谷氨酸清洁发酵工艺研究

为了解决谷氨酸发酵培养基中色素、杂质多所引起的发酵过程稳定性差、产酸低等问题，该研究采用生物氮素对发酵培养基中的主要氮源（玉米浆和豆粕水解液）进行替代，并通过单因素试验和正交试验对清洁发酵培养基中的关键因素生物氮素、生物素、VB1和甲硫氨酸的添加量进行优化，进而获得谷氨酸清洁发酵培养基，进行谷氨酸的清洁发酵工艺研究。结果表明，清洁发酵培养基中关键成分的最佳添加量为生物氮素2.0 g/L、生物素7 μg/L、VB1 10 mg/L、甲硫氨酸0.6 g/L。在最优工艺条件下，清洁发酵菌液OD600 nm值为84.2，谷氨酸产量为171 g/L，糖酸转化率为68.5%，分别较对照提高16.14%、12.50%、4.74%，发酵上清液透光率由0.9%提高至31%，说明清洁发酵培养基能够较好地提升谷氨酸发酵性能。

Study on clean fermentation process of glutamic acid

In order to solve the problems of poor stability and low acid production caused by many pigments and impurities in glutamic acid fermentation medium, in this study, the major nitrogen sources (corn pulp and soybean meal hydrolyzate) were replaced by biological nitrogen in the fermentation medium. The key factors including the addition of biological nitrogen, biotin, VB1 and methionine in clean fermentation medium were optimized by single factor test and orthogonal test. The clean fermentation medium of glutamic acid was obtained and was used to study on clean fermentation process of glutamic acid. The results showed that the optimum addition of key compositions in the clean fermentation medium were biological nitrogen 2.0 g/L, biotin 7 μg/L, VB1 10 mg/L, methionine 0.6 g/L. Under the optimal process conditions, the OD600 nm value of clean fermented liquid was 84.2, the production of glutamic acid was 171 g/L and the conversion rate of glucose was 68.5%, compared with control group, they were increased by 16.14%, 12.50%, 4.74%, respectively. The light transmittance of fermentation supernatant increased from 0.9% to 31%, which showed that the clean fermentation medium could improve the fermentation property of glutamic acid.