Biodecolourization of Textile Effluents using Lignolytic Enzymes Produced from Selected Bacterial and Fungal Isolates from Waste Dump Site

Abstract

Textile effluent contains enormous chemicals with detrimental environmental effects on both fauna and flora due to its chemical compositions. In this study, the effect of lignolytic enzymes produced by microorganisms for the treatment of textile effluent was examined using standard microbiological techniques. The potential of the isolates to produce laccase (L), lignin peroxidases (LiP) and manganase peroxidase (MnP) was investigated using streak plate method and assay methods. The L, LiP and MnP enzymes produced with the optimal processing parameter were used to decolorize textile effluent singly and as consortia for ten (10) days. Fourteen (14) microbial isolates which include eight (8) bacterial and four (4) fungi were isolated from soil contaminated with textile effluents. Aspergillus terreus and Aspergillus niger showed higher production of laccase with 8.0 mm diameter zone of inhibition. Bacillus licheniformis and Bacillus subtilis had the widest zone of inhibition (12.0 and 8.0 mm) respectively. Only Aspergillus flavus however had the potential to produce lignin peroxidase (with 10 mm zones of clearance) of all the fungi isolated in this study. Laccase recorded the highest decolourization (72.5%) comparable to 71.1% observed for the three-enzyme combination while LiP has 57.0%. This finding established the potential use of bacterial and fungal ligninocellulolytic enzymes for the decolourization of textile effluent.