酿酒酵母静息细胞转化合成2-苯乙醇

利用酿酒酵母静息细胞转化合成2-苯乙醇，确定了静息细胞转化菌龄、转化液缓冲液体系和辅酶NADH再生辅助底物。在单因子试验基础上，用Plackett-Burm设计从影响转化6个因素中筛选出影响细胞转化的显著因素：辅助底物乙醇质量浓度、转化液pH和转化温度，以Box-Benhnken试验设计结合响应面法分析确定显著因子的最优水平。结果表明，最佳转化条件为乙醇质量浓度16.5 g/L、pH 5.1、转化温度26 ℃，2-苯乙醇产量为3.49 g/L（转化率58.8%），比优化前提高了49.14%，静息细胞重复使用8次，2-苯乙醇产量明显下降。转化液中加入10%的大孔吸附树脂对产物进行原位产物吸附，转化40 h，2-苯乙醇总质量浓度达9.34 g/L，L-苯丙氨酸转化率为83.9%，产量比未加入大孔树脂提高了171.5%。
The bioconversion conditions on the production of 2-phenylethanol with Saccharomyces cerevisiae resting cell were optimized. Incubation time of resting cell，buffer solution and co-substrate of coenzyme NADH regeneration were determined. Based on the results of single factor test and Plackett-Burm design，three factors including concentration of co-substrate ethanol，pH and reaction temperature were picked out as prominent factors affecting bioconversion of 2-phenylthanol. The optimal bioconversion conditions were determined by Box-Benhnken design and response surface analysis，i.e.，ethanol concentration 16.5 g/L，pH 5.1，temperature 26 ℃，The yield of 2-phenylethanol reached 3.49 g/L，increased by 49.14% compared with the original condition. The cell could maintain their bioconversion activity in repeated utilization at least eight times. After 40 h bioconversion，9.34 g/L of 2-phenylethanol and 83.9% of transformation ratio were obtained under the condition of adding 10% macroporous resin in situ product removal，the yield of 2-phenylethanol increased 171.5