The effects of various conditions such as initial pH, dye concentrations, amount of pellet, temperature and agitation on decolourising 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. (C) 2001 Elsevier Science Ltd. All rights reserved.
C1 Inonu Univ, Art & Sci Fac, Dept Biol, TR-44069 Malatya, Turkey.