title: Ionic liquid biodegradability depends on specific wastewater microbial consortia.
abstract: Complete biodegradation of a newly-synthesized chemical in a wastewater treatment plant (WWTP) eliminates the potential for novel environmental pollutants. However, differences within- and between-WWTP microbial communities may alter expectations for biodegradation. WWTP communities can also serve as a source of unique consortia that, when enriched, can metabolize chemicals that tend to resist degradation, but are otherwise promising green alternatives. We tested the biodegradability of three ionic liquids (ILs): 1-octyl-3-methylpyridinium bromide (OMP), 1-butyl-3-methylpyridinium bromide (BMP) and 1-butyl-3-methylimidazolium chloride (BMIM). We performed tests using communities from two WWTPs at three time points. Site-specific and temporal variation both influenced community composition, which impacted the success of OMP biodegradability. Neither BMP nor BMIM degraded in any test, suggesting that these ILs are unlikely to be removed by traditional treatment. Following standard biodegradation assays, we enriched for three consortia that were capable of quickly degrading OMP, BMP and BMIM. Our results indicate WWTPs are not functionally redundant with regard to biodegradation of specific ionic liquids. However, consortia can be enriched to degrade chemicals that fail biodegradability assays. This information can be used to prepare pre-treatment procedures and prevent environmental release of novel pollutants.
authors.affiliation: Western Michigan University, Department of Biological Sciences, United States. Electronic address: kathryn.docherty@wmich.edu.
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Docherty
authors.affiliation: Western Michigan University, Department of Biological Sciences, United States.
authors.forename: Steven W
authors.initials: SW
authors.lastname: Aiello
authors.affiliation: Western Michigan University, Department of Biological Sciences, United States.
authors.forename: Barbara K
authors.initials: BK
authors.lastname: Buehler
authors.affiliation: University of Notre Dame, Department of Biological Sciences, United States.
authors.forename: Stuart E
authors.initials: SE
authors.lastname: Jones
authors.affiliation: Western Michigan University, Department of Chemistry, United States.
authors.forename: Blair R
authors.initials: BR
authors.lastname: Szymczyna
authors.affiliation: Western Michigan University, Department of Biological Sciences, United States.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Walker
mesh_terms: D001673:Biodegradation, Environmental; D001965:Bromides; D004785:Environmental Pollutants; D007093:Imidazoles; D052578:Ionic Liquids / Q000737:chemistry / Q000378:metabolism*; D059013:Microbial Consortia; D011726:Pyridinium Compounds; D062065:Wastewater / Q000382:microbiology*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D001965:Bromides; D004785:Environmental Pollutants; D007093:Imidazoles; D052578:Ionic Liquids; D011726:Pyridinium Compounds; D062065:Wastewater; D014874:Water Pollutants, Chemical; C539248:1-butyl-3-methylpyridinium; C502841:1-butyl-3-methylimidazolium chloride; C014677:1-methylpyridinium
keywords: Biodegradation; Ionic liquids; Microbial; Proactive; Wastewater