Degradation of dibutyl phthalate (DBP) by a bacterial consortium and characterization of two novel esterases capable of hydrolyzing PAEs sequentially.

Degradation of dibutyl phthalate (DBP) by a bacterial consortium and characterization of two novel esterases capable of hydrolyzing PAEs sequentially. Ecotoxicol Environ Saf. 2020 Mar 25;195:110517 Authors: Lu M, Jiang W, Gao Q, Zhang M, Hong Q Abstract Phthalate esters (PAEs), a class of toxic anthropogenic compounds, have been predominantly used as additives or plasticizers, and great concern and interests have been raised regarding its environmental behavior and degradation mechanism. In the present study, a bacterial consortium consisting of Microbacterium sp. PAE-1 and Pandoraea sp. PAE-2 was isolated by the enrichment method, which could degrade dibutyl phthalate (DBP) completely by biochemical cooperation. DBP was converted to phthalic acid (PA) via monobutyl phthalate (MBP) by two sequential hydrolysis steps in strain PAE-1, and then PA was further degraded by strain PAE-2. Strain PAE-1 could hydrolyze many dialkyl Phthalate esters (PAEs) including dimethyl, diethyl, dibutyl, dipentyl, benzyl butyl, dihexyl, di-(2-ethyhexyl) and their corresponding monoalkyl PAEs. Two esterase genes named dpeH and mpeH, located in the same transcription unit, were cloned from strain PAE-1 by the shotgun method and heterologously expressed in Escherichia. coli (DE3). The Km and kcat values of DpeH for DBP were 9.60 ± 0.97 μM and (2.72 ± 0.06) × 106 s-1, while those of MpeH for MBP were 18.61 ± 2.00 μM and (5.83 ± 1.00) × ...
Source: Ecotoxicology and Environmental Safety - Category: Environmental Health Authors: Tags: Ecotoxicol Environ Saf Source Type: research