Biotechnology Journal DOI 10.1002/biot.200600238 Biotechnol. J. 2007, 2, 1014–1025 1014 © 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 1 Introduction The textile industry utilizes about 10 000 different dyes and pigments. The worldwide annual production of dyes is over 7 × 10 5 tons [1]. Synthetic dyestuffs are used ex- tensively in textile, paper, printing industries and dye houses. The effluents of these industries are highly col- ored and the disposal of these wastes into receiving wa- ters causes damage to the environment. The majorities of the dyes are toxic and even carcinogenic, and cause dam- age not only to aquatic life but also to humans [2]. Photo- synthesis [3] is also reduced due to inhibition of sunlight penetration and may also be toxic to some aquatic life due to the presence of aromatics, metals, chlorides, etc. Be- cause of environmental legislations [4], industrial con- cerns are forced to treat dye-bearing effluents before dis- charging into water streams. Most of the commercial dyes are of synthetic origin with complex aromatic structures, Research Article Liquid-phase separation of reactive dye by wood-rotting fungus: A biotechnological approach Arthur R. Binupriya 1 , Muthuswamy Sathishkumar 2 , Kavitha Dhamodaran 3 , Rasu Jayabalan 1 , Krishnaswamy Swaminathan 1 and Sei Eok Yun 2 1 Microbial Biotechnology Division, Department of Biotechnology, Bharathiar University, Coimbatore, Tamil Nadu, India 2 Division of Biotechnology, Department of Food Science and Technology, Institute of Agricultural Science and Technology, Chonbuk National University, Chonju, Republic of Korea 3 Department of Chemical Engineering, Yonsei University, Seodaemun-gu, Seoul, Republic of Korea The live and pretreated mycelial pellets/biomass of Trametes versicolor was used for the biosorp- tion of a textile dye, reactive blue MR (RBMR) from aqueous solution. The parameters that affect the biosorption of RBMR, such as contact time, concentration of dye and pH, on the extent of RBMR adsorption were investigated. To develop an effective and accurate design model for re- moval of dye, adsorption kinetics and equilibrium data are essential basic requirements. Lager- gren first-order, second-order and Bangham’s model were used to fit the experimental data. Re- sults of the kinetic studies showed that the second order kinetic model fitted well for the present experimental data. The Langmuir, Freundlich and Temkin adsorption models were used for the mathematical description of the biosorption equilibrium. The biosorption equilibrium data obeyed well for Langmuir isotherm and the maximum adsorption capacities were found to be 49.8, 51.6, 47.4 and 46.7 mg/g for live, autoclaved, acid- and alkali-pretreated biomass. The dye uptake ca- pacity order of the fungal biomass was found as autoclaved > live> acid-treated > alkali-pretreat- ed. The Freundlich and Temkin models were also able to describe the biosorption equilibrium on RBMR on live and pretreated fungal biomass. Acidic pH was favorable for the adsorption of dye. Studies on pH effect and desorption show that chemisorption seems to play a major role in the adsorption process. On comparison with fixed bed adsorption, batch mode adsorption was more efficient in adsorption of RBMR. Keywords: Trametes versicolor · Biomass · Reactive blue MR · Adsorption · Kinetics Correspondence: Dr. Muthuswamy Sathishkumar, Division of Biotechnology, Department of Food Science and Technology, Institute of Agricultural Science and Technology, Chonbuk National University, Chonju 561-756, Republic of Korea E-mail: sathishkumar77@gmail.com Fax: +82 63270 2572 Abbreviations: BDST, Bed-depth-service-time model; RBMR, reactive blue MR Received 30 November 2006 Revised 11 April 2007 Accepted 14 April 2007