52 European Journal of Biotechnology and Bioscience Online ISSN: 2321-9122 www.biosciencejournals.com Volume 3; Issue 10; October 2015; Page No. 52-57 The potentials of white-rot fungi to decolorizing azo dyes and organic components of textile effluents 1 MS Shinkafi, 2 IU Mohammed, 3 AA Audu 1 Department of Medical Laboratory Science, College of Health Science & Technology Tsafe, Zamfara State, Nigeria 2 School of Science, Engineering & Technology, University of Abertay Dundee, Scotland, United Kingdom 3 Department of Pure & Industrial Chemistry, Bayero University Kano, Nigeria Abstract Synthetic dyes released by various textile industries are a source of concern to environmental safety. Existing physicochemical methods of dye removal from effluents suffer setbacks like high operational cost, low efficiency and large amount of sludge generation. Over the last two decades considerable work has been done with the goal of using microorganisms as remediation agents in the treatment of dyes containing wastewaters. Microorganisms are capable of removing dyes due to their high metabolic potentials and one of the best organisms that is known to display these wonderful features are the white-rot fungi. In this present study we demonstrate successfully using white-rot fungi (Phanerochaete chrysosporium) for this purpose and the role of each culture in the decolorization process was elucidated. The effect of temperature, pH, concentration, mean weight (g) and optical density were studied after every 48hrs in 12 days period. The enhancement of the degradation was effected by UV-radiation. The adsorption capacity of textile waste effluent and reactive dyes i.e. Congo red and Direct blue 80 was determined spectrophotometrically by monitoring absorbance of different dyes at constant wavelengths (λmax). The shift in the absorption maxima in decolorizing samples indicated the ability of the fungus to degrade dyes and this can be exploited for bioremediation of dyes and their derivatives containing wastes. Keywords: Decolourization, degradation, dyes, Phanerochaete chrysosporium, textile effluents. 1. Introduction The basidiomycete, P. chrysosporium belongs to the white rot class of wood-rotting fungi (reviewed by Kües, 2015) [16] . White-rot fungi are those organisms that are capable of degrading lignin, the structural polymer found in woody plants (reviewed by Mathews et al., 2015) [18] . The most widely studied white-rot fungus with regards to xenobiotic degradation is Phanerochaete chrysosporium (Singh et al., 2015) [24] . This fungus is capable of degrading dioxins, polychlorinated biphenyls (PCBs) and other chloro-organics (see reviews by Gowri et al., 2014 [12] ; Marco-Urrea et al., 2015) [17] . White-rot fungi are able to degrade dyes using enzymes such as lignin peroxidases (LiP), manganese dependent peroxidases (MnP). Other enzymes used for this purpose include H 2 O 2 - producing enzymes such as glucose-1-oxidase and glucose-2- oxidase with laccase and a phenoloxidase enzyme (Archibald & Roy, 1992 [1] ; Thurston, 1994 [25] ; Schliephake & Lonergan, 1996) [23] . Azo dyes, the largest class of commercially produced dyes are not readily degraded by micro-organisms but can be degraded by P. chrysosporium (Robinson et al., 2001) [22] . Other fungi such as Hirschioporus larincinus, Inonotus hispidus, Phlebia tremellosa and Coriolus versicolor have also been reported to decolorize dye-containing effluent (Banat et al., 1996 [4] ; Kirby, 1997 [15] ; Jebapriya & Gnanadoss, 2013). P. chrysoporium has also been shown to mineralize a range of obstinate aromatic pollutants (Asamodu et al., 2005 [3] ; Dafale, 2011) [8] . It has also been reported that white rot fungi can efficiently degrade various organic pollutants other than lignin including polycyclic aromatic hydrocarbons and persistent environmental pollutants such as DDT (Bumpus et al., 1985) [5] , alkyl halide insecticides (Kennedy et al., 1990) [14] and xenobiotic compounds (Paszczynski & Crawford, 1995) [19] . One distinct advantage these fungi have over bacterial systems is that they do not require preconditioning to the particular pollutant. Bacteria usually must be pre-exposed to a pollutant to allow the enzymes that degrade the pollutant to be induced and the pollutant must also be in a significant concentration for the enzyme synthesis to follow. Thus, there is a finite level to which bacteria can degrade pollutants. But this is not the case with fungi, because the induction of the degrading enzyme is not dependent on the pollutants, therefore, the pollutant can be degraded to a near non-detectable level. In contrast to the bacterial system, the degradative enzymes of white rot fungi are induced by nutrient limitation. Thus, cultivation of the white rot fungi on a nutrient-limited substrate will initiate the process (Tuomela, 2002 [26] ; Piggott et al., 2015) [20] . The basidiomycete produce different other extracellular enzymes involved in pollutant degradation (Wesenberg et al., 2003; Ghani et al., 2015) [11, 27] . The objective of this paper is to examine the decolorization activities of the white-rot fungi for the treatment of textile waste effluents and two most widely used reactive dye in cultures of Phanerochaete chrysosporium and also to monitor and optimize the kinetic parameters for remediation of the organic effluent in different conditions of pH, mean weight, concentration and optical density in a biotreatment system. 2. Materials and Methods 2.1 Collection of textile wastewater sample The textile waste water was collected in the premises of effluent treatment plant of textile industry in Kano, Nigeria. The waste water sampling site is situated behind the wax and super production confluent units. This point contains a mixture of all effluents from the various units of the production, and is capable of holding the effluent volume of about 1550 m 3