地衣芽孢杆菌α-乙酰乳酸脱羧酶的纯化及酶学性质  

PURIFICATION AND PROPERTIES OF α-ACETOLACTATE DECARBOXYLASE FROM BACILLUS LICHENIFORMIS

作　　者：郑华军[1] 鲍晓明[1] 侯爱华[1] 杨国梁[1] 沈煜[1] 高东[1] 

机构地区：[1]山东大学微生物技术国家重点实验室,济南250100

出　　处：《山东大学学报（理学版）》2002年第2期180-183,188,共5页Journal of Shandong University(Natural Science)

摘　　要：地衣芽孢杆菌 (Bacilluslicheniformis)AS10 10 6α 乙酰乳酸脱羧酶经硫酸铵沉淀 ,聚乙二醇沉淀 ,DEAE SepharoseFastFlow离子交换 ,GigapiteK 10 0S柱层析及SephadexG 10 0分子凝胶过滤柱等分离纯化步骤 ,得到SDS PAGE电泳纯 ,α 乙酰乳酸脱羧酶的比活提高了 5 3.5倍。对该酶性质的研究表明 ,酶单亚基分子量为 32Kda ,等电点为 4 .5 ;该酶的最适反应温度为 4 0℃ ,最适反应 pH为 6 .0 ,对热 (40℃以上 )敏感 ,在 pH5 .0～ 6 .5之间稳定。酶活不需要金属阳离子 ,Cu2 +、Co2 +强烈抑制酶的活性。摇瓶实验表明 ,纯化的地衣芽孢杆菌αThe α acetolactate decarboxylase from B.licheniformis was purified to homogeneity from the cell free extract by ammonium sulfate fractionation,polyethylene glycol precipitation,DEAE Sepharose Fast Flow,Gigapite K 100S and Sephadex G 100 column chromatographies.The enzyme was purified about 53.5 fold.Its molecular weight was estimated to be about 32Kda by SDS PAGE.Its pI was 4.5.It showed optimal activity at 40℃ and pH 6.The enzyme showed stability at pH range of 5.0 to 6.5 at the temperature below 40℃.Cu 2+ (1mM)?Co 2+ produced a strong inhibitory effect while the other tested metal ions and EDTA had no effect on the enzyme.Laboratory scale fermentation experiment revealed that the purified α acetolactate decarboxylase had significant effect to reduce the concentration of diacetyl in wort.

关 键 词：地衣芽孢杆菌 Α-乙酰乳酸脱羧酶 蛋白纯化 酶学性质 酶活性 分子凝胶过滤柱 

分 类 号：Q939.124[生物学—微生物学] Q936