Fe^(2+)螯合剂对羟脯氨酸发酵的影响

Effect of Fe^(2+)chelating agent on hydroxyproline fermentation

为解决反式-4-羟基脯氨酸发酵过程中Fe^(2+)供应不足、产酸效率低等问题。该研究以大肠杆菌HYP-08为供试菌株,首先通过单因素实验探究Fe^(2+)螯合剂种类及添加量对羟脯氨酸发酵生产的影响,并通过5 L发酵放大验证,以羟脯氨酸产量、生物量,糖酸转化率为指标,进一步探究其在放大过程中的影响,结果表明葡萄糖酸亚铁对羟脯氨酸发酵效果最好,流加发酵生产中,最终确定了10 h开始持连续流加的补料方式,反式-4-羟基脯氨酸生物量及产量达到最高,分别为146.2、118.6 g/L,较优化前提高了12.1%和4.2%,副产物乙酸减少到1.05 g/L,葡萄糖酸亚铁的添加有效增强了菌体活力,提高了羟脯氨酸的产量和糖酸转化率,为微生物发酵生产羟脯氨酸提供了依据。

In order to solve the problems of insufficient supply of Fe^(2+)and low acid production efficiency in the fermentation process of trans-4-hydroxyproline.In this study,Escherichia coli HYP-08 was used as the test strain.Firstly,the stability of ferrous glycinate,ferrous gluconate,ferrous fumarate and their effects on the production of hydroxyproline fermentation were investigated by single factor experiments.Through 5 L fermentation amplification verification,the yield of hydroxyproline,biomass,and sugar acid conversion rate were used as indicators to further explore their effects in the amplification process.The results showed that ferrous gluconate had the best effect on hydroxyproline fermentation.In the fed-batch fermentation production,the feeding method of continuous feeding from 10 h was finally determined,and the biomass and yield of trans-4-hydroxyproline reached the highest.They were 146.2 and 118.6 g/L,respectively,which were 12.1%and 4.2%higher than those before optimization,and the by-product acetic acid was reduced to 1.05 g/L.The addition of ferrous gluconate effectively enhanced the cell viability,improved the yield of hydroxyproline and the conversion rate of sugar and acid,and provided a basis for the production of hydroxyproline by microbial fermentation.