Biotransformation Of ¦Ã-aminobutyric Acid And Its Separation And Purification Of Monascus

γ-aminobutyric acid(GABA),presenting in the mammalian central nervous system as a major inhibitory neurotransmitter in the central nervous system,is one of natural non-protein amino acid,with the physiological activity of lowering blood pressure,soothing the nerves, treating epilepsy,enhancing memory,regulating hormone secretion,controling asthma,and activating of liver and kidney function.As a new functional factor,GABA has broad prospects for the development and applicationin in the field of functional foods.In the paper,the Monascus strains produced GABA were selected from the preserved beancurd.It ferments on the rice culture medium though solid-state fermentation to study the conditions of producting GABA.And accordingly,it optimize the fermented conditions and the substrate to determine the best,and then preliminary extract pure GABA.Specific content and the results are as follows:Five Monascus strains were screened from the commercial Sufu producted in Guizhou, identified as Monascus purpureus,and named severally MP1101,MP1102,MP1103,MP1104 and MP1105.The five was tested with several carbon and nitrogen sources,gelatin hydrolysis, ethanol resistance,biomass production,and the synthesis ability of GABA.It uses response surface methodology to optimize conditions of solid-state fermentation for production of GABA by MP1104 which is the best of five Monascus strains.By means of single factor experiment, the result showed that when temperature is at 30℃,rice 70g per flask and ferment 7 days,a higher yield of GABA could be reached.And then under the response surface analysis of 3 factors,the optimization of fermentation condition was deteimined.The result showed that the content of GABA was 0.27mg/g in the optimum condition,which contained rice 71.667g per flask,temperature at 27.05℃,and ferment 8.6 d.At the base of optimized condition,soybean power,yeast extract,sodium nitrate,vitamin B6, Calcium chloride,potassium phosphate dibasic,heartleaf houttuymia herb,and rhizome gastrodiae was added in rice culture medium.3 factorst which could accelerate positively the production of GABA was screened by using Plackett-Burman design.The optimization content of these 3 factors was determined by response surface analysis.It showed that the content of GABA was 0.31mg/g in the optimum condition,which contained 0.66%soybean power,0.014% calcium chloride,0.405%vitamin B₆.Verification experiment showed that the optimized culture medium leaded the average yield of GABA to be increased 14.81 percent than before optimization. It used activated carbon and macroporous ion exchange resin to decolorize the extract of red yeast rice.Comprehensively considering decoloring ratio,GABA yield and convenience of operation,macroporous ion exchange resin D4020 was a good idea.Static experiment determined that ion exchange resins and extract is 1:1,and then choosing aqua ammonia with 2mol/1 consistence as the eluant was a recommended value.After ppreliminary crystallization, the purity of GABA crystals whose color is fawn could reach 45%.