PRODUCTION OF BACTERIAL LIGNINOLYTIC ENZYMES AND THEIR POTENTIAL APPLICATION IN DECOLORIZATION OF DYES

Abstract

Lignin is a complex, three-dimensional aromatic polymer, consisting of dimethoxylated, monomethoxylated and non-methoxylated phenylpropanoid subunits, and is recalcitrant in nature. In this study, the isolation of lignin degrading bacteria was carried out from decaying wood samples. Ligninolytic activity was evaluated by growing bacterial isolates on lignin monomers and by the degradation of indicator dyes. Out of 16, the bacterial isolates L8, L12, L13 and L15 exhibited growth on monomers viz., vanillin, veratryl alcohol, phenol, guaiacol and lignin, with efficient dye decolourization. Further, the production of ligninolytic enzymes (laccase, lignin peroxidase and manganese) was estimated for the 4 selected bacterial isolates. The maximum enzymatic activity response was noted in the case of isolate L15, with the best growth on every lignin monomer.