摘要
在高密度培养条件下,考察不同pH值环境对产朊假丝酵母生物合成S-腺苷甲硫氨酸(S-adenosylmethionine,SAM)和谷胱甘肽(glutathione,GSH)的影响。结果发现弱酸胁迫(pH 3.5)有利于提升酵母细胞的SAM和GSH合成能力,实现SAM和GSH联合高产。通过对关键酶活性、能量物质供给和胞内氧化还原环境进行测定,发现弱酸胁迫提高了SAM合成酶、γ-谷氨酰半胱氨酸合成酶、己糖激酶、ATP合成酶以及过氧化氢酶的活性,提高了胞内NADH和ATP的水平和再生能力,为SAM和GSH的过量合成提供了充足的物质和能量保障。研究结果揭示了弱酸胁迫促进SAM和GSH生物合成的生理机制,也为类似小分子活性化合物的过量合成提供可行的思路。
The effect of different pH conditions on the biosynthesis of S-adenosylmethionine(SAM)and glutathione(GSH)by Candida utilis under high cell density culture was investigated.Moderate acid stress(pH 3.5)was found to be beneficial for SAM and GSH biosynthesis and consequently the high-yield co-production of SAM and GSH by the yeast cells.By measuring the key enzymes activities,energy supply,and the intracellular redox environment,moderate acid stress was shown to be able to increase the activities of SAM synthase,γ-glutamylcysteine synthase,hexokinase,ATP synthase and catalase,and elevate the intracellular levels and regeneration abilities of NADH and ATP,thereby ensuring sufficient substance and energy supply for the over-production of SAM and GSH.Results obtained in this study present adequate evidence to reveal the physiological mechanism of moderate acid stress in improving SAM and GSH biosynthesis,which may provide a feasible idea for the over-production of other similar small molecular bioactive compounds.
作者
王大慧
徐若烊
黎德超
卫功元
WANG Dahui;XU Ruoyang;LI Dechao;WEI Gongyuan(School of Biology and Basic Medical Sciences,Soochow University,Suzhou 215123,China)
出处
《食品科学》
EI
CAS
CSCD
北大核心
2020年第10期61-67,共7页
Food Science
基金
国家自然科学基金面上项目(21376155,21506136)。
