An optimized technique for rapid genome modifications of Bacillus subtilis.

The transformation efficiency of naturally competent Bacillus subtilis cells can be significantly increased using ß recombinase binding sequences, as revealed by the results of this study. Plasmids containing different variations of these so called six-site-marker-cassettes were investigated. Furthermore, an optimized protocol for knock-out or knock-in mutations combining the Cre-lox-system and the six-sites is presented, which can be used for multiple genome modifications of B. subtilis.