White rot fungus Calocybe indica: Incredulous factory of lignocellulolytic enzymes and their potential applicability for mushroom cultivation

Abstract

Cultivation of specialty mushrooms on lignocellulosic wastes represents one of the most economical organic recycling processes. Compared with other cultivated mushrooms, very little is known about the nature of the lignocellulolytic enzymes produced by the edible fungus Calocybe indica, its enzymatic activity profiles during submerged and solid state fermentation. The intracellular activity of laccase (7.67 U mg−1), manganese peroxidase (7.48 U mg−1), cellobiohydrolase (5.46 U mg−1), and endoxylanase (4.21 U mg−1) was best obtained in C. indica on 14th and 21st day of incubation. The extracellular activity of laccase (11.57 U mL−1), lignin peroxidase (8.45 U mL−1), and endoxylanases (6.22 U mL−1) were found to be highest on the 14th day. Ligninolytic enzyme activity was substantial during substrate colonisation but quickly dropped during fruiting body development. C. indica, on the other hand, showed relatively modest hydrolase activity during substrate colonisation. The activity of hydrolytic enzymes increased dramatically when primordia formed and peaked at the mature fruiting body stage. The yield of the crude enzyme-treated wheat straw utilised for mushroom production was 52.47%. These findings showed that the activities of lignocellulolytic enzymes were regulated in line with developmental phase of growth of C. indica.