基于两阶段氨基酸添加的谷胱甘肽发酵高产方法

Improved Glutathione Production in Candida utilis by Two-Stage Amino Acid Addition

为提高产朊假丝酵母(Candida utilis SZU 07-01)发酵生产谷胱甘肽(glutathione,GSH)的产量,分别考察L-蛋氨酸和L-半胱氨酸在GSH分批发酵和流加发酵中的作用,结果发现L-蛋氨酸提升了酵母细胞在生长期的GSH合成能力,而L-半胱氨酸显著提高了细胞生长结束后的GSH产量。在此基础上,提出了两阶段氨基酸添加策略,即在分批发酵初始时(0 h)添加60 mmol/L L-蛋氨酸,在流加发酵过程中细胞干质量达到最大值时(第27小时)一次性添加30 mmol/L L-半胱氨酸。最终,GSH产量和胞内GSH含量进一步提高,分别达到1 247.1 mg/L和24.1 mg/g。该两阶段氨基酸添加策略在GSH发酵高产中的成功应用,对其他类似化合物的高效生产具有一定的借鉴意义。

In order to improve glutathione production by Candida utilis SZU 07-01, the effects of addition of L-methionine and L-cysteine on glutathione biosynthesis during batch and fed-batch fermentation, respectively, were investigated. The results indicated that addition of L-methionine improved the glutathione biosynthesis ability of yeast during cell growth phase while addition of L-cysteine significantly enhanced the production of glutathione after cell growth. Based on this finding, a two-stage strategy for amino acid addition was proposed for high glutathione production, that is, 60 mmol/L of L-methionine was added into the medium at the beginning of fermentation（0 h）, and 30 mmol/L of L-cysteine was then added when the biomass achieved the maximum level（27 h） during fed-batch culture. The two-stage strategy ultimately resulted in further improvements in glutathione production and intracellular glutathione content, which were 1 247.1 mg/L and 24.1 mg/gat 48 h, respectively. The successful application of the two-stage amino acid addition strategy for improved glutathione production also provides a feasible approach for the efficient production of other similar compounds.