酵母菌谷胱甘肽合成能力比较及催化条件优化  

Comparison of glutathione synthesis ability and catalysis conditions by yeast

作　　者：熊福星[1] 段学辉[1] 胡明明[1] 王娟[1] 吴量[1] 陈加利[1] 

机构地区：[1]南昌大学食品科学与技术国家重点实验室,江西南昌330047

出　　处：《中国酿造》2012年第5期117-122,共6页China Brewing

基　　金：南昌大学食品科学与技术国家重点实验室自由探索课题(SKLF-TS-201113)

摘　　要：试验收集培养了9株酵母菌,分别测定他们的细胞生物量和胞内谷胱甘肽(GSH)含量,酿酒酵母SP004细胞干重达到11.39g/L,啤酒酵母TS013胞内GSH含量达到1.5282mg/g湿细胞;验证考察了4种不同提取方法对细胞内GSH含量测定的影响,结果表明,温差破碎法提取效果较好。同时比较9株酵母菌催化合成GSH的能力,结果显示,絮凝酵母SP5 GSH合成酶活力相对较高,酶活达到2.385mg/g湿细胞,每克湿细胞催化前体氨基酸(AA)合成GSH转化率为7.76%。用单因素试验和正交试验分析法研究不同反应液体积与菌体量比、硫酸镁浓度、磷酸钾缓冲液浓度以及葡萄糖浓度对絮凝酵母SP5细胞催化前体AA合成GSH的影响,结果表明,合成GSH的适宜条件为:谷氨酸60mmol/L、半胱氨酸20mmol/L、甘氨酸20mmol/L、七水合硫酸镁20mmol/L、葡萄糖0.5mol/L、pH值为7.0磷酸钾缓冲液100mmol/L,30℃下,160r/min,振荡反应时间6h。在此条件下,絮凝酵母SP5细胞GSH合成酶活力平均达到2.9498mg/g湿细胞,每克絮凝酵母SP5湿细胞催化前体AA合成GSH的转化率平均为9.60%。The cell biomass and intracellular GSH content produced by 9 yeasts strain were measured.The cell dry weight of Saccharomyces cerevisiae SP004 reached 11.39g/L and the intracellular GSH content of brewer＇s yeast TS013 reached 1.5282mg/g wet cells.The effects of four different extraction methods on intracellular GSH content were evaluated.The results showed that the temperature difference method was optimal method to extract GSH.The abilities of GSH synthesis by 9 yeast strains were investigated.The results showed that the GSH synthetase activity of flocculation yeast SP5 is relatively higher,which reached 2.385mg/g wet cells,and the synthesis conversion rate of precursor amino acids to GSH per gram of wet cells was 7.76%.The effects of different reaction solution volume with the yeast cell mass,MgSO4·7H2O concentration,potassium phosphate buffer concentration and glucose concentration on the GSH synthesis by precursor amino acids were investigated by using single-factor and orthogonal experiment.The optimal conditions were as followed： glutamic acid concentration 60mmol/L,cysteine 20mmol/L,glycine 20mmol/L,MgSO4·7H2O 20mmol/L,glucose 0.5mol/L,pH value 7.0,potassium phosphate buffer 100mmol/L,30℃,160r/min and the oscillation reaction time 6h.Under these conditions,the average GSH synthetase activity of flocculation yeast SP5 reached 2.9498mg/g wet cells,and the synthesis conversion rate of precursor amino acids to GSH was 9.60% per gram of flocculation yeast SP5 wet cells.

关 键 词：谷胱甘肽 酵母菌 酶催化 前体AA 

分 类 号：TQ920.1[轻工技术与工程—发酵工程]