利用菊芋菊粉制备R,R-2,3-丁二醇发酵工艺条件的优化

为了提高Paenibacillus polymyxa ZJ-9发酵菊芋菊粉制备R,R-2,3-丁二醇的产量、减少生产成本,考察了发酵温度、pH、接种量和溶氧(搅拌转速)对菌体生长繁殖、菊粉的利用率和R,R-2,3-丁二醇合成的影响。实验结果表明,Paenibacillus polymyxa ZJ-9发酵的最适温度、pH和接种量分别为30℃、6.0和8%。通过对不同搅拌转速条件下的菌体比生长速率μ_x和产物比合成速率μ_p分析,制定了一种两步溶氧控制策略发酵生产R,R-2,3-丁二醇:在发酵前24h,控制搅拌转速调控为240r/min有利于菌体生长,而24h后,控制发酵液搅拌转速调控为160r/min,能有效促进R,R-2,3-丁二醇合成,在上述条件下,R,R-2,3-丁二醇的产量高达27.83g/L,比恒定搅拌转速条件的最大值提高了10.15%。

Optimization of Fermentation Conditions for R,R-2,3-butanediol Production Using Inulin Extract from Jerusalem artichoke tubers

To increase the quality of R,R-2,3-Butanediol using inulin extract from Jerusalem artichoke tubers by Paenibacillus polymyxa ZJ-9 and decrease the costs of production,the fermentation conditions including cultural temperature, initial pH,inoculum concentration and agitation speed were optimized.The optimal conditions were confirmed as follows;cultural temperature 30℃,the optimization initial pH 6.0,inoculum concentration 8%(v/v).A two-stage agitation speed control strategy was proposed based on analyzing the microbiol physiological characteristics under different agitation speeds.During the first 24 h,agitation speed was controlled at 240 r/min to obtain high specific cell growth rate for cell growth,subsequently agitation speed was controlled at 160 r/min to maintain high specific R,R-2,3-BD formation rate for high R,R-2,3-BD accumulation.The concentration of the obtained R,R-2,3-BD was 27.83 g/L under this optimal conditions,increase 10.15%than that before optimization.