Bacillus subtilis ccpA gene mutants specifically defective in activation of acetoin biosynthesis

A large number of carbon source utilization pathways are repressed in Bacil lus subtilis by the global regulator CcpA, which also acts as an activator of carbon excretion pathways during growth in media containing glucose. In this study, CcpA mutants defective in transcriptional activation of the als SD operon. which is involved in acetoin biosynthesis, were identified. Thes e mutants retained normal glucose repression of amyE, encoding alpha-amylas e, and acsA, encoding acetyl-coenzyme A synthetase, and normal activation o f ackA, which is involved in acetate excretion; in these ccpA mutants the C cpA functions of activation of the acetate and acetoin excretion pathways a ppear to be separated.