摘要
采用基因工程方法对酿酒酵母进行代谢改造,使酵母产生乳酸代谢途径。将来源于L.mesenteroides和E.coli的D-乳酸脱氢酶基因,分别插入带有G418抗性的酵母穿梭质粒p YX212-kan MX上,电转化酵母,得到2株生产D-乳酸的酿酒酵母重组菌S.cerevisiae WE1510和S.cerevisiae WB1186。进一步摇瓶发酵试验表明:重组菌S.cerevisiae WB1186在YEPD培养基、20 g/L糖、p H 5的条件下生长条件最好,并具有更好的产乳酸能力。经3 L发酵罐条件下验证,S.cerevisiae WB1186分批发酵96 h,最终乳酸积累量达到18.0 g/L;发酵条件为培养基YEPD,接种量10%,溶解氧(DO)30%,转速150 r/min,初始葡萄糖质量浓度10 g/L,控制pH 5.0,通气量3 L/min,OD600最大值转为厌氧发酵。
A Saccharomyces cerevise strain was constructed by genetic engineering method, with lactic acid metabolic pathways. The gene dldh, encoding a lactate dehydrogenase from L. mesenteroides and E. coli, was cloned into a yeast shuttle vector PYX212-kanMX. The resultant plasmid pYX212-kanMX-DLDH was introduced into W303-1A by electroporation method and obtained two recombinant S. cerevisiae WE1510 and S. cerevisiae WBl186. Subsequently, a recombinant D-lactic acid producing yeast WBl186 was obtained,which had a better ability to produce D-lactic acid. It was up to 18.0 g/L of the lactic acid accumulation by batch fermentation in a 3-L fermenter for 96 h and the preliminary fermentation conditions were as follows, culture medium YEPD, inoculating rate 10%, DO 30%, stirring rate 150 r/min, concentration of glucose 10 g/L, pH 5.0, aeration rate 3 L/min, when OD60o up to maximum, the fermentation was turned to anaerobic.
出处
《生物加工过程》
CAS
2015年第6期6-12,共7页
Chinese Journal of Bioprocess Engineering
基金
国家高技术研究发展计划(863计划)(2011AA02A205
2012AA021201)
教育部新世纪优秀人才支持计划(NCET-11-0665)
