复合有机氮源对灵芝三萜液态深层发酵的影响

以灵芝为材料,在前期研究基础上,以不同酵母粉作为氮源,研究复合有机氮源对灵芝三萜液态深层发酵的影响。首先,由单因素实验考察3种不同的酵母粉对灵芝菌丝体合成灵芝三萜的影响,确定酵母粉的最适宜浓度范围。在此基础上,根据中心组合实验设计,对3种酵母粉分别采用2种复合和3种复合的方式,优化复合有机氮源的最佳组合配比。结果表明：当基础培养基中添加6.6g/L的酵母粉N-1与6.6g/L的酵母粉N-2时,灵芝三萜产量可达0.478g/L（理论产量为0.485g/L）,比添加单一酵母粉N-1、N-2、N-3分别提高了21%、139%、103%,其氮源用量为两种组合时最低。当基础培养基中酵母粉N-1、N-2与N-3添加量分别为5.07g/L、3.78g/L、7.63g/L时,灵芝三萜产量达0.514g/L（理论产量为0.510g/L）,比单因素对照组分别提高了30%、157%和74%。本研究优化的复合氮源添加方式可明显提高灵芝菌丝体液态深层发酵生产灵芝三萜的产量,为其规模化液态深层发酵的生产提供科学数据。

Effects of complex organic nitrogen source on triterpene production by Ganoderma lingzhi based on liquid submerged fermentation

Effects of complex organic nitrogen sources on triterpene liquid submerged fermentation of Ganoderma lingzhi were studied based on previous research, using different yeast as nitrogen source. The effects of different yeast during fermentation process on production of triterpenes were investigated by single-factor experiment so as to determine the optimum concentration range of yeast. According to the central composite design, two or three kinds of yeast were combined for the optimization of fermentation medium, and the best ratio of composite organic nitrogen source was optimized. The results showed that when 6.6g/L of N-1 and 6.6g/L of N-2 were added to the basic medium, the yield of Ganoderma triterpene was 0.478g/L (theoretical yield was 0.485g/L), respectively about 21%, 139%, and 103% higher than the addition of yeast N-1, N-2, and N-3 alone. The concentration of nitrogen was the lowest when combinations of two kinds of yeast were used. When the added amounts of N-1, N-2 and N-3 in the basic medium were espectively 5.07g/L, 3.78g/L, and 7.63g/L, the yield of Ganoderma triterpene reached 0.514g/L (theoretical yield was 0.510g/L), respectively 30%, 157%, and 74% higher than the single factor control group. Optimized replenishment of the complex nitrogen source can significantly improve the yield of triterpenes produced by Ganoderma lingzhi based on liquid submerged fermentation, and our results provide a scientific basis for the large-scale production of Ganoderma triterpene under liquid submerged fermentation.