Development of a new integration site within the Bacillus subtilis chromosome and construction of compatible expression cassettes.

The Bacillus subtilis lacA gene, coding for beta-galactosidase, has been explored as a new site able to accept DNA sequences from nonreplicating delivery vectors. Two such delivery expression vectors have been constructed and shown to be useful in obtaining regulated expression from the chromosomal location. In another experiment, it was shown that the integration of a regulatory gene at the lacA locus was able to control the expression of a transcriptional fusion at the amyE locus. These experiments demonstrate that both integration sites can be used simultaneously to obtain regulated expression of desired genes.