Tannin acyl hydrolase (EC 3.1.1.20), called tannase, is an enzyme of great biotechnological interest for applications in food, chemical, beverage and pharmaceutical industries. Therefore, the objective of this study was to isolate, select and identify strains of endophytic fungi from rich tannin plants collected in the Caatinga, as well as, the optimization of culture conditions for the best producers. Sixteen endophyte fungi were isolated from the barks of mastic (Myracrodruon urundeuva Allemão), angico (Anadenanthera colubrina Vell.), barauna (Schinopsis brasiliensis Engl.), cajueiro (Anacardium occidentale L.) and catingueira (Caesalpinia pyramidalis Tul). All strains showed ability of using tannic acid as carbon source. The species A. niger and A. fumigatus isolated from angico and cajueiro, respectively, presented the highest enzyme production. The optimum conditions for the production of tannase by A. niger were 24 h cultivation in Khanna medium containing 2% tannic acid, in the absence of nitrogen source, at 37 °C. A. fumigatus showed increased production of tannase when cultured in mineral medium for 24 h using 2% tannic acid as carbon source and peptone as additional nitrogen source, at 37ºC. The optimum apparent temperature and pH of activity for the enzymes produced by both fungal species were 30 ºC and 4.0, respectively.
Key words: Aspergillus; Submerged Fermentation; Tannase; Caatinga; Endophytic fungi.
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