NTU Undergraduates' research April 2014 - Biosciences | Page 29

ABSTRACT

Water is the most important resource utilised on a daily basis. The risks imposed upon this vital source can
be fatal, especially on those who have a compromised immune system. Various methods have been
designed in order to determine the quality of water such as the membrane filter method, most probable
number, presence & absence test or traditional plating methods. In order to evaluate the microbiological
quality of both environmental and commercial water exposed to the public, a total of 13 samples were
collected from recreational environments, drinking water facilities and in store bottled water located in
Nottingham. By incorporating traditional plating methods (Miles-Misra and spread plate), followed by an
altered version of the most probable number technique whereby the confirmed test was removed, 39% of
total samples were found to have coliform bacteria present. This excluded all drinking water samples and
the market square fountain. These coliforms were among the genera of Klebsiella, Enterobacter, Citrobacter
and Escherichia. The abundance of E. coli isolated among five of the samples including the River Trent, the
canal and a pond located in the Bunny Old West Wood nature reserve, suggested that this may be a result of
recent faecal contamination. The effect of rainfall and fluctuating temperatures was observed among the
River Trent samples that were repeated, showing a significant increase in the numbers of both coliform
bacteria and heterotrophic bacteria observed on the plates. In conclusion, the resulting data added to
knowledge of the importance of coliforms as indicators for other opportunistic organisms.
Key words: water, environmental, total coliforms (TC), indicator organisms, Escherichia coli, water, Multipletube fermentation (MTF/MPN)

Coliform and total bacterial counts in environmental and commercial water samples. – N0372487