Co‐production of 2,3‐BDO and succinic acid using xylose by <scp><i>Enterobacter cloacae</i></scp>

BACKGROUND 2,3‐Butanediol and succinic acid are staple chemicals that are widely used in the chemical industry. In this study, a new strategy for the simultaneous fermentation of 2,3‐butanediol and succinic acid by Enterobacter cloacae using xylose was developed. The mechanism by which the succinic acid pathway was enhanced during 2,3‐butanediol fermentation in E. cloacae was studied. In addition, the sodium bicarbonate feeding mode and time, pH, and aeration rate were optimized. Fed‐batch fermentation was performed under the optimal conditions using industrial xylose as a raw material. RESULTS The succinic acid pathway was enhanced by the addition of sodium bicarbonate during 2,3‐butanediol fermentation. Interestingly, a simple increase of the initial pH had no effect on the production of succinic acid. The sodium bicarbonate feeding mode and time, pH and aeration rate were optimized. Under the optimum conditions, including a sodium bicarbonate feeding mode of 2 and time of 12 h, a pH of 6.5 and an aeration rate of 0.4 vvm, a maximum of 40.67 g L ‐1 of 2,3‐butanediol and 21.79 g L ‐1 of succinic acid were obtained after a 72 h fed‐batch fermentation when xylose was used as raw material, with a total 2,3‐butanediol + succinic acid yield of 0.69 mol mol ‐1 xylose. CONCLUSION 2,3‐Butanediol and succinic acid were produced in a single fermentation step using E. cloacae . The production of 2,3‐butanediol and succinic acid was enhanced by controlling the sodium bicarbonate feeding mode and time, pH, and aeration rate. This type of fermentation provides a promising means of lowering the cost of production of these chemicals by reducing the fermentation operating time and fermentation equipment maintenance. © 2017 Society of Chemical Industry