaemolyticuswas also determined for shellfish samples. Shellfish contamination was directly related to the bacteriological pollution of the water, such that in growing areas not contaminated with sewage discharges, 100% of shellfish samples presented themselves as being safe to be consumed.Salmonellawas absent in all samples analyzed andV. parahaemolyticuswas present in lower densities in shellfish samples. The percentage of water samples that did not comply to the standard were much higher than those of shellfish samples, indicating the need to reevaluate the permitted values of the Brazilian legislation both for shellfish “in natura” and for growing waters. This study also establishes the need for a better management of shellfish‐producing areas, especially those more polluted, in parallel with the development of a Brazilian Shellfish Sanitation Program, in order to protect the quality of these organisms and consequently human health.
Detoxification and reclamation of Suncor's oil sand tailings ponds
Authors: Nix P. G. , Martin R. W. 
Published: October 2006

AbstractSuncor, Inc., operates an oil sands mining and extraction plant in northern Alberta, and uses tailings ponds for disposal of waste tailings sludge and for conditioning recycle water. In their active state, tailings ponds consist of a layer of toxic top water overlying a viscous layer of sludge containing toxic interstitial water as well as particles of unprocessed bitumen and clay fines. To address the need for reclamation of the mine site, Suncor is exploring a concept of sludge disposal whereby mature sludge would be pumped out of existing tailings ponds into a mined pit area with an overlying layer of top water. This reclamation strategy would retain both top water and sludge on site in contrast to conventional schemes whereby sludge would be dewatered and reclaimed using dry land reclamation techniques (i.e., revegetation). The success of this wet pond reclamation scheme would rely on natural processes of microbial biodegradation and detoxification over time to achieve improvements in the quality of the top water layer. Although anaerobic interstitial water in the sludge may remain toxic for long periods, the sludge would be permanently isolated beneath a surface layer of top water.Bench‐scale and field‐scale tests (e.g., test tanks and large pits) were utilized in a series of experiments to assess the feasibility of wet pond reclamation. Toxicological testing of the top water layer characterized the rate of detoxification, and elucidated the nature and extent of subsequent colonization by aquatic plants and animals. The results suggest that after mine abandonment, a reclaimed tailings pond could be designed such that it is transformed over time from a toxic waste pond into a viable and productive ecosystem with biologically complex aquatic communities in its surface water.
Glyphosate effects on microbial biomass in a coniferous forest soil
Authors: Stratton Glenn W. , Stewart K. Elaine 
Published: October 2006

AbstractThe herbicide glyphosate (Roundup) was applied aerially to a conifer forest that had previously been clear‐cut and reforested. Glyphosate was tested for effects on microbial biomass, numbers of selected microorganisms, and soil respiration over a period of 8 months by comparing treated and untreated zones of the clay loam forest soil (FS) and the overlying litter (FL), both pH 3.8. With microbial biomass, glyphosate generally had a stimulatory effect in FL, but usually no significant effect in FS. Glyphosate had no significant effect on numbers of bacteria, fungi, and actinomycetes in either FL or FS. The herbicide generally stimulated respiration in both FL and FS. In laboratory bioassays using FL, FS, and three agricultural soils, glyphosate had no significant effect on respiration when used at concentrations up to 100 times higher than recommended field application rates. Respiration rates in FL, as measured with Warburg respirometry, were unaffected by glyphosate. Respiration rates in FS were stimulated by glyphosate concentrations 10 and 100 times higher than recommended field rates. Glyphosate should have no deleterious effects on microbial biomass and respiration in forest soils when used under recommended conditions. © 1992 John Wiley & sons, Inc.
Cadmium biosorption and toxicity to six cadmium‐resistant gram‐positive bacteria isolated from contaminated soil
Authors: Boularbah Ali , Morel J. L. , Bitton G. , Guckert A. 
Published: October 2006

