title: Biodegradation of ether pollutants by Pseudonocardia sp. strain ENV478.
abstract: A bacterium designated Pseudonocardia sp. strain ENV478 was isolated by enrichment culturing on tetrahydrofuran (THF) and was screened to determine its ability to degrade a range of ether pollutants. After growth on THF, strain ENV478 degraded THF (63 mg/h/g total suspended solids [TSS]), 1,4-dioxane (21 mg/h/g TSS), 1,3-dioxolane (19 mg/h/g TSS), bis-2-chloroethylether (BCEE) (12 mg/h/g TSS), and methyl tert-butyl ether (MTBE) (9.1 mg/h/g TSS). Although the highest rates of 1,4-dioxane degradation occurred after growth on THF, strain ENV478 also degraded 1,4-dioxane after growth on sucrose, lactate, yeast extract, 2-propanol, and propane, indicating that there was some level of constitutive degradative activity. The BCEE degradation rates were about threefold higher after growth on propane (32 mg/h/g TSS) than after growth on THF, and MTBE degradation resulted in accumulation of tert-butyl alcohol. Degradation of 1,4-dioxane resulted in accumulation of 2-hydroxyethoxyacetic acid (2HEAA). Despite its inability to grow on 1,4-dioxane, strain ENV478 degraded this compound for > 80 days in aquifer microcosms. Our results suggest that the inability of strain ENV478 and possibly other THF-degrading bacteria to grow on 1,4-dioxane is related to their inability to efficiently metabolize the 1,4-dioxane degradation product 2HEAA but that strain ENV478 may nonetheless be useful as a biocatalyst for remediating 1,4-dioxane-contaminated aquifers.
authors.affiliation: Shaw Environmental, Inc., Lawrenceville, NJ 08648, USA.
authors.forename: Simon
authors.initials: S
authors.lastname: Vainberg
authors.forename: Kevin
authors.initials: K
authors.lastname: McClay
authors.forename: Hisako
authors.initials: H
authors.lastname: Masuda
authors.forename: Duane
authors.initials: D
authors.lastname: Root
authors.forename: Charles
authors.initials: C
authors.lastname: Condee
authors.forename: Gerben J
authors.initials: GJ
authors.lastname: Zylstra
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Steffan
mesh_terms: D000192:Actinomycetales / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D001673:Biodegradation, Environmental; D003470:Culture Media; D004269:DNA, Bacterial / Q000032:analysis; D004146:Dioxanes / Q000378:metabolism*; D017753:Ecosystem; D004987:Ethers / Q000378:metabolism*; D005663:Furans / Q000378:metabolism; D008969:Molecular Sequence Data; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D014873:Water Pollutants / Q000378:metabolism*
chemical_list: D003470:Culture Media; D004269:DNA, Bacterial; D004146:Dioxanes; D004987:Ethers; D005663:Furans; D012336:RNA, Ribosomal, 16S; D014873:Water Pollutants; C018674:tetrahydrofuran; C025223:1,4-dioxane