title: Immobilization of an enzyme from a Fusarium fungus WZ-I for chlorpyrifos degradation.
abstract: The free enzyme extracted from WZ-I, which was identified as Fusarium LK. ex Fx, could effectively degrade chlorpyrifos, an organophosphate insecticide. The methods of immobilizing this free enzyme and determined its degradation-related characteristics were investigated. The properties of the immobilized enzyme were compared with those of the free enzyme. The optimal immobilization of the enzyme was achieved in a solution of 30 g/L sodium alginate at 4 degrees C for 4-12 hr. The immobilized enzyme showed the maximal activity at pH 8.0, 45 degrees C. The maximum initial rate and the substrate concentration of the immobilized enzyme were less than that of the free enzyme. The immobilized enzyme, therefore, had a higher capacity to withstand a broader range of temperatures and pH conditions than the free enzyme. With varying pH and temperatures, the immobilized enzyme was more active than the free enzyme in the degradation reaction. In addition, the immobilized enzyme exhibited only a slight loss in its initial activity, even after three repeated uses. The results showed that the immobilized enzyme was more resistant to different environmental conditions, suggesting that it was viable for future practical use.
authors.affiliation: College of Resources and Environment, Shandong Agricultural University, Taian 271018, China. huixie@sdau.edu.cn
authors.forename: Hui
authors.initials: H
authors.lastname: Xie
authors.forename: Lusheng
authors.initials: L
authors.lastname: Zhu
authors.forename: Tingting
authors.initials: T
authors.lastname: Ma
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Jinhua
authors.initials: J
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Su
authors.forename: Bo
authors.initials: B
authors.lastname: Shao
mesh_terms: D000464:Alginates; D001673:Biodegradation, Environmental; D004390:Chlorpyrifos / Q000378:metabolism*; D004800:Enzymes, Immobilized / Q000378:metabolism*; D005670:Fusarium / Q000201:enzymology*; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007306:Insecticides / Q000378:metabolism*; D010573:Pesticide Residues / Q000378:metabolism*; D011142:Polyvinyl Alcohol; D013997:Time Factors
chemical_list: D000464:Alginates; D004800:Enzymes, Immobilized; D006603:Hexuronic Acids; D007306:Insecticides; D010573:Pesticide Residues; D020723:Glucuronic Acid; D011142:Polyvinyl Alcohol; D004390:Chlorpyrifos