title: Identification of metabolites involved in the biodegradation of the ionic liquid 1-butyl-3-methylpyridinium bromide by activated sludge microorganisms.
abstract: Ionic liquids (ILs) are low melting organic salts that potentially comprise wide application due to their fascinating properties and have emerged as promising "green" replacements for volatile organic solvents. Despite their nonmeasurable vapor pressure, some quantities of ILs will soon be present in effluent discharges since they do have significant solubility in water. Recently, the toxic effects of ILs toward aquatic communities have been intensively investigated, but little information is available concerning the biodegradable properties of these compounds. The objective of this study was to identify the metabolites generated during the biotransformation of 1-butyl-3-methylpyridinium by microorganisms in aerobic activated sludge. The obtained results revealed that the alkylpyridinium salt was metabolized through the sequential oxidization in different positions of the alkyl side chains. High-performance liquid chromatography and mass-spectrometry analyses demonstrated that this biodegradation led to the formation of 1-hydroxybutyl-3-methylpyridinium, 1-(2-hydroxybutal)-3-methylpyridinium, 1-(2-hydroxyethyl)-3-methylpyridinium, and methylpyridine. On the basis of these intermediate products, biodegradation pathways were also suggested. These findings provide the basic information that might be useful for assessing the factors related to the environmental fate and behavior of this commonly used pyridinium IL.
authors.affiliation: Department of Bioprocess Engineering, Chonbuk National University, Chonbuk 561-756, Republic of Korea.
authors.forename: Thi Phuong Thuy
authors.initials: TP
authors.lastname: Pham
authors.forename: Chul-Woong
authors.initials: CW
authors.lastname: Cho
authors.forename: Che-Ok
authors.initials: CO
authors.lastname: Jeon
authors.forename: Yun-Jo
authors.initials: YJ
authors.lastname: Chung
authors.forename: Min-Woo
authors.initials: MW
authors.lastname: Lee
authors.forename: Yeoung-Sang
authors.initials: YS
authors.lastname: Yun
mesh_terms: D001673:Biodegradation, Environmental; D001965:Bromides / Q000737:chemistry / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D052578:Ionic Liquids / Q000737:chemistry / Q000378:metabolism*; D013058:Mass Spectrometry; D011726:Pyridinium Compounds / Q000737:chemistry / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology*; D013997:Time Factors
chemical_list: C539248:1-butyl-3-methylpyridinium; D001965:Bromides; D052578:Ionic Liquids; D011726:Pyridinium Compounds; D012722:Sewage