A novel strategy for integrated utilization of Jerusalem artichoke stalk and tuber for production of 2,3-butanediol by Klebsiella pneumoniae

Jerusalem artichoke stalk and tuber can serve as a low cost feedstock for the production of 2,3-butanediol. However, like other lignocellulosic materials, the sugar concentration in the hydrolysate prepared from Jerusalem artichoke stalk is too low to be utilized effectively by microorganisms. In this paper a novel strategy was proposed to increase the sugar concentration by adding Jerusalem artichoke tuber into the hydrolysate of the stalk. The sugar was then biotransformed into high-valued 2,3-butanediol by Klebsiella pneumoniae. Fed-batch simultaneous saccharification and fermentation (SSF) was effectively performed and 901.2 mmol/l (80.5 g/l) target products (2,3-butanediol plus acetoin) was obtained in 68 h by a stage-shift aeration strategy. The concentration, yield and productivity of target products were 16.9%, 16.8% and 23.4%, respectively, higher than the best results obtained with SSF operated under constant aeration. This showed that adding tuber to the stalk hydrolysate was a useful strategy for increasing the production of 2,3-butanediol from Jerusalem artichoke via fermentation.