Biodegradation of synthetic textile dyes by Mn dependent peroxidase produced by Phanerochaete chrysosporium

Invention of permanent and un-removable dyes created a revolution in textile industries but at the same time posed a severe problem of ground water contamination due to their recalcitrant nature and its release in rivers. This problem can be resolved by application of ligninolytic enzymes produced by white rot fungus. Therefore, a wild strain of Phanerochaete chrysosporium growing on dead wood logs collected from Girnar Forest (Gujarat, India) was evaluated for its biodecolourisation and biodegradation of common textile dyes (i.e. Reactive Golden yellow HRNL, Reactive yellow FG, Reactive orange 2R, and Reactive magenta HB). On the 11^th day of inoculation, complete disappearance of all dyes except Reactive Yellow FG (which took only 9 days) was observed on solid and liquid medium. Growth media supplemented with different carbon and nitrogen sources enhanced the rate of decolourisation. Among them, dextrose and asparagine were found to be the best carbon and nitrogen sources respectively to boost up the rate of decolourisation. Visual decolourisation of dyes does not prove its degradation; therefore, breakdown of different bonds within dyes structure was confirmed by FTIR analysis of all dyes after treating with partially purified Manganese Peroxidase enzyme (52.8 kDa molecular weight) extracted from P. chrysosporium through solid state fermentation.