Characterization of a multi-tolerant tannin acyl hydrolase II from Aspergillus carbonarius produced under solid-state fermentation

• Larissa Serrani Valera ^[1] ; João Atílio Jorge ^[2] ; Luis Henrique Souza Guimarães ^[2]
  1. [1] Universidade Estadual Paulista

     Universidade Estadual Paulista

     Brasil

     
  2. [2] Universidade de São Paulo

     Universidade de São Paulo

     Brasil

     
• Localización: Electronic Journal of Biotechnology, ISSN-e 0717-3458, Vol. 18, Nº. 6, 2015, págs. 464-470
• Idioma: inglés
• Enlaces
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• Resumen

  • Background Tannases are enzymes with biotechnological potential produced mainly by microorganisms as filamentous fungi. In this context, the production and characterization of a multi-tolerant tannase from Aspergillus carbonarius is described. Results The filamentous fungus A. carbonarius produced high levels of tannase when cultivated under solid-state fermentation using green tea leaves as substrate/carbon source and tap water at a 1:1 ratio as the moisture agent for 72 h at 30°C. Two tannase activity peaks were obtained during the purification step using DEAE-Cellulose. The second peak (peak II) was purified 11-fold with 14% recovery from a Sepharose CL-6B chromatographic column. The tannase from peak II (tannase II) was characterized as a heterodimeric glycoprotein of 134.89 kDa, estimated through gel filtration, with subunits of 65 kDa and 100 kDa, estimated through SDS-PAGE, and 48% carbohydrate content. The optimal temperature and pH for tannase II activity was 60°C and 5.0, respectively. The enzyme was fully stable at temperatures ranging from 20-60°C for 120 min, and the half-life (T1/2) at 75°C was 62 min. The activation energy was 28.93 kJ/mol. After incubation at pH 5.0 for 60 min, 75% of the enzyme activity was maintained. However, enzyme activity was increased in the presence of AgNO3 and it was tolerant to solvents and detergents. Tannase II exhibited a better affinity for methyl gallate (Km = 1.42 mM) rather than for tannic acid (Km = 2.2 mM). Conclusion A. carbonarius tannase presented interesting properties as, for example, multi-tolerance, which highlight its potential for future application.