Stress regulator T. aidingensis KB25

In this study, we report a novel bacterial strain belonging to Terribacillus aidigensis isolated from thermal spring due to its antifungal effect against Phytophthora infestans caused late blight disease, besides its salt stress resistance. In addition, physiological and morphological studies using electron microscopy have indicated a prominent property of the strain under salt- stressed conditions. Furthermore, the strain identified with 16S DNA and MLST analysis of the bacterial strain using whole-genome sequence data annotation also showed that it harbours the various genes encoding secondary metabolites. The bacterial strain KB25, known for being non-pathogenic and resistant to salt stress, holds great promise as a biocontrol agent against plant pathogens, particularly in environmental conditions impacted by salinity. We have found high similarity between KB25 and tomato proteins playing role in salt stress regulation. Its pathogen-