Optimization Of Sugar Consumption Process For Threonine Mother Liquor By Beer Yeast Fermentation

Threonine is one of the essential amino acids for human body.It can alleviate fatigue,promote growth and development.Threonine is used in medicine,chemical reagents,food fortifiers and feed additives,especially in feed additives.With the fermentation technology development,extraction and refining of L-Threonine from starch and other sugars by submerged microbial fermentation has been widely used.However,it is difficult to treat the remaining mother liquor after the extraction of L-Threonine crystalline material,which has become an important factor restricting production.At present,the mother liquor is mainly treated by the method of direct secondary concentration,crystallization and extraction to produce L-Threonine.But the sugar content of mother liquor is high.the method is difficult to crystallize and the yield is low.The research is mainly about a method that increases the yield of crystalline material produced by the second concentration of mother liquor,and improve the yield of the total product.The Beer yeast can use reducing sugar in mother liquor during fermentation to reduce the residual sugar content in mother liquor of L-Threonine,so that mother liquor is easier to crystallize in the second concentration.The optimum inoculation amount was screened.The inoculation amount was 0.5%,0.75%,1%,1.25% and 1.5%,respectively.The optimum inoculation amount was determined as 1%.The optimum culture temperature was screened at 30?,31?,32?,33? and 34?,respectively.The optimum culture temperature was determined at 32?.According to the optimum inoculation amount,the optimum incubation time was screened under the conditions of 12 hr,15 hr,18 hr,21 hr and 24 hr,respectively.The optimum incubation time was 18 hr.Under the optimum conditions,the yield of L-Threonine from the mother liquor fermented by Beer yeast was compared with that from the mother liquor without Beer yeast action,the yield of L-Threonine from the former was about 6.27% higher than that from the latter.Saccharomyces cerevisiae was used to reduce the residual sugar content in the mother liquor of L-Threonine,and then the mother liquor of L-Threonine was prepared by secondary concentration,crystallization and extraction.The results showed that this method could increase the yield,thus reducing production costs,energy consumption,pollutant emissions and environmental protection.