Objective: In this study, the samples from ten various sites of Uzuncayir Dam Lake
(Tunceli, Turkey) were microbiologically evaluated for the number of total and fecal coliform
bacteria.
Methods: Water samples (I 00 ml) were collected at ten various sites and sterile
screw-capped glass bottles stored at 4 °C until analysis in the laboratory within 2 h and
analyzed within one day. The number of total and fecal coli forms was performed by the most
probable number (MPN) method. Statistical tables were used to interpret the results to give
the MPN of the bacteria. MPN of coliforms determined using three replicate tubes containing
lactose broth medium, double and single strengths were used for 1 0, I and 0.1 ml,
respectively. The tubes were then incubated at 37°Cfor total coliforms and at 44°C for fecal
coliforms during 48 h. The positive tubes were streaked on the Eosin Methylene Blue (EMB)
agar plates using sterile loop and incubated at 37°C for 24 h.The formation ofgreen
coloniesmetallicshowed the presenceof E. coli.
Results and Discussion: The most widely accepted bacterial indicators of fecal
pollution in water have been the coliform group of bacteria. In this study, microbial indicators
of microbial pollution total coliform and fecal coliform were recorded as MPN/100 ml.
Microbial pollution values found in water samples collected from the ten different sites
inUzuncayir Dam Lake. The highest total coliform value (2:2400 MPN/100 ml) and the
highest fecal coliform levels (2:2400 MPN/1 00 ml) were found in lake water collected from
sites 6 and 8, respectively, while the lowest total coliform (75 MPN/100 ml) and the lowest
fecal coliform (23 MPN/100 ml) were determined in samples from site 4. Level of
microbiological pollution was determined according to the surface water quality standard
which is declared in water pollution law (Turkey). Results indicated that quality of the water
at some regions of the lake may be classified as class II whereas, at some regions where
contamination is higher, it appeared to be class III
