Bacillus subtilis pgsE (Formerly ywtC) stimulates poly-γ-glutamate production in the presence of zinc.

Poly-γ-glutamate (PGA) is a versatile nylon-like material, and enhanced production of PGA is required for various bio-industrial applications. In this study, we first examined the effects of available sugars on the production of Bacillus subtilis PGA, and demonstrated the good applicability of pentoses (e.g., D-xylose). Then, we characterized the pgsE gene of B. subtilis, which encodes a 6.5-kDa protein of 55 amino acids (PgsE), as a genetic tool for increasing the yield of PGA without changing its structural features (e.g., polymer stereochemistry and molecular size distribution). In the presence of Zn(2+), the induction of PgsE tripled the PGA productivity of B. subtilis subsp. chungkookjang. This finding will contribute to the establishment of an improved PGA-production system.