Enhanced 2,3-butanediol production from biodiesel-derived glycerol by engineering of cofactor regeneration and manipulating carbon flux in Bacillus amyloliquefaciens

• DOI: 10.1186/s12934-015-0317-2
• Publication Date: 2015-08-21T10:35:20Z
• Authors: Taowei Yang; Zhiming Rao; Xian Zhang; Meijuan Xu; Zhenghong Xu; Shang-Tian Yang
• Keywords: Bacillus amyloliquefaciens; Acetoin; Metabolic Engineering

Bacillus amyloliquefaciens B10-127 exhibited an excellent ability for industrial-scale microbial fermentation of 2,3-butanediol (2,3-BD) from biodiesel-derived glycerol. However, the accumulation by-products (acetoin, acetoin, lactate and succinate) 2,3-BD yield remains prohibitively low commercial production. Several strategies were developed to manipulate carbon flux branch in a designed B. amyloliquefaciens. Firstly, extra copies NADH/NAD+ regeneration system introduced into by co-overproduction glycerol dehydrogenase acetoin reductase, which resulting improvement production suppression accumulation. Subsequently, transcriptional regulator ALsR under control moderate promoter PbdhA was amyloliquefaciens, increased branch. Finally, three-stage dissolved oxygen strategy proposed based on analysis characteristic fermentation, two-stage pH different preferences ACR reduction oxidation. Following these strategies, high titer (102.3 g/L), (0.44 g/g), productivity (1.16 g/L/h) achieved. To our knowledge, this is highest reported using as substrate, should be candidate producing industrial scale.