The culture pH did not affect the optical purity. The production rate was the highest at pH 5.5. However, the specific growth rates of the indigenous lactic acid bacteria in the rice bran were estimated to be close to that ofL. delbrueckiiIFO 3202 at the pH. The growth rates of the indigenous lactic acid bacteria in the rice bran were lower at pH 4.5–5.0 than that of L.
delbrueckiiIFO 3202 although the production rate of lactic acid by the latter strain was lower than at pH 5.5 (Fig. 3)