High Production of 2,3-Butanediol (2,3-BD) by Raoultella ornithinolytica B6 via Optimizing Fermentation Conditions and Overexpressing 2,3-BD Synthesis Genes
Fig 2
Fed-batch fermentation of glucose by R. ornithinolytica B6 with an agitation speed of 200 rpm; (a) without pH control; (b) with pH maintained at 7.0; (c), pH controlled at 5.5 after pH dropped to 5.5 from the initial pH of 7.0.; ■, glucose; □, growth; ♢, ethanol; ●, acetoin; ○, 2,3-BD; ♦, acetic acid; ▲, succinic acid; △, lactic acid; +, butyric acid.