摘要
对保加利亚乳杆菌中的亚油酸异构酶的提取和性质进行了研究。利用超声波对乳酸杆菌细胞进行破碎,以提取细胞中的亚油酸异构酶,并就超声波破碎条件对亚油酸异构酶释放的影响进行了研究。通过单因素试验和正交试验得出保加利亚乳杆菌的最佳超声破碎条件为:间歇破碎次数80次(每次破碎3s,中间间隔4s),破碎菌液体积60mL,菌悬液浓度15g/50mL,破碎时的抽提缓冲液最佳pH值4.8,NaCl浓度0.3mol/L。保加利亚乳杆菌亚油酸异构酶的粗酶液经硫酸铵盐析、超滤、凝胶过滤层析等步骤进行分离纯化后,酶的纯化倍数为23.00。经SDS-PAGE后只显示一条谱带,分子量约为33000D。对保加利亚乳杆菌亚油酸异构酶的部分酶学性质也进行了研究,结果表明:能专一性地将亚油酸转化为共轭亚油酸,转化产物中活性异构体的比例达到93.626%。
The extract and properties of linoleate isomerase in LactobaciUus bulgaricus was studied in this paper. Ultrasonic wave was used to disrupt the cells of LactobaciUus bulgaricus so as to extract linoleate isomerase from the cells, and the influence of the disruption condition to the release of linoleate isomerase was studied. After single-factor experiment and orthogonal experiment, the optimum disruption condition for LactobaciUus bulgaricus was： intermittent ultrasonic treatment 80 times （time for each treatment was 3 s, with a 4 s interval）, volume of the treated cell suspension 60 mL, concentration of cell suspension 15 g/50 mL, pH value of the extraction buffer 4.8, concentration of NaCl 0.3 mol/L.Crude enzyme extract from LactobaciUus bu/gar/cus was purified by ammonium sulfate salting-out, ultrafiltration and gel fractionation chromatography. Purification of about 23.00-fold was achieved. After those steps, there was only one distinct protein band by SDS-PAGE, which showed that the relative molecular weight of linoleate isomerase was about 3 3000 Dal.Some of the enzymatic properties was also studied. Results showed that, linoleate isomerases could specifically transform linolenic acid to conjugated linoleic acid isomers with physiological activities, and the ratio of those isomers amounted to 93.626 %.
出处
《食品研究与开发》
CAS
北大核心
2006年第7期102-107,共6页
Food Research and Development
基金
河南省杰出青年基金项目(04120001800)
关键词
亚油酸异构酶
保加利亚乳杆菌
提取
性质
linoleate isomerase
LactobaciUus b ulgaricus
extract
property
