title: Degradation of dexamethasone by acclimated strain of Pseudomonas Alcaligenes.
abstract: This study is to investigate the use of microbial remediation technology for degradation of dexamethasone in polluted water. A strain of Pseudomonas Alcaligenes with the ability of dexamethasone degradation was isolated from hospital polluted water. This strain was further acclimated into a bacterial strain that could highly degrade dexamethasone. Domesticated bacterial proteins were separated by osmotic shock method and were analyzed using SDS-PAGE. Enzyme activity of dexamethasone degradation was detected by high performance liquid chromatography. Protein bands with different molecular weight were found in all regions of the bacteria and a band with molecular weight of about 100 kDa was most obvious. In intracellular and periplasmic liquid, there was a band with molecular weight of about 41 kDa. Enzyme activity mainly existed in intracellular liquid. The 41 kDa protease was purified using ammonium sulfate precipitation, DEAE-52 ion exchange column and Sephadex G-100 column. Dexamethasone and dexamethasone sodium phosphate degrading rates of the purified enzyme were 36% and 95%, respectively. The 100 kDa protein had a 19% coverage rate to TonB receptor dependent protein, with 11 peptides matching. The 41 kDa protein had a 56% coverage rate to isovaleryl coenzyme A dehydrogenase, with 5 peptides matching. The 41 kDa protein had good degradation between the temperature of 25-40°C and PH value of 6.5-8.5. The enzyme kinetics equation was Ct = C0 e(-0.1769t), in accordance with the first-order kinetic equation. This study laid the foundation for further preparation of bioremediation agents for clearance of dexamethasone pollution in water.
authors.affiliation: Department of Pathogenic Biology, Basic Medical College of Chongqing Medical University Chongqing 400016, P. R. China.
authors.forename: Lili
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Laboratory of Pathogenic Biology and Immunology, Basic Medical Experimental Teaching Center, Chongqing Medical University Chongqing 400016, P. R. China.
authors.forename: Zhibang
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Department of Pathogenic Biology, Basic Medical College of Chongqing Medical University Chongqing 400016, P. R. China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Department of Pathogenic Biology, Basic Medical College of Chongqing Medical University Chongqing 400016, P. R. China.
authors.forename: Zeng
authors.initials: Z
authors.lastname: Tu
authors.affiliation: Pharmacy Experimental Teaching Center, Chongqing Medical University Chongqing 400016, P. R. China.
authors.forename: Lianju
authors.initials: L
authors.lastname: Ma
authors.affiliation: Department of Immunology and Pathogenic Biology, Chongqing Three Gorges Medical College Chongqing 404120, P. R. China.
authors.forename: Zhongquan
authors.initials: Z
authors.lastname: Shi
authors.affiliation: Department of Pathogenic Biology, Basic Medical College of Chongqing Medical University Chongqing 400016, P. R. China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Li
keywords: Pseudomonas Alcaligenes; degrading enzymes; dexamethasone; extraction; properties; purification