供氧对产丙三醇假丝酵母产丙三醇发酵研究

The Effect of Oxygen Supply on Production of Glycerol with Candida glycerolgenesis

研究了产丙三醇假丝酵母(Candidaglycerolgenesis)产丙三醇及副产物与氧供给的关系。摇瓶试验发现其它营养条件一定,玉米浆添加量决定酵母量。在04%的玉米浆和装液比008时产丙三醇最高,副产物乙醇、乙酸和乙酸乙酯最小,玉米浆和装液比影响丙三醇和副产物的形成。在5L的反应器中以搅拌转速控制供氧水平,菌体生长阶段比耗氧速率为28mg/(g·h),在发酵阶段比耗氧速率16mg/(g·h)。适量供氧能得到高产率的丙三醇,而只产生微量的乙醇、乙酸和乙酸乙酯。

The relationship between oxygen supply and production of glycerol or byproduct with Candida glycerolgenesis have been studied.The experiments in shake flasks indicated that the biomass was determined by the concentration of corn steep liquor when other fermentation condition was constant,the concentration of corn steep liquor and the ratio of the volume of the medium to the capacity of the flask affected the yield of glycerol and other byproducts because of different oxygen supply.With 0.4% corn steep liquid and the ratio of the volume of the medium to the capacity of the flask was 0 08,the yeast yielded higher level of glycerol concentration and little other byproducts,while oxygen was insufficient for glycerol production such as the ratio was 0.24,the yeast would produce much more alcohol and other byproduct,then decreased the yield of glycerol.In the fermentation process of 5L fermentor,agitator speed mostly affected the DO level in the medium.In growth phase the specific oxygen consumption rate of C.glycerolgenesis was 28 mg/(g·h),and during fermentation process it was 16 mg/(g·h).With suitable oxygen supply, C.glycerolgenesis can produce high level of glycerol whereas ethanol and other byproducts was nearly zero.