title: Effective utilization of dichloromethane by a newly isolated strain Methylobacterium rhodesianum H13.
abstract: An effective dichloromethane (DCM) utilizer Methylobacterium rhodesianum H13 was isolated from activated sludge. A response surface methodology was conducted, and the optimal conditions were found to be 4.5 g/L Na2HPO4·12H2O, 0.5 g/L (NH4)2SO4, an initial pH of 7.55, and a temperature of 33.7 °C. The specific growth rate of 0.25 h(-1) on 10 mM DCM was achieved, demonstrating that M. rhodesianum H13 was superior to the other microorganisms in previous investigations of DCM utilization. DCM mineralization paralleled the production of cells, CO2, and water-soluble metabolites, as well as the release of Cl(-), whereas the carbon distribution and Cl(-) yield varied with DCM concentrations. The facts that complete degradation only occurred with DCM concentrations below 15 mM and repetitive degradation of 5 mM DCM could proceed for only three cycles were ascribed to pH decrease (from 7.55 to 3.02) though a buffer system was employed.
authors.affiliation: College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou, 310032, China.
authors.forename: Dong-Zhi
authors.initials: DZ
authors.lastname: Chen
authors.forename: Du-Juan
authors.initials: DJ
authors.lastname: Ouyang
authors.forename: Hong-Xia
authors.initials: HX
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.forename: Qing-Feng
authors.initials: QF
authors.lastname: Zhuang
authors.forename: Jian-Meng
authors.initials: JM
authors.lastname: Chen
mesh_terms: D001483:Base Sequence; D001673:Biodegradation, Environmental; D008752:Methylene Chloride / Q000032:analysis / Q000378:metabolism*; D020580:Methylobacterium / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D012722:Sewage / Q000382:microbiology; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*; D018508:Water Purification / Q000379:methods
chemical_list: D012722:Sewage; D014874:Water Pollutants, Chemical; D008752:Methylene Chloride