title: Biodegradation and metabolic pathway of sulfamethoxazole by Pseudomonas psychrophila HA-4, a newly isolated cold-adapted sulfamethoxazole-degrading bacterium.
abstract: Sulfamethoxazole is a common antibiotic that is frequently detected in wastewater and surface water. This study investigated the biodegradation and metabolic pathway of sulfamethoxazole by Pseudomonas psychrophila HA-4, a cold-adapted bacterium. Strain HA-4, which uses sulfamethoxazole as its sole source of carbon and energy, was isolated at a low temperature (10 °C) and identified as P. psychrophila by physico-biochemical characterization and 16S rRNA gene sequence analysis. Strain HA-4 removed sulfamethoxazole at temperatures ranging from 5.0 °C to 30 °C, with the maximal removal rate at 10 °C. The maximal removal rate of sulfamethoxazole by strain HA-4 was 34.30 % after 192 h at 10 °C. The highest percentage of unsaturated fatty acid was determined to be 23.03 % at 10 °C, which adheres to the characteristic for cold-adapted psychrophiles and psychrotrophs. At low concentrations of sulfamethoxazole, the growth kinetics correlated well with the Haldane model. The single-substrate parameter values of sulfamethoxazole on cell growth were determined to be μ max = 0.01 h(-1), K s = 20.91 mg/l and K i = 170.60 mg/l. Additionally, the major intermediates from sulfamethoxazole biodegradation by strain HA-4, including aniline, 3-amino-5-methylisoxazole, 4-aminothiophenol and sulfanilamide, were identified by GC-MS and high-resolution mass spectrometry (HR-MS) analysis. The results demonstrate that strain HA-4 has the potential to degrade sulfamethoxazole at low temperatures.
authors: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin, 150090, China.
authors: Benchao
authors: B
authors: Jiang
authors: Ang
authors: A
authors: Li
authors: Di
authors: D
authors: Cui
authors: Rui
authors: R
authors: Cai
authors: Fang
authors: F
authors: Ma
authors: Yingning
authors: Y
authors: Wang
mesh_terms: D001711:Biotransformation; D002244:Carbon / Q000378:metabolism; D016000:Cluster Analysis; D003080:Cold Temperature; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D004734:Energy Metabolism; D005231:Fatty Acids, Unsaturated / Q000032:analysis; D013058:Mass Spectrometry; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D010802:Phylogeny; D011549:Pseudomonas / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism* / Q000528:radiation effects; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013420:Sulfamethoxazole / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005231:Fatty Acids, Unsaturated; D012336:RNA, Ribosomal, 16S; D002244:Carbon; D013420:Sulfamethoxazole