Navegando por Assunto "Biotechnology"

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Acesso aberto (Open Access)
Avaliação do potencial biotecnológico para o tratamento de um minério de ouro de uma mina do estado do Amapá
(Universidade Federal do Pará, 2016-04-08) GRANGEIRO, Luana Cardoso; BEVILAQUA, Denise; http://lattes.cnpq.br/9156111627025084; MACÊDO, Emanuel Negrão; http://lattes.cnpq.br/8718370108324505
One of the most commonly used pre-treatments prior conventional cyanidation is the biooxidation. This technical is a biological process capable of promote solubilization of metals such as copper, iron through the oxidative action of microorganisms in metal sulfides and it is applied as a pretreatment in the cyanidation process to reduce free cyanide consumption making this a feasible and economic process. Thus, the aim of this work was to study the best biotechnology route for the pretreatment of the gold ore in order to reduce cyanide consumption during the convencional cyanidation and increasing the gold recovery. For this purpose, biological tests has been investigated at laboratory scale on a gold ore sample coming from Estado do Amapá, Brazil (90 g/ton). Bacterial cultures utilised in the biological tests of 20 days consisted of Acidithiobacillus ferrooxidans-LRe Acidithiobacillus thiooxidans-LR. The biooxidated samples were submitted to cyanidation tests for gold recovery and tests of consumption of cyanide. Experimental studies demonstrate that after 24h leaching time by direct cyanidation, the gold recovery was 93% (32 mg/L) with a cyanide consumption of 2,84 kg.t-1, while the best gold extraction between biooxidated samples was from bioreactor R2 with 87% (30 mg/L), and the cyanide consumption of 2,64 kg.t-1. Experimental results have shown the technical feasibility of the biooxidative prior to convencional leaching for for reducing the consumption of reagent cyanide.
Acesso aberto (Open Access)
Obtenção de extratos da polpa de açaí (Euterpe oleracea) por extração supercrítica: isotermas de rendimento global, atividade alelopática dos extratos, enriquecimento de antocianinas e compostos fenólicos
(Universidade Federal do Pará, 2016-10-04) BATISTA, Camila de Cássia Rodrigues; MACHADO, Nélio Teixeira; http://lattes.cnpq.br/5698208558551065; CARVALHO JUNIOR, Raul Nunes de; http://lattes.cnpq.br/5544305606838748
Açaí is one of the most popular functional foods of the Amazon, widely consumed in Brazil and became known in other countries, especially due to the many benefits it has for a wide use in the growing market for nutraceuticals. Açaí extracts derived have a number of components with antioxidant, vasodilatory, anti-inflammatory and energy. Among the appropriate technologies in the processes, supercritical technology has become advantageous to obtain extracts with higher quality, adding value to products and by-products of the process. This work presents as objective a study of the supercritical extraction process of acai pulp to obtain extracts rich in bioactive compounds. A evaluation of the variables of the supercritical extraction process with CO2 (temperature, pressure, and solvent density) of Açai pulp showed the conditions that maximize the amount extracts (lipid fraction) obtained, and enable the concentration anthocyanins in açai pulp defatted for subsequent extraction of these compounds. The extracts obtained from extraction with CO2 were evaluated for fatty acid composition and allelopathic activities. The overall yield isotherms showed that the maximum amount of extract obtained in the process was in the condition of 70°C/490 bar followed by the condition of 50°C/350 bar.
Acesso aberto (Open Access)
Produção de carotenoides por leveduras Rhodotorula rubra, utilizando caroço de açaí (Euterpe oleracea Mart.) como substrato para a fermentação
(Universidade Federal do Pará, 2020-12-28) IGREJA, Willen Silva; LOPES, Alessandra Santos; http://lattes.cnpq.br/8156697119235191; https://orcid.org/0000-0002-8584-5859; CHISTÉ, Renan Campos; http://lattes.cnpq.br/0583058299891937; https://orcid.org/0000-0002-4549-3297
Carotenoids are fat-soluble bioactive compounds present in plants, animals and in microorganisms, with wide biotechnological, pharmaceutical and food applications. Rhodotorula yeasts are able to biosynthesize carotenoids inside their cells when they are subjected to adverse environmental conditions, this biotechnological process can be industrially viable if the production cost can be minimized with low-cost by-products as sources of nutrients. Therefore, the objective of this work was the production of carotenoids using açai seed as a substrate for the fermentation of the yeast Rhodotorula rubra. The açai seeds were characterized and exhibited 3,62% of cellulose; 58,61% hemicellulose, 11,63% lignin; 14% extractive; 4,63% 1,52% protein and 1,93% ash. The liquor from acid hydrolysis with diluted sulfuric acid was characterized and provided a liquor with 45.25 g/L of sugars, consisting mainly of xylose (93%), and low concentrations of inhibitors (0.0088 g / L of furfural; 0,2382 hydroxymethylfurfural and 1,76 ± acetic acid). Regarding the cultivation of yeast with acai seed as substrate, the best conditions for the production of biomass were pH 7, 40 °C and 200 rpm, while the best conditions for carotenoid biosynthesis were pH 7, 30 °C and 200 rpm. These conditions provided 2 g of dry yeast biomass and a carotenoid concentration of 37.59 µg/g of dry biomass. Among the identified carotenoids, β-carotene (77%), cis-g-Carotene (6,9%) and torulene (4,5%) were the major carotenoids. Therefore, açaí seed showed a high potential to be used as a fermentation substrate for the yeast R. rubra to biosynthesize carotenoids as a product with high added value.