Potent fungi for decolourisation of olive oil mill wastewaters

A broad screening of 58 fungi including 46 white rot strains on solid media resulted in the selection of 13 white rot fungi, which were active in decolourising the poly R-478 lignin model and were capable of growing on crude olive oil mill wastewaters (OOMW) with a COD of 100 g l(-1). Decolourisation of the dye in liquid media in static as well as agitated conditions was studied in relation with ligninolytic enzymes production. Tests on OOMW-based media diluted at different COD concentrations and without any additional carbon source, showed that Pycnoporus coccineus, Pleurotus sajor caju, Coriolopsis polyzona and Lentinus tigrinus were very active in decolourisation and COD removal of OOMW at 50 and 75 g l(-1) COD. At 100 g l(-1) COD only the first two fungi were effective. In particular, P. sajor caju and C. polyzona showed levels of decolourisation as high as 75% when COD of the effluent was 50 g l(-1). Both mono and polyaromatics were considerably reduced after 20 days incubation with C. polyzona as confirmed by gel filtration analysis. Marked differences in enzyme activity of individual strains suggest that different mechanisms are possible for OOMW decolourisation. (C) 2003 Elsevier Inc. All rights reserved.