Negative regulator of sigma G-controlled gene expression in stationary-phase Bacillus subtilis.

In some media, Bacillus subtilis can maintain a prolonged stationary growth phase; however, in other media, nutrient depletion triggers a complex differentiation that culminates in production of a dormant endospore. This differentiation requires the expression of many genes. We found that during the stationary phase in media in which the cells do not form endospores and do not normally express these sporulation-essential genes, a recessive mutation in spoIIAB caused increased transcription of a set of genes essential for sporulation. Evidently, the wild-type product of spoIIAB acts during the stationary phase to prevent expression of additional sporulation-specific genes.