Isolation and characterisation of lignin-degrading fungus from coir

Abstract

Lignin is a complex natural polysaccharide primarily present in secondary wood or secondary xylem and phloem elements of the plant body. It constitutes one-fourth to one-third of the dry mass of wood and also, provides rigidity and strength. Lignin lacks a defined primary structure and is a heterogeneous biopolymer. Lignin-degradation is a major challenge because it can be a potential source of edible polysaccharide including glucose. In this investigation, commercial coir was considered as the source of isolating lignin-degrading fungus. A simple bioassay was carried out in coconut fibre (coir) and wood. In case of the fungal sample, the coir was inoculated in dry and wet conditions which resulted in 5.63% and 48.35% degradation respectively. On the basis of this, different lignin-degrading enzymes were assayed and purified. The fungus was identified as Microascus sp. on the basis of colony morphology, spore structure and perithecium formation. Further studies were conducted on the degraded coir and scanning electron microscope (SEM) images were taken. In future, these organisms can be a potential source of ligninolytic enzymes useful in different activities.