Oxidative biodegradation of 4-chlorophenol by using recombinant monooxygenase cloned and overexpressed from Arthrobacter chlorophenolicus A6. (September 2017)

• Record Type: Journal Article
• Authors: Kang, Christina; Yang, Jun Won; Cho, Wooyoun; Kwak, Seonyeong; Park, Sungyoon; Lim, Yejee; Choe, Jae Wan; Kim, Han S.
• Is Part Of: Bioresource technology. Volume 240(2017)
• Page Start: 123
• Page End: 129
• Publication Date: 2017-09
• Subjects: 4-Chlorophenol -- Arthrobacter chlorophenolicus A6 -- Two-component flavin-diffusible monooxygenase -- Flavin reductase -- Enzymatic decomposition; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2017.03.078
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Color change from yellow to orange-red after 4-CP degradation by CphC-I. CphC-I concentration from 0.1 to 25 μM from left to right. Highlights: Arthrobacter chlorophenolicus A6 possesses DNA genes for 4-chlorophenol degradation. Soluble form CphC-I was expressed, whereas CphB expressed in an insoluble form. CphC-I exhibited high specific activity when coupled with a flavin reductase, Fre. v max = 223.3 μM·min −1, KM = 249.4 μM, and kcat /KM = 0.052 min −1 ·μM −1 . Abstract: In this study, cphC-I and cphB, encoding a putative two-component flavin-diffusible monooxygenase (TC-FDM) complex, were cloned from Arthrobacter chlorophenolicus A6. The corresponding enzymes were overexpressed to assess the feasibility of their utilization for the oxidative decomposition of 4-chlorophenol (4-CP). Soluble CphC-I was produced at a high level (∼50%), and subsequently purified. Since CphB was expressed in an insoluble form, a flavin reductase, Fre, cloned from Escherichia coli was used as an alternative reductase. CphC-I utilized cofactor FADH2, which was reduced by Fre for the hydroxylation of 4-CP. This recombinant enzyme complex exhibited a higher specific activity for the oxidation of 4-CP (45.34 U/mg-protein) than that exhibited by CphC-I contained in cells (0.18 U/mg-protein). The Michaelis-Menten kinetic parameters were determined as: vmax = 223.3 μM·min −1, KM = 249.4 μM, and kcat /KM = 0.052 min −1 ·μM −1 . These results could be useful for the development of a new biochemical remediation technique based on enzymatic agents catalyzing the degradation of phenolic contaminants.