金霉素发酵后期效价增长率提升研究

Study on increasing synthesis rate of aureomycin titer in late stage fermentation

为提高金霉素发酵后期效价增长率,首先研究了种子罐消后总糖、种子罐接种孢子量、种子罐种龄,以及发酵配方的迟效有机氮源与速效有机氮源的质量比、发酵配方玉米浆总氮量、发酵配方碳氮比、发酵罐培养基灭菌保压时间、发酵过程变温时间、第一次带放时间对后期效价增长率的影响;然后对后期效价增长率有显著性影响的因子进行试验设计优化,确认最佳组合水平。研究结果表明:种子罐消后总糖、种子罐接种孢子量、发酵配方玉米浆总氮量、发酵配方碳氮比、发酵罐培养基灭菌时间对后期效价增长率无显著影响(P>0.05);种子罐种龄、发酵配方的迟效有机氮源与速效有机氮源的质量比、发酵过程变温时间对后期效价增长率有显著影响(P<0.05);当种子罐种龄为22.8 h,发酵配方迟效有机氮源与速效有机氮源的质量比为2.03,发酵过程变温时间为17.5 h时,后期效价增长率最高,达到192.3 U/(mL·h),提高了27.6%。因此,在金霉素发酵过程中,将种子罐种龄、发酵配方的迟效有机氮源与速效有机氮源的质量比、发酵过程变温时间控制在合适的范围内,对提高金霉素的效价水平具有显著意义。

To improve the titer growth rate of aureomycin fermentation,the effects of total sugar after digestion in the seed tank,the amount of spores inoculated in the seed tank,the age of seed tank,and the mass ratio of the slow-acting organic nitrogen source and the quick-acting organic nitrogen source of the fermentation formula,the total nitrogen content of fermentation formula corn pulp,the carbon-nitrogen ratio of fermentation formula,the sterilization and holding time of the fermentation tank,the temperature change time of the fermentation process,and the impact of the first release time on the titer growth rate were studied firstly.Then the factors significantly affecting on the titer growth rate were optimized by experimental design to confirm the optimal combination level.The results showed that:the total sugar after sterilization of the seed tank,the amount of spore sinoculated in the seed tank,the total nitrogen content of corn pulp in the fermentation formula,the carbon-nitrogen ratio of the fermentation formula,and the sterilization time of the fermentation tank had no significant impact on the late titer growth rate(P>0.05);the age of the seed tank,the mass ratio of the late organic nitrogen source to the fast organic nitrogen source of the fermentation formula,and the variable temperature time of the fermentation process had a significant impact on the late titer growth rate(P<0.05).The highest titer growth rate of 192.3 U/(mL·h)was achieved when the age of the seed tank was 22.8 h,the ratio of late-acting organic nitrogen source to fast-acting organic nitrogen source of the fermentation formulation was 2.03,and the fermentation process temperature change time was 17.5 h,which increased by 27.6%.Therefore,it is significant to control the age of the seed tank,the mass ratio of late-effective organic nitrogen source to fast-acting organic nitrogen source of fermentation formulation,and the variable temperature time of fermentation process in the appropriate range to improve the potency level of aureomycin in the fermentation process.