营养和环境条件对光滑球拟酵母葡萄糖代谢速度的影响  

Effect of Nutrient and Environmental Factors on Glycolytic Flux in Torulopsis glabrata

作　　者：刘立明[1] 邓禹[1] 李寅[1] 陈坚[1] 

机构地区：[1]江南大学工业生物技术教育部重点实验室,江苏无锡214036

出　　处：《应用与环境生物学报》2006年第5期688-692,共5页Chinese Journal of Applied and Environmental Biology

基　　金：教育部高等学校博士点建设专项资金(20040294003);江苏省自然科学基金项目(BK2002072);江苏省研究生创新计划项目~~

摘　　要：增加培养基中Mg^2＋浓度，使磷酸果糖激酶和3-磷酸甘油醛脱氢酶活性提高22．2％和23．4％，葡萄糖消耗速率从1．94g L^-h^-1提高到2．43g L^-1h^-1，提高了25％．较低kLa（200h^-1）导致胞内ATP处于较低的水平，变构激活糖酵解关键酶活性，与高kLa（450h^-1）比较，葡萄糖消耗速率（2．31g L^-1h^-1）提高了35％，低kLa虽能加快葡萄糖消耗，但不利于丙酮酸产量的提高．烟酸（NA）是细胞合成NAD^＋的前体，培养基中缺乏NA导致细胞生长微弱，葡萄糖消耗缓慢；NA质量浓度从4mg／L增加到8mg／L时，葡萄糖消耗速度（2．01g L^-1h^-1）和丙酮酸产量（46．4g/L）分别提高了48．4％和29％，高NA浓度有利于高葡萄糖消耗速度的提高，但降低了丙酮酸对葡萄糖的产率．一定浓度的（0～10mg／L）的外源电子受体乙醛提高了光滑球拟酵母中醇脱氢酶活性（提高8．6％），加速NAD^＋再生，降低NADH／NAD^＋比率，从而促进细胞生长和提高葡萄糖消耗速度．以上结果表明。The effect of magnesium, dissolved oxygen, nicotinic acid and acetaldehyde on the glucose consumption rate of Torulopsis glabrata was investigated. With increasing of Mg^2＋ concentration in fermentation medium, the specific activities of phosphofructokinase （PFK） and glyceraldehyde 3 - phosphatedehydrogenase were increased by 22.2% and 23.4% , respectively, and the glucose consumption rate increased by 25% from 1.94 g L^-h^-1 to 2.43 g L^-h^-1. Compared with high kLa （450 h^-1 ）, the level of intracellular NADH and ATP kept lower at the condition of low kLa （200 h^-1 ）, the activities of PFK and GADPH were activated by the lower level of intracellular ATP and NADH, and the glucose consumption rate （2.31 g L^-h^-1 ） was enhanced by 35%. Although low kLa accelerated the glucose consumption rate, the yield of pyruvate was decreased. Nicotinic acid was the precursor of synthesizing NAD^＋ , and when nicotinic acid was absent from the media, weak growth and little glucose consumed were observed. When the concentration of nicotinic acid increased from 4 mg/L to 8 mg/L, the glucose consumption rate and the yield of pyruvate were increased by 48.4 % and 29 % , reaching at 2.01 g L^-h^-1 and 46.4 g/L, respectively. High concentration of nicotinic acid in media could increase the glucose consumption rate, but it decreased the yield of pyruvate. The specific activity of alcohol dehydrogenase in T. glabrata was enhanced by 8.6% at presence of 0 - 10 mg/L acetaldehyde, the exogenous electron acceptor, in fermentation medium. It led to the enhancement of regeneration ability of NAD^＋ , and resulted in a higher level of intracellular NAD^＋ and a lower ratio of NADH to NAD^＋ . The growth of T. glabrata and glucose consumption rate were enhanced under the condition that acetaldehyde was present at media. Those results illustrated that the intracellular cofactors could be regulated by the nutrition and environment conditions, the activities of key enzymes in glycolytic pathway were increased, and the gluco

关 键 词：光滑球拟酵母 辅因子 葡萄糖消耗速度 

分 类 号：TQ920.1[轻工技术与工程—发酵工程]