505 research outputs found

    Zebrafish as animal model for aquaculture nutrition research.

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    The aquaculture industry continues to promote the diversification of ingredients used in aquafeed in order to achieve a more sustainable aquaculture production system. The evaluation of large numbers of diets in aquaculture species is costly and requires time-consuming trials in some species. In contrast, zebrafish (Danio rerio) can solve these drawbacks as an experimental model, and represents an ideal organism to carry out preliminary evaluation of diets. In addition, zebrafish has a sequenced genome allowing the efficient utilization of new technologies, such as RNA-sequencing and genotyping platforms to study the molecular mechanisms that underlie the organism's response to nutrients. Also, biotechnological tools like transgenic lines with fluorescently labeled neutrophils that allow the evaluation of the immune response in vivo, are readily available in this species. Thus, zebrafish provides an attractive platform for testing many ingredients to select those with the highest potential of success in aquaculture. In this perspective article aspects related to diet evaluation in which zebrafish can make important contributions to nutritional genomics and nutritional immunity are discussed

    Minhocas como indicadoras da fertilidade do solo.

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    Numa área da cordilheira dos Andes se avaliaram diversos parâmetros socioeconômicos e variáveis do solo para verificar suas relações com os processos de transformação da cobertura vegetal e dos usos do solo, e construir possíveis indicadores do panorama atual após aprox. 120 anos de colonização e perturbação dos ecossistemas colombianos. Se realizaram entrevistas aos agricultores para obter a informação socioeconômica. Em nove janelas selecionadas ao azar, se amostraram algumas variáveis físico-químicas do solo e as comunidades de minhocas em 22 usos do solo. Encontraram-se fortes relações entre produtores com maiores ingrsesos econômicos, alto nível de educação, maior perturbação do solo, solos compactados, e alto uso de fertilizantes. Nas propriedades menores os agricultores tinham menores ingressos e egressos de dinheiro e nível mais baixo de educação, e essas propriedades tinham maiores teores de matéria orgânica, maior riqueza de espécies de minhocas, e os solos estavam menos compactados. Demonstrou-se a importância do trabalho com enfoques interdisciplinares no processo de construção de indicadores, e destacou-se o valor das ferramentas desenvolvidas para predizer a condição atual dos agroecossistemas e a qualidade do solo.Resumo expandido

    Electrodialysis for concentrating cobalt, chromium, manganese, and magnesium from a synthetic solution based on a nickel laterite processing route

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    [EN] Due to environmental and human health concerns, the need for cleaner techniques able to extract and recover metals from mining process solutions has been increasing. In this work, the use of electrodialysis for recovering cobalt, magnesium, manganese, and chromium ions from an acid multicomponent solution generated in the nickel laterite processing was evaluated. Values of percent extraction above 98% were obtained for Co2+, Mn2+, and Mg(2+ )ions. For Cr3+, the greatest percent extraction obtained was 83%. The results of percent concentration of the species showed the same trend: for Cr3+ ions, it was significantly lower than the others. Such difference in the transport of the metals through the membranes may have occurred due to the lower molar concentration, lower diffusion coefficient, and greater Stokes radius of chromium ions. Thus, the transfer of Cr3+ was hindered by the presence of other cationic species. This was also evidenced by the results of current efficiency and energy consumption associated with each species in solution. Lastly, the results of solution pH throughout the experiments and the final condition of the membranes, which were analyzed by SEM/EDS, indicated that the water dissociation phenomenon occurred at their surfaces.The authors gratefully acknowledge the financial support given by funding agencies CNPq (Process 141346/2016-7; 171241/2017-7; 160320/2019-4) and FAPESP (Process 2012/51871-9) . This study was financed in part by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior-Brasil (CAPES) -Finance Code 001 (Processes 88881.190502/2018-01 and 88887.362657/2019-00) .Feijoo, GC.; Santana-Barros, K.; Scarazzato, T.; Espinosa, D. (2021). Electrodialysis for concentrating cobalt, chromium, manganese, and magnesium from a synthetic solution based on a nickel laterite processing route. Separation and Purification Technology. 275. https://doi.org/10.1016/j.seppur.2021.11919227

    Genetic stabilization of Saccharomyces cerevisiae oenological strains by using benomyl

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    Wild-type oenological strains of Saccharomyces cerevisiae are usually aneuploid and heterozygotes; thus, when they are used as starters in must fermentation the resulting wine characteristics may vary from year to year. Treatment of a wild-type S. cerevisiae oenological strain with benomyl (methyl-l-butylcarbamoyl-2-benzimidazole carbamate), an antifungal agent shown to cause chromosome loss in yeasts, resulted in a stable starter strain in which the parental oenological traits were unchanged. The oenological S. cerevisiae strain was treated with benomyl in two different ways (A and B), and sporulation ability and spore viability were subsequently assayed. Treatment A resulted in both the highest numbers of tetrads and a reduction in DNA cell content, while treatment B increased spore viability. Fermentation assays were carried out with spore clones obtained from treatment A, and the concentrations of glycerol, lactic acid, acetic acid, and ethanol resulting from the treated strains were found to be similar to those of the parental strain. Benomyl treatment thus achieved stable, highly sporulating oenological S. cerevisiae strains of low ploidy, but preserved the desirable oenological properties of the parental strain

    Environmental assessment of viticulture waste valorisation through composting as a biofertilisation strategy for cereal and fruit crops

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    Composting is a solid waste management alternative that avoids the emission of methane associated with its disposal in landfill and reduces or eliminates the need for chemical fertilisers if compost is applied. The main objective of this study was to analyse the environmental burdens of composting as a way to achieve a more circular valorisation of wine waste. To do so, with the purpose of identifying optimal operational conditions and determining the “hotspots” of the process, the life cycle assessment (LCA) methodology was used. The consumption of diesel fuel in machinery was determined to be the main critical point in the environmental effects of the system, followed by the transport and distribution of the compost. After the application of compost instead of mineral fertilisers, corn, tomato and strawberry crops would have a better environmental performance in most impact categories. In this sense, a maximum improvement of 65% in terrestrial ecotoxicity is achieved in strawberry cultivation. In light of the results obtained, it is demonstrated that composting is a suitable way of organic waste valorisation according to Circular Economy principles
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