Colorimetric enumeration of Escherichia coli based on beta-glucuronidase activity
Adams, M. R., Grubb, S. M., Hamer, A. and Clifford, M. N. (1990) Colorimetric enumeration of Escherichia coli based on beta-glucuronidase activity Applied and Environmental Microbiology, 56. pp. 2021-2024.
A medium containing a chromogenic substrate was developed for the enumeration of Escherichia coli on the basis of beta-glucuronidase activity. In this medium there was an inverse linear relationship between the log initial E. coli concentration and the time taken for the color to reach a threshold optical density of 0.05. This relationship applied even when the E. coli population contained 5% beta-glucuronidase-negative cells. Incubation at 44 degrees C reduced the time taken for color development and allowed the procedure to be used in the presence of a competitive microflora that outnumbered the E. coli population by a factor of 10(4). Sodium lauryl sulfate as an additional selective agent gave no significant improvement. In the analysis of environmental water samples, the technique gave a good correlation with a standard cultural method. The procedure shows promise as a simple method for testing the compliance of environmental samples with microbiological criteria for E. coli.
|Divisions :||Faculty of Health and Medical Sciences > Nutrition and Metabolism|
|Date :||1 July 1990|
|Additional Information :||Published in Applied and Environmental Microbiology, Vol. 56 (7), p.p. 2021-2024. © American Society for Microbiology, 1990.|
|Depositing User :||Mr Adam Field|
|Date Deposited :||27 May 2010 14:39|
|Last Modified :||23 Sep 2013 18:31|
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