THE KEY ENZYMES OF METABOLISMS OF GLYCEROL IN CANDIDA GLYCEROLGENESIS
产甘油假丝酵母甘油代谢关键酶的研究

The specific enzymes for glycerol formation and dissimilation in Candida glycerolgenesis were studied. C.glycerolgenesis hardly assimilated glycerol without glucose and a little amount of glucose remarkably stimulated this dissimilation pathway and the activity and expression of mitochondrial glycerol 3 phosphate dehydrogenase was induced strongly by glycerol 3 phosphate and repressed by glucose metabolism. During glycerol production fermented by C.glycerolgenesis , the activity of cytoplasmic glycerol 3 phosphate dehydrogenase maintained at a higher level and existed two peaks of activity, which appeared at 36h and 60h, respectively. The activity level of the first activity peak determines glycerol productivity and becomes a key enzyme of glycerol formation. The activity of glycerol 3 phosphatase maintained at a higher level just between 18h and 48h and appeared on paek activity at 36h. In that period, the activity of glycerol 3 phosphatase was up to more than two times of cytoplasmic glycerol 3 phosphate dehydrogenase and that was inosculated with the phase of rapid accumulation of glycerol during glycerol production by C.glycerolgenesis . In the phase of slowly accumulation of glycerol between 48h and 72h, the activity of glycerol 3 phosphatase decreased below that of cytoplasmic glycerol 3 phosphate dehydrogenase. So, cytoplasmic glycerol 3 phosphate dehydrogenase is a key enzyme of glycerol formation in the phase of rapid accumulation of glycerol and glycerol 3 phosphatase becomes a more effective factor after glycerol fermentation reached into slowly accumulation phase. In a conclusion, it is a fundamental for C.glycerolgenesis over producing high level of glycerol that its cytoplasmic glycerol 3 phosphate dehydrogenase maintains at high activity and the activity of glycerol 3 phosphatase is much higher than that of cytoplasmic glycerol 3 phosphate dehydrogenase.