含α-乙酰乳酸脱羧酶基因重组酿酒酵母的啤酒发酵

BEER FERMENTATION USING RECOMBINANT SACCHARMYCES CEREVISIAE CLONED α-ACETOLACTATE DECARBOXYLASE

利用E .coli和酿酒酵母的穿梭质粒pYES2为载体 ,将地衣芽孢杆菌α 乙酰乳酸脱羧酶基因导入酿酒酵母中 ,构建了重组质粒pYEA ,实现了α 乙酰乳酸脱羧酶基因在酵母菌中的表达 .α 乙酰乳酸脱羧酶基因在酵母菌中的表达与菌体生长有关 .pYEA质粒在无选择压力的发酵条件下 ,仅能保持一定的稳定性 ,并具有降解α 乙酰乳酸的能力 ,但丢失率比较高 .

An expression recombinant plasmid pYEA in S.cerevisiae contained α acetola ctate decarboxylase gene fragment of B.licheniformis was constructed by the yeast E.coli shuttle vector pYES2.S.cerevisiae H158 transformed with pY EA plasmid had expressed α acetolactate decarboxylase activity.Without selecti ve condition,pYEA plasmid can only obtain about 30% in wort after fermentation 7 2h though the α acetolactate decarboxylase gene cloned into yeast cells still had shown the ability to reduce the formation of α acetolactate during fermen tation.