【摘要】 目前,应用解脂亚洛酵母发酵生产α-酮戊二酸由于产量和底物转化率低、生产周期长等问题,仍未大规模工业化生产。为了解决这些问题,以研究室诱变选育获得的1株高产α-酮戊二酸的解脂亚洛酵母Yarrowia lipolytica WSH-Z06 C3为出发菌株,考察了该菌株在50 L发酵罐中转速、碳酸钙浓度、溶氧以及补料方式(多节点补料、恒速补料)等因素对α-酮戊二酸积累的影响。结果表明,当转速为300 r/min时,α-酮戊二酸和丙酮酸的产量分别为32.4 g/L和19.66 g/L;碳酸钙质量浓度为20 g/L时,α-酮戊二酸的产量提高至38.55 g/L,丙酮酸降低至8.28 g/L;控制溶氧水平在50%时,α-酮戊二酸产量为42.39 g/L,此时丙酮酸为6.22 g/L。比较高初始甘油浓度和不同的补料发酵策略,发现恒速补料效果最好,发酵144 hα-酮戊二酸产量达到66.27 g/L,丙酮酸产量为20.82 g/L。通过上述发酵过程参数的优化,α-酮戊二酸的产量和底物的转化率比未优化前分别提高了67.3%和4.56%,为解脂亚洛酵母工业化生产α-酮戊二酸提供一定参考。更多还原

【Abstract】 Currently, problems of low output, low substrate conversion rate and long fermentation cycle restricted the industrial production of α-ketoglutaric acid(α-KG) by Yarrowia lipolytica in large scale. A mutant strain, Y. lipolytica WSH-Z06 C3, with capacity of high output of α-KG, obtained in previous research was taken as starting strain to solve these three problems. Accumulation effects of rotating speed, calcium carbonate concentration, dissolved oxygen and feeding methods(multi-node feeding and constant speed feeding) and other factors on α-KG with Y. lipolytica WSH-Z06 C3 were investigated in 50 L fermentor. The results showed that when the rotating speed was set at 300 r/min, the concentration of α-KG and pyruvate reached 32.4 g/L and 19.66 g/L respectively. The output of α-KG was increased to 38.55 g/L, and pyruvate decreased to 8.28 g/L; when the concentration of calcium carbonate was at 20 g/L. The output of α-KG was further increased to 42.39 g/L with pyruvate at 6.22 g/L by controlling the level of dissolved oxygen at 50%. With the strategies of high initial glycerol concentration and different feeding methods investigated, it was found that the constant feeding mode had the best effect. The production of α-KG and pyruvate reached 66.27 g/L and 20.82 g/L, respectively. The output of α-KG and pyruvate increased 67.3% and 4.56%, respectively, as compared with the process before optimization, and provided considerable reference for industrial production of α-KG with Y. lipolytica.更多还原