Low-cost Production Of Poly ?-glutamic Acid

Poly y-glutamic acid is a biomarker that can be directly obtained by microbial fermentation.It is known for its biocompatibility,degradability and adhesiveness,which can be used in medicine,agriculture,environmental protection and other fields.At present in the popularization of gamma-poly glutamic acid mainly because the cost is too high,this study proposed by changing the production process to reduce gamma-poly glutamic acid raw material costs,at the same time does not affect its existing technological process.The glutamic acid-poly y-glutamic acid coupling fermentation process was studied.After centrifugation,uv and high temperature treatment,the yield of the poly ?--glutamic acid decreased by 7%,17%and 23%respectively.The cost of the raw materials needed for the production of poly y-glutamate fell by 14%,4%and 5%,respectively.To further reduce the cost,glutamic acid was replaced by citric acid.When the amount of glutamine added was less than 0.1 gL-1,the yield of poly y-glutamic acid was reduced by 14%and 0%respectively by using citric acid instead of 50%and 25%glutamate.The cost of producing 1t poly y-glutamic acid was reduced by 9%and 11%,respectively.The effect of environmental stress on the synthesis of poly y-glutamic acid was studied.Under the conditions of increasing osmotic pressure,increasing temperature and increasing pH,the yield of the poly?-glutamic acid increased by 6.5%,10.3%and 6.4%respectively.It can partially offset the decline in production caused by coupling fermentation or citric acid substitution.At the same time,the environmental stress process does not increase the extra cost.In this paper,the process of the process of environmental stress was studied,and the effects of spray drying conditions on the yield and content of the powder were investigated.In the fermentation experiment of 1000L fermentation tank,the yield of poly y-glutamic acid was 52gL-1,and the time and space yield and glutamate conversion rate were 0.72 gL-1h-1 and 78%respectively.Using centrifugal spray drying tower drying,the product yield can reach more than 95%,the product of the poly y-glutamic acid can reach more than 20%.