67 Biodegradation of Textile Azo dye reactive Green-19 by an Isolated Basidiomycete Pleurotus pulmonarius, A tree Mushroom Rakesh U. Thakare*, Bharat J. Wadher, Arun B. Ingle 1 and Kunal Roychaudhury 1 P.G. Department of Microbiology, RTM. Nagpur University, Nagpur, India 1 Department of Microbiology, S.K. Porwal College, Kamptee, Nagpur, India *Corresponding author email : rakesh_rut@rediffmail.com INTRODUCTION Azo dyes are the largest group of dyes used in industry (Ramalho et al. 2004) representing more than half of the annual production (Stolz 2001). It has been estimated that about 10% of the dye stuff used during this dyeing processes does not bind to the fibers and is therefore released into the sewage treatment systems or environment. Azo dyes have structural properties that are not easily degradable under natural conditions and are not removed from water by conventional wastewater treatment systems. Azo dyes are designated to resist chemical and micro- bial attacks (Ramalho et al. 2004) and to be stable in light and during washing. Basidiomycetous fungi now are being recog- nized for their degradative capacity of highly recalcitrant com- pounds; hence basidiomycetous fungus isolated from soil sam- ple was used for the study of its degradative capacity. The ob- jective of this work was to study the aerobic degradation of azo dye, Reactive Green-19 by Pleurotus pulmonarius, a tree mush- room and evaluate the performance in vitro with a view to un- derstand their potential; for treating waste water especially con- sidering the potential for toxicity reduction of the dye solution. MATERIALS AND METHODS Microorganism and culture conditions The basidiomycetous fungus, Pleurotus pulmonarius was isolated from dye disposable site around industrial area in Nagpur city (Maharashtra, India). The fungus was grown on potato dextrose agar at 28 ± 2°C till sporulated and stored at 4° C. Subculturing after every 3 weeks was done. For decoloriza- tion studies the fungus was grown in 1% glucose medium (pH 7.0) at room temperature 28 ± 2°C. Dye stuff, chemicals and cultural media The textile dye was obtained from Tilakraj Inderpal, Dealers in Dyes and Chemicals, Nagpur, Maharashtra, India. Guiuacol and Media for isolation were purchased from Hi- media, India. Decolorization Assay The ability of Pleurotus pulmonarius to decolorize Reactive Green-19 was carried out in 1% glucose medium. Textile dye Reactive Green-19 (λmax 630nm) was used at 100 mg/L concentration. Agitated cultures of fungal species were grown for 7 days in an incubator shaker at 28±2ºC and 150 rpm. Samples were withdrawn aseptically on alternate days, The isolated Basidiomycete, Pleurotus pulmonarius, a tree mushroom was confirmed by amplification of 18S rRNA and found to decolorize and degrade textile dye Reactive Green-19. This azo dye was decolorized and de- graded completely by Pleurotus pulmonarius in both shaking and static conditions in 1% glucose medium at pH 2- 3 range. The biodegradation was monitored by UV- Vis spectroscopy and GCMS analysis and Hexadecanoic acid, methyl ester- is the degradation product elected by GC-MS (Gas Chromatography-Mass Spectroscopy) analysis. Keywords: Reactive Green-19 dye, Pleurotus pulmonarius, biodegradation, azo dye, GCMS. Vol. 26 (Special) : 67-69 (2013) VEGETOS 10.5958/j.2229-4473.26.2s.123