8 research outputs found

    A new lipase isolated from oleaginous seeds from Pachira aquatica (Bombacaceae)

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    A new lipase from seeds of Pachira aquatica was purified to homogeneity by SDS-PAGE obtaining an enzyme with a molecular weight of approximately 55 kDa. The purified lipase exhibited maximum activity at 40 degrees C and pH 8.0, for an incubation time of 90 min. Concerning temperature stability, at the range from 4 to 50 degrees C, it retained approximately 47% of its original activity for 3 h. The enzyme activity increased in the presence of Ca(++) and Mg(++), but was inhibited by Hg(++), Mn(++), Zn(++), Al(+++) and various oxidizing and reducing agents. The lipase was highly stable in the presence of organic solvents, and its activity was stimulated by methanol. The values of K(m) and V(max) were 1.65 mM and 37.3 mu mol mL(-1) min(-1), respectively, using p-nitrophenylacetate as substrate. The enzyme showed preference for esters of long-chain fatty acids, but demonstrated significant activity against a wide range of substrates

    Production, partial characterization, and immobilization in alginate beads of an alkaline protease from a new thermophilic fungus Myceliophthora sp.

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    Thermophilic fungi produce thermostable enzymes which have a number of applications, mainly in biotechnological processes. In this work, we describe the characterization of a protease produced in solidstate (SSF) and submerged (SmF) fermentations by a newly isolated thermophilic fungus identified as a putative new species in the genus Myceliophthora. Enzyme-production rate was evaluated for both fermentation processes, and in SSF, using a medium composed of a mixture of wheat bran and casein, the proteolytic output was 4.5-fold larger than that obtained in SmF. Additionally, the peak of proteolytic activity was obtained after 3 days for SSF whereas for SmF it was after 4 days. The crude enzyme obtained by both SSF and SmF displayed similar optimum temperature at 50A degrees C, but the optimum pH shifted from 7 (SmF) to 9(SSF). The alkaline protease produced through solid-state fermentation (SSF), was immobilized on beads of calcium alginate, allowing comparative analyses of free and immobilized proteases to be carried out. It was observed that both optimum temperature and thermal stability of the immobilized enzyme were higher than for the free enzyme. Moreover, the immobilized enzyme showed considerable stability for up to 7 reuses.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Immobilization effects on the catalytic properties of two Fusarium verticillioides lipases: Stability, hydrolysis, transesterification and enantioselectivity improvement

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    This article belongs to the Special Issue Immobilized Biocatalysts.Fusarium verticillioides lipases were purified in a “cascade” method using octadecyl Sepabeads and octyl Sepharose resins, which led to the isolation of two proteins with lipolytic activities. Lip 1 was purified after octyl Sepharose adsorption presenting 30.3 kDa and, Lip 2 presented 68.0 kDa after octadecyl adsorption. These immobilization processes resulted in an increase of 3-fold in activity of each immobilized enzyme. These enzymes presented optima of pH of 5.0 and 6.0, respectively and temperature at 40 °C. They were thermostable at 40 °C and both remained more than 50% of its activity at the pH range of 5.0 to 7.0, with 180 min of incubation. The sardine oil hydrolysis showed higher EPA/DHA ratio. Concerning the ethanolysis reaction, Lip 2 showed higher conversion (5.5%) and both lipases showed activity in the release of the S enantiomers from 2-O-butyryl-2-phenylacetic acid (mandelic butyrate acid) and HPBE hydrolysis. Lip 2 also demonstrated capacity of transesterification. These applications made these enzymes attractive for industrial application.This work was supported by grants from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, nº 2013/50892-5) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, nº 406838/2013-5). This project is also part of the National Institute of Science and Technology of the Bioethanol (FAPESP, nº 2010/52322-3). MLTMP is Research Fellow of CNPq. FDAF was recipient of a FAPESP fellowship (nº 2012/14615-4). MGP and ACV are supported by CNPq.Peer reviewe
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