Short communication Decolourisation of the textile dye Astrazon Red FBL by Funalia trogii pellets O. Yesilada * , S. Cing, D. Asma Art and Science Faculty, Department of Biology, Inonu University, 44069 Malatya, Turkey Received 11 April 2001; received in revised form 28 June 2001; accepted 4 July 2001 Abstract The eects of various conditions such as initial pH, dye concentrations, amount of pellet, temperature and agitation on deco- lourising activity of Funalia trogii were investigated. These, except initial pH, were all found to be important for dye decolourising activity of F. trogii. The decolourisation of the dye involved adsorption of the dye compound by fungal pellets at the initial stage, followed by the decolourisation through microbial metabolism. Heat-killed pellets were also tested for their ability to decolourise Astrazon Red dye. These pellets adsorbed the dye and 55% decolourisation was obtained in 24 h. But at the second cycle there was only 24% decolourisation. Our observation showed that Astrazon Red dye decolourisation by heat-killed pellets was mainly due to biosorption. The longevity of the decolourisation activity of F.trogii pellets was also investigated in repeated batch mode. Variations in the amount of pellet increased % decolourisation and stability of pellets. Ó 2001 Elsevier Science Ltd. All rights reserved. Keywords: Textile dye; Dye; White rot fungi; Funalia trogii; Decolourisation 1. Introduction Synthetic dyes are released into the environment in industrial euents from textiles and the dyestu indus- tries Chang and Kuo, 2000). The removal of colour from this type of wastewater is often more important than the removal of the soluble colourless organic sub- stances which usually contribute the major fraction of the chemical and biochemical oxygen demand Banat et al., 1996). The elimination of coloured substances in wastewater is based mainly on physical or chemical methods. All of these methods have shortcomings. An eective and inexpensive alternative would be of great value Zhang and Yu, 2000). Textile dyes are also relatively resistant to microbial degradation. Anaerobic microorganisms are able to degrade some dyes. But aromatic amines produced by these organisms may be toxic and carcinogenic Meyer, 1981). Because conventional wastewater treatment sys- tems generally do not remove all of the dyes, wastewa- ters from industry and from dye manufacturers result in pollution of the environment. White rot fungi can de- grade a wide variety of structurally diverse pollutants Kumar et al., 1998; Yesilada et al., 1999; Kapdan et al., 2000; Robles et al., 2000). In recent years many studies have demonstrated that the white rot fungi were able to decolourise dyes Yesilada, 1995; Yesilada and Ozcan, 1998; Sani et al., 1998; Swamy and Ramsay, 1999). Most researches on dye decolourisation involve two fungi Phanerochaete chrysosporium and Coriolus versicolor. Funalia trogii degrades and decolourises recalcitrant ef- ¯uents such as olive oil mill and alcohol factory waste- water Yesilada et al., 1998) and is therefore a good candidate for treatment of dyes and textile wastewater. There is almost no study on textile dye decolourising ability of F. trogii and to our knowledge, Astrazon dyes, that are widely used basic textile dyes, have not been investigated for decolorisation by white rot fungi before. In this paper we reported studies on the utilisation of white rot fungus, F. trogii ATTC 200800, pellets for the decolourisation of Astrazon Red FBL. 2. Methods 2.1. Pellet preparation F. trogii ATCC 200800 was cultured at 30 °C on slant SDA. After 1 week, a conidial suspension was prepared and used for the cultivation of inoculum. Five ml of the Bioresource Technology 81 2002) 155±157 * Corresponding author. Tel.: +90-42234-10010x3729; fax: +90-422- 3410037. E-mail address: oyesilada@inonu.edu.tr O. Yesilada). 0960-8524/02/$ - see front matter Ó 2001 Elsevier Science Ltd. All rights reserved. PII: S 0 9 6 0 - 8 5 2 4  0 1 ) 0 0 1 1 7 - 1