响应面分析法优化黑根霉胞外多糖发酵工艺

实验以商品化的马铃薯葡萄糖液体培养基为基础培养基,以胞外粗多糖产量为考察指标,运用响应面分析法考察玉米浆浓度、KH₂PO₄浓度和发酵时间3个因素对胞外多糖发酵产量的影响,以获得黑根霉胞外多糖发酵最优工艺,建立高产、稳定、可控的胞外多糖发酵生产工艺技术方案。经响应面分析,各因素按照对响应值的影响顺序为：玉米浆浓度>发酵时间> KH₂PO₄浓度,且玉米浆浓度、发酵时间对胞外多糖产量的影响极显著,KH₂PO₄浓度对胞外多糖产量的影响不显著。胞外多糖发酵最优工艺为：玉米浆3.2mg/mL、KH₂PO₄ 1.5mg/mL和发酵时间132h,在此条件下胞外多糖的最大预测产量为0.824mg/mL。实验重复性好,是一个高产、稳定、可控的胞外多糖发酵生产工艺技术方案,可以指导黑根霉胞外多糖发酵。

Optimization of fermentation process of exopolysaccharides from Rhizopus nigricans by response surface methodology

Response surface methodology was used to investigate the effects of corn steep liquor concentration, KH₂PO₄ concentration and fermentation duration on the yield of exopolysaccharides of Rhizopus nigricans. Commercial potato dextrose broth was used as basic medium. Response surface analysis showed that the factors influencing the response value was arranged in effectivity order of corn steep liquor concentration > fermentation duration > KH₂PO₄ concentration. The effects of corn steep liquor concentration and fermentation duration were significant on the yield of exopolysaccharides, while that of KH₂PO₄ concentration were not significant. The optimum fermentation condition was the use of corn steep liquor 3.2mg/mL as culture medium with additional KH₂PO₄ 1.5mg/mL and fermentation for 132h. Under such a condition, the maximum predicted yield of exopolysaccharides was 0.824mg/mL. The technological process was high-yielding, stable, controllable and repeatable for production of Rhizopus nigricans exopolysaccharides.