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- Studies on enantioselective biodegradation of fluoxetinePublication . Moreira, Irina S.; Ribeiro, Ana R.; Amorim, Catarina L.; Tiritan, Maria E.; Castro, Paula M. L.Fluoxetine (FLX) is a chiral fluorinated pharmaceutical indicated mainly for treatment of depression and is one of the most dispensed drugs in the world. There is a clear evidence of environmental contamination with this drug. Granular sludge sequencing batch reactors (SBR) constitute a promising technology for the treatment of effluents containing micropollutants. In this study, a SBR was operated in order to assess its performance when treating a synthetic wastewater containing racemic FLX (rac-FLX), under continuous and intermittent feeding of the compound. The concentration of FLX enantiomers was followed using an enantioselective HPLC method. A removal of 70% of the total supplied FLX was observed in the first continuous feeding period. However, the subsequent feeding periods revealed a significant decrease in the FLX removal; FLX liberation occurred during periods when no compound was supplied. This can be probably explained by desorption of FLX previously adsorbed to the granules. No intermediate metabolites or fluoride release were detected, corroborating the hypothesis that adsorption of FLX to the aerobic granules occurred. Moreover, the absence of enantioselectivity in the decrease of FLX enantiomers concentration is also an indicator of an abiotic mechanism. In face of the incapacity of the aerobic granules to biodegrade FLX, the ability of Labrys portucalensis F11, a previously isolated microbial strain with the capacity to degrade a range of fluorinated aromatic compounds, to biodegrade this compound was investigated. In this study, the enantioselective biodegradation of rac-FLX and of its enantiomers was assessed. The results obtained revealed that this strain is able to degrade both enantiomers of FLX, when supplemented as a racemic mixture, as well as when supplemented as a single enantiomers. Preferential degradation of the (R)-enantiomer was observed. This feature makes L. portucalensis F11 a potential candidate for devising biodegradation technologies able to deal with contamination by this pharmaceutical. Acknowledgements: I.S. Moreira, A.R. Ribeiro and C.L. Amorim wish to acknowledge a research grant from Fundação para a Ciência e Tecnologia (FCT), Portugal (Ref. SFRH/BPD/87251/2012, SFRH/BD/64999/2009 and SFRH/BD/47109/2008 , respectively) and Fundo Social Europeu (Programa Operacional Potencial Humano (POPH), Quadro de Referência Estratégico Nacional (QREN)). This work was supported by FCT through the projects PTDC/EBB-EBI/111699/2009, CEQUIMED-Pest-OE/SAU/UI4040/2011 and PEst-OE/EQB/LA0016/2011.
- Biodegradation of carbamazepine by the bacterial strain labrys portucalensis F11 : metabolism and toxicologic studiesPublication . Bessa, Vânia S.; Moreira, Irina; Murgulo, Sapia; Piccirillo, Clara; Mascolo, Giuseppe; Castro, Paula M. L.Background: Occurrence of pharmaceuticals in the environment is a topic of concern. Most pharmaceuticals are not completely mineralized and are released on the sewage systems through excretion and by improper elimination and disposal. Municipal wastewater treatment plants (WWTPs) are not designed to remove them and they are released into the environment. They are classified as persistent microcontaminants due to their continuous release even if at low concentrations. Carbamazepine (CBZ) is an widely used anticonvulsant and has been suggested as a molecular marker of contamination in surface water and groundwater. Method Biodegradation of CBZ by the bacterial strain Labrys portucalensis F11 was tested as sole carbon and energy source (0.04 mM) and in the presence of acetate as primary carbon source. Transformation products (TPs) were detected and identified by UPLCQTOF/MS/MS. Ecotoxicologiacl effects of CBZ and the TPs resultant from biodegradation were evaluated at different trophic levels, i) zooplanckton (Dapnhia magna) and ii) plants (Lipidium sativum). The 24–48 h immobilization of D. magna bioassays were performed following the Standard Operational Procedures of Daphtoxkit FTM. The toxicity was measured as the immobilization of D. magna according to the procedures OCED Guideline 202. The bioassay with L. sativum evaluated the potential toxicity considering the root elongation according to OECD Guideline 208. Results & Conclusions Strain F11 was able to degrade 95% of initial CBZ concentration during 30 days experiment. Supplementation with acetate increased degradation to 100% in 24 days. A group of 12 TPs formed in the microbial process were identified; CBZ degradation by strain F11 proceeds mainly by oxidation, hydroxilation and cleavage of the aromatic ring. The effect of whole biodegradation products on root elongation of L. sativum was practically neglectable; however the same exhibited toxicity to D. magna. Strain Labrys portucalensis F11 proved to be able to degrade CBZ and may be potentially useful for biotechnological applications.
- Strategies for Biodegradation of Fluorinated CompoundsPublication . Moreira, Irina S.; Amorim, Catarina L.; Murphy, Cormac D.; Castro, Paula M. L.
