Decolorization of semisolid olive residues of “alperujo” during the solid state fermentation by Phanerochaete chrysosporium, Trametes versicolor, Pycnoporus cinnabarinus and Aspergillus niger

Studies were carried out on decolorization of semisolid olive mill residues called “alperujo” (AL), by four strains of Phanerochaete chrysosporium, Trametes versicolor, Pycnoporus cinnabarinus and Aspergillus niger in solid state frementation (SSF). Fungal strains were selected by their ability to grow on olive mill waste water. The treatment of AL with P. chrysosporium led to higher removal of organic matter and decolorization than P. cinnabarinus and T. versicolor. The strain A. niger leads to a relative improvement of the biodegradability of OMW. Using P. chrysosporium, the treatment of AL substrate in SSF showed an efficient decolorization and an appreciable COD and phenolic content removal only in the presence of a support. Sugarcane bagasse used as support improved the oxygen transfer in the culture. The extracellular fluid of P. chrysosporium (composed mainly of LiP) exhibited high ability to decolorize AL showing the efficiency of the enzyme produced. A percentage of sugarcane bagasse equal to 30% was an optimal condition to improve the growth and the decolorization of AL. The results showed good prospects of using the three basidiomycetes, in particular P. chrysosporium, for the Decolorization of AL.