B. J. Dutka

Coprostanol as an indicator of fecal pollution

Coprostanol is a fecal sterol formed by microbial reduction of cholesterol in the intestines of man and higher animals. The fact that this sterol is ubiquitously present in the feces of man and is excreted at the rate of about 1 g/capita/day has prompted investigators to suggest the use of this sterol as an indicator of fecal pollution. It has been found to be particularly useful in problem situations such as toxic or heated effluents and seawater environments where the use of the usual indicator bacteria is suspect. This review discusses the advantages and disadvantages of using coprostanol as an indicator sterol, details the results of numerous field studies, and examines the future prospects for this pollution indicator.

Bacterial and biochemical tests for assessing chemical toxicity in the aquatic environment: A review

This review describes the use of biochemical and microbial tests to assess the toxicity of aquatic pollutants. Biochemical assays include the use of enzymes (dehydrogenase, ATPases, and others), luminescence, and ATP for measuring chemical toxicity in the aquatic environment. Bacterial tests also can serve as a tool for toxicity testing. These tests are based on measurement of growth inhibition or viability of bacteria and alteration of bacterial metabolism. These tests are relatively simple, rapid, and inexpensive as compared to fish bioassays.

Coliphage and bacteriophage as indicators of recreational water quality

Abstract Five popular beaches in Southwestern Ontario, Canada, were investigated for the presence of coliphage, bacteriophage and the standard bacterial indicators of fecal waste. Using current phage enumeration techniques, both coliphage and bacteriophage were recovered at all five beaches on each of ten sampling trips. Coliphage and bacteriophage results were available in 6 and 18 h, respectively. Based on recent reports on the association of coliphage and bacteriophage with enteroviruses in surface waters, and the consistent occurrence of both coliphage and bacteriophage at the five beaches investigated, future studies, on the determination of health risks related to bathers, should involve virological analyses including the enumeration of coliphage and bacteriophage.

Cell permeability to toxicants: An important parameter in toxicity tests using bacteria

There is a need to monitor quickly and inexpensively the toxicity of the myriad of exotic chemicals that are introduced daily into the environment. A wide range of microbial ecotoxicity tests have been developed to assess the impact of these toxicants on natural and manmade ecosystems. Criteria used for assessing the ideal microbial ecotoxicity test are simplicity, sensitivity, rapidity, and low cost. Much work has been done to develop simple short‐term and low‐cost ecotoxicity tests, but less is known about ways to increase the sensitivity of the test microorganisms, which are mostly Gram‐negative bacteria. During the past 3 decades, efforts have been made toward obtaining a better understanding of the structure of the outer membrane of Gram‐negative bacteria. There are serveral approaches for increasing the permeability of the outer membrane to hydrophilic, hyrophobic, and surface active compounds. This review explores these methods and their potential application to enhance the sensitivity of the test ...

Evaluation of disinfected and untreated drinking water supplies in chile by the h2s paper strip test

Abstract Potable water studies have suggested that the presence of coliforms in contaminated potable water supplies was also associated with hydrogen sulphide producing organisms. Based on these observations, a paper strip testing method was used and modified to screen for bacteriological contamination of potable waters. The simplicity and low cost of the H 2 S paper strip technique, if applicable to tropical and subtropical potable waters, would provide countries with an affordable, locally produced water quality monitoring test. To evaluate the feasibility of this test, 622 drinking water samples, disinfected and non-disinfected, were collected from three districts in Chile and tested by the H 2 S paper strip method and total coliform MPN method and for coliphages. Results from this study indicated that (l) in treated and untreated drinking waters tested by the H 2 S paper strip and total coliform MPN test, the H 2 S test produced slightly more (10%) positive findings and (2) when the positive H 2 S paper strip samples were tested for coliforms, the number of H 2 S positive samples containing coliforms was similar to the number of samples testing positive by the total coliform MPN.

