title: Isolation and characterization of an Alcaligenes sp. strain DG-5 capable of degrading DDTs under aerobic conditions.
abstract: In this study, an Alcaligenes sp. strain DG-5 that can effectively degrade dichlorodiphenyltrichloro-ethanes (DDTs) under aerobic conditions was isolated from DDTs-contaminated sediment. Various factors that affect the biodegradation of DDTs by DG-5 were investigated. About 88 %, 65 % and 45 % of the total DDTs were consumed within 120 h when their initial concentrations were 0.5, 5 and 15 mg L⁻¹, respectively. However, almost no degradation was observed when their concentration was increased to 30 mg L⁻¹, but the addition of nutrients significantly improved the degradation, and 66 % and 90 % of the total DDTs were degraded at 336 h in the presence of 5 g L⁻¹ peptone and yeast extract, respectively. Moreover, the addition of 20 mM formate also enhanced the ability of DG-5 to transform DDTs, and its DDT transformation capacity (T(c)) value was increased by 1.8 - 2.7 fold for the pure (p,p'-DDT or o,p'-DDT only) and mixed systems (p,p'-DDT, o,p'-DDT, p,p'-DDD and p,p'-DDE). Furthermore, it was found that competitive inhibition in the biodegradation by DDT compounds occurred in the mixed system.
authors.affiliation: School of Life Science and Biotechnology, Dalian University of Technology, Dalian, P. R. China.
authors.forename: Bo
authors.initials: B
authors.lastname: Gao
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Liu
authors.forename: Ling-Yun
authors.initials: LY
authors.lastname: Jia
authors.forename: Li
authors.initials: L
authors.lastname: Xu
authors.forename: Jian
authors.initials: J
authors.lastname: Xie
mesh_terms: D000332:Aerobiosis; D000421:Alcaligenes / Q000187:drug effects* / Q000302:isolation & purification / Q000378:metabolism; D001673:Biodegradation, Environmental; D003634:DDT / Q000145:classification / Q000378:metabolism / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004784:Environmental Monitoring; D004980:Ethane / Q000031:analogs & derivatives / Q000378:metabolism / Q000633:toxicity; D007306:Insecticides / Q000378:metabolism / Q000633:toxicity*; D012989:Soil Pollutants / Q000378:metabolism / Q000633:toxicity*; D013997:Time Factors
chemical_list: D007306:Insecticides; D012989:Soil Pollutants; D003634:DDT; D004980:Ethane