Characterization of a thermostable extracellular tannase produced under submerged fermentation by Aspergillus ochraceus



Título del documento: Characterization of a thermostable extracellular tannase produced under submerged fermentation by Aspergillus ochraceus
Revue: Electronic journal of biotechnology
Base de datos: PERIÓDICA
Número de sistema: 000358908
ISSN: 0717-3458
Autores: 1
1
2
2
2
Instituciones: 1Universidade Estadual Paulista "Julio de Mesquita Filho", Instituto de Quimica, Araraquara, Sao Paulo. Brasil
2Universidade de Sao Paulo, Faculdade de Filosofia, Ciencias e Letras, Sao Paulo. Brasil
Año:
Volumen: 15
Número: 5
País: Chile
Idioma: Inglés
Tipo de documento: Artículo
Enfoque: Experimental
Resumen en inglés Tannases are enzymes that may be used in different industrial sectors as, for example, food and pharmaceutical. They are obtained mainly from microorganisms, as filamentous fungi. However, the diversity of fungi stays poorly explored for tannase production. In this article, Aspergillus ochraceus is presented as a new source of tannase with interesting features for biotechnological applications. Results: Extracellular tannase production was induced when the fungus was cultured in Khanna medium with tannic acid as carbon source. The extracellular tannase was purified 9-fold with 2% recovery and a single band corresponding to 85 kDa was observed in SDS-PAGE. The native apparent molecular mass was estimated as 112 kDa. Optima of temperature and pH were 40ºC and 5.0, respectively. The enzyme was fully stable from 40ºC to 60ºC during 1 hr. The activity was enhanced by Mn2+ (33-39%) and NH4+ (15%). The purified tannase hydrolyzed tannic acid and methyl gallate with Km of 0.76 mM and 0.72 mM, respectively, and Vmax of 0.92 U/mg protein and 0.68 U/mg protein, respectively. The analysis of a partial sequence of the tannase encoding gene showed an open read frame of 567 bp and a sequence of 199 amino acids were predicted. TLC analysis revealed the presence of gallic acid as a tannic acid hydrolysis product. Conclusion: The extracellular tannase produced by A. ochraceus showed distinctive characteristics such as monomeric structure and activation by Mn2+, suggesting a new kind of fungal tannases with biotechnological potential. Further, it was the first time that a partial gene sequence for A. ochraceus tannase was described
Disciplinas: Química,
Biología
Palabras clave: Bioquímica,
Hongos,
Fermentación,
Biotecnología,
Hongos filamentosos,
Enzimas,
Taninoasa,
Aspergillus ochraceus,
Acido gálico,
Acido tánico
Keyword: Chemistry,
Biology,
Biochemistry,
Fermentation,
Fungi,
Biotechnology,
Filamentous fungi,
Aspergillus ochraceus,
Enzymes,
Tannase,
Gallic acid,
Tannic acid
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