透性化处理对嗜酸乳杆菌细胞亚油酸异构酶表观活力的影响

来源嗜酸乳杆菌的亚油酸异构酶是胞内酶,完整的细胞呈现较低的酶活。研究了乙醇、乙醚、甲苯、溴化十六烷三甲基铵(CTAB)等透性剂对嗜酸乳杆菌细胞亚油酸异构酶活力的影响。结果表明,经过透性化处理的细胞亚油酸异构酶活力显著提高,其中最好的透性剂为CTAB。当CTAB的浓度为1%,30℃保温20～30min,酶活高达405.6U/g,是超声波破碎的细胞表观酶活的5.4倍。透性化细胞中亚油酸异构酶热稳定性提高,60℃保温2h,残余酶活为80%。透性化细胞生物转化共轭亚油酸转化率达84.5%,用透性化细胞可有效转化亚油酸为共轭亚油酸。

Effect of permeabilization of Lctobacillus acidophilus cells on apparent activity of linoleate isomerase

Linoleate isomerase is an intracellular enzyme.The whole cells of Lctobacillus acidophilus exhibited low enzyme activity, but cells treated by ethanol, ethylether, toluene and CTAB apparently had higher activity of enzyme.The maximum enzyme activity (405.6U/g) was obtained when cells were treated with 1% CTAB at 30℃ for 20～30min.The enzyme activity in permeabilized cells was .5.4 fold higher than that in the cell free extract prepared by ultrasonic.The enzyme activity in permeabilized cells retained 80% at 60℃ for 2h, which showed the thermo-stability of enzyme and was higher than that in the cell free extract.Linoleic acid could be effectively converted into conjugated linoleic acid by permeabitized Lctobacillus acidophilus cells.The conversion of CLA reached 84.5 %.