为了获得腺嘌呤合成腺苷甲硫氨酸(SAM)的高产菌株,将酿酒酵母的SAM合成酶基因sam 2克隆至整合型质粒pCB1004-Pgpd的多克隆位点,获得重组质粒pCB1004-Pgpd-sam 2。在PEG-CaCl2介导下,重组质粒导入至雅致放射毛霉原生质体内,获得SAM工程菌。以腺嘌呤为合成前提物的条件下,通过菌株筛选获得1株高产的SAM工程菌,其SAM产量相对于出发菌株提高了1.5倍。

In this paper,Saccharomyces cerevisiae genome was used as a template,and the key enzyme gene sam2 was cloned into multiple cloning sites of the integrated plasmid pCB1004-Pgpd by PCR to obtain the recombinant plasmid for synthesis of SAM.The recombinant plasmid was transformed into Actinomucor elegans protoplast under the mediation of PEG-CaCl2 to get SAM productive engineering strain.With the adenine as precursor,the SAM production of screened strain increased from 0.40 g /L to 1.00 g /L as compared to the original strain,which increased by1.5 times.