Effect of chlorination on β-D-galactosidase activity of sewage bacteria and Escherichia coli

Tryland,; Pommepuy,; Fiksdal,

doi:10.1046/j.1365-2672.1998.00465.x

Cited by 24 publications

(32 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The DVC method showed a 1.40-log reduction in able to divide counts after 1 hour, indicating a rapid decrease in the ability to form colonies but still retaining the capacity for dividing. Similar findings have been described for E. coli cells in chlorinated drinking water [21] and biofilm [22].…”

Section: Resultssupporting

confidence: 75%

See 1 more Smart Citation

The Effect of Chlorination on Escherichia Coli Viability in Drinking Water

Denisova

Mežule

Juhna

2014

Material Science and Applied Chemistry

View full text Add to dashboard Cite

-The assessment of drinking water disinfection efficiency traditionally involves the estimation of faecal indicator inactivation rates in the form of reduction of cultivable counts. Widely described, viable but noncultivable (VBNC) state as a form of bacterial survival strategy in oligotrophic conditions is not considered in these estimations. The aim of the present research is to assess the effect of free chlorine disinfection on faecal indicator Escherichia coli in order to study the succession of cellular alterations in response to chlorine exposure. To determine the inactivation rates, cell ability to form colonies, ability to divide as such and metabolic activity have studied. 0.064 mg/L min -1 free chlorine has been needed to obtain 99 % inactivation of cultivable counts; however, 5 till 200 times higher disinfectant dose x contact time has been required to reduce cell ability to divide and metabolic activity, respectively. The results have shown that to determine correct drinking water disinfectant doses multiple cell viability parameters should be analyzed.

show abstract

Section: Resultssupporting

confidence: 75%

“…The choice of the viability parameters in this study was based on the review of previous studies [21], [25], [27], [28] which described that the respiratory activity (CTC), substrate responsiveness (DVC assay) and cultivability were more direct methods for cell viability.…”

Section: Discussionmentioning

confidence: 99%

The Effect of Chlorination on Escherichia Coli Viability in Drinking Water

Denisova

Mežule

Juhna

2014

Material Science and Applied Chemistry

View full text Add to dashboard Cite

show abstract

“…Lack of correlation has been explained by enzyme activity from sources other than the culturable fecal indicator bacteria (E. coli, FC or total coliforms) that were used for comparison, for example, activity from non-fecal sources like algae and marine vibrios, non-specific cell-free enzymes or other cell-free substances capable of hydrolyzing the actual substrate, GAL-positive fecal microorganisms others than coliforms or by active, but non-culturable coliforms, and variations in the contribution from such sources [11,12,[23][24][25][26]. Disinfection or environmental stresses are shown to reduce the number of culturable fecal indicator bacteria more than the GAL activity, which may often explain why the enzyme activity is high even if the numbers of culturable coliforms are low [27][28][29][30].…”

Section: Discussionmentioning

confidence: 99%

Monitoring of β-d-Galactosidase Activity as a Surrogate Parameter for Rapid Detection of Sewage Contamination in Urban Recreational Water

Tryland

Braathen

Wennberg

et al. 2016

Water

View full text Add to dashboard Cite

Simple, automated methods are required for rapid detection of wastewater contamination in urban recreational water. The activity of the enzyme β-D-galactosidase (GAL) can rapidly (<2 h) be measured by field instruments, or a fully automated instrument, and was evaluated as a potential surrogate parameter for estimating the level of fecal contamination in urban waters. The GAL-activity in rivers, affected by combined sewer overflows, increased significantly during heavy rainfall, and the increase in GAL-activity correlated well with the increase in fecal indicator bacteria. The GAL activity in human feces (n = 14) was high (mean activity 7ˆ10 7 ppb MU/hour) and stable (1 LOG 10 variation), while the numbers of Escherichia coli and intestinal enterococci varied by >5 LOG 10 . Furthermore, the GAL-activity per gram feces from birds, sheep and cattle was 2-3 LOG 10 lower than the activity from human feces, indicating that high GAL-activity in water may reflect human fecal pollution more than the total fecal pollution. The rapid method can only be used to quantify high levels of human fecal pollution, corresponding to about 0.1 mg human feces/liter (or 10 3 E. coli/100 mL), since below this limit GAL-activity from non-fecal environmental sources may interfere.

