高产RNA酿酒酵母培养条件及发酵培养基的优化

Optimization of Culture Conditions and Fermentation Medium of Saccharomyces cerevisiae of High-yield RNA

RNA是食品工业鲜味物质酵母抽提物的重要鲜味成分。以酿酒酵母J-5为试验菌株,以菌株细胞内RNA积累量和生物量为指标,通过单因素试验和正交试验对高产RNA酿酒酵母基础发酵培养基的碳氮磷源成分进行优化,同时对摇瓶培养条件进行了优化。结果得到最优发酵培养基配方为:葡萄糖5%,酵母浸粉1%,(NH4)2SO41.5%,KH2PO40.2%。最佳培养条件为:初始pH 5.0,培养温度30℃,转速为200r/min。在此培养基上生长,菌体RNA积累量提高到12.6%以上,细胞干重超过12.2g/L。

RNA is the important flavor component of yeast extract.Saccharomyces cerevisiae J-5 is used as the producing strain.Take RNA content and cell dry weight in the fermentation medium as target parameters,carbon sources,nitrogen sources and phosphorus sources in the fermentation medium are optimized by single-factor test and orthogonal experimental design.At the same time,the shaking fermentation conditions are also optimized.The optimal fermentation medium is obtained as follows：glucose 5%,yeast extract 1%,（NH4）2SO4 1.5%,KH2PO4 0.2%.The optimal conditions are as follows：pH of 5.0,cultural temperature of 30 ℃and rotate speed of 200 r/min.Strain J-5 grows in the optimized fermentation medium,the content of RNA is increased to 12.6% and dry cell weight is increased to 12.2 g/L.