Construction of acetoin high-producing Bacillus subtilis strain

Abstract

This paper describes the construction and selection of a high-producing mutant, Bacillus subtilis HB-32, with enhanced acetoin yield and productivity. The mutant was obtained by the protoplast fusion of a Bacillus subtilis mutant TH-49 (Val−) producing acetoin and Bacillus licheniformis AD-30 producing α-acetolactate decarboxylase, with the fusogen polyethylene glycol and after the regeneration and selection, etc. of the fusant. The acetoin production reached 49.64 g/L, which is an increase of 61.8% compared to that of B. subtilis strain TH-49. Random amplified polymorphic DNA analysis was performed to determine the mutagenic and protoplast fusion effects and the genomic changes in the acetoin high-producing strain compared to the parent strains at the molecular level. The constructed strain was shown to be promising for large-scale acetoin production. Future studies should focus on the application of the mutant strain in practice.