title: Identification of metabolites produced during the complete biodegradation of 1-butyl-3-methylimidazolium chloride by an enriched activated sludge microbial community.
abstract: Ionic liquids (ILs) are highly polar solvents with unique physicochemical properties that make them promising green alternatives to volatile organic solvents. Since ILs can be toxic to organisms, the development of methods to degrade ILs into harmless molecules prior to disposal is critical to enhancing their green properties. In this study, metabolites generated during the biodegradation of 1-butyl-3-methylimidazolium chloride (BMIMCl) by an enriched, activated sludge microbial community were investigated. Biodegradation of BMIM and the metabolic products released into the growth media were examined using1H-NMR spectroscopy and mass spectrometry. To the best of our knowledge, this is the first reported complete primary catabolism of the biodegradation-resistant BMIMCl ionic liquid. The bacterial community responsible for degradation was analyzed using a 16S-rRNA amplicon approach. Although the community was diverse, Bacteroidetes was the predominant phylum. The study provides a greater insight into imidazolium-based IL biodegradability and a means to proactively prevent the ecotoxicity of the BMIM cation and its metabolites, by complete primary biodegradation of the cation and removal of most resulting metabolites, prior to release into aquatic waste streams.
authors.affiliation: Department of Chemistry, Western Michigan University, Kalamazoo, MI 49008-5413, USA.
authors.forename: Wisam A
authors.initials: WA
authors.lastname: Al Isawi
authors.affiliation: Department of Chemistry, Western Michigan University, Kalamazoo, MI 49008-5413, USA.
authors.forename: Sepideh
authors.initials: S
authors.lastname: Rahbarirad
authors.affiliation: Department of Biological Sciences, Western Michigan University, Kalamazoo, MI 49008-5410, USA.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Walker
authors.affiliation: Department of Chemistry, Western Michigan University, Kalamazoo, MI 49008-5413, USA.
authors.forename: Andre R
authors.initials: AR
authors.lastname: Venter
authors.affiliation: Department of Biological Sciences, Western Michigan University, Kalamazoo, MI 49008-5410, USA.
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Docherty
authors.affiliation: Department of Chemistry, Western Michigan University, Kalamazoo, MI 49008-5413, USA. Electronic address: blair.szymczyna@wmich.edu.
authors.forename: Blair R
authors.initials: BR
authors.lastname: Szymczyna
mesh_terms: D001673:Biodegradation, Environmental; D007093:Imidazoles / Q000378:metabolism*; D052578:Ionic Liquids / Q000378:metabolism*; D013058:Mass Spectrometry; D012722:Sewage / Q000737:chemistry / Q000382:microbiology*; D012997:Solvents / Q000378:metabolism
chemical_list: D007093:Imidazoles; D052578:Ionic Liquids; D012722:Sewage; D012997:Solvents; C502841:1-butyl-3-methylimidazolium chloride
keywords: Biodegradation; Ionic liquid; Mass spectrometry; Microbial community; NMR spectroscopy; Wastewater