AbstractSix Cd‐resistant bacterial strains were isolated from a soil receiving dredged sediments and containing Cd at concentration of 50 mg kg−1. The isolates, identified as gram‐positive, were studied with regard to their ability to tolerate and accumulate Cd at concentrations varying from 0 to 100 mg L−1. Results showed an increase in accumulated Cd in bacteria with increasing Cd concentrations in solution. Isolates were shown to tolerate higher Cd concentrations than a Bacillus subtilis strain used as a control. One of the isolates, identified as Bacillus brevis, was found to be the most resistant to Cd, with an ability to accumulate the toxic metal up to 70 mg−1 of cells (dry weight). Mn was found to reduce Cd toxicity and accumulation in B. brevis. This strain may have some potential interest in reclamation of metal‐contaminated soils. © 1992 John Wiley & sons, Inc.
Multiple assays of uranium toxicity in soil
Authors: Sheppard S. C. , Evenden W. G. , Anderson A. J. 
Published: October 2006

AbstractThe literature offers conflicting information on the phytotoxicity of uranium (U) in soil. Levels as low as 5 mg U/kg soil, well within the normal background range, have been cited as toxic, whereas many studies report no toxicity at levels 100‐ to 1000‐fold higher. Uranium in soil does not often present a radiological hazard to humans, but toxicity to plants could lead to prescribed cleanup and assessment criteria for industrial activities. This study was designed to identify the toxic threshold of soil U. Nine levels of U were added to background‐level soils. Beans were grown to maturity in an outdoor lysimeter study with 2 soils. Germination tests in the growth chamber were done with 11 soils and with 5 plant species. A rapid cyclingBrassica rapacultivar, proposed as a new toxicity test subject, was grown to maturity on 2 soils in the growth chamber, and germination of the second‐generation seeds was investigated. Earthworm survival and soil phosphatase activity were measured. Measures of soil‐extractable and tissue U concentrations were obtained. None of the measurements indicated detrimental effects of U below 300 mg/kg. In one of the soils,B. rapaproduced seed at concentrations as high as 10,000 mg U/kg. The phytotoxicity of U occurred at concentrations 8‐ and 3‐fold higher than the concentrations of As and Zn, respectively, which gave the same effect. © 1992 John Wiley & sons, Inc.
Sulfate elimination to improve water quality of mine process effluents. I. Sequencing batch bioreactor growth kinetics of desulfovibrio desulfuricans
Authors: Herrera Leandro , Duarte Sergio , Hernandez Jose 
Published: October 2006

AbstractThe sulfate reducing bacterium, Desulfovibrio desulfuricans NCIMB 8372, was cultured in a 1‐L biochemical reactor. The reactor was operated in a sequential batch mode and the results of four sequential runs are presented (the first run was a recently inoculated reactor).Results fall within the range of published results, reaching sulfate reduction rates up to 2764.8 mg/L/day. The bacteria attached to the reactor walls and a method was proposed to evaluate the magnitude of the adhered cells fraction, which resulted in a value of 1.2–3.0 · 106 cells/cm2, a value that correlated well with cells counted in scanning microscope photographs taken from a tube in the reactor. © 1993 John Wiley and Sons.
Ecotoxicity testing of heavy metals using methods of sediment microbiology
Authors: Reichardt W. , Heise S. , Piker L. 
Published: October 2006

