Each 50 ml sample and a control, was thoroughly vortexed to
evenly distribute the microorganisms. A 1 ml aliquot of each sample
was pipetted into 9 ml quarter strength Ringers’ solution to prepare
serial dilutions of 100 to 109. The dilutionwas thoroughly vortexed
and aseptically pour plated into selective media (Table 1) to determine
the number of cells in colony forming units (cfu ml1).