Panus tigrinus efficiently removes phenols, color and organic load from olive-mill wastewater

Abstract

This study was aimed at assessing the potential of the white-rot fungus Panus tigrinus CBS 577.79 in removing organic load, color and toxic phenols from agro-industrial effluent olive-mill wastewater (OMW). The influence of wastewater composition on P. tigrinus degradative capability was investigated in shaken cultures using two different OMWs. The initial soluble COD of 85 000 mg l −1 led to a delay in removal of color, organic load and phenol by the fungus. This was associated with delayed onset of laccase and Mn-dependent peroxidase. On the other hand, P. tigrinus, when grown on OMW with an initial soluble COD content of 43 000 mg l −1, promptly and efficiently removed the aforementioned components. Chromatographic analyses showed that 4-hydroxy-substituted simple phenols were predominantly removed. The polymeric aromatic fraction underwent simultaneous polymerization and depolymerization. This study is a contribution to the understanding of the degradative specificity of P. tigrinus on OMW aromatic components and provides good indications for possible future applications of the fungus.