植物乳杆菌ZS2058中亚油酸异构酶的定位研究

Study on location of linoleate isomerase from Lactobacillus plantarum ZS2058

植物乳杆菌ZS2058是本实验室从泡菜中筛选到的一株具有亚油酸异构酶活性的乳酸菌。本文对植物乳杆菌ZS2058中亚油酸异构酶的部分粗酶性质进行了考察,建立了初酶活性检测方法,在此基础上对此亚油酸异构酶在细胞中的定位进行了研究,这将为后续分离纯化此亚油酸异构酶提供理论依据与指导。考察的结果是超声波破碎获得亚油酸异构酶初酶液的最佳条件为破碎功率400W,破碎时间7.5min(破碎5s,间歇9s)。初酶活性测定时的最适亚油酸底物浓度为0.08mg/mL;EGTA等金属螯合剂及Ca2+对亚油酸异构酶活性的影响均不显著;粗酶液经超高速离心分级沉淀和加入去垢剂Triton X-100提取的实验结果表明,该亚油酸异构酶为细胞膜结合酶。

Lactobacillus plantarum ZS2058, which was screened from the Chinese traditional fermented vegetable, has the capacity to convert the linoleic acid （LA） into conjugated linoleic acid （CLA）. The location of Lactobacillus plantarum ZS2058 linoleate isomerase and partial characterization of the crude enzyme extract were studied. The optimum disruption conditions of ultrasonics for Lactobacillus plantarum ZS2058 were as follows, power of treatment 400W, time of treatment 7.5min （time for each treatment was 5s, with a 9s interval）. The optimum concentration for linoleic acid was determined to be 0.08mg/mL. The effect of the metal- chelators （1, 10phenanthrene and EGTA） and Ca^2＋ were not significant. These results supported the conclusion that Lactobacillus plantarum ZS2058 linoleate isomerase was a membrane protein.