title: Isolation and characterization of comprehensive polychlorinated biphenyl degrading bacterium, Enterobacter sp. LY402.
abstract: A Gram-negative bacterium, named LY402, was isolated from contaminated soil. 16S rDNA sequencing and measurement of the physiological and biochemical characteristics identified it as belonging to the genus Enterobacter. Degradation experiments showed that LY402 had the ability to aerobically transform 79 of the 91 major congeners of Aroclor 1242, 1254, and 1260. However, more interestingly, the strain readily degraded certain highly chlorinated and recalcitrant polychlorinated biphenyls (PCBs). Almost all the tri- and tetra-chlorobiphenyls (CBs), except for 3,4,3',4'-CB, were degraded in 3 days, whereas 73% of 3,4,3',4'-, 92% of the penta-, 76% of the hexa-, and 37% of the hepta-CBs were transformed after 6 days. In addition, among 12 octa-CBs, 2,2',3,3',5,5',6,6- CB was obviously degraded, and 2,2',3,3',4,5,6,6'- and 2,2',3,3',4,5,5',6'-CB were slightly transformed. In a metabolite analysis, mono- and di-chlorobenzoic acids (CBAs) were identified, and parts of them were also transformed by strain LY402. Analysis of PCB degradation indicated that strain LY402 could effectively degrade PCB congeners with chlorine substitutions in both ortho- and para-positions. Consequently, this is the first report of an Enterobacteria that can efficiently degrade both low and highly chlorinated PCBs under aerobic conditions.
authors.affiliation: Department of Bioscience and Biotechnology, Dalian University of Technology, Dalian 116024, PR China. lyj81@dlut.edu.cn
authors.forename: Ling-Yun
authors.initials: LY
authors.lastname: Jia
authors.forename: Ai-Ping
authors.initials: AP
authors.lastname: Zheng
authors.forename: Li
authors.initials: L
authors.lastname: Xu
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Huang
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhang
authors.forename: Feng-Lin
authors.initials: FL
authors.lastname: Yang
mesh_terms: D001140:Aroclors / Q000378:metabolism; D001673:Biodegradation, Environmental; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D004754:Enterobacter / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D004785:Environmental Pollutants / Q000378:metabolism; D010802:Phylogeny; D011078:Polychlorinated Biphenyls / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012988:Soil Microbiology
chemical_list: D001140:Aroclors; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D004785:Environmental Pollutants; D012336:RNA, Ribosomal, 16S; D011078:Polychlorinated Biphenyls