Abstract

A procedure for counting viable heterotrophic bacteria in the aerobic treatment processes of fellmongery and tannery effluent was evolved. The basic procedure was modified at the different stages of enumeration, the modification yielding the highest numerical value at each stage being adopted. Counts were significantly affected by the plating medium, pH of plating and incubation temperature but not by the homogenising procedure. A suitable routine technique for enumerating bacteria based on these experiments is discussed.