title: Biodegradation of di-n-butyl phthalate by a newly isolated halotolerant Sphingobium sp.
abstract: A Gram-negative strain (TJ) capable of growing aerobically on mixed phthalate esters (PAEs) as the sole carbon and energy source was isolated from the Haihe estuary, Tianjin, China. It was identified as belonging to the Sphingobium genus on the basis of morphological and physiological characteristics and 16S rRNA and gyrb gene sequencing. The batch tests for biodegradation of di-n-butyl phthalate (DBP) by the Sphingobium sp. TJ showed that the optimum conditions were 30 °C, pH 7.0, and the absence of NaCl. Stain TJ could tolerate up to 4% NaCl in minimal salt medium supplemented with DBP, although the DBP degradation rates slowed as NaCl concentration increased. In addition, substrate tests showed that strain TJ could utilize shorter side-chained PAEs, such as dimethyl phthalate and diethyl phthalate, but could not metabolize long-chained PAEs, such as di-n-octyl phthalate, diisooctyl phthalate, and di-(2-ethyl-hexyl) phthalate. To our knowledge, this is the first report on the biodegradation characteristics of DBP by a member of the Sphingobium genus.
authors: Decai
authors: D
authors: Jin
authors: Xiao
authors: X
authors: Kong
authors: Bingjian
authors: B
authors: Cui
authors: College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China. zhbai@rcees.ac.cn.
authors: Zhihui
authors: Z
authors: Bai
authors: Hongxun
authors: H
authors: Zhang
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D001673:Biodegradation, Environmental; D027081:DNA Gyrase / Q000737:chemistry / Q000235:genetics; D003993:Dibutyl Phthalate / Q000737:chemistry / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D042301:Sphingomonadaceae / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D012336:RNA, Ribosomal, 16S; D003993:Dibutyl Phthalate; D027081:DNA Gyrase