一株产α-半乳糖苷酶菌的分离与选育

Screening and Mutation Breeding of α-galactosidase-producing Microorganism

主要研究了α-半乳糖苷酶产生菌的筛选及选育。以发酵豆制品和用于食品酿造的菌株为材料,通过在平板上显示蓝色作为初筛依据,结合摇瓶复筛获得1株产α-半乳糖苷酶酶活高的曲霉菌株,其96h酶活达到22.27U/mL,初步鉴定为臭曲霉,并定名为AspergillusfoetidusZU-G。该菌株经60Co-γ辐射诱变和N+离子束诱变,其酶活比各出发菌株分别提高了20.7%和23.4%,分别达到26.88U/mL和33.18U/mL。

This work mainly investigated the screening and breeding of α-galactosldase-producing microorganisms. The strain was isolated by preliminary screening with selection plate and re-screening with shaking flask culture from soy fermented products and other strains from traditional fermented foods. The strain selected can pro- duce α-galactosidhse of 22.27 U/mL at 96h cultivation. The isolated strain was tentatively identified by traditional identification methods as Aspergillus foetidus, and denominated as Aspergillus foetidus ZU-G. The Aspergillus foetidus ZU-G was further breed by ^60Co -gamma irradiation and low energy N^ ＋ implanting methods. Experimental results demonstrated that α-galactosidase activity was increased by 20.7 %, 23.4 % contrasting with the original strain, and enzyme activities were about 26.88 U/mL and 33.18 U/mL after breeding, respectively.