Study On Synthesize Of β-Alanine Use Enzyme

In this experiment,the conditions of breaking cell-wall of E.coli, extraction techniques of aspartic acid 1-C decarboxylase and the cell's zymologic Properties were studied.The best method for breaking cell wall is grinding and adding 1 mg / mL lysozyme for 1h,the best medium is pH 8,0.05 mol /L phosphate buffer.Optimum temperature is 37℃,and optimum pH is 7.The enzyme activity fall to 0 after treatment in 100℃water for 1h,treatment in pH3 water for 1 h the enzyme activity is only 33 U. 24 h is the best time of transform.After salting-out,ion-exchange and gel chromatography,the enzyme was purified well.As the loss of enzyme activity in the experiment,and the final activity fall to 3.66%.Study on the conditions of the immobilize cell of E.coli BL21(DE3)/ pET28 b(+),and study the property of the immobilized cell.Immobilized cell that the best conditions for crosslinking is 30℃,pH5.5,6 h.The optimum temperature is 37℃and pH7.5.Lay the immobilized cell in pH2 and pH11 water 30 min still reserve enzyme activity.Lay it in 100℃water for 1h the enzyme activity approach to 0.After three consecutive transform still reserve about 85%of the enzyme activity.Study on the process conditions of enzymatic synthesis ofβ-ala.The best fermentation conditions is:inoculation 0.5%,fermentation temperature 37℃,28 h incubation time,induced by adding time 3 h,induced concentration 4 g / L.The best Transformation conditions is:substrate type of aspartate ammonia,substrate concentration of 0.1 M,transform temperature 37℃,pH6,transforming time is 24 h,after 24h the peak area ofβ-ala begin to stably.