Abstract

The effect of cytochrome c_550 encoded by cccA in Bacillus subtilis during the event of sporulation was investigated. The sporulation of cccA-overexpressing mutant was significantly accelerated, while disruptant strain showed delayed sporulation in spite of the same growth rate. Activity of sporulation stage-0-specific enzyme, extracellular [alpha]-amylase of mutant strains was similar to that of the control strain, but cccA-overexpressing mutant exhibited higher activity of stage-II-specific alkaline phosphatase and stage-III-specific glucose dehydrogenase when compared to deletion mutant and control strain. Northern blot analysis also revealed that cccA-overexpressing mutant showed high level of spo0A transcripts, while the disruptant rarely expressed spo0A. These results suggested that although cytochrome c_550 is dispensable for growth and sporulation, expression of cccA may play an important role for initiation of sporulation through regulation of spo0A expression.

• Keywords: B. subtilis; cytochrome c_550; cccA; spo0A; sporulation