[The key enzymes of metabolisms of glycerol in Candida glycerolgenesis].
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 36 h and 60 h, 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 18 h and 48 h and appeared on peak activity at 36 h. 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 48 h and 72 h, 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.
Wang
Z
Z
Research Center of Microorganisms, School of Biotechnology, Wuxi University of Light Industry, Wuxi 214036.
Zhuge
J
J
Cao
Y
Y
Chen
J
J
Fang
H
H
D002175:Candida / Q000201:enzymology* / Q000378:metabolism; D003593:Cytoplasm / Q000201:enzymology; D005285:Fermentation; D005990:Glycerol / Q000378:metabolism*; D005993:Glycerolphosphate Dehydrogenase / Q000378:metabolism*; D008928:Mitochondria / Q000201:enzymology; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*
D005993:Glycerolphosphate Dehydrogenase; D010744:Phosphoric Monoester Hydrolases; C040842:glycerol-1-phosphatase; D005990:Glycerol