核黄素产生菌阿舒假囊酵母发酵条件的初步研究

Primary research on the optimization of riboflavin fermentation by Eremothecium ashbyii

对阿舒假囊酵母摇瓶发酵条件进行了初步研究。首先,考察了不同碳源(葡萄糖、蔗糖、麦芽糖和淀粉)和有机氮源(牛肉膏、酵母膏、玉米浆和蛋白胨)对阿舒假囊酵母发酵的影响,结果表明葡萄糖和酵母膏最利于核黄素的合成。在此基础上,采用L9(43)正交设计对阿舒假囊酵母的发酵培养基进行优化,结果表明有机氮源对核黄素产量的影响最显著,优化后的发酵培养基配方为:葡萄糖50g/L,酵母膏20g/L,玉米浆20g/L,KH2PO42.0g/L,MgSO41.0g/L,NaCl1.0g/L,此最佳配方下的核黄素产量达1145.67(±82.08)mg/L,比原始发酵培养基配方下的核黄素产量提高了230.05%。最后,对阿舒假囊酵母摇瓶培养条件进行了研究,结果表明装液量为30mL、接种量为5%、发酵培养基初始pH值控制在6.0时,所得到的核黄素产量最高。

In order to improve the productivity of riboflavin by E. ashbyii in shake-flask cultivation, a primary research about the fermentation optimization was conducted in this paper. Firstly, various carbon sources （glucose, sucrose, maltose and starch） and organic nitrogen sources （beef extract, yeast extract, corn steep liquor and peptone） were investigated in detail, respectively, which demonstrated that glucose and yeast extract were the optimal components for the fermentation medium. Based on this fact, the fermentation medium of E. ashbyii were optimized with L9 （43） orthogonal design. The results showed that the organic nitrogen sources had a significantly positive effect on the production of riboflavin in shake-flask cultivation, and the optimal fermentation medium for E. ashbyii was composed of （g/L） glucose 50, yeast extract 20, corn steep liquor 20, KH2PO4 2.0, MgSO4 1.0, NaCl 1.0. The riboflavin production obtained under the optimal fermentation medium was 1 145.67 （±82.08）mg/L, with 230.05% higher than that obtained with the original fermentation medium recipe. Finally, the effects of various medium volumes, inoculum levels and initial pH values on riboflavin biosynthesis were investigated, and the results demonstrated that the optimal fermentation conditions were 30 mL, 5% and 6.0, respectively.