多粘类芽孢杆菌同步糖化发酵玉米粉生产(R，R)-2，3-丁二醇

Simultaneous Sccharification and(R,R)-2,3-butanediol Fermentation from Corn Flour by Paenibacillus polymyxa

【目的】对多粘类芽孢杆菌Paenibacillus polymyxa的玉米粉同步糖化发酵工艺进行优化,以获得低成本、高效的(R,R)-2,3-丁二醇生产技术。【方法】研究玉米粉浓度、氮源种类和氮源浓度对菌体生长、耗糖能力以及(R,R)-2,3-丁二醇产量、产率、得率和转化率的影响,并在此基础上进一步考察培养基中其它成分对(R,R)-2,3-丁二醇发酵的影响。【结果】优化后的培养基组分为玉米干粉140g/L,酵母粉30g/L,Na_2HPO_4 3g/L,KH_2PO_43g/L,(NH_4)2SO_42g/L,MgSO_40.8g/L,微量元素溶液2mL/L。使用优化后的培养基进行同步糖化发酵,发酵50h后(R,R)-2,3-丁二醇产量达到56.28g/L(光学纯度为98.3%),对葡萄糖的得率为0.44g/g,产率为1.13g/(L·h)。【结论】(R,R)-2,3-丁二醇生产技术低价高效,可为其工业化生产提供参考。

【Objectives】In this study,corn flour simultaneous saccharification and fermentationprocess was optimized to achieve a low-cost and efficient(R,R)-2,3-butanediol production technology.【Methods】The effects of different types and concentrations of nitrogen,and different concentrations of corn flour on cell growth,consumption of sugar,(R,R)-2,3-butanediol production,productivity,yield and conversion rate were investigated based on corn flour simultaneous saccharification and fermentation.Furthermore,the effects of other components in the medium on(R,R)-2,3-butanediol fermentation were observed.【Results】The optimized composi-tion of culture medium was as follows:140g/L dried corn flour,30g/L yeast extract,3g/L Na_2HPO_4,3g/L KH_2PO_4,2g/L(NH_4)2SO_4,0.8g/L MgSO_4 and 2mL/L trace element solution.Under abovementioned conditions,up to 56.28g/L(R,R)-2,3-butanediol(optical purity>98.3%)could be achieved within 50 hwith the yield on glucose of 0.44g/g and the conversion rate of 1.13g/(L·h).This is the highest production of(R,R)-2,3-butanediol titer so far reported from low-cost carbon source.【Conclusion】This study develops a technology utilizing low-cost carbon to produce(R,R)-2,3-butanediol efficiently,which provides meaningful guidance for its future industrial production.