Water and sediment ecotoxicity studies in Temuco and Rapel River Basin, Chile

Five samples were collected from the Rapel River Basin near the city of Rancagua and three from the city of Temuco. Three of the samples were collected from raw drinking water supplies. The following bioassays were performed on some or all of the samples: Microtox; Microtox solid phase test; SOS-Chromotest with and without S9; Toxi-Chromotest; Sediment-Chromotest; Panagrellus redivivus percent survival and percent maturation; submitochondrial reverse electron transfer and forward electron transfer tests; Daphnia magna 24 h acute toxicity; ECHA biocide monitor, and the competitive immunoassay tests for benomyl, metolachlor, atrazine, and triazines. All the sampling sites were positive for the presence of genotoxicants requiring S9 activation while three sites also indicated the presence of direct-acting genotoxicants/mutagens (−S9). Also, all the sites were positive for the presence of pesticides. In some samples there was 100% inhibition of P. redivivus maturation. Details and discussion on the implication of the results are presented.

River evaluation using ecotoxicological and microbiological procedures

One of the many problems researchers and managers face is to try and interpret data collected from various river studies. There is an underlying awareness of the incompleteness of most data bases due to a variety of problems outside of those concerning sample processing.In this study we have attempted, by using the battery of tests approach (12 tests) and the examination of different types of samples such as water, Milli-Q water extracted sediments, and organic solvent extracted sediments, to explore the implication of spacial and temporal sampling programmes.The results obtained were not unexpected: there were spatial and temporal influences, sometimes so great that it would appear that you were examining samples from different parts of the country. However, data arising from solvent extracted sediments were found to be much less influenced by temporal sampling than by spatial variation. Another interesting and important observation was that sediment composition appeared to have no relationship to toxicant content.In this study, the first field application of the Mutatox test (genotoxicity) was carried out and it was found to be a very responsive test in all three types of samples. This test shows great promise as laboratory studies indicate it is sensitive to many of the chemicals which trigger the Ames test.

Urban Impacts on River Shoreline Microbiological Pollution

Impacts of urban sources on fecal bacterial pollution of the near-shore zone of the St. Marys River in Sault Ste. Marie, Ontario, were studied during the period from June to November, 1991. For this purpose, water samples collected from 11 river sites and from five fecal pollution sources were analyzed for coliphage, Escherichia coli, fecal coliforms, and Pseudomonas aeruginosa. Observed microorganism densities were used to assess the levels of fecal bacterial pollution in relation to bacterial sources and the compliance with the recreational water quality guidelines. Almost the entire reach of the river studied exhibited very good bacteriological water quality with low fecal bacterial concentrations and high probabilities (generally greater than 90%) of compliance with the recreational water quality guideline taken as 100 E. coli/7 00 mL.

Distribution of Mutagens and Toxicants in Lake Ontario Waters as Assessed by Microbiological Procedures

Water samples collected from inshore and offshore waters in Lake Ontario, Toronto waterfront and Hamilton Bay were tested for mutagenic activity (Ames’ Test) and presence of acute toxicants (Spirillum volutans test). Data indicate many inshore waters contain mutagenic compounds which cause reversion of Salmonella tester strain TA 1535. The majority of samples tested did not contain acute toxicants based on the Spirillum volutans test.

The presence of bacterial virus in groundwater and treated drinking water

Ten raw urban well water samples and twelve water samples collected from distribution lines after the well waters were treated were examined for bacteriological and coliphage/bacteriophage populations. The raw well waters were found to contain <1/100 ml total coliforms and fecal streptococci, but they all contained varying concentrations of coliphage and bacteriophage. The treated waters were all found to have <1 total coliforms and fecal streptococci per 100 ml with the exception of one treated water sample from Community C. However, even though the treated water samples contained free and total chlorine levels varying from 0.05 to 1.5 ppm, they were all found to contain usually greater amounts of coliphage and bacteriophage than the raw well waters.