土生拉乌尔菌Y20产乳糖氧化酶发酵条件优化

Optimum Fermentation Condition of Production Lactose Oxidase by Raoultella terrigena Y20

摘要:

以选育的土生拉乌尔菌（Y20）为生产菌株，在单因素和响应面分析的基础上考察了不同发酵条件对乳糖氧化酶活性的影响。方差分析结果表明，发酵条件对乳糖氧化酶活性影响次序：初始pH>发酵时间>接种体积分数>发酵温度。响应面分析优化的最适发酵条件：发酵时间25 h，发酵温度28 ℃，初始pH 7.2，接种体积分数2%。最优发酵条件下乳糖氧化酶的实际酶活可达78.36 U/g，与预测的酶活78.85 U/g接近。

Abstract:

The effects of fermentation conditions on lactose oxidase activity producing by Raoultella terrigena Y20，which was screened by our lab，were studied by single factor experiment and response surface methodology. The results showed that the four independent variables as initial pH value，fermentation time，inoculation amount and fermention temperature had significant and sequence effects on the lactose oxidase activity. The optimal fermention conditions were as follows， inoculum amount of 2%，initial pH at 7.2，fermented 25 h，temperature at 28 ℃. Under the optimal conditions，the lactose oxidase activity was 74.96 U/g，which was almost consistent with predicted value of 78.87 U/g.