title: Quantitative structure-biodegradation relationships for ortho-substituted biphenyl compounds oxidized by Methylosinus trichosporium OB3b.
abstract: Methanotrophs, bacteria that thrive in the presence of stable methane and oxygen concentrations, can cometabolically oxidize ortho-substituted biphenyls to yield a variety of hydroxylated products. Despite awareness of the susceptibility of ortho-substituted biphenyls and other aromatic compounds to methanotrophic oxidation, the molecular properties relevant for predicting rates of methanotrophic oxidation are unknown. To this end, we have developed quantitative structure-biodegradation relationships using oxygen uptake activity by the type 2 methanotroph. Methylosinus trichosporium OB3b, expressing the soluble form of methane monooxygenase and in the presence of nine ortho-substituted biphenyls. Multivariate analysis yielded the strongest correlations using the initial slope of the oxygen uptake rate versus substrate concentration curve as the dependent variable. Quantum mechanical descriptors, including the sum of carbon charges on the substituted ring, the charge on the substituted carbon, and the width of compound calculated using computationally derived bond lengths and dihedral angles, correlated more strongly with oxygen uptake activity than did empirically derived electronic descriptors. The resulting models suggest a significant influence of substituent electronic nature and size and the involvement of the substituted carbon site in the oxidation of these compounds by M. trichosporium OB3b.
authors.affiliation: Department of Environmental Engineering Sciences, University of Florida, A.P. Black Hall, P.O. Box 116450, Gainesville, Florida 32611-6450, USA. alind@eng.ufl.edu
authors.forename: Angela S
authors.initials: AS
authors.lastname: Lindner
authors.forename: Callie
authors.initials: C
authors.lastname: Whitfield
authors.forename: Ning
authors.initials: N
authors.lastname: Chen
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Semrau
authors.forename: Peter
authors.initials: P
authors.lastname: Adriaens
mesh_terms: D001673:Biodegradation, Environmental; D004785:Environmental Pollutants / Q000378:metabolism*; D020602:Methylosinus trichosporium / Q000201:enzymology* / Q000235:genetics*; D010084:Oxidation-Reduction; D010105:Oxygenases / Q000494:pharmacology*; D011078:Polychlorinated Biphenyls / Q000378:metabolism*; D021281:Quantitative Structure-Activity Relationship
chemical_list: D004785:Environmental Pollutants; D011078:Polychlorinated Biphenyls; D010105:Oxygenases; C021555:methane monooxygenase