乙醇对法夫酵母发酵合成虾青素的影响

摘要

利用摇瓶培养法夫酵母JMU-MVP14菌株,通过乙醇传感器检测乙醇含量,研究乙醇对法夫酵母细胞生长及虾青素合成的影响.结果表明,在10 g/L和20 g/L葡萄糖初始培养基中分别添加1～2 g/L乙醇时,均可提高虾青素的产量;而添加高浓度乙醇,则会抑制细胞生长和虾青素的合成.以10 g/L葡萄糖为初始培养基,控制发酵中恒定乙醇浓度为2 g/L,虾青素质量浓度可达到50.1 mg/L,比只添加2 g/L乙醇提高了20.3％,且虾青素细胞产率达到13.1 mg/g,葡萄糖的利用率能达到77.2％以上,说明恒定乙醇控制策略更有利于法夫酵母虾青素的合成.在10 g/L初始葡萄糖浓度,恒定乙醇浓度2 g/L,并每24 h补加5 g/L葡萄糖的优化条件下,虾青素产量最大值达到55.3 mg/L,虾青素细胞产率为19.7 mg/g,比对照组(14.1 mg/g)提高了39.7％.%With the detection of ethanol by ethanol sensor,the effects of ethanol on cell growth and astaxanthin production by Phaffia rhodozyma JMU-MVP14 were investigated in shake flask.The results indicated that 1 ～2 g/L ethanol was conducive to astaxanthin accumulation in initial medium with 10 g/L or 20 g/L glucose,while high concentration of alcohol inhibited the cell growth and astaxanthin production of P.rhodozyma.When ethanol concentration was maintained at 2 g/L in initial medium with 10 g/L glucose,astaxanthin production was 50.1 mg/L,which increased by 20.3％ compared with the control group.The yield of astaxanthin in a cell was 13.1 mg/g and the utilization rate of glucose was over 77.2％.The results demonstrated that the constant ethanol control strategy was conductive to astaxanthin accumulation in yeast cells.The maximum yield of astaxanthin was 55.3 mg/L under the optimized condition of 10 g/L initial glucose concentration,2 g/L constant ethanol concentration and 5 g/L glucose supplemented per 24 h during the fermentation.And the yield of astaxanthin in a cell was 19.7 mg/g,which increased by 39.7％ compared with the control group (14.1 mg/g).