Journal of Pure and Applied MicrobiologyVol. 7 No. 4

Purification and Properties of Dibutyl Phthalate Esterase from Arthrobacter sp. ZJUTW

Qiu Lequan, Chen Yang, Zhong Li, Wu Shijin and Zhong Weihong*

College of Biology and Environment Engineering, Zhejiang University of Technology, Hangzhou - 310 032, China.

Received on 23 September 2013 and accepted on 06 November 2013

 

ABSTRACT

In the natural environment, various microorganisms are mainly responsible for the degradation of phthate acid esters. phthate acid esterase is one of key enzymes in the degradation pathway. A dibutyl phthalate esterase from Arthrobacter sp. ZJUTW was purified at 45-70% saturation with ammonium sulfate, ion-exchange chromatography (IEC) on Sepharose Q-XL column and hydrophobic interaction chromatography (HIC) on Hiprep Octyl FF column. The purified enzyme appeared homogeneous on SDS-PAGE, and its molecular weight was estimated to be 56.17 KDa. The optimal pH and temperature were pH 9.0 and 35 ?C, respectively. The enzyme was stable in a pH range from 7.0 to 9.0 and below 25 ?C. The enzyme activity was stimulated by Mg2+, but inhibited by several metals such as Cu2+, Zn2+, Ba2+, EDTA, and strongly inhibited by Fe3+. The Km for DBP of the enzyme was 0.487 mmol/l, Vmax was 223.3 ?mol/min?l.

Keywords : Arthrobacter sp; dibutyl phthalate; esterase; purification.