AbstractCurrent measures of microbe‐mediated biogeochemical processes in sediments were examined for their potential use as indicators of heavy metal ecotoxicity in both river sediments and bacterial cultures. Assays were carried out with HgCl2, CuSO4, and 3CdSO4 · 8H2O added to sediment samples and bacterial cell suspensions at concentrations ranging from 0.1 to 10 mM and 0.1 μM to 1 mM, respectively.Chemoautotrophic CO2 fixation by Elbe River sediment microbiota was most sensitive to Hg2+ and Cd2+, but not to Cu2+.Among the estimates of heterotrophic productivity, incorporation of leucine into cellular protein showed clearer dose responses than incorporation of thymidine into bacterial DNA. Thymidine incorporation was highly resistant to and even stimulated by metal ions, particularly in starved and anaerobic cultures of a test strain of Vibrio anguillarum. Similar metal ion induced “overshoot” responses beyond the levels of untreated controls were noted for mineralization of 14C‐glucose by V. anguillarum and, in the case of Cd2+, also in sediment.As a less complex measure of microbial respiratory activity, succinate dehydrogenase (SDH) showed normal dose responses without stimulatory effects, as long as bacterial cell homogenates were assayed. Despite this result, it is concluded that levels of SDH in natural sediment microbiota are inevitably affected by metal‐induced processes of selection and enzyme synthesis, and would thus fail to provide an appropriate measure of metal ecotoxicity. The final conclusion is that current parameters of microbial production and activity often reveal dose responses that do not fulfill basic requirements of ecotoxicity testing in metal‐polluted sediments. © 1993 John Wiley & Sons, Inc.
Monitoring sãto paulo state rivers in brazil for mutagenic activity using the ames test
Authors: Valent Gisela U. , Sato Maria Ines Z. , Cristina Maria , Coelho L. S. , Coimbrão Carlos Alberto , Sanchez Petra S. , Martins Maria Therezinha , Bonatelli Renato 
Published: October 2006

AbstractOrganic extracts of raw water from 11 water courses of São Paulo State, Brazil, were collected during one year bimonthly and tested for mutagenicity using the Ames test, with strains TA98 and TA100 of Salmonella typhimurium with and without metabolic activation. The samples were extracted with XAD2 resin and eluted with methanol and methylene chloride. From the 75 samples analyzed, 14 showed positive responses and 8 were considered marginal, making up 29% of mutagenic samples. The percentage of mutagenic samples in October (spring) was 9%, increasing to 64% in February (summer), and decreased to 9% again in August (winter). Paraiba do Sul river showed the higher percentage of mutagenic samples (67%) and Capivari river the highest mutagenic sample (1787 and 3265 revertants per liter for TA98 without and with S9, respectively).The amplitude of the mutagenic response was 39–3265 revertants per liter for TA98 and 83–467 for TA100. The mutagenic samples showed direct and indirect mutagens, and TA98 detected the majority of responses, indicating prevalence of frameshift mutagens in these samples. © 1993 John Wiley & Sons, Inc.
Potential application of biophysical interrelationships for faster evaluation of sequencing batch reactor effluent quality
Authors: Sim T. S. , Ng W. J. , Ong S. L. , Ng K. Y. , Ramasamy M. , Tan K. N. 
Published: October 2006

AbstractConventional parameters for assessing effluent quality like the 5‐day biological oxygen demand, (BOD5), total suspended solids (TSS), and coliforms take from one to five days before the tests are completed. Simple, rapid, economical, and reliable methods to determine wastewater quality parameters are essential for the effective control of effluent discharges and the monitoring of process performance. If disinfection is necessary, these rapid methods may be used to quickly estimate the disinfection requirements and to ensure that the final effluent quality is microbiologically adequate. This is especially applicable to the sequencing batch reactor system, which treats wastewater in a batchwise manner. The 6‐h coliphage, 3‐h chemical oxygen demand (COD) and 1/2‐h total organic carbon (TOC) tests have been identified as rapid tests. Being microbiologically related, the coliphage test was shown to have a good degree of correlation with coliform levels in the effluent. Predictions of coliform numbers may be made by enumeration of the phages. The COD was also correlated and shown to produce a quick estimate of the total BOD5, TSS, and coliform values. Although the TOC test is based on the dissolved portion of the effluent, it may also be used as a rapid estimation of the total BOD5, TSS, and coliform values. © 1994 by John Wiley & Sons, Inc..
Microbial toxicity mechanism of copper‐8‐quinolinolate
Authors: Liu D. , Maguire R. J. , Pacepavlcius G. J. , Carey J. 
Published: October 2006

