Characterization and application of a recombinant dopa decarboxylase from Harmonia axyridis for the efficient biosynthesis of dopamine  

作　　者：Siyuan Gao Yuanke Guo Chen Ma Ding Ma Kequan Chen Pingkai Ouyang Xin Wang 

机构地区：[1]State Key Laboratory of Materials-Oriented Chemical Engineering,College of Biotechnology and Pharmaceutical Engineering,Nanjing Tech University,Nanjing 211816,China

出　　处：《Chinese Journal of Chemical Engineering》2022年第1期449-456,共8页中国化学工程学报（英文版）

基　　金：funded by the National Natural Science Foundation of China(21576134 and 21706126);the National Key Research and Development Program(2016YFA0204300)。

摘　　要：Here,a dopa decarboxylase(DDC)from Harmonia axyridis was heterogeneously expressed in Escherichia coli for the efficient biosynthesis of dopamine.For the production of recombinant DDC,the cultivation conditions including IPTG concentration,temperature and induction time were optimized and obtained an optimal specific enzyme activity of 51.72 U·mg^(-1) crude extracts.After the purification of DDC with a recovery yield of 68.79%,its activity was further characterized.The Vmax,Km,Kcat,and Kcat/Km of DDC for d ihyd roxy pheny la la nine(dopa)were 0.02 mmol·ml^(-1)·s^(-1),2.328 mmol·ml^(-1),10435.90 s^(-1) and4482.77 ml,mmol respectively.The highest DDC activity was observed at the condition of pH 7.5 and 45℃.With the purified DDC,the feasibility to produce dopamine from L-dopa was evaluated.The optimal yield was determined at the following bioconversion conditions:pH of 7,0,the reaction temperature of 40℃,0.4 mmol·L^(-1) of PLP and 4 g·L^(-1) of L-dopa,Subsequently,a fed-batch process for the production of dopamine was developed and the effect of oxygen was evaluated.The titer,yield and productivity of dopamine reached up to 21.99 g·L^(-1)80.88%and 14.66 g·L^(-1)·h^(-1) at 90 min under anaerobic condition.

关 键 词：Dopa decarboxylase DOPAMINE Enzyme catalysis Fed-batch bioconversion 

分 类 号：TQ246.31[化学工程—有机化工]