Abstract
The mobile genetic element IS4Bsu1 of Bacillus subtilis (natto), the commercial strain used for natto fermentation, was found to spontaneously translocate to the swrA gene, which led to a defect in poly-γ-glutamic acid (γPGA) synthesis. The γPGA defect of NAFIS1 (swrA::IS4Bsu1) was restored by a plasmid harboring the swrA gene. The insertion of IS4Bsu1 to the swrA gene appeared not to interfere with minJ gene expression, located downstream of the swrA gene, because a defect in cell motility exhibited by NAF16 (minJ::Spcr) was not observed in NAFIS1 (swrA::IS4Bsu1). We found that the minJ gene is essential for γPGA synthesis.
