变色圈法筛选高产氨基酰化酶米曲霉菌株

将变色圈法用于筛选高产氨基酰化酶的米曲霉菌株,减少了筛选过程的工作量、缩短了筛选周期。通过实验验证了该方法在筛选高产氨基酰化酶米曲霉菌株时的可行性,并将其用于筛选经紫外线和硫酸二乙酯复合诱变的米曲霉。从突变株中获得了一株高产氨基酰化酶菌株W53,对其生长特性和产酶特性进行了研究。结果表明,米曲霉的氨基酰化酶是生长偶联型,菌体生物量和氨基酰化酶活力同时达到最高;突变株W53和出发菌株W19的产酶过程基本一致;W53拆分N-乙酰-DL-蛋氨酸的酶活力最高可达2569 U/g,比出发菌株W19提高了14.9%。

Screening of Aspergillus oryzae strain with a high production of aminoacylase by color-changing circle method

The color-changing circle method was adopted to screening Aspergillus oryzae(Asp.)strains with a high yield of aminoacylase,which reduced the screening load and selection time.This method was validated by experiments and applied further to screening of Asp.strains induced by ultraviolet ray and diethyl sulfate,a mutation named W53 with a high yield of aminoacylase was obtained,whose growth characteristics and enzyme activity time course were investigated.The results show that the enzyme production rate and growing rate of Asp.Strains are synchronized and the cell biomass and the enzyme activity both reach their highest simultaneously.The enzyme production process of the mutation W53 is found consistent with that of original Asp.strain W19;however,the enzyme activity of mutation W53 can reach as high as 2 569 U/g when disposing N-acetyl-DL-methionine(N-Ac-DL-Met),which is 14.9% higher than that of strain W19.