The effect of pH is crucial in terms of growth of the producing organism and the
biosynthesis of α-amylase. According to our studies, both the growth of Bacillus sp.
WA21 and the α-amylase production continued over a wide range of pH (3-11) as shown
in Fig. 3. However, optimum growth and enzyme production was achieved at pH 6.
Utong et al., (2006) had described the ability of Bacillus sphericus to produce
extracellular enzyme if grown at pH 6-9 range.