Evaluation of Chinese mushroom (Volvariella Spp) for their cellulases in relation to yield potential

Volvariella spp., known as Chinese mushroom or paddy straw mushroom has been reported to have good cellulo-lytic potential. Four different strains of Volvariella volvacea (Vv-1, Vv-2, Vv-3 and Vv-957) and one strain of V. diplasia (Vd) were grown on different sources of cellulose (paddy straw, cotton waste and carboxy-methyl cellulose) under submerged fermentation conditions for evaluating their cellulolytic potential for three main enzymes of cellulase system i.e. exocellobiohydrolase (EC 3.2.1.91, 1,4-β-D-glucan cellobiohydrolase), endo-1,4-β-D-glucanase (EC 3.2.1.4, 1,4-β-D-glucan glucanohydrolase) and β-glucosidase (EC, 3.2.1.21, β-D-glucoside glucohydrolase). The course of cellulase production on different substrates was studied upto 12 days. For all the strains, the enzyme activity increased with the incubation period, reaching a maximum on 5^th to 7^th day and declined thereafter. The comparison of the cellulase activity with yield potential of the different strains of Volvariella spp. cultivated on paddy straw bundles showed highest exocellobiohydrolase activity of, 0.50 IU and, 0.42 IU with yield potential of, 15.6 and, 15.1 kg/100 kg straw for V. diplasia (Vd) and V. volvacea (Vv-3), respectively. Though Vv-2 resulted in a yield of, 13.2 kg/100 kg straw but it showed low (0.25 IU) exocellobiohydrolase activity. Vv-1 and Vv-957 showed maximum endoglucanase activity but were low yielders.