苯酚羟化酶生物转化吲哚及甲基吲哚研究

摘要

The gene engineering strain PH_IND expressing phenol hydroxylase is used to catalyze the biotransformation of indole and methylindoles . The experimental results indicate that indole , 2-methylindole ,4-methylindole and 7-methylindole can be transformed into various indigoid pigments except for 3-methylindole . The predominant color products are identified by thin-layer chromatography and liquid chromatography-mass spectrometry analyses ,and the major products (blue pigment) derived from indole and 4-methylindole are authenticated as indigo and 4 ,4′-dimethylindigo , respectively .Meanwhile ,the biotransformation pathways of indole and 4-methylindole by PH_IND are proposed .Response surface methodology is applied to optimize the biotransformation conditions of indole ,2-methylindole and 4-methylindole by PH_IND .Under the optimal conditions ,the indigo yield and transformation efficiency of indole are 93 .74 mg/L and 52 .63% , respectively , while the maximum transformation rates of 2-methylindole and 4-methylindole are 67 .66% and 95 .61% , respectively .%　　利用苯酚羟化酶基因工程菌PH＿IND对吲哚及甲基吲哚进行生物转化．结果表明，除了3-甲基吲哚外，PH＿IND能将吲哚、2-甲基吲哚、4-甲基吲哚和7-甲基吲哚转化成靛蓝类色素．采用薄层色谱和液相-质谱等手段对转化产物进行鉴定，结果表明，PH＿IND转化吲哚和4-甲基吲哚得到的蓝色产物分别为靛蓝和4，4′-二甲基靛蓝，并推测了PH＿IND转化吲哚及4-甲基吲哚的反应途径．采用表面响应法对PH＿IND转化吲哚、2-甲基吲哚及4-甲基吲哚的条件进行了优化，在最优条件下，菌株PH＿IND转化吲哚合成靛蓝的最大产量为93．74 mg/L ，其吲哚的转化效率为52．63％，且菌株PH＿IND对2-甲基吲哚和4-甲基吲哚的最大转化率分别为67．66％和95．61％．