RESUMO
Pichia pinus was found to be capable of growing on mango wastes, producing pectinase (pectin lyase, EC-4.2.2.10) and lactase (beta-galactosidase, EC-3.2.1.23) enzymes. The two enzymes were successively purified by precipitation with ammonium sulfate followed by chromatography on Sephadex G-120. The purification procedure provided 1,846 and 929 fold purification with 20.6 and 24% yield recovery of pectinase and lactase, respectively. the km value of pectinase was 0.33% for pectin at pH 4.5 and that for lactase was 0.166% for lactose at pH 7.0. The purified enzymes, pectinase and lactase are stable up to 50 degrees C for 60 and 45 min, respectively, with 20 and 35% loss of their activity. Gel filtration on Sephadex G-200 indicated that the molecular weights of the purified pectinase was 90 x 10(3) Dalton and of lactase 115 x 10(3) Dalton. On the basis of the evaluation tests done, the enzymes were considered to have a potential technological interest as treating mango pastes (residues left after mango juice preparation) with the two prepared enzymes resulted in an increase of the colour intensity, total carbohydrate content and juice yield. Treating milk with the purified lactase also showed an increase in the total carbohydrate and reducing sugar produced.
Assuntos
Pichia/enzimologia , Poligalacturonase/análise , beta-Galactosidase/análise , Cromatografia em Gel , Cromatografia por Troca Iônica , Fermentação , Indústria de Processamento de Alimentos , Frutas , Concentração de Íons de Hidrogênio , Resíduos Industriais , Cinética , Lactase , Peso Molecular , Poligalacturonase/isolamento & purificação , Poligalacturonase/metabolismo , Temperatura , beta-Galactosidase/isolamento & purificação , beta-Galactosidase/metabolismoRESUMO
Proteolytic activity of a fibrinolytic enzyme isolated from B. subtilis was tested on fibrin plates plasminogen-free and plasminogen-rich. Results showed that the enzyme is not a plasminogen activator. Inhibitory effect of human serum and plasma was also tested. The plasma and not serum showed a slight inhibitory effect on proteolytic activity of this enzyme.
Assuntos
Bacillus subtilis/enzimologia , Fibrinólise , Peptídeo Hidrolases/metabolismo , Fibrinogênio , Humanos , Cinética , PlasminogênioRESUMO
A fibrinolytic enzyme obtained from B. subtilis was purified, using DEAE-cellulose column chromatography, and gel filtration on Sephadex G-100. The preparation was homogeneous as tested by gel filtration on Sephadex G-200, and disc electrophoresis. The molecular weight of this enzyme was 29.400 estimated by gel filtration on Sephadex G-100. The optimum pH for enzyme activity was 7.2 Copper ions significantly increased enzyme activity, while Zn++ and Mn++ caused marked inhibition.
Assuntos
Bacillus subtilis/enzimologia , Fibrinolíticos/isolamento & purificação , Peptídeo Hidrolases/isolamento & purificação , Sistema Livre de Células , Fibrina/metabolismo , Concentração de Íons de Hidrogênio , Peptídeo Hidrolases/metabolismo , Especificidade por Substrato , TemperaturaRESUMO
Two fibrinolytic enzymes isolated from B. subtilis and from B. polymyxa were purified using a five step method. The pH optimum for the enzyme from B. subtilis was 7.2 and for the enzyme from B. polymyxa was 7.0. Both enzymes were activated by Cu++. The molecular weight of the first enzyme was 29,400 and that for the second enzyme was 18,000 on the basis of gel filtration on Sephadex G-100. The enzyme from B. subtilis has higher affinity to buffalo fibrin than towards human fibrin. The enzyme from B. polymyxa has higher affinity to human fibrin than towards buffalo fibrin.