Bacillus subtilis overproduces industrially important extracellular enzymes upon the targeted deletion of bacilysin biosynthetic operon

Özcengiz, Gülay
Aytekin, S.
Islerel, E. Tekin
Aktas, C.
Bacilysin being produced by Bacillus subtilis is the smallest peptide antibiotic ever known. It is composed of an N-terminal l-alanine and a modified amino acid at its C-terminal, namely anticapsin. bacABCDEF operon and a monocistronic gene bacG are functional for bacilysin production in the organism, bacABCDFG being needed for the flux from prephenate to anticapsin and then to mature bacilysin while bacE gene within the operon is involved in resistance of the producer by pumping bacilysin out of the cell. Our earlier studies demonstrated that quorum sensing global regulation operates in bacilysin biosynthesis through the action of ComQ/ComX, PhrC (CSF), ComP/ComA and molecular regulation also requires an intact surfactin biosynthetic operon, srfA. We recently performed a dynamic secretome analysis of B. subtilis PY79 and its bac operon-deleted derivative OGU1 by taking 2DE MALDI TOF/MS and LC–MS MS as complementary approaches and identified ca. 200 proteins (extracellular, membrane and wall-associated proteins) differentially expressed between two strains. Since B. subtilis is one of the most important cell-factories with a significant capacity to produce a wide range of extracellular enzymes, of biotechnological interest was a significant increment in levels of the industrially-important extracellular enzymes upon the deletion of bac operon. These enzymes included chitosanase, arabinanase, levanase, lipase, phytase, endonuclease, bacillopeptidase F and minor extracellular protease. In this report, the results of quantitative transcript analysis of the respective csn, abn2, sac, estA, phy, yhcR, bpr and vpr genes as well as enzymatic activities of their products are presented.