Heat-inducible DNA fragments of Bacillus subtilis were cloned with two different promoter probe vectors. The increased synthesis of the reporter enzymes seemed to be due to a transient increase in the transcription of the encoding genes. The structure of the heat-sensitive promoters resembles the consensus sequence of promoters recognized by the vegetative form of RNA polymerase of B. subtilis. Our results support data in literature that the heat shock response of B. subtilis is regulated by a different mechanism than in Escherichia coli, where alternative sigma factors direct the transcription of heat shock genes.