AbstractSapstain, an abnormal discoloration in wood caused by microbial growth, can significantly lower the price of a lumber and thus fresh sawn softwood lumber of a susceptible species is often treated with a biocide such as pentachlorophenol (PCP) to prevent the development of sapstain during shipping and prolonged storage. Very recently, chlorophenol‐based antisapstain agents have been banned in Canada, because of environmental toxicity. The purpose of this study was to elucidate the microbial toxicity mechanism of the copper salts of 8‐quinolinolate (Cu‐8‐HQ), one of the replacement chemicals for PCP in sapstain control. The results revealed that the biocidal activity of Cu‐8‐HQ originates from a stable metal (copper) chelate and that the molecular integrity of the chelate is most critical in the expression of its toxicity potential. The chelating power of 8‐hydroxyquinoline for trace metals was not found to be directly responsible for the biocidal activity of Cu‐8‐HQ as suggested in the literature. The anion groups were found to have no significant impact on the biocidal activity of Cu‐8‐HQ, which has been observed with other organometallic compounds. © 1994 by John Wiley & Sons, Inc..
Distribution of dichlorodiphenyltrichloroethane (DDT) and its metabolites in an Indian waterway
Authors: Sujatha C. H. , Nair S. M. , Kumar N. C. , Chacko J. 
Published: October 2006

AbstractThis paper reports on the results of systematic analyses carried out to assess the distribution of dichlorodiphenyltrichloroethane (DDT) and its metabolites, o,p′‐DDT, p,p′‐DDE, and p,p′‐DDD in a tropical waterway, the Cochin Estuarine System. Six sampling stations along the system were studied. Analyses were carried out during premonsoon, monsoon, and postmonsoon seasons. ΣDDT concentrations as high as 55.422 μg L−1 were detected. The predominant DDT metabolite was found to be p,p′‐DDE. During the monsoon season, o,p′‐DDT was not detected at any of the sampling Stations. Station 1 (riverine) and station 6 (coastal zone barmouth) emerged as DDT‐free zones and the analytical results have enabled the identification of DDT “hot spots” in the estuary. © 1994 by John Wiley & Sons, Inc..
Removal of influenza A virus, phage T1, and PP7 from fluids with a nylon 0.04‐μM membrane filter
Authors: Oshima Kevin H. , Highsmith Anita K. , Ades Edwin W. 
Published: October 2006

AbstractWe tested the ability of a 0.04‐μm nylon membrane filter to remove viral agents (influenza A virus, 80–120 nm; phage T1, 50–150 nm; and phage PP7, 25 nm) from the following media: ultrapure water (UPW), Dulbecco's modified Eagle minimum essential medium (DMEM), gelatin phosphate (GP), DMEM with 10% (DMEM‐10) fetal bovine serum (FBS), and 100% FBS. When challenged with at least 3.0 × 107 plaque‐forming units/mL, no influenza A virus was detected downstream of the filter with any of the fluids tested. The titer reduction (Tr) was determined using the equation:

equation image
.Higher concentrations of phage T1 were removed from UPW (Tr = 1.6 × 106) and DMEM (Tr = 1.1 × 106) than from GP (Tr = 9.3 × 103), DMEM‐10 (Tr = 1.5 × 102), and 100% FBS (Tr = 2.4 × 102). Phage PP7 was removed in significant numbers only in ultrapure water (Tr = 8.5 × 104). The results indicate that adsorption enhanced the titer reduction in fluids containing low levels of protein. The titer reduction in DMEM‐10 and 100% FBS may reflect the sieving properties of the 0.04‐μm filter. As expected, a much smaller Tr was observed in the filtrate of the 0.2‐μm filters, compared to the 0.04 μm filters. In contrast to the 0.04‐μm filter, no increase in Tr was detected when the 0.2‐μm filters were challenged with virus diluted in UPW compared with virus diluted in GP. These results suggest that the 0.04‐μm filter has greater adsorptive properties than the 0.2‐μm filter. © 1994 by John Wiley & Sons, Inc..
The effects of chromium on the growth and activity of a pentachlorophenol‐degrading bacterium
Authors: Wall A. James , Stratton Glenn W. 
Published: October 2006

