Evaluation of dye decolourization ability of native lignin degrading fungi and bacteria from organic farm fields of Hyderabad-Karnataka region

Abstract

Dyedecolourization was used as substrate to evaluate ligninolytic activity in lignin degrading fungi and bacterial strains isolated from organic farming fields of Hyderabad-Karnataka region. Eleven fungal and eight bacterial strains were selected and tested for their capacity to degrade lignin by subjecting them to the Bavendamm test using malt extract tannic acid medium (META), low nitrogen agar with methylene blue [LNAM (MB)] and low nitrogen agar with phenol red media [LNAM (PR)]. Eleven fungal strains viz., KGST-1, KGST-2, KGSA, KKST, KKSU-1, KKSP, BKST, RLST-1, RLSP-1, RMSP and KKSU-2 and eight bacterial strains viz., KGSB-1, KGSP, KGSB-2, KKSB-2, BKSB, RMSP-1, RMSP-2 and RMSB were positive on all the three media. The ability of the strains to decolourize different indicators Remazol Brilliant Blue R (RBBR), Methyl Green (MG), Methylene Blue (MB) and Congo Red (CR) of the respective indicator on NA and PDA agar plates was tested. The fungal isolates KGST-1, KGST-2 and KKSP could decolourize RBBR and Congo Red even better than the reference strains. KGSA and RMSP could efficiently decolourize methylene green along with RBBR. Among the bacterial isolates KGSB-1 and RMSP-2 could decolourize RBBR even better than native isolates and reference strains.