Biodecolourisation of Methyl Red Dye by Bacterial-Fungal Consortium

Abstract

The textile industry is known to use massive amount of dyes to colour fabrics and subsequently the treatment of textile effluent is one of the greatest challenge. The aim of this research is to investigate the ability of the bacterial- fungal consortium to decolourise methyl red dye. The synergy effects of microbial consortium offer considerable advantages over single culture in mineralisation of complex dye compounds. The consortia were developed by using isolated white rot fungi and strain of Bacillus subtilis. The sample of white rot fungi were isolated from rotten wood and then were observed under microscope to determine its morphology. The individual cultures of white rot fungi designated as WRF D1, WRF E1, WRF F1, WRF G1 and WRF H1 and Bacillus subtilis were tested on the ability of decolourising 50 mg/L of methyl red. The results of the study were compared with the performance of microbial consortium of white rot fungi and Bacillus subtilis. Based on the observation, the strain of isolated fungi exhibited similar morphological characteristics of white rot fungi with the filamentous shape and the presence of basidiospores. The preliminary study demonstrated the ability of the isolated white rot fungi to produce ligninolytic enzyme by formation of brown ring on PDA plate containing MnCl₂. The decolourisation of methyl red by the individual cultures was in the range of 35 - 40 %. The result revealed that consortium of white rot fungi and Bacillus subtilis significantly enhanced the decolourisation of methyl red dye with more than 80 % of dye removal. The highest percentage of decolourisation (82.16 %) was exhibited by the consortium of WRF E1 and Bacillus subtilis after 72 h in shaking conditions (120 rpm, 30 ºC and pH 5). The data collected from this research provided convincing evidence on the potential of bacterial-fungal consortium for dye decolourisation.