AbstractThe effects of chromium (or chromate, as supplied by CrO3) on a pentachlorophenol‐degrading Flavobacterium sp. (ATCC 53874) were examined in a liquid bacterial growth medium. Cr6+ concentrations ⩾ 5.0 μg mL−1 caused the complete inhibition of bacterial growth. The EC25, EC50, and EC75 calculated after 96 h of incubation were 0.44, 1.44, and 3.82 μg mL−1, respectively. Cr6+ caused an irreversible reduction in total cell yield during the 21‐day incubation. Cr6+ also elicited an increase in the lag time recorded before there was measurable pentachlorophenol (PCP) degradation by this bacterium. There was also an increase in the overall time required for complete degradation of PCP to nondetectable levels. A similar response was noted with all PCP concentrations examined from 10 to 100 μg mL−1. However, a more pronounced response occurred at the lower PCP concentrations. The significance of these data relative to the in situ use of PCP‐degrading bacteria for site bioremediation is outlined. © 1994 by John Wiley & Sons, Inc..
Toxicity and genotoxicity enhancement during polycyclic aromatic hydrocarbons' biodegradation
Authors: Belkin Shimshon , Stieber Michael , Tiehm Andreas , Frimmel F. H. , Abeliovich Aharon , Werner Peter , Ulitzur Shimon 
Published: October 2006

AbstractSeveral laboratory column percolators were operated in order to study the bioremediation potential of polycyclic aromatic hydrocarbons (PAH)‐contaminated soils. The columns contained either soil artificially amended with specific PAH mixtures or contaminated soil from a site in Karlsruhe, Germany. In all cases, biodegradative processes led to the elimination of the original contaminants. This, however, was accompanied by a marked increase in genotoxic activity of the column effluents as determined by the MutatoxTM assay. Genotoxicity was practically abolished, however, when a surfactant was added to the percolating fluids. While in some cases the changes in genotoxicity were paralleled by toxicity (MicrotoxTM) data, in others the trend was opposite.It is concluded that when degradation is incomplete, the potential exists for toxicity and genotoxicity enhancement, with the latter hazard not always predictable by short‐term toxicity assays. Routine genotoxicity monitoring is thus advocated for bioremediation projects; the MutatoxTM assay appears to be a convenient tool for this purpose. © 1994 by John Wiley & Sons, Inc..
Utilization of a bioluminescence toxicity assay for optimal design of biological and physicochemical wastewater treatment processes
Authors: Brenner Asher , Belkin Shimshon , Ulitzur Shimon , Abeliovich Aharon 
Published: October 2006

AbstractA comprehensive laboratory investigation was conducted to test the feasibility of employing biological and physicochemical treatment processes for complex wastewaters discharged by several chemical industries. Results obtained during this study indicated that the wastes contain a fraction of toxic and nonbiodegradable organic matter, which limits the implementation of a conventional biological treatment process for the combined wastewater stream.Toxicity, as measured by a bioluminescence assay (Microtox), served as a valuable tool to assess biological treatability of various waste sources, with the aim to select an economically feasible and environmentally acceptable treatment/management program for an industrial park. Toxicity values served as quantitative indices for the establishment of baseline data of removability potential, defined either by biodegradation or carbon adsorption. This removability data enabled identification of problematic waste sources, which are only partially biodegradable and/or possess considerable toxicity.Further investigation of the problematic waste streams focused on the evaluation of activated carbon adsorption characteristics, using toxicity balances instead of traditional chemical determinations. This method could be successfully employed to yield simultaneously both adsorption characteristics and an assessment of the impact of the treated effluent on biota in receiving waters. © 1994 by John Wiley & Sons, Inc..