Exploration of earthwormcast associated actinobacteria for plant growth promoting properties

Abstract

Due to their wide varieties of chemicals with a variety of biological actions, earthworms, cast, and gut are potential sources of significant biotechnological interest. The finding new microorganisms in peculiar and uncharted habitats were investigated. Actinobacteria are exceptional makers of secondary metabolites and have a wide range of bioactive substances of economic significance. In the current investigation, actinobacteria from earthworm casting were isolated for their potential antibacterial capabilities. Earthworm cast from the Kanchipuram agricultural area had a total of 12 actinobacterial colonies. Human and plant pathogens such as Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa and Ralstonia solanacearum were tested against each actinobacterial cultures. The selected potential culture was examined for the presence of Indole Acetic Acid (IAA), Phosphate (P) solubilization, extracellular enzymes such as cellulase and amylase. For the promising active trains, optimization, characterization and taxonomy were carried out. Colonies with various morphologies were separated and subcultured for testing their activities. Six of the twelve isolates proved positive for antibacterial activity against one or more pathogens. Of the six isolates tested, strain EWCA 21 was chosen for further screening because it had the greatest effectiveness against tested pathogens. IAA, Phosphate (P) solubilization, and extracellular enzyme activities such amylase and cellulase were demonstrated in EWCA21. Carbon and nitrogen sources expressed an increase in activity and output during optimization. The putative strain was determined to be Streptomyces based on phenotypic analysis. The study concluded that the strain EWCA21 would be developed as a crucial resource for biofertilizer applications.