- Biodegradation of fluoroquinolones by single bacteriaPublication . Amorim, Catarina L.; Moreira, Irina S.; Maia, Alexandra; Tiritan, Maria E.; Castro, Paula M. L.
- Photocatalytic degradation of diclofenac by hydroxyapatite-TiO2 composite material: Identification of transformation products and assessment of toxicityPublication . Murgolo, Sapia; Moreira, Irina S.; Piccirillo, Clara; Castro, Paula M. L.; Ventrella, Gianrocco; Cocozza, Claudio; Mascolo, GiuseppeDiclofenac (DCF) is one of the most detected pharmaceuticals in environmental water matrices and is known to be recalcitrant to conventional wastewater treatment plants. In this study, degradation of DCF was performed in water by photolysis and photocatalysis using a new synthetized photocatalyst based on hydroxyapatite and TiO2 (HApTi). A degradation of 95% of the target compound was achieved in 24 h by a photocatalytic treatment employing the HApTi catalyst in comparison to only 60% removal by the photolytic process. The investigation of photo-transformation products was performed by means of UPLC-QTOF/MS/MS, and for 14 detected compounds in samples collected during treatment with HApTi, the chemical structure was proposed. The determination of transformation product (TP) toxicity was performed by using different assays: Daphnia magna acute toxicity test, Toxi-ChromoTest, and Lactuca sativa and Solanum lycopersicum germination inhibition test. Overall, the toxicity of the samples obtained from the photocatalytic experiment with HApTi decreased at the end of the treatment, showing the potential applicability of the catalyst for the removal of diclofenac and the detoxification of water matrices.
- Biphasic apatite-carbon materials derived from pyrolysed fish bones for effective adsorption of persistent pollutants and heavy metalsPublication . Piccirillo, C.; Moreira, I. S.; Novais, R. M.; Fernandes, A. J. S.; Pullar, R. C.; Castro, P. M. L.Biphasic apatite-carbon biochar-type materials were prepared from pyrolysed cod fish bones and were assessed for the adsorption of persistent organic pollutants (pharmaceuticals diclofenac and fluoxetine), and heavy metals (Pb(II)). The materials, prepared with a simple pyrolysis process at different temperatures (200–1000 °C), were characterised with XRD, FTIR, Raman and SEM. Results showed that the pyrolysis temperature had a significant effect on the features/composition of the materials: up to 800 °C, carbonate apatite Ca10(PO4)6(CO3) was the main component, while for higher temperatures oxyapatite Ca10(PO4)6O was the dominant phase. Graphitic carbon was also detected. The mixed apatite-carbon products (bone char) exhibited high adsorption efficiency. Graphite carbon was the main adsorber for the pharmaceuticals, the best performing material being that pyrolysed at 1000 °C. Xm values of 43.29 and 55.87 mg/g were observed (Langmuir fitting), while KF values of 5.40 and 12.53 (mg/g)(L/mg)nF were obtained with the Freundhlich model (diclofenac and fluoxetine respectively). This is the first time that a biochar-like material has been used for fluoxetine adsorption. For Pb (II), the powder pyrolysed at 600 °C was the most effective, with the apatite playing a key role (Xm = 714.24 mg/g). This work shows that a by-product of the fish industry could be converted into efficient materials for environmental remediation; according to the pyrolysis conditions, powders effective in the removal of either organics or heavy metals can be obtained. Moreover, with pyrolysis at intermediate temperatures, materials capable of adsorbing both kinds of pollutants can be produced, even if less efficient.
- Enantioselective Degradation of Enantiomers of Fluoxetine Followed by HPLC- FDPublication . Ribeiro, Ana R.; Maia, Alexandra S.; Moreira, Irina S.; Afonso, Carlos; Castro, Paula M.L.; Tiritan, Maria E.Environmental fate assessment of chiral pharmaceuticals is an important issue and little information is known about enantioselectivity in the environment. This kind of information is important for regulamentation of pharmaceutical industry and chiral switching processes. Fluoxetine (FLX), an anti-depressant worldwide used, is a chiral pharmaceutical prescribed in racemic form, and its main metabolite norfluoxetine (NFLX) is also chiral. In this study, enantioselective degradation of rac-FLX and degradation of its enantiomers separately, in a minimal salts medium inoculated by a bacterium consortium was examined both at light and dark conditions. Theassays were performed in a shaker at aerobic and ambient temperature conditions. The analytical method used was an enantioselective HPLC-FD method using a vancomycin-based chiral stationary phase in reversed mode to monitor enantiomers of FLX and NFLX. No degradation of enantiomers of FLX in the abiotic controls was observed. In theall assays (R)-FLX was degraded faster and totally until day 24th while (S)-FLX remained up to 20% of its initial concentration until the end of the experiment (38 days). NFLX wasdetected in all biotic experiments.
- Pharmaceuticals biodegradation by activated sludge and pure culturesPublication . Bessa, Vânia S.; Moreira, Irina S.; Maia, Alexandra S.; Tiritan, Maria E.; Castro, Paula M. L.The occurrence of pharmaceuticals in the environment have been a topic of increasing concern. Most of the pharmaceuticals are not completely mineralized in the human body and are released on the sewage systems as the pharmaceutical itself and as their “biologically active” metabolites through excretion, as well as by improper elimination and disposal. Once current wastewater treatment plants (WWTPs) are not designed to remove these emerging pollutant, they are easily released into the environment.The effects of halogen on biological properties of molecules have had a marked impact on various fields such as pharmacology. It can improve metabolic stability, bioavailability and interactions with the biological target. However, it also increases the recalcitrance of the molecule to biotic and abiotic degradation. Ciprofloxacin (CPF) and Diclofenac (DCF) are two widely used halogenated pharmaceuticals, commonly found in the environment in concentrations that can range ng L−1 to mg L−1. CPF is a common human and veterinary broad-spectrum fluoroquinolone antibiotic. DCF is a non-steroidal anti-inflammatory drug (NSAID), also used as analgesic and antithermic treatment. In the present study, biodegradation of CPF and DCF was assessed by selective enrichements with actived sludge and with pure cultures of three different strains - Labrys portucalensis (F11) and two Rhodococcus spp. (FP1 and S2) – which had previously demonstrated capacity to degrade a range of halogenated compounds. For CPF selective enrichments, a degradation of 100% was achived after 206 days, although without fluoride release. These findings indicate that these selective enrichments are good candidates to find a bacterial strain able to biodegrade CPF. Regarding the pure cultures, F11 exhibited the highest degradation capacity (57%) after 62 days, but also without fluoride release. Concerning DCF selective enrichments, it was released 68% of the stoichiometrically expected cloride ion behind 131 days. In the experiments with pure cultures, F11 and S2, was released the totality of the stoichiometrically expected cloride, elapsed 131 days. These results indicate that these two strains are promising for DCF biodegradation.
- Biodegradation of ofloxacin, norfloxacin, and ciprofloxacin as single and mixed substrates by Labrys portucalensis F11Publication . Amorim, Catarina L.; Moreira, Irina S.; Maia, Alexandra S.; Tiritan, Maria E.; Castro, Paula M. L.Fluoroquinolone (FQ) antibiotics are extensively used both in human and veterinary medicine, and their accumulation in the environment is causing an increasing concern. In this study, the biodegradation of the three most worldwide used FQs, namely ofloxacin, norfloxacin, and ciprofloxacin, by the fluoroorganic-degrading strain Labrys portucalensis F11 was assessed. Degradation occurred when the FQs were supplied individually or as mixture in the culture medium, in the presence of an easily degradable carbon source. Consumption of individual FQs was achieved at different extents depending on its initial concentration, ranging from 0.8 to 30 μM. For the lowest concentration, total uptake of each FQ was observed but stoichiometric fluoride release was not achieved. Intermediate compounds were detected and identified by LC-MS/MS with a quadrupole time of flight detector analyzer. Biotransformation of FQs by L. portucalensis mainly occurred through a cleavage of the piperazine ring and displacement of the fluorine substituent allowing the formation of intermediates with less antibacterial potency. FQ-degrading microorganisms could be useful for application in bioaugmentation processes towards more efficient removal of contaminants in wastewater treatment plants.
- Sediments in the mangrove areas contribute to the removal of endocrine disrupting chemicals in coastal sediments of Macau SAR, China, and harbour microbial communities capable of degrading E2, EE2, BPA and BPSPublication . Moreira, Irina S.; Lebel, Alexandre; Peng, Xianzhi; Castro, Paula M. L.; Gonçalves, DavidThe occurrence of endocrine disrupting chemicals (EDCs) is a major issue for marine and coastal environments in the proximity of urban areas. The occurrence of EDCs in the Pearl River Delta region is well documented but specific data related to Macao is unavailable. The levels of bisphenol-A (BPA), estrone (E1), 17α-estradiol (αE2), 17β-estradiol (E2), estriol (E3), and 17α-ethynylestradiol (EE2) were measured in sediment samples collected along the coastline of Macao. BPA was found in all 45 collected samples with lower BPA concentrations associated to the presence of mangrove trees. Biodegradation assays were performed to evaluate the capacity of the microbial communities of the surveyed ecosystems to degrade BPA and its analogue BPS. Using sediments collected at a WWTP discharge point as inoculum, at a concentration of 2 mg l−1 complete removal of BPA was observed within 6 days, whereas for the same concentration BPS removal was of 95% after 10 days, which is particularly interesting since this compound is considered recalcitrant to biodegradation and likely to accumulate in the environment. Supplementation with BPA improved the degradation of bisphenol-S (BPS). Aiming at the isolation of EDCs-degrading bacteria, enrichments were established with sediments supplied with BPA, BPS, E2 and EE2, which led to the isolation of a bacterial strain, identified as Rhodoccoccus sp. ED55, able to degrade the four compounds at different extents. The isolated strain represents a valuable candidate for bioremediation of contaminated soils and waters.