Characterization and optimization of Bacillus subtilis ATCC 6051 as an expression host.

The genome sequence of Bacillus subtilis ATCC 6051 and its suitability as an expression host for recombinant protein production was determined. The comparison of this undomesticated wild type with the widely used laboratory strain B. subtilis 168 reveals a high degree of congruency between the two strains. Differences could only be detected on the level of point mutations or small insertions. B. subtilis ATCC 6051 shows none of the auxotrophies known for B. subtilis 168 and is able to produce polyketides. It exhibits better use of complex media and higher genomic stability through reduced natural competence. Consequently, B. subtilis ATCC 6051 was genetically modified to yield an optimized strain for the production of heterologously expressed proteins under control of an acetoin-inducible promoter.