Enzyme production also occurred over a pH range of 6 to 9, with highest production occurring at pH 7 and pH 9 for most substrates but differences in enzyme production at different pH were not significant and were more likely to be due to the substrates used rather than to the pH of the medium. Nevertheless, the pH of the medium is one of the main parameters which affect enzyme yields because pH changes can affect the stability of amylases in the medium. Maximum activities of amylases are between 4.5 and 7.0,slightly in the acidic region, although differences might occur depending on the source of the enzyme. This coincides with the observed result obtained for the optimum activity of the amylase at pH 7.Enzymatic activities observed at pH 9 could not only be due to the ability of the isolate to grow at a slightly alkaline pH but could also possibly suggest stability of the amylase at this pH, a fact which is yet to be determined.