show abstract

“…In our system (12 ml), a value of 1 ppb of MU accumulated over a period of 7 to 8 h corresponds to an enzyme activity from 1.6 ϫ 10 Ϫ7 to 1.4 ϫ 10 Ϫ7 mol of MU min Ϫ1 . According to previous studies on the interference of ␤-galactosidase-positive noncoliforms and the effect of chlorination on ␤-galactosidase activity (20,21), this value would correspond to the activity of approximately 10 6 VNC nontarget organisms or 10 3 to 10 4 E. coli also in a VNC state. The pass level value will therefore act as a "buffer" of at least 2 ppb, compensating for ca.…”

Section: Discussionmentioning

confidence: 99%

Field Evaluation of a Semiautomated Method for Rapid and Simple Analysis of Recreational Water Microbiological Quality

d’Auriac

Roberts

Shaw

et al. 2000

Appl Environ Microbiol

View full text Add to dashboard Cite

An early warning system using a rapid enzymatic semiautomated method suitable for fecal coliform detection in recreational waters within 8 h was developed further and evaluated in this study. This rapid method was compared to the standard method followed in the United Kingdom. We used 1,011 samples originating from 206 different locations in Wales. When we assessed the presence or absence of fecal coliforms, targeting very low levels of contamination, we obtained 83.9% agreement between the rapid method and the lauryl sulfate broth-membrane filtration technique, whereas direct confirmation of the samples processed by the rapid method showed 89.3% agreement. Environmental enzymatic background activity was found to be the main limiting factor for this method. Owing to a specific and integrated handling of the results by the software of the instrument, the percentage of false-positive results (a consequence of enzymatic background) was successfully limited to 2.9% by the direct confirmation evaluation. However, 7.8% false-negative results due to "late-growers" had to be accepted in order to produce results within a working day. At present, the method can be used in a more conservative way to assess the environmental threshold of 100 CFU of fecal coliforms per 100 ml in recreational waters. The implications of our findings with regard to the applicability of rapid enzymatic methods are discussed.The hygienic quality of water is of utmost importance to society, and efficient bacteriological control of water is essential for implementing a good management of this vital resource. To meet the need for a reliable and easy method for testing water microbiological quality, the coliform index was created (11), and in Europe the "guideline value" threshold for fecal coliforms has been set at 100 CFU/100 ml for bathing waters (19).The most commonly used quantification reference methods for monitoring the microbial quality of water employ membrane filtration or most probable number approaches, which both as a rule require 24 to 48 h for completion (2). In order to improve public safety and to reduce operational costs, faster microbiological detection is desirable for shortening the time required to implement appropriate measures in the case of an unacceptable level of contamination. To be useful, such methods ought to produce results within a working day; be quantitative, sensitive, and specific; require less work than the current standard methods; have a high throughput; and be nondestructive to the target organisms so as to allow confirmation work (17).For the identification of fecal coliform bacteria (FC), acid and gas production have been the basis of numerous methods. However, the finding that ␤-galactosidase-positive fecal coliforms, in particular Escherichia coli, in some cases do not produce gas due to the lack or loss of the enzyme formatehydrogen lyase (13) has led to the proposition of new definitions. The revised edition of Report 71 (14) no longer mentions the requirement for gas formation and requires instead the...

show abstract

Effect of chlorination on β-D-galactosidase activity of sewage bacteria and Escherichia coli

Cited by 24 publications

References 45 publications

The Effect of Chlorination on Escherichia Coli Viability in Drinking Water

The Effect of Chlorination on Escherichia Coli Viability in Drinking Water

Monitoring of β-d-Galactosidase Activity as a Surrogate Parameter for Rapid Detection of Sewage Contamination in Urban Recreational Water

Field Evaluation of a Semiautomated Method for Rapid and Simple Analysis of Recreational Water Microbiological Quality

Contact Info

Product

Resources

About