Abstract

Tannery waste is complex and may, in some cases, be toxic to plants, animals and micro-organisms. This study aimed to evaluate the biodegradability of vegetable tannins used in the tanning industry by filamentous fungi. We evaluated the influence of the concentration of tannin, the forms of culture and the type of tannin used in the cultivation of Aspergillus niger. No differences were observed between the concentrations and the forms of cultivation. However, the type of tannin used influenced the consumption reaching 15% for a condensed tannin and only 7% for the hydrolysable. The results of the tests carried out proved the fungistatic action of the phenolic compounds present in the tannins on Aspergillus niger. With the new fungal strains, the fungi named Pe G8 showed to be more efficient in the biodegradation of tannins reaching 97.3% of the consumption of acacia tannin. The expressive results obtained from the consumption of acacia condensed tannin by the fungi of the genus Penicillium have demonstrated that the biodegradation of condensed tannins by filamentous fungi may be the promising alternative treatment with the potential to minimise tannery waste.