Percorrer por autor "Bessa, V. S."
A mostrar 1 - 4 de 4
Resultados por página
Opções de ordenação
- 2-Fluorophenol degradation by aerobic granules in a sequencing batch reactorPublication . Duque, A. F.; Bessa, V. S.; Carvalho, M. F.; De Kreuk, M. K.; Loosdrecht, M. C. M. van; Castro, P. M. L.
- Biodegradation of 2-fluorophenol in a rotating biological contactorPublication . Duque, A. F.; Bessa, V. S.; Franco, A. R.; Carvalho, M. F.; Castro, P. M. L.
- Biodegradation of carbamazepine by the bacterial strain labrys portucalensis F11Publication . Bessa, V. S.; Moreira, I. S.; Murgolo, Sapia; Piccirillo, Clara; Mascolo, Giuseppe; Castro, P. M. L.Introduction and Objectives: The occurrence of pharmaceuticals in the environment is a topic of concern. Most pharmaceuticals are not completely mineralized in the human body and are released to the sewage systems as the pharmaceutical itself and as their “biologically active” metabolites Wastewater treatment plants (WWTPs) are not designed to remove them and they are released into the environment. Despite generally found at low concentrations (ranging from ngL−1 to μgL−1), they are classified as persistent microcontaminants due to their continuous release. Carbamazepine (CBZ) is a widely used anticonvulsant which has been found in different environmental compartments and has been suggested as a molecular marker of contamination in surface water and groundwater. In the present study, biodegradation of CBZ by strain Labrys Portucaliensis F11 was assessed. Transformation products (TPs) resulting from CBZ degradation were analysed. Methodology: CBZ biodegradation assays were performed in minimal salts medium (MM) supplemented with 2.0, 4.0, 10.0, 20.0 and 40.0 𝜇M of CBZ as a sole carbon and energy source and in the presence of acetate (5.9mM); CBZ was quantified by High Performance Liquid Chromatography (HPLC); Transformation products (TPs) were detected and identified by UPLCQTOF/MS/MS; Ecotoxicological effects of cultures containing CBZ and of cultures containing the TPs after microbial degradation were assessed using Daphnia magna (OCED Guideline 202) and Lepidium sativum (OECD Guideline 208). Highlights: Supplementation with a second carbon source had a positive effect on CBZ degradation by strain Labrys Portucalensis F11; CBZ degradation by strain F11 proceeds mainly by oxidation, hydroxilation, hydrolysis and cleavage of the aromatic ring; CBZ TPs were detected until the end of the experiment time; CBZ and transformation products exhibited high toxicity on D. magna whereas inhibition of root elongation of L. sativum was practically neglectable.
- Enrichment of bacterial strains for the biodegradation of diclofenac and carbamazepine from activated sludgePublication . Bessa, V. S.; Moreira, I. S.; Tiritan, M. E.; Castro, P. M. L.Carbamazepine and diclofenac have been pointed out as important markers for environmental pollution by pharmaceuticals. This study reports on the isolation of bacterial strains capable to degrade these micropollutants from activated sludge of a municipal wastewater treatment plant (WWTP). After selective enrichments, one strain able to degrade diclofenac and two strains able to degrade carbamazepine were isolated. The strains were identified by 16S rRNA gene sequencing. Strain Brevibacterium sp. D4 was able to biodegrade 35% of 10 mg L−1 of diclofenac as a sole carbon source; periodic feeding with acetate as a supplementary carbon source resulted in enhancing biodegradation to levels up to 90%, with a concomitant increase of the biodegradation rate. Strains Starkeya sp. C11 and Rhizobium sp. C12 were able to biodegrade 30% of 10 mg L−1 of carbamazepine as a sole carbon source; supplementation with acetate did not improve the biodegradation of carbamazepine by these strains. The activated sludge harboured bacteria capable to degrade the two top priority environmental contaminants and may be potentially useful for biotechnological applications.