The profiling of ligninase, hemicellulase and cellulase of Pleurotus sajor-caju after inoculation of spawn in bags containing sawdust was done at monthly intervals for a period of 6 months. Xylanase (EC 3.2.1.8) was produced throughout the 6 months studied with the productivity range from 5.60 to 7.51 U g −1 . Cellulase (EC 3.2.1.4) and β-glucosidase (EC 3.2.1.21) productivities were highest at 4 months, producing 3.31 U g −1 and 121.13 U g −1 respectively. Laccase (EC 1.10.3.2) productivity was highest at 2 months with a value of 7.59 U g −1 . Lignin peroxidase (EC 1.11.1.14) productivity was highest at 5 months with a value of 206.20 U g −1 . Total soluble proteins were highest at 4 months with a value of 0.139 mg cm −3 . The profiling of lignin peroxidase in 5-month-old spent mushroom compost was monitored over a period of 10 months. It was observed that lignin peroxidase was produced throughout the period but productivity was variable. The average lignin peroxidase productivity ranged from 30 to 110 U g −1 . The activities of the enzymes extracted in tap water at pH 8.4 were comparable to that extracted in 50 mmol sodium citrate buffer at pH 4.8 and distilled water at pH 5.2 at 4• C using an incubator shaker at 200 rpm for 18 h. The optimum extraction time was 1 h using an incubator shaker at 4• C. When an incubator shaker was used, there was no significant difference in the recovery of xylanase, cellulase and laccase at different pH values at 4• C and 28 • C. No significant difference was observed in the recovery of β-glucosidase using an incubator shaker at different pH values at 4• C although the enzyme recovery was slightly higher at pH 8.12, with a value of 29.27 U g −1 . The optimum extraction of β-glucosidase was at pH 4 at room temperature using an incubator shaker. For the lignin peroxidase enzyme, the optimum pH for extraction was 6 at 4• C and pH 7 at room temperature using an incubator shaker at 200 rpm for 1 h. Homogenization for 8 min at 8000 rpm using tap water at pH 4 had an advantage over the use of the incubator shaker for the extraction as high titers of enzymes were recovered.

The potential of ligninolytic enzymes, including lignin peroxidase (LiP) as the main enzyme from the spent mushroom substrate of Pleurotus sajor-caju was evaluated for the decolourisation of five dyes from azo and anthraquinone dye groups. Among the azo dyes, reactive black 5 and reactive orange 16 were 84.0 and 80.9% decolourised respectively, after 4 h of incubation with 45 U of LiP as compared to 32.1% decolourisation of disperse blue 79. Among the anthraquinone dyes, disperse red 60 was decolourised to 47.2% after 4 h of incubation with 45 U of LiP as compared to 5.9% decolourisation of disperse blue 56. Increasing the LiP concentration and incubation time had a positive effect on the decolourisation of anthraquinone dyes as compared to azo dyes. A 67.9% decolourisation of synthetic textile waste-water was achieved after 4 h of incubation with 25 U of LiP. Increasing the incubation time significantly increased (P \ 0.05) the decolourisation of synthetic textile wastewater. Further, there was a 52.4% reduction in the toxicity of synthetic textile waste-water treated with 55 U of LiP for 4 h. However, only 35.7% reduction in toxicity was achieved when the synthetic textile waste-water was treated with 55 U of LiP for 24 h. In this study, it was shown that the spent mushroom substrate of P. sajor-caju could be a cheap source of ligninolytic enzymes for the decolourisation of dyes in textile industry wastewaters.