Efficient production of 2,3-butanediol from cheese whey powder (CWP) solution by Klebsiella pneumoniae through integrating pulsed fed-batch fermentation with a two-stage pH control strategy

Abstract

In this study, several strains were investigated to evaluate their ability to produce 2,3-butanediol (2,3-BD) from cheese whey powder (CWP). The capacity of these strains for 2,3-BD production was assessed in lactose medium and two strains Klebsiella pneumoniae CICC 10781 and K. oxytoca CICC 21518 were selected. Fully assessing the fermentation performances indicate that CICC 10781 was more suitable for 2,3-BD production from CWP than CICC 21518. Response surface methodology was applied to optimize the medium composition. Na3C6H5O7·2H2O, CH3COONa, and urea were the key factors influencing 2,3-BD synthesis, and the optimal concentrations were 3.65, 5.45, and 0.54g/L, respectively. Two-stage pH control strategy with pulsed fed-batch fermentation was then developed, in which the pH was maintained at 6.5 for the first 8h and then shifted to 6.0 till the end of fermentation. Using this strategy, the maximal 2,3-BD production reached 57.63g/L. The results may provide new guidance for industrial-scale production of 2,3-BD from CWP.