Effects of pH and dissolved CO2 level on simultaneous production of 2,3-butanediol and succinic acid using Klebsiella pneumoniae

Abstract The influences of pH and dissolved CO 2 level on the regulation of growth and formation of catabolic end products have been investigated in Klebsiella pneumoniae . With increasing CO 2 levels, there were no apparent changes in 2,3-butanediol production but succinic acid productions were enhanced significantly. A novel strategy for co-production of 2,3-butanediol and succinic acid using K. pneumoniae was developed by controlling pH and dissolved CO 2 concentration in fermentation medium. Under the optimum condition, maximal 77.1 g l −1 2,3-butanediol and 28.7 g l −1 succinic acid were obtained after 60 h of fed-batch fermentation, giving a 2,3-butanediol + succinic acid yield of 1.03 mol mol −1 glucose. This type of fermentation producing two commercial interests at the same fermentation process might be considered for a promising biological production process which will decrease the production cost by sharing the operation and recovery cost.