title: Biodefluorination and biotransformation of fluorotelomer alcohols by two alkane-degrading Pseudomonas strains.
abstract: Fluorotelomer alcohols [FTOHs, F(CF(2))(n) CH(2)CH(2)OH, n = 4, 6, and 8] are emerging environmental contaminants. Biotransformation of FTOHs by mixed bacterial cultures has been reported; however, little is known about the microorganisms responsible for the biotransformation. Here we reported biotransformation of FTOHs by two well-studied Pseudomonas strains: Pseudomonas butanovora (butane oxidizer) and Pseudomonas oleovorans (octane oxidizer). Both strains could defluorinate 4:2, 6:2, and 8:2 FTOHs, with a higher degree of defluorination for 4:2 FTOH. According to the identified metabolites, P. oleovorans transformed FTOHs via two pathways I and II. The pathway I led to the production of x:2 ketone [dominant metabolite, F(CF(2))(x)C(O)CH(3); x = n - 1, n = 6 or 8], x:2 sFTOH [F(CF(2))(x)CH(OH)CH(3)], and perfluorinated carboxylic acids (PFCAs, perfluorohexanoic, or perfluorooctanoic acid). The pathway II resulted in the formation of x:3 polyfluorinated acid [F(CF(2))(x) C(2)CH(2) COOH] and relatively minor shorter-chain PFCAs (perfluorobutyric or perfluorohexanoic acid). Conversely, P. butanovora transformed FTOHs by using the pathway I, leading to the production of x:2 ketone, x:2 sFTOH, and PFCAs. This is the first study to show that individual bacterium can bio-transform FTOHs via different or preferred transformation pathways to remove multiple --CF(2) -- groups from FTOHs to form shorter-chain PFCAs.
authors.affiliation: Zachry Department of Civil Engineering, Texas A&M University, College Station, Texas 77843-3136, USA.
authors.forename: Myung Hee
authors.initials: MH
authors.lastname: Kim
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
authors.forename: Thomas
authors.initials: T
authors.lastname: McDonald
authors.forename: Kung-Hui
authors.initials: KH
authors.lastname: Chu
mesh_terms: D000473:Alkanes / Q000378:metabolism*; D001673:Biodegradation, Environmental; D001711:Biotransformation; D004785:Environmental Pollutants / Q000737:chemistry / Q000378:metabolism*; D005466:Fluorocarbons / Q000737:chemistry / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D011549:Pseudomonas / Q000378:metabolism*
chemical_list: D000473:Alkanes; D004785:Environmental Pollutants; D005466:Fluorocarbons