Produção e caracterização parcial de tanase pelo fungo endofítico Aspergillus niger ANG18 em fermentação em estado sólido.

Abstract

Tannases (tannin acyl hydrolase, EC 3.1.1.20) are enzymes of great biotechnological interest, with potential for application in different industrial sectors such as food, chemical, beverage and pharmaceutical industries. These enzymes act in the hydrolysis of hydrolysable tannins, releasing glucose and gallic acid from gallotannins. In this context, filamentous fungi, especially endophytic fungi, have been highlighted as enzymatic sources. Therefore, the objective of this study was the production of tannase by the endophytic fungus Aspergillus niger ANG18, isolated from bark of angico (Anadenanthera colubrina Vell), under Solid-State Fermentation (SSF), using agroindustrial residues and agroforestry products as substrates, selecting the best conditions for maximum enzymatic production, as well as the determination of some physical-chemical properties of the enzyme. The endophytic fungus A. niger ANG18 presented higher enzymatic production (29.82 U/g of substrate) when cultivated under SSF using eucalyptus (Eucalyptus ssp.) leaves as substrate/carbon source moistened with 1:1 (m/v) Khanna salts for 96 h at 37°C and 60% relative humidity. The tanase contained in the crude filtrate presented temperature and apparent optimum pH of activity between 40 and 45ºC, and pH 5.0, respectively, being slightly activated (16.93%) in the presence of BaCl2.In this way, A. niger ANG18 can be considered as an alternative producer of tannases in SSF, being this the first report of production of tannase by an endophytic fungus in SSF.