Discharge of textile dyes causes major health problem to entire ecosystem due to their toxic impacts on receiving waters . Synthetic dyes are generally very stable to light, temperature, and microbial attack, making them recalcitrant . Furthermore, dye wastewater has a large amount of suspended solids, a broadly fluctuating pH, and is highly colored . However, during last decades researchers focussed on for an effective treatment technology of dyes waste water, but no satisfactory solution has been searched for broad spectrum of dyes degradation. The methodological disadvantages reported were found in physio-chemical remediation techniques and financial disadvantage . Microorganisms have enormous dye degrading capabilities for successful bioremediation of textile dyes .
White-rot fungi possess unique property of bioremediation due to the strong machinery of synthesizing extracellular ligninocellulolytic enzymes, which shows low specificity with substrate able for degradation of a wide range of xenobiotic compounds including textile dyes. The literature evidences number of white-rot fungi producing the lignin-degrading enzymes, lignin peroxidase (LiP), manganese peroxidase (MnP), and laccase which can degrade dyes. Manganese peroxidase (MnP) and lignin peroxidase (LiP) reported as the main enzyme involved in dye decolorization by Phanerochaete chrysosporium , Pleurotus florida and Agaricus bisporus. Involvement of enzymatic system of basidiomycetes has a great efficiency for dye bioremediation process. Laccase is documented as the main enzyme involved in dye decolorization by the cultures of Phlebia tremellosa and Pleurotus sajor-caju .
Several microorganisms, including fungi, bacteria, yeasts and algae, can decolorize and even completely mineralize azo dyes under certain environmental conditions (Khelifi et al., 2008). Decolorization of dye could also happen through biosorption onto the biomass of either live or dead fungus. Most of the studies on the biotreatment of dyes and effluents deal mainly with decolorization by single fungal cultures despite only few reports on mixed cultures . Co-culture is a potential strategy in bioremediation producing high activity enzymes due to the synergistic action . There are so many observed examples for the co-existence of different microorganisms such as forest soils, compost piles and mammalian intestines.
The current study was aimed to evaluate dye decolorization efficiency of two fungi including Pleurotus florida and Rhizoctonia solani using potent co-culture technology.