The effect of Oidium lactis on the sporulation of Bacillus coagulans in tomato juice.

Oidium lactis can raise the pH of tomato juice in thin layers to a pH range optimum for sporulation of Bacillus coagulans in 24 hr at 25 C and in 48 hr at 35 C. The percentage of sporulation of B. coagulans was greater in tomato juice where O. lactis had grown than in the thermoacidurans broth. As high as 61.7% sporulation occurs within 24 hr in the tomato juice in which Oidium lactis had grown when this juice was incubated at 52 C. When tomato juice was adjusted to pH 5.0 and B. coagulans or a mixture of O. lactis and the vegetative cells of B. coagulans were added as an inoculum, only in the juice in which O. lactis was growing were spores produced within 72 hr at 35 C.