Browsing by Author "Mata, Leonardo"
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- Concise review of the genus Asparagopsis Montagne, 1840Publication . Zanolla, Marianela; Carmona, Raquel; Mata, Leonardo; De la Rosa, Julio; Sherwood, Alison; Barranco, Carlos Navarro; Muñoz, Antonio Román; Altamirano, MaríaAsparagopsis (Bonnemaisoniaceae, Rhodophyta) species are distributed in most temperate and tropical waters of the world, where they are considered an iconic invader. Despite a low number of species in the genus, Asparagopsis armata and A. taxiformis are considered species complexes, revealing remarkable genetic diversity in native and introduced distribution ranges. Macroscopic life stages that characterize the life cycle, gametophytes, and tetrasporophytes, present diferent morphologic, photosynthetic, physiological, and ecological features, which may aid in the course of an invasive process. Asparagopsis presence lowers diversity and abundance of native macroalgal communities. Despite hosting a relatively high number of epiphytes and epifauna, lower numbers are consistently found in these invasive species when compared to native fora. The chemical composition of A. armata and A. taxiformis and thus, its commercial applications have been studied since the 1970s. Recently, the discovery of its properties as a potent methane release inhibitor from ruminant animals has boosted a renewed scientifc, media, and commercial interest in the genus. Sourcing biomass remains a challenge, and while techniques of cultivation are available, more needs to be done to reach the scale needed to ft such large-volume application. Much is yet to be expected from this red algal genus.
- Draft genome sequence of Vibrio chagasii 18LP, isolated from Gilthead Seabream (Sparus aurata) larvae reared in aquaculturePublication . Sanches-Fernandes, Gracinda M. M.; Califano, Gianmaria; Keller-Costa, Tina; Castanho, Sara; Soares, Florbela; Ribeiro, Laura; Pousão-Ferreira, Pedro; Mata, Leonardo; Costa, RodrigoWe report the draft genome sequence of Vibrio chagasii strain 18LP, isolated from gilthead seabream larvae at a fish hatchery research station in Portugal. The genome presents numerous features underlying opportunistic behavior, including genes coding for toxin biosynthesis and tolerance, host cell invasion, and heavy metal resistance.
- Draft genome sequence of vibrio jasicida 20LP, an opportunistic bacterium isolated from fish larvaePublication . Sanches-Fernandes, Gracinda M. M.; Califano, Gianmaria; Keller-Costa, Tina; Castanho, Sara; Soares, Florbela; Ribeiro, Laura; Pousão-Ferreira, Pedro; Mata, Leonardo; Costa, RodrigoWe present the genome sequence of Vibrio jasicida 20LP, a bacterial strain retrieved from larvae of gilthead seabream (Sparus aurata), a highly valuable, model fish species in land-based aquaculture. Annotation of the V. jasicida 20LP genome reveals multiple genomic features potentially underpinning opportunistic associations with diverse marine animals.
- Effects of live feed manipulation with algal‐derived antimicrobial metabolites on fish larvae microbiome assembly: a molecular‐based assessmentPublication . Sanches‐Fernandes, Gracinda M. M.; Califano, Gianmaria; Castanho, Sara; Soares, Florbela; Ribeiro, Laura; Pousão‐Ferreira, Pedro; Mata, Leonardo; Costa, RodrigoOpportunistic microorganisms acquired through rearing water or live feed ingestion are believed to underpin high mortality rates of fish larvae, constituting a production bottleneck for the aquaculture industry. We employed 16S rRNA gene sequencing to determine whether treatment of live feed (rotifers and Artemia) with algal-derived, antibacterial metabolites could alter bacterial community structure of gilthead seabream (Sparus aurata) larvae in a larviculture facility. Owing to a large degree of sample-to-sample variation, pronounced 'legacy effects' of live feed manipulation on the total fish larvae bacterial community could not be verified. Notwithstanding, the approach induced shifts in relative abundance of specific bacterial phylotypes in both the live feed and fish larvae. Some phylotypes representing opportunistic taxa such as Stenotrophomonas, Pseudomonas and Klebsiella displayed reduced abundances in the bacterial community of fish larvae fed metabolite-treated vs. control live feed. Conversely, potentially beneficial phylotypes in the Alphaproteobacteria clade were consistently-although not significantly-promoted in the treated larval samples. These outcomes encourage future microbiome manipulation attempts to improve fish larviculture. However, successful host colonization and competition with resident symbionts are primary barriers that need to be overcome if live feeds are to be used as effective delivery systems of beneficial bacteria to fish larvae.
- Genetic homogeneity in the seagrass Cymodocea nodosa at its northern Atlantic limit revealed through RAPDPublication . Alberto, Filipe; Mata, Leonardo; Santos, RuiRandom amplified polymorphic DNA (RAPD) markers were used to analyse the genetic variability of the dioecious seagrass Cymodocea nodosa Ucria (Ascherson) in the Ria Formosa lagoon, Portugal, the species' northern limit in the Atlantic. Three individuals from each of 6 meadows were genotyped with 28 primers. Meadows described previously as having flower marks were compared with meadows where flowers did not occur. A single polymorphic band, specific for one meadow, was observed in a total of 177 fragments. The lack of genetic variability among meadows both with and without flower indicates that flower production is not associated with a higher level of genetic variation. The genetic homogeneity of C, nodosa in the Ria Formosa suggests a founder effect, produced by a single or a limited number of migrants composing the colonising gene pool, This hypothesis is supported by the geographic isolation from other populations as the nearest populations lie more than 300 km away from the Ria Formosa. The lack of reproductive success of C, nodosa in Ria Formosa natural park and its low genetic variability are important factors in the conservation of this species since recolonisation can only occur through vegetative growth.
- Molecular Taxonomic Profiling of Bacterial Communities in a Gilthead Seabream (Sparus aurata) HatcheryPublication . Califano, Gianmaria; Castanho, Sara; Soares, Florbela; Ribeiro, Laura; Cox, C. J.; Mata, Leonardo; Costa, RodrigoAs wild fish stocks decline worldwide, land-based fish rearing is likely to be of increasing relevance to feeding future human generations. Little is known about the structure and role of microbial communities in fish aquaculture, particularly at larval developmental stages where the fish microbiome develops and host animals are most susceptible to disease. We employed next-generation sequencing (NGS) of 16S rRNA gene reads amplified from total community DNA to reveal the structure of bacterial communities in a gilthead seabream (Sparus aurata) larviculture system. Early-(2 days after hatching) and late-stage (34 days after hatching) fish larvae presented remarkably divergent bacterial consortia, with the genera Pseudoalteromonas, Marinomonas, Acinetobacter, and Acidocella (besides several unclassified Alphaproteobacteria) dominating the former, and Actinobacillus, Streptococcus, Massilia, Paracoccus, and Pseudomonas being prevalent in the latter. A significant reduction in rearing-water bacterial diversity was observed during the larviculture trial, characterized by higher abundance of the Cryomorphaceae family (Bacteroidetes), known to populate microniches with high organic load, in late-stage rearing water in comparison with early-stage rearing-water. Furthermore, we observed the recruitment, into host tissues, of several bacterial phylotypes-including putative pathogens as well as mutualists-that were detected at negligible densities in rearing-water or in the live feed (i.e., rotifers and artemia). These results suggest that, besides host-driven selective forces, both the live feed and the surrounding rearing environment contribute to shaping the microbiome of farmed gilthead sea-bream larvae, and that a differential establishment of host-associated bacteria takes place during larval development.
- Nitrogen uptake kinetics of an enteric methane inhibitor, the red seaweed Asparagopsis armataPublication . Torres, Raquel; Mata, Leonardo; Santos, Rui; Alexandre, AnaThe use of red seaweeds of the genus Asparagopsis as a feed ingredient drastically decreases the enteric methane production by ruminant livestock, thereby reducing the environmental impact of this industry. To address the world demand for Asparagopsis mass production, it is essential to understand the species nutrition. In this study, we evaluated for the first time the uptake kinetics of inorganic and organic nitrogen forms of the tetrasporophyte of Asparagopsis armata, to identify the different uptake phases (surge and internally controlled) and to reveal the species preferential nitrogen sources. The time course of nitrogen uptake rates was followed, and the preferential nitrogen sources were assessed in choice-uptake experiments through the incorporation of (15) N-labelled ammonium, nitrate and amino acids. As expected, the short-term, surge uptake rates were much higher than the stabilized internally controlled uptake rates. Ammonium was the preferred form during the internally controlled phase but surprisingly, the surge uptake rates of amino acids were much higher than those of inorganic forms. The importance of amino acids for A. armata nutrition was further supported by its internally controlled uptake rates that where higher than those of nitrate. Ammonium is, thus, the main nitrogen form for the species nutrition, but pulses of organic nitrogen may be considered in the mass production of Asparagopsis for the enteric methane inhibition of the livestock industry.