抄録
The pattern of development of amylase activity during growth of a transformable B. subtilis 168 grown at 52°C was different from that observed at 37°C. Amylase was produced during the stationary phase, but not at the exponential growth phase at 37°C, while, at 52°C, it was produced during the exponential growth phase, but not at the stationary phase. A type of mutants, whose pattern of development of amylase activity at 37°C was quite similar to that observed when B. subtilis 168 was grown at 52°C, were isolated from B. subtilis 168. They exhibited alterations of different phenotypic traits, such as loss of spore forming ability and altered pattern of cell growth, which were also found when B. subtilis 168 was grown at 52°C. Genetic studies showed that these phenotypic traits might be controlled by a single gene. The fact that one of these mutants was found to have a defect in the citric acid cycle, suggested an important role of functional citric acid cycle on the regulation of amylase production, especially in specifying the pattern of development of amylase activity during growth of B. subtilis 168.
