Optimization of expression conditions and characteristics of gene engineered strain PH_IND
苯酚羟化酶基因工程菌表达优化及特性研究

Response surface methodology was applied to optimize the culture conditions(seed age and level) and expression conditions(OD600 for inducing,IPTG concentration,induction time and temperature) of phenol hydroxylase,and to study characteristics of crude enzyme.The optimal expression conditions were seed age 7.19 h,level 1.39%,OD600 for inducing 0.54,IPTG concentration 0.19 mmol · L-1,induction time 2.37 h and temperature 35 ℃.Under the optimal conditions,the maximal activity of phenol hydroxylase could reach 0.6167 U · mg-1.The optimal pH and temperature for phenol hydroxylase was 8.0 and 40 ℃,respectively.The enzyme activity was stimulated by Ba2+,Fe3+,Hg2+ and Pb2+,but inhibited by Ca2+,Co2+,Cu2+,Mg2+ and Mn2+.Furthermore,phenol hydroxylase exhibited strong degradation ability of aromatic compounds.