Browsing by Author "Wijayahena, Mindula K."
Now showing 1 - 4 of 4
Results Per Page
Sort Options
- Bacterial degradation of perfluorooctane sulfonic acid (PFOS): detection of by-products by target and non-target analysisPublication . Wijayahena, Mindula K.; Moreira, Irina S.; Wallace, Joshua S.; Castro, Paula M. L.; Aga, Diana S.Introduction: Per- and poly-fluoroalkyl substances (PFAS) are highly fluorinated synthetic chemicals with a wide variety of uses1,2. The carbon- fluorine bonds exhibit very high bond dissociation energies: around 536 kJ/mol, making PFAS generally resistant to degradation by oxidation, thermal treatment, and biological mechanisms, which has led to their classification as “forever chemicals”3. Strategies to enhance the biodegradation of these compounds are of great interest, such as identifying bacterial species that may be used for bioaugmentation. Labrys portucalensis F11 is an aerobic bacterium that has been isolated in Portugal and can degrade fluorinated pharmaceuticals, fluorobenzene, and fluoxetine4,5. This F11 strain has the ability to cleave C-F bonds in these fluorinated organic compounds and was therefore tested for its ability to degrade perfluorooctane sulfonate (PFOS), the most frequently detected PFAS in the environment. Objectives: To determine whether the F11 bacteria strain can degrade PFOS; To identify biodegradation products by non-targeted analysis. Conclusions: Labrys portucalensis strain F11 degraded PFOS. Shorter-chain PFAS, from C7 to C3 were formed as metabolites. Non-target analysis facilitated the identification of the unsaturated and hydrogenated C8 compounds. IMS separation exhibited the separation of isomers of PFOS as well as defluorinated PFOS isomers including isomers of H-PFOS and isomers of unsaturated PFOS.
- Biodegradation of perfluorooctane sulfonic acid (PFOS) by the bacterial strain Labrys portucalensis F11 and identification of metabolitesPublication . Wijayahena, Mindula K.; Moreira, Irina S.; Wallace, Joshua S.; Castro, Paula M. L.; Aga, Diana S.Introduction: Per- and poly-fluoroalkyl substances (PFAS) are highly fluorinated synthetic chemicals with a wide variety of uses1,2. The carbon-fluorine bonds exhibit very high bond dissociation energies: around 536 kJ/mol, making PFAS generally resistant to degradation by oxidation, thermal treatment, and biological mechanisms, which has led to their classification as “forever chemicals”3. Strategies to enhance the biodegradation of these compounds are of great interest, such as identifying bacterial species that may be used for bioaugmentation. Labrys portucalensis F11 is an aerobic bacterium that has been isolated in Portugal and can degrade fluorinated pharmaceuticals, fluorobenzene, and fluoxetine4,5. This F11 strain has the ability to cleave C-F bonds in these fluorinated organic compounds. Objectives: To determine whether the F11 bacteria strain can degrade PFAS; To identify biodegradation products by non-targeted analysis. Conclusions: Labrys portucalensis strain F11 can degrade PFOS under aerobic conditions. Microbial degradation products were identified for PFOS from C8 to C3 compounds. Non-target analysis facilitated the identification of the unsaturated and hydrogenated C8 compounds. IMS separation exhibited the separation of isomers of PFOS as well as defluorinated PFOS isomers including isomers of H-PFOS and isomers of unsaturated PFOS.
- PFAS biodegradation by Labrys portucalensis F11: evidence of chain shortening and identification of metabolites of PFOS, 6:2 FTS, and 5:3 FTCAPublication . Wijayahena, Mindula K.; Moreira, Irina S.; Castro, Paula M. L.; Dowd, Sarah; Marciesky, Melissa I.; Ng, Carla; Aga, Diana S.The biodegradation of three per- and polyfluoroalkyl substances (PFAS), namely perfluorooctane sulfonic acid (PFOS), 6:2-fluorotelomer sulfonic acid (6:2 FTS), and 5:3-fluorotelomer carboxylic acid (5:3 FTCA), were evaluated using Labrys portucalensis F11, an aerobic bacteria known to defluorinate fluorine-containing compounds. Cultures of L. portucalensis F11 were grown in minimal salts media and treated with 10,000 μg/L of individual PFAS as the sole carbon source in separate flasks. In PFOS-spiked media, several metabolites were detected, including perfluoroheptane sulfonic acid (PFHpS), perfluorohexane sulfonic acid (PFHxS), perfluorohexanoic acid (PFHxA), perfluoropentanoic acid (PFPeA), perfluorobutanoic acid (PFBA), and perfluoropropanoic acid (PFPrA). After 194-day incubation three de-fluorinated metabolites were identified: PFOS-F (m/z = 480.940, PFOS-2F (m/z = 462.980), and unsaturated PFOS-3F (m/z = 442.943). During the biodegradation of 5:3 FTCA, the following metabolites were observed: PFHxA, PFPeA, PFBA, PFPrA, and two fluorotelomer unsaturated carboxylic acids (5:3 FTUCA and 7:2 FTUCA). The biodegradation of 6:2 FTS was slower, with only 21 % decrease in concentration observed after 100 days, and subsequent formation of 4:2 FTS. On the contrary, 90 % of PFOS and 58 % of 5:3 FTCA were degraded after 100 days. These results indicate that L. portucalensis F11 can be potentially used for PFAS biodegradation in contaminated environments.
- PFAS biodegradation by Labrys portucalensis F11: identification of metabolites of PFOS, 6:2 FTS, and 5:3 FTCA by target and non-target analysisPublication . Wijayahena, Mindula K.; Moreira, Irina S.; Castro, Paula M. L.; Aga, Diana S.Introduction Per- and poly-fluoroalkyl substances (PFAS) are highly fluorinated synthetic chemicals with a wide variety of uses1,2. The carbon- fluorine bonds exhibit very high bond dissociation energies: around 536 kJ/mol, making PFAS generally resistant to degradation, which has led to their classification as “forever chemicals”3. Strategies to enhance the biodegradation of these compounds are of great interest, such as identifying bacterial species that may be used for bioaugmentation. Labrys portucalensis F11 is an aerobic bacterium that has been isolated in Portugal and can degrade fluorinated pharmaceuticals, fluorobenzene, and fluoxetine4,5. This F11 strain has the ability to cleave C-F bonds in these fluorinated organic compounds and was therefore tested for its ability to degrade perfluorooctane sulfonic acid (PFOS), 6:2-fluorotelomer sulfonic acid (6:2 FTS), and 5:3-fluorotelomer carboxylic acid (5:3 FTCA). Objectives: To determine whether the F11 bacteria strain can degrade PFOS, 6:2 FTS, and 5:3 FTCA; To identify biodegradation products by non-targeted analysis. Conclusions: Labrys portucalensis F11 strain degraded PFOS, 6:2 FTS, and 5:3 FTCA. Shorter-chain PFAS, from C7 to C3 were formed as metabolites. Non-target analysis facilitated the identification of the unsaturated and hydrogenated C8 compounds. IMS separation exhibited the separation of isomers of PFOS as well as defluorinated PFOS isomers including isomers of H-PFOS and isomers of unsaturated PFOS.