Differential Laccase Production among Diverse Fungal Endophytes in Aquatic Plants of Hulimavu Lake in Bangalore, India

Abstract

The ability of plants to acclimatise and thrive in stressed environments can be attributed, in part, to the reserve of endophytic fungi that they harbour, that help enhance physiological and immunological defence and tolerance to various biotic and abiotic stressors. The present work has focussed on screening laccase producing endophytic fungi residing in different aquatic plants isolated from Hulimavu Lake, Bengaluru. This lake is well known for its water pollution contributed by anthropogenic factors. Survival of plants in this lake can hence be associated with their rich repertoire of endophytic fungi that enhance host plant defence towards stressors. Upon isolation and culturing of endophytic fungi, qualitative laccase detection using laccase specific growth media and quantitative laccase estimation using ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) substrate were performed. Differential production rates were observed for the laccase enzyme by different endophytic fungi; production rates also varied between fungi isolated from different parts like node, stem, root and leaf of the same plant species too. Phylogenetic analysis of fungal isolates with highest laccase production was performed and the species was found to be Cladosporium tenuissimum. Even the crude extract of this strain displayed laccase production of 42.16U/L, as revealed by ABTS assay. Hence this strain is a promising candidate for optimization studies for utilisation in the domain of bioremediation and industrial applications.