Fluorotelomer alcohols (FTOHs, F(CF2)nCH2CH2OH) are emerging contaminants in the environment. Biodegradation of 6:2 and 8:2 FTOHs has been intensively studied using soils and activated sludge. However, little is known about the bacteria responsible for biotransformation of FTOHs. This study deciphered factors affecting biodefluorination of FTOHs and their metabolites, and developed three effective FTOH-degrading consortia. Two alkane-degrading Pseudomonas strains (P. oleovorans and P. butanovora) can 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. Pathway I led to formation of x:2 ketone (x = n-1), x:2 sFTOH and perfluorinated carboxylic acids (PFCAs). Pathway II resulted in the formation of x:3 polyfluorinated acid and relatively minor shorter-chain PFCAs. Conversely, P. butanovora transformed FTOHs by pathway I only. Mycobacterium vaccae JOB5 (a C1-C22alkane-degrading bacterium) and P. fluorescens DSM 8341 (a fluoroacetate-degrading bacterium) can transform 6:2 FTOH via both pathways I and II with the formation of odd-numbered short-chain PFCAs. In the presence of dicyclopropylketone or formate, P. oleovorans transformed 6:2 FTOH six times faster and produced odd-numbered PFCAs. P. butanovora, utilized both pathways I and II in the presence of lactate, and it also produced odd-numbered PFCAs. Unlike P. oleovorans, P. fluorescens DSM 8341 could slightly convert 5:3 polyfluorinated acid (a key metabolite during 6:2 FTOH degradation, [F(CF2)5CH2CH2COOH]) to 4:3 acid and PFPeA via one-carbon removal pathways. Three FTOH-degrading consortia transformed FTOHs, with enhanced removal of FTOHs in the presence of n-octane. A higher copy number of alkB gene was found to correspond to better removal of FTOHs, suggesting that alkane-degrading bacteria might be the key degraders in the enrichments. The three enrichment cultures showed a similar microbial community structure. This is the first study reporting that pure strains of alkane- and fluoroacetate-degrading bacteria can bio-transform FTOHs via different or preferred transformation pathways to remove multiple –CF2– groups from FTOHs to form shorter-chain PFCAs, and to other perfluorinated acids. The results of this study also suggest that enhanced FTOH biodegradation is possible through co-substrate addition and/or using enrichment cultures.

The aim of this study was to develop an analytical method for fluorinated silanes. Furthermore, as a secondary aim, to explore if there would be possible to detect 1H,1H,2H,2H-perfluorooctyl triethoxysilane (6:2 PTrEtSi) and 1H,1H,2H,2H-perfluorodecyl triethoxysilane (8:2 PTrEtSi) in two different matrices, sludge and cosmetic extract. The method development included experiments using LC-MS, LC-MS/MS, UPC2, GC-MS and APGC-MS/MS and was carried out using standards containing 6:2 PTrEtSi and 8:2 PTrEtSi. The analytical method that worked best for the compounds was GC-MS/MS and an analytical method using APGC-MS/MS was developed for fluorinated silanes. The IDL for 6:2 PTrEtSi was 0.0012 μg/mL and 1.32 μg/mL for 8:2 PTrEtSi. This makes the developed method suitable for high contaminated samples, such as extracts from cosmetic products. It was concluded that a method using LC as the analytical instrument would not work for the two target compounds since they were too reactive with the mobile phase. However, LC could be a good choice for siloxanes, compounds that are formed from hydrolysis and condensation of fluorinated silanes. The samples analyzed in this study were three sludge extracts and one extract from a cosmetic product. 6:2 PTrEtSi was expected to be detected in the cosmetic sample since the compound was stated on the table of contents of the cosmetic product. No detection of 6:2 TrEtSi or 8:2 TrEtSi could be made in either of the samples. The reason for this was suspected to be transformation or degradation of the compounds into other compounds. Therefore, a full scan of the cosmetic sample using LC-MS/MS was included in the experiment as an addition to verify the suspicions that compounds such as siloxanes could have been formed. An interesting peak was discovered with m/z 947 which could be a disiloxane of 6:2 PTrEtSi.