Simultaneous Production Of Ergosterol And Glutathione By Saccharomyces Cerevisiae Fermentation

Saccharomyces cerevisiae is one kind of carrier of biosynthesis, and a commonly used host cell in gene combination. To enhance the production process and the economic competitiveness of their products in the market, the biotechnology researchers created more economical, more effective methods and optimize the production process to achieve high productivity. The high-density fermentation method is a significant mean to enhance the level of production.Ergosterol and glutathione are both significant in pharmaceutical and health-care industries. The former is the precursor of vitamin D2, and the latter is an important reducer of in vivo.In this paper, a feasibility method of simultaneous producing ergosterol and glutathione by Saccharomyces cerevisiae fermentation was discussed, and a simple, effective and feasible method was carried out. The components of culture medium and the effect of NaNO3and amino acid were studied. The fermentation method was optimized, too. To summarize:(1). There were two strain of yeast preserved by our lab. We used T65 ferment for24h, the content of ergosterol was1.89%-1.95%, and the content of glutathione was1.13%-1.18%, higher than Y-E-1. So the fermentation strain was T65.(2). An Orthogonal experiment was designed to confirm the components of culture medium:glucose60g·L1,corn steep liquor44g·L-1, KH2PO42g·L-1, MgSO43g·L-1, Zn2+12ppm, Fe2+、Cu2+、 Mn2+各4ppm.(3). An increasing air-flow rate and stir rate method was used during fermentation.(4). An ethanol controlled fermentation with glucose fed-batch strategy was used during fermentation.(5). The additive was:NaNO3and amino acid mixture. As the result shown the method NaNO3added at prophase and amino acid mixture added at metaphase was the feasible way. The dosage of molasses was determined by the changes of biomass.(6). Considering the glutathione synthesis was a nitrogen-consuming process, ammonia was used as alkali to adjusting pH5.5-6.5of the broth. This method could accelerate the biomass remarkably.(7). With molasses fed-bath at anaphase, nutriment was supplied for the secondary growth of yeast. The fermentation time was extended, and the yield was enhanced. In this experiment culture condition, we got the maximum yield (the yield of ergosterol was1121mg/L, glutathione1561mg/L, biomass124g/L). This method has the meaning of industrialization.