摘要
乙醛脱氢酶Ald6是啤酒酵母乙醛代谢途径的关键酶，它能催化乙醛脱氢，生成乙酸。设计引物，RT-PCR扩增得到啤酒酵母CRB2菌株Ald6基因，在大肠杆菌中进行克隆、表达、测序，并对表达产物的酶学性质进行了研究。结果表明，Ald6基因的大小为1503bp，编码的乙醛脱氢酶由500个氨基酸组成，与其它菌株的乙醛脱氢酶相比，核苷酸序列的同源性为7％-100％。乙醛脱氢酶以乙醛为底物时的Km值为28．14μmol／L，Vmax为98．03μmol·min^-1 mg^-1，最适反应条件为15℃，pH8．0。中试酿造试验发现K^＋、Mg^2＋、Fe^2＋对降低乙醛含量有显著作用。
The Aldehyde dehydrogenase Ald6, an important enzyme in yeast aldehyde metabolism pathway, catalyzes aldehyde to form acetic acid. Ald6 amplified by RT-PCR, which primers are based on the high conserved sequence, was cloned and expressed in E. cob. The DNA sequence and the enzyme properties of the expressed product were investigate. The results indicate Ald6 is 1503bp and encodes a protein that contains 300 animo acid. CRB2 Ald6 possesses 7% - 100% identity to other aldehyde dehydrogenase. When the enzyme＇ s substrate is aldehyde, Km and Vmax are 28.14 μmol/L and 98.03 μmaol·min^-1 mg^-1 . The optimal reaction conditions are temperature 15℃, pH 8.0. K^＋ .Mg^2＋ and Fe^2＋ can reduce aldehyde of the beer remarkably in the trial test.
出处
《啤酒科技》
2007年第12期24-28,共5页
Beer Science and Technology
