Contribution of lignin degrading enzymes in decolourisation and degradation of reactive textile dyes

Investigating the potential of Phanerochaete chrysosporium to decolourise and degrade two reactive textile dyes (Reactive Yellow MERL and Reactive Red ME4BL) was the main intend of the study. The fungus analysed for its decolourising potential has shown the significant success by removing the colour of tested dyes (10 mg/L concentration) within 11 days of incubation. Supplementing media with different carbon/nitrogen sources proved dextrose and aspargine as efficient decolorizing enhancers, while inoculum size of 1 and 3 (10 mm diameter agar plug) were more supportive for solid and liquid decolourisation respectively. The ligninolytic enzyme production under solid state fermentation involved different agro-industrial wastes, among which wheat straw with 1 mm particle size was responsible for optimum production of manganese peroxidase (607.35 IU/ml), manganese independent peroxidase (539.27 IU/ml) and laccase (263.03 IU/ml). The partially purified enzymes produced by P. chrysosporium was achieved at four different percent saturations i.e. 20, 40, 60 and 80, where 60% saturated fraction produced the maximum 607.35 IU/ml of manganese peroxidase having 52.8 kDa molecular weight. The biodegradation of Reactive Yellow MERL (7-(4-{4-chloro-6-[3-(2-sulfoxy-ethanesulfonyl)-phenylamino]-[1,3,5]triazin-2-ylamino}-2-ureido-phenylazo)-naphthalene-1,3,6-trisulfonic acid) and Reactive Red ME4BL (5-{4-choloro-6-[4-(2-sulfo-ehtanesulfonyl)-phenylamino]-[1,3,5]triazin-2-ylamino}-3-(1,5-disulfo-napthalen-2-ylazo)-4-hydroxy-naphthalena-2,7-disulfonic acid) were studied by FTIR analysis where shifting of peaks confirmed the complete degradation of both the dyes.

► Phanerochaete chrysosporium exhibited elevated degradation potential for textile dyes. ► Solid state fermentation is very propitious for ligninolytic enzyme production. ► The molecular weight of MnP determined through gel-electrophoresis was 52.8 kDa. ► FTIR analysis of dyes treated with enzymes proved biodegradation of complex dyes.