Distribution and Statistical Analysis of Bacteria in Lake Alau in the Arid Northern Nigeria

The direct microscopic count using bright field illumination was subjected to a statistical comparison with four different microbial cell viability procedures viz., pour plate, spread plate, most probable number (MPN) and membrane filtration (MF) for the analysis of the distribution of bacteria in water samples from Lake Alau Dam in the arid Northern Nigeria. A total of 27 samples were collected from three locations of the dam site and analysed. The total coliform represented 32% of the 22 isolates and of this 10% represented the fecal coliform bacteria. The fecal coliform level of 6.0 x 10² to 8.8 x 10²/100ml placed lake Alau Dam water samples in the EEC Grade A2 and thus, the water is recommended for further treatments before it can be distributed to municipalities for domestic use. Statistical analysis using one-way analysis of variance (ANOVA) showed significant differences in counts between three locations, based on the direct microscopic counts. There were no significant differences in counts between locations using the four cultural methods. There was an honestly significant difference (hsd, 5% level, Tukeys test) between the direct microscopic counts and the four cultural methods, but there was not honestly significant difference (hsd, 5% level) between the four cultural methods. It is concluded that in the absence of more sophisticated procedures, the four cultural methods together with the direct bright field microscopic count procedure served to establish a good measure of the microbiological quality of the Lake Alau water, this is strengthened by the statistical correlations. @JASEM