摘要
为获得藏区牦牛酸奶酪中的产乳糖酶活力高的菌株,采用含X-gal的培养基进行初筛,从购买的10份样品中筛选到10株产乳糖酶细菌;发酵复筛后,发现其中RTM-111菌株的产酶活力最高。综合形态学特征、生理生化实验及16S rDNA序列分析,确定该菌株为枯草芽孢杆菌(Bacillus subtilis)。对该菌株所产乳糖酶的酶学性质研究表明,该酶的最适反应温度为50℃,最适pH为7.5。稳定性实验表明,该酶在温度40～50℃、pH6.5～8.0时具有较高稳定性。金属离子Na^+、Mg^(2+)和Mn^(2+)对酶活性具有较强的激活作用,而Cu^(2+)、Zn^(2+)和EDTA对酶活有显著的抑制作用。枯草芽孢杆菌RTM-111产乳糖酶活力高、酶的性质稳定,具有潜在应用价值。
Using the screening medium containing X-gal,10 strains with high producing lactase activity were isolated from 10 yak yogurt cheese samples purchased from Xizang.An efficient lactase producing strain RTM-111 rescreened out from the 10 strains was identified as Bacillus subtilis by the means of morphological feature,physiological and biochemical characteristics measurement and 16S rDNA sequence analysis.Lactase enzyme properties research showed that the optimal reaction temperature and pH were 50 ℃ and 7.5.The enzyme was stable at 40 ~50 ℃ and pH6.5 ~8.0. The lactase activity was promoted by Na+,Mg2+and Mn2+,and strongly inhibited by Cu2+,Zn2+and EDTA.The high producing activity of B. subtilis RTM-111 and the stability of the lactase made it potentially useful.
作者
陆云彪
王盈桐
李学威
刘晓东
赵凤春
田园
LU Yun-biao;WANG Ying-tong;LI Xue-wei;LIU Xiao-dong;ZHAO Feng-chun;TIAN Yuan(Taishan Medical University,Taian 271016,China;Shandong Key Laboratory of Agricultural Microbiology,Shandong Agricultural University,Taian 271018,China)
出处
《食品工业科技》
CAS
北大核心
2019年第5期124-129,共6页
Science and Technology of Food Industry
基金
国家自然科学基金项目(21602152)
山东省自然科学基金项目(ZR2016BB01)
泰安市科技发展计划项目(2016NS1214)
国家级大学生创新创业计划项目(201610439263
201710439309)
山东省农业微生物重点实验室开放课题基金(SDKL2017015)
泰山医学院生命科学学院大学生攀登计划项目
关键词
牦牛酸奶酪
乳糖酶
分离
鉴定
酶学性质
yak yogurt cheese
lactase
isolation
identification
enzymatic properties
