title: Characterization of a novel melamine-degrading bacterium isolated from a melamine-manufacturing factory in China.
abstract: Melamine (2,4,6-triamino-1,3,5-triazine, C3H6N6), belonging to the s-triazine family, is an anthropogenic and versatile raw material for a large number of consumer products and its extensive use has resulted in the contamination of melamine in the environment. A novel melamine-degrading bacterium strain CY1 was isolated from a melamine-manufacturing factory in China. The strain is phylogenetically different from the known melamine-degrading bacteria. Approximately, 94 % melamine (initial melamine concentration 4.0 mM, initial cell OD 0.05) was degraded in 10 days without the addition of additional carbon source. High-performance liquid chromatography showed the production of degradation intermediates including ammeline, ammelide, cyanuric acid, biuret, and urea. Kinetic simulation analysis indicated that transformation of urea into ammonia was the rate-limiting step for the degradation process. The melamine-cyanurate complex was formed due to self-assembly of melamine and cyanuric acid during the degradation. The tracking experiment using CY1 cells and (13)C3-melamine showed that the CY1 could mineralize s-triazine ring carbon to CO2. The strain CY1 could also catalyze partial transformation of cyromazine, a cyclopropyl derivative of melamine, to 6-(cyclopropylamino)-[1,3,5]triazine-2,4-diol.
authors.affiliation: Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China.
authors.forename: Han
authors.initials: H
authors.lastname: Wang
authors.forename: Chunnu
authors.initials: C
authors.lastname: Geng
authors.forename: Jiangwei
authors.initials: J
authors.lastname: Li
authors.forename: Anyi
authors.initials: A
authors.lastname: Hu
authors.forename: Chang-Ping
authors.initials: CP
authors.lastname: Yu
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001711:Biotransformation; D002681:China; D002851:Chromatography, High Pressure Liquid; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004783:Environmental Microbiology; D007553:Isotope Labeling; D053858:Metabolic Networks and Pathways; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D014227:Triazines / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D014227:Triazines; C011907:melamine