Consulta: subjectFacets:"Enzyme stability"
Registros recuperados: 5
Data/hora: 11/06/2024 01:24:08

Bordonein-L, a new L-amino acid oxidase from Crotalus durissus terrificus snake venom: isolation, preliminary characterization and enzyme stability
Provedor de dados: Journal of Venomous Animals and Toxins Including Tropical Diseases
Autores: Bordon,Karla C. F.; Wiezel,Gisele A.; Cabral,Hamilton; Arantes,Eliane C.
BackgroundCrotalus durissus terrificus venom (CdtV) is one of the most studied snake venoms in Brazil. Despite presenting several well known proteins, its L-amino acid oxidase (LAAO) has not been studied previously. This study aimed to isolate, characterize and evaluate the enzyme stability of bordonein-L, an LAAO from CdtV.Methods The enzyme was isolated through cation exchange, gel filtration and affinity chromatography, followed by a reversed-phase fast protein liquid chromatography to confirm its purity. Subsequently, its N-terminal amino acid sequence was determined by Edman degradation. The enzyme activity and stability were evaluated by a microplate colorimetric assay and the molecular mass was estimated by SDS-PAGE using periodic acid-Schiff...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Crotalus durissus terrificus; L-amino acid oxidase; Rattlesnake; Enzyme activity; Enzyme stability; Chromatography; Snake venom; Yellow venom; Stabilization.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992015000100335

Production and characterization of endo-polygalacturonase from Aspergillus niger in solid-state fermentation in double-surface bioreactor
Provedor de dados: Brazilian Archives of Biology and Technology
Autores: Hendges,Diogo Henrique; Montanari,Queli; Malvessi,Eloane; Silveira,Mauricio Moura da.
Endo-polygalacturonase (endo-PG) production by Aspergillus niger T0005/007-2 in solid medium with 170 mm of height was evaluated in a cylindrical double surface bioreactor in 96-h experiments. Cell concentration close to 92 mg.g -¹ dm (mg per g of dry medium) in the standard condition (static) was achieved, whereas in tests under forced aeration of 1.4 and 2.8 L.min-1. Kg-1 mm (L of air per minute per Kg of moist medium) and with the central shaft fungal biomass attained approximately 100 mg.g-1 dm. Superior endo-PG activity was obtained with the central-shaft system, 78 U.g-1 dm (units per g of dry medium). Forced aeration and pressure pulse showed no positive effect on the production of endo-PG, 45 U.g-1 dm and 28 U.g-1 dm, respectively. None of the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Aspergillus niger; Double-surface bioreactor; Endo-polygalacturonase; Solid-state fermentation; Enzyme stability.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132011000200005

Investigation of factors affecting xylanase activity from Trichoderma harzianum 1073 D3
Provedor de dados: Brazilian Archives of Biology and Technology
Autores: Isil,Seyis; Nilufer,Aksoz.
In this study, some physiological conditions affecting the activity of xylanase enzyme produced from Trichoderma harzianum 1073 D3 were determined. In addition, stabilization of pH and temperature in liquid and semi-solid state cultivation media were investigated. It was concluded that for maximum xylanase activity, incubation at 60°C in an enzyme incubation medium with pH 5 that contained 1 % xylan was appropriate. The stability studies showed that the enzyme was relatively stable in the pH range 3-7 and retained more than 50 % of its original activity after four months.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Trichoderma harzianum; Xylan; Xylanase; Lignocellulosic material; Enzyme stability; Metal ions.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132005000200004

Production of extracellular protease by a Brazilian strain of Beauveria bassiana reactivated on coffee berry borer, Hypothenemus hampei
Provedor de dados: Brazilian Archives of Biology and Technology
Autores: Ito,Eliana Tiemi; Varéa-Pereira,Geni; Miyagui,Dalva Tomoe; Pinotti,Maria Helena Pimenta; Neves,Pedro Manoel Oliveira Janeiro.
Studies were carried out on extracellular protease production by Beauveria bassiana CG432 in liquid medium containing glucose and yeast extract. B. Bassiana presented active growth after lag period of 24 h., produced 80% of the total of the extracellular protease activity in 48 h which was maximum on the 5th culture day. The extracellular protease presented optimum activity at 60ºC, was stable up to 1M Cl-, maintained the stability during 15 day at 4ºC and -18ºC, but was not stable if frozen repeatedly.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Protease activity; Beauveria bassiana; Enzyme stability.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132007000200006

Chemical modification of Aspergillus nigerβ-glucosidase and its catalytic properties
Provedor de dados: Brazilian Journal of Microbiology
Autores: Ahmed,Samia A.; El-Shayeb,Nefisa M.A.; Hashem,Abdel-Gawad M.; Saleh,Shireen A.A.; Abdel-Fattah,Ahmed F.
Aspergillus niger β-glucosidase was modified by covalent coupling to periodate activated polysaccharides (glycosylation). The conjugated enzyme to activated starch showed the highest specific activity (128.5 U/mg protein). Compared to the native enzyme, the conjugated form exhibited: a higher optimal reaction temperature, a lower Ea (activation energy), a higher Km (Michaelis constant) and Vmax (maximal reaction rate), and improved thermal stability. The calculated t1/2 (half-life) values of heat in-activation at 60 °C and 70 °C were 245.7 and 54.5 min respectively, whereas at these temperatures the native enzyme was less stable (t1/2of 200.0 and 49.5 min respectively). The conjugated enzyme retained 32.3 and 29.7%, respectively from its initial activity...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Β-glucosidases; Glycosylation; Soluble polysaccharides; Enzyme stability.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822015000100023