Combining in vitro and in silico studies to unravel the antifungal potential of chitinase from a marine bacterial isolate Cellulosimicrobium cellulans RS7

Abstract

The main aim of this research is to identify, screen and optimize physio-chemical characteristics for the production of extracellular chitinase from a marine bacterial isolate RS7. The bacterium isolated from Pamban Island, Rameshwaram was characterized as Gram-positive, pleomorphic and was identified as Cellulosimicrobium cellulans RS7 based on 16S rRNA profiling. The growth profile analysis showed maximum chitinase activity at 48 h of inoculum age. The optimization of physio-chemical parameters was performed using OFAT and statistical approach via RSM which resulted in 3.23-fold increase in chitinase activity from 20.89 to 67.6 U/ml. This study investigates the anti-fungal activity of chitinase against pathogenic fungus Mucor sp. where 80 μl (5 U) of enzyme resulted in a 22 mm zone of inhibition. Furthermore, molecular docking studies were done to understand the active properties of chitinase against fungal pathogens. The Molecular Operating Environment module was utilized and the docking poses were visually examined for interaction. The results indicated that chitinase exhibited high affinity towards selected ligand/protein (N-acetylglucosamine, β-1, 3 glucanase and β-1, 3 glucan) which participate in synthesis of fungal cell wall. The docking scores and root mean square deviation values for the selected target molecules were determined and specific interactions and residues were identified.