Research in Biotechnology, 4(5): 20-23, 2013 ISSN: 2229-791X www.researchinbiotechnology.com Received: 22.7.2013; Revised: 17.9.2013; Accepted: 23.9.2013 Short communication Decolourization of synthetic dyes using free and immobilized Aspergillus species J. Joel Gnanadoss * and G. Roseline Jebapriya Microbial and Environmental Biotechnology Research Centre, Department of Plant Biology and Biotechnology, Loyola College (Autonomous), Chennai – 600 034 * Corresponding Author Email: joelgna@gmail.com The aim of the present investigation was to study the biosorption and decolourization of congo red and erichrome black T by Aspergillus sp. (A. niger LCJ 1 and A. nidulans LCJ 2). Decolourization of both the dyes was determined on free and immobilized cell of Aspergillus sp. in culture media containing 25 mg/L of the respective dyes. The amount of decolourization was determined by monitoring the decrease in absorbance of each dye. Spectrophometric data revealed that, the maximum decolourization of congo red and erichrome black T was in immobilized mycelium of Aspergillus sp. on polyurethane foam (PUF). This study showed that fungal biomass (A. niger and A. nidulans) could effectively be used as an alternative to the conventional physico-chemical methods. Keywords: Dye decolourization; biological method; free and immobilized cells; Aspergillus species. The effluent released by the textile industry is one of the important pollutant among all industrial effluents and these effluents contain strong colour, suspended particles, high BOD, COD and pH. Worldwide it is estimated that, more than 100, 000 commercial dyes are available (Robinson et al., 2001) and nearly 10 to 15% of the dyestuffs are discharged as industrial effluents in the environment, these dye containing effluents causes serious environmental problem and a public health concern because they are carcinogenic and toxic to humans and aquatic life (Pappic et al., 2000). Due to these concerns, the removal of dyes from wastewater has received important consideration. The conventional methods for treatment of dye containing effluents are usually ineffective, expensive and slightly adaptable to a wide range of dyes (Stolz 2001). Robinson et al. (2001) reviewed current treatment technologies including biosorption with proposed alternatives for removal of dyes in textile effluent. Numerous researchers have focused on biosorption of dyes by microorganisms which include algae, fungi, bacteria and yeast. Among these, fungal biomass appears to be most appropriate, inexpensive and effective biological agent in the treatment of dye containing wastewater (Ezeronye and Okerentugba, 1999). When compared with freely suspended cells, immobilized microbial cell systems could provide additional advantages, which include