Engineered Enterobacter aerogenes for efficient utilization of sugarcane molasses in 2,3-butanediol production

Sugarcane molasses is considered to be a good carbon source for biorefinery due to its high sugar content and low price. Sucrose occupies more than half of the sugar in the molasses. Enterobacter aerogenes is a good host strain for 2,3-butanediol production, but its utilization of sucrose is not very efficient. To improve sucrose utilization in E. aerogenes, a sucrose regulator (ScrR) was disrupted from the genomic DNA. The deletion mutation increased the sucrose consumption rate significantly when sucrose or sugarcane molasses was used as a carbon source. The 2,3-butanediol production from sugarcane molasses by the mutant was enhanced by 60% in batch fermentation compared to that by the wild type strain. In fed-batch fermentation, 98.69 g/L of 2,3-butanediol production was achieved at 36 h.