静息细胞降解叶黄素生产香味物质的条件优化

OPTIMIZATION OF LUTEIN DEGRADATION PROCESS FOR PRODUCING AROMA COMPONENTS BY USING RESTING CELLS

在单因素试验基础上,应用响应面设计对霍氏肠杆菌(Enterobacter hormaechei)A20的静息细胞降解叶黄素生产香味物质进行条件优化。确定最佳转化条件为:培养时间120 min,温度31.14℃,pH值为4.98,细胞浓度为17.64%,底物质量浓度为70 mg/L,此时叶黄素降解率为71.37%,与软件预测值71.54%相吻合,表明优化方案达到了预期效果,且具有良好的稳定性。对静息细胞降解叶黄素的发酵液中的主要成分进行气相色谱-质谱联用(gas chromatography-mass spectrometry,GC-MS)分析,得到其主要产物为8-甲基-α-紫罗兰酮和3-氧化-α-紫罗兰酮。

Based on single factor experiments,the Box-Behnken response surface design was conducted to optimize the degradation conditions of lutein for producing aroma components by using resting cells of Enterobacter hormaechei A20. The optimized conditions were as follows： incubation time 120 min,temperature 31.14 ℃ ,pH 4.98,cell concentration 17.64% ,and substrate concentration 70 mg/L. Under the optimum conditions,the degradation rate of lutein was up to 71.37% ,consistent with the software prediction value 71.54%, which indicated that the optimized scheme reached the expected effect and had good stability. The main components in fermentation broth of lutein degraded by resting cells were detected by GC-MS, and were identified as 8-methyl-α-ionone and 3-oxo-α-ionone.