Interaction of tannase from Aspergillus niger with polycations applied to its primary recovery

The interaction of tannase (TAH) with chitosan, polyethyleneimine and Eudragit®E100 was studied. It was found that TAH selectively binds to these polycations (PC), probably due to the acid nature of the target protein. TAH could interact with these PC depending on the medium conditions. The effect of the interaction on the secondary and tertiary structure of TAH was assayed through circular dichroism and fluorescence spectroscopy. TAH was recovered from Aspergillus niger culture broth by means of precipitation and adsorption using chitosan.