title: [Promotion effects of vitamin B12 on the degradation of 2, 4, 4'-trichlorobiphenyl by Nostoc PD-2].
abstract: Polychlorinated biphenyls are typical persistent chlorinated organic compounds in the environment. Bioremediation of PCB-contaminated environment has become one of the hot issues. In this study, vitamin B12 (VB12) and chlorine-free culture medium were applied to study the effects of VB12 on the degradation of 2,4,4'-trichlorobiphenyl (PCB28) by Nostoc PD-2 and the gene expression during the PCB-degradation process. Results showed that addition of different concentrations of vitamin B12 could improve the PCB-biodegradation rates by Nostoc PD-2. Compared with the control group, the 7-day degradation rate in 10 microg x L(-1), 100 microg x L(-1), and 1 000 microg x L(-1) VB12-treated groups increased by 11.0%, 19.7%, and 21.9% , respectively. The degradation half-time decreased from 5.53 days (treated with 10 microg x L(-1) VB12) to 3.08 days (treated with 100 microg x L(-1) VB12). The expression of cytochrome b6f complex iron-sulfur protein gene and dioxygenase gene showed significant correlation with PCB28-degradation by Nostoc PD-2. While the expression of iron-sulfur protein gene showed more significant correlation with PCB28-degradation. Results in this study indicated that adding VB12 could promote PCB28-degradation by Nostoc PD-2. Moreover, VB12 addition improved the PCB-degradation activity of Nostoc PD-2 at the gene level. The above conclusions could provide a new choice for developing efficient bioremediation technology for PCB-contaminated environment and a new insight into the PCB-biodegradation mechanism by Nostoc PD-2.
authors.forename: Jia-Yu
authors.initials: JY
authors.lastname: Liu
authors.forename: Wen-Feng
authors.initials: WF
authors.lastname: Xiao
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Lu
authors.forename: Hang-Jun
authors.initials: HJ
authors.lastname: Zhang
mesh_terms: D001673:Biodegradation, Environmental; D046937:Nostoc / Q000187:drug effects / Q000378:metabolism*; D011078:Polychlorinated Biphenyls / Q000737:chemistry*; D014805:Vitamin B 12 / Q000737:chemistry*
chemical_list: C081766:2,4,4'-trichlorobiphenyl; D011078:Polychlorinated Biphenyls; D014805:Vitamin B 12