Shrimycocin-A, a next generation broad spectrum and systemic biofungicide from coconut shell agro waste for crop protection.

Abstract

The excessive use of chemical fungicides has resulted in severe health and environmental concerns; exploration of sustainable alternatives to the chemical pesticides remains a challenge. In this study we developed a novel bio-fungicide fraction, Shrimycocin-A (Shri-A), obtained from the coconut shells through the process of thermal extraction and activity guided fractionation. The chemical profile of Shri-A was established and physicochemical properties were characterized. Our results demonstrated the superior fungicidal activity of Shri-A (300 µg/ml) against fungicide-tolerant wide-host range phytopathogenic fungi. Shri-A exhibited multiple modes of action, including fungal cell wall disruption, cell membrane depolarization, alteration of ergosterol content, and mitochondrial transmembrane potential. The MIC of Shri-A was ranged between 37.5 and 300 µg/ml and its corresponding MFC was ranged from 75 to 350 µg/ml against different plant and human pathogenic fungi. Shri-A showed systemic absorption, bioavailability without causing phytotoxicity, and acute toxicity to earthworms up to the concentrations 300 µg/ml, 700 µg/ml, and 200 µg/cm² respectively. Further, the bio-efficacy studies revealed that disease control efficiency of Shri-A (300 µg/ml) is comparable to or exceeds that of commercial synthetic fungicides. Our study suggests that the Shri-A has the potential to be a next-generation bio-fungicide and a promising alternative to chemical fungicides in agriculture.