产酶培养条件对一株嗜酸乳杆菌亚油酸异构酶活力的影响

本实验用MRS培养基嗜酸乳杆菌,并通过添加亚油酸(LA)诱导其产亚油酸异构酶。单因素试验结果表明,在MRS培养基中添加糖类物质总体上不利于产酶,添加尿素、牛肉膏、酵母膏、酪蛋白等有机氮源后,酶活力比对照组有较大幅度提高,而添加无机氮源酶活力增加幅度不如有机氮源。在培养基中添加一定量的NaCl和卵磷脂也有助于酶活力的提高。由正交试验结果确定的最佳产酶条件为:培养温度37℃,培养时间24h,每100ml培养基中添加10mgLA,接种量3%(V/V)。

Effects of Cultivation Conditions on Enzyme Activity of Lactobacillus acidophilus Linoleate Isomerase

MRS culture medium was used for the cultivation of Lactobacillus acidophilus in this paper. Linoleate isomerase was produced with the inducement of linoleic acid added in the culture medium. Single factor experiment results showed that, the addition of saccharide has no obvious effect on enzyme activity. The addition of organic nitrogen such as urea, beef extract, casein or yeast extract can obviously improve the enzyme activity, while effects of inorganic nitrogen are not as high as organic nitrogen. Addition of certain concentration of NaCl and lecithin is also helpful for the improvement of enzyme activity. Optimal conditions determined by orthogonal test for obtaining the highest enzyme activity are as follows: cultivation temperature 37 ℃, cultivation time 24h, LA level 10 mg/100ml culture medium, and inoculation quantity 3%(V/V).