Process Biochemistry 40 (2005) 337–342 Decolourisation of Reactive Black 5 by Funalia trogii immobilised on Luffa cylindrica sponge M. Ali Mazmanci ∗ , Ali Ünyayar Department of Environmental Engineering, Faculty of Engineering, Mersin University, Ciftlikköy Campus, 33343 Mersin, Turkey Received 17 June 2003; received in revised form 14 November 2003; accepted 3 January 2004 Abstract The decolourisation of Reactive Black 5 (RB5) by immobilised Funalia trogii was investigated. Cultures of F. trogii immobilised on Luffa cylindrica sponge could effectively decolourise the dye. The effect of mycelial age was also studied, and decolourisation rate of a 3-day-old age culture was higher (8.22 mg dye/g dmw day) than those of 0- and 6-day-old cultures (6.86 and 7.80 mg dye/g dmw day). Macroscopic and microscopic examinations showed that dye was not biosorbed on the fungal mycelium. The growth of F. trogii was inhibited by all tested dye concentrations with compared to controls but this effect was minimised when the fungus was completely immobilised on the sponge. Using optimal mycelial age, cultures of L. cylindrica sponge were tested for their ability for dye decolourisation at different initial concentration. The kinetic parameters of decolourisation were calculated according to Lineweaver–Burk plots (K m of 106.04 mg dye/l and V max of 117.64 mg dye/l day). © 2004 Elsevier Ltd. All rights reserved. Keywords: Reactive Black 5; Funalia trogii; Immobilisation; Luffa cylindrica; Sponge; Decolourisation 1. Introduction Synthetic dyes have been increasingly used in the tex- tile, paper, cosmetics, pharmaceutical and food industries because of their ease of use, cost effectiveness in synthesis, stability and variety of colour compared with natural dyes [1]. The effluents of these industries are highly coloured and the disposal of these wastes into receiving waters causes damage to the environment as they may significantly effect photosynthetic activity in aquatic life due to reduced light penetration and may also be toxic to some aquatic life due to the presence of metals, chlorides, etc. [2]. Their removal is therefore of great importance. Many synthetic dyestuffs are resistant to biological degradation due to the presence of large content of aromatic substances. Thus, colour removal by bioprocess is difficult and not complete [3]. Decolorisation of these dyes is possible using physi- cal and chemical methods such as adsorption, oxidation, coagulation–flocculation, chemical degradation and pho- todegradation [4–6]. These methods are very expensive ∗ Corresponding author. Tel.: +90-324-3610001-592; fax: +90-324-3610032. E-mail address: mazmanci@mersin.edu.tr (M.A. Mazmanci). and have operational problems. Because synthetic textile dyes are resistant to biological degradation, colour removal by bioprocess is also difficult. However, many bacteria and fungi are used for the development of biological pro- cesses for the treatment of textile effluents [7–9]. To date, the majority of studies on biological decolourisation have focused on fungal strains. Phanerochaete chrysosporium [10], Trametes vesicolor [11], Coriolus versicolor [12,13], Cunninghamella polymorpha [14], Geotrichum candidum [15] and Rhizopus arrhizus [16] are the major fungal strains used for decolorisation purposes. There are a few studies on the textile dye decolourising ability of Funalia trogii ATTC 200800 which degrades and decolourises the recal- citrant dyes Astrazon Red FBL [17], A. Black, A. Blue [18]. Luffa cylindrica, a natural material consisting of cellulose and lignin (1.4:2.9% of sponge dry weight) [19] was used to immobilise various plant cells [20,21], microalgal cells such as Chlorella sorokiniana [22], Porphyridium cruen- tum [23,24], and microbial cells such as Penicillium cyclop- ium [25,26]. Researchers reported that sponge was found to be a good support matrix for immobilisation because of its high degree of porosity, high specific pore volume, stable physical properties, non-toxicity and low cost. Its use as an 0032-9592/$ – see front matter © 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.procbio.2004.01.007