Browsing by Author "Couto, Ana T."
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- Aerobic granular sludge, a feasible technology for the treatment and recirculation of trout aquaculture water streamsPublication . Couto, Ana T.; Amorim, Catarina L.; Castro, Paula M. L.Aquaculture is one of the fastest growing food production sectors. However, land-based aquaculture faces water scarcity and space restrictions which hamper its development. Aquaculture recirculation systems (RAS) help tackle these problems, although in most systems the recycling of water increases nutrient and organic matter concentrations, which often translates to fish mortality. This work aimed to evaluate the feasibility of an aerobic granular sludge (AGS) system as a novel alternative for the treatment of aquaculture streams, characterized by low nutrient and carbon concentrations. The efficiency for nutrients removal aiming at water recirculation was assessed as well as the AGS microbiome composition dynamics over operation. The AGS system was inoculated with mature granules from a full-scale WWTP and fed with a synthetic medium mimicking a trout farm aquaculture recycling water. High ammonium removal efficiencies of 87-100% and ammonium removal rate of approximately 14.5 mg NH4+-N/(L⋅d) were achieved. The AGS microbiome, mainly composed by members of the Proteobateria phylum, had a core microbiome composed of different functional groups (e.g. denitrifying bacteria, nitrogen fixing bacteria, ammonium oxidizing bacteria, phosphorus accumulating bacteria and extracellular polymeric substance (EPS) producing bacteria). The AGS system was able to produce effluents of high-quality, with ammonium content below the toxic levels for fish, and thus suitable for recirculating in the aquaculture.
- Aerobic granular sludge, a feasible technology for the treatment and recirculation of trout aquaculture water streamsPublication . Couto, Ana T.; Amorim, Catarina L.; Castro, Paula M. L.
- Bacterial degradation of the veterinary antibiotic florfenicolPublication . Couto, Ana T.; Amorim, Catarina L.; Castro, Paula M. L.Florfenicol (FF) is a synthetic antibiotic, widely used in veterinary medicine. It is one of the few approved antibiotics for use in aquaculture during both production and processing operations, mainly to prevent and treat bacterial diseases. Therefore, this antibiotic is inevitably presented in the effluents from fish farms and eventually directly discharged in surface waters. Removal of FF has been mainly reported using physical-chemical processes but reports on its removal by biological processes is scarce. Bioremediation has been considered the strategy of choice to reduce the risk of hazardous chemicals in the environment. Therefore, microorganisms able to tolerate and degrade FF could represent added value towards more efficient biological removal processes. The main aim of this study was to investigate FF degradation by the bacterial strain Labrys portucalensis F11, capable to degrade other pharmaceuticals.
- Bacterial degradation of the veterinary antibiotic florfenicolPublication . Couto, Ana T.; Amorim, Catarina L.; Castro, Paula M. L.Florfenicol (FF) is an antibiotic largely used in aquaculture and its presence in their aqueous streams can affect the treatment process. Bacteria can play an important role in the cleanup of contaminated sites due to their ability to degrade an impressive variety of pollutants, using them as carbon and energy source. This study aimed to investigate the degradation of FF by a single bacterial strain, Labrys portucalensis F11. Biodegradation of FF was assessed in batch mode in the presence of a conventional carbon source and the bacterium was capable to remove ca. 80% of the FF supplied. When acetate was periodically added, although the cell growth was improved, no effect on the uptake of FF was observed but its defluorination was greatly enhanced.
- Control of zootechnology leads to improved cuttlefish (Sepia officinalis, L.) reproduction performance up to pre-industrial levelsPublication . Capaz, Juan C.; Hernández-Brooke, Daniel; Balvet, Safia; Couto, Ana T.; Alves, Alexandra C.; Gonçalves, Rui A.; Frias, Paulo A.; Andrade, José P.; Sykes, António V.Cephalopods are gaining momentum as an alternate group for aquaculture species diversification, not only because they are a good food source (highly appreciated in some worldwide markets) but they also have the potential to quickly reach a market size. However, there are some bottlenecks impeding the transition of culture technology from the laboratory to industry. One is related to control over reproduction in captivity. The objective of the present experiment was to verify the effects of tanks with different bottom areas/volumes on the reproduction performance of S. officinalis breeding stocks, when sex ratios were controlled a priori; and the food cost associated with such performance when individuals are fed a natural frozen diet. One hundred and ninety two juvenile cuttlefish were used to compare three different round-shaped tanks: one type with 3000L volume and two types with 9000L volume (with differences in bottom areas and water column). Individuals had their sex and maturity stage determined to establish a sexual ratio of 2♀:1♂ per tank and assure that cuttlefish were still immature. Biological data was collected during both growth and reproduction stages and until the death of all females in each tank. The experiment lasted nearly 300 days. Temperature differences between tank types were registered during both stages. The optimizing of rearing conditions has allowed for higher growth and a higher amount of cuttlefish available for breeding purposes. A total of 123,751 eggs (in 85 batches) was obtained during this experiment, which is a number that may meet a small scale cuttlefish commercial hatchery facility requirements. The present conditions contributed to a better and predictable reproduction performance in specific 9000L tanks, with values reaching pre-industrial numbers (≈ 24,000 eggs/tank). Moreover, both the amount of eggs per batch and the overall quality of eggs has increased. Three of these 9000L tanks have an overall consumption of ≈ 38.64 Kg tank–1, which translates in an investment in feed of ≈ 193 € tank–1, 8.40 € per cuttlefish and an overall daily tank expense of 1.76 € d–1.
- Cultivable microalgae diversity from a freshwater aquaculture filtering system and its potential for polishing aquaculture derived water streamsPublication . Couto, Ana T.; Cardador, Martim; Santorio, Sergio; Arregui, Luz; Sicuro, Benedetto; Mosquera‐Corral, Anuska; Castro, Paula M. L.; Amorim, Catarina L.Aims: Microalgae are ubiquitous in aquatic environments, including aquaculture farms, but few studies have delved into their phytoplankton diversity and bioremediation potential. In this study, the cultivable phytoplankton of a rainbow trout freshwater aquaculture farm was isolated, phylogenetically analysed and used to assemble a consortium to polish an aquaculture derived effluent, with low concentrations of ammonium, nitrite and nitrate. Methods and Results: Through standard plating in different selective media, a total of 15 microalgae strains were isolated from sludge from a rotary drum filtering system which removes suspended solids from the water exiting the facility. Based on 18S rRNA gene sequences, isolates were assigned to nine different genera of the Chlorophyta phylum: Asterarcys, Chlorella, Chloroccocum, Chlorosarcinopsis, Coelastrella, Desmodesmus, Micractinium, Parachlorella and Scenedesmus. Species from most of these genera are known to inhabit freshwater systems in Galicia and continental Spain, but the Coelastrella, Asterarcys or Parachlorella genera are not usually present in freshwater streams. In an onsite integrative approach, the capacity of a consortium of native microalgae isolates to grow on aquaculture derived effluents and its nutrient removal capacity were assessed using a raceway pond. After 7 days, removal efficiencies of approximately 99%, 92% and 49% for ammonium, nitrite and nitrate, respectively, were achieved concomitantly with a microalgae biomass increase of ca. 17%. Conclusions: Sludge from the aquaculture filtering system presents a high diversity of microalgae species from the Chlorophyta phylum, whose application in a consortial approach revealed to be efficient to polish aquaculture derived effluents with low nutrient content. Significance and Impact of the Study: The use of native microalgae consortia from aquaculture systems can contribute to the development of efficient treatment systems for low nutrient wastewater, avoiding nutrients release to the environment and promoting water recirculation. This may further strengthen the use of phycoremediation at the industrial scale, as an environment friendly strategy.
- Development of microalgae-bacteria granular sludge for the treatment of aquaculture wastewaterPublication . Amorim, Catarina L.; Couto, Ana T.; Miranda, Catarina; Castro, Paula M.L.The use of microalgae–bacteria systems is particularly attractive for wastewater treatment as combining microorganisms with different metabolic machineries could allow the development of a robust biological system. The aim of this study was to evaluate the feasibility to develop microalgae-bacterial granular sludge through the self-immobilization of microorganisms under SBR mode. After the addition of the suspended microalgae consortia containing several strains isolated from an aquaculture facility, adhesion of microalgae to the bacterial granules was observed. Reactor removal performance for carbon and nutrients was followed to assess the effect of the microalgae bioaugmentation process.
- Granular sludge technology for valorization of water use: from high to low strength effluents in aquaculturePublication . Couto, Ana T.; Santorio, Sergio; Miranda, Catarina; Amorim, Catarina L.; Rio, Angeles Val del; Arregui, Luz; Mosquera-Corral, Anuska; Castro, Paula M. L.
- Microalgae attachment to aerobic granular sludge for the treatment of freshwater aquaculture effluentsPublication . Miranda, Catarina; Couto, Ana T.; Amorim, Catarina L.; Castro, P. M. L.
- Microalgae-bacterial biomass outperforms PN-anammox biomass for oxygen saving in continuous-flow granular reactors facing extremely low-strength freshwater aquaculture streamsPublication . Santorio, Sergio; Rio, Angeles Val del; Amorim, Catarina L.; Couto, Ana T.; Arregui, Luz; Castro, Paula M. L.; Mosquera-Corral, AnuskaThe dissolved oxygen (DO) concentration in water streams is one of the most important and critical quality parameters in aquaculture farms. The main objective of this study was to evaluate the potential of two Continuous Flow Granular Reactors, one based on Partial Nitrification-Anammox biomass (Aquammox CFGR) and the other on Microalgae-Bacteria biomass (AquaMab CFGR), for improving dissolved oxygen availability in the recirculation aquaculture systems (RAS). Both reactors treated the extremely low-strength effluents from a freshwater trout farm (1.39 mg NH4 +-N/L and 7.7 mg TOC/L). The Aquammox CFGR, removed up to 68% and 100% of ammonium and nitrite, respectively, but the DO concentration in the effluent was below 1 mg O2/L while the anammox activity was not maintained. In the AquaMab CFGR, bioaugmentation of aerobic granules with microalgae was attained, producing an effluent with DO concentrations up to 9 mg O2/L and removed up to 77% and 80% of ammonium and nitrite, respectively, which is expected to reduce the aeration costs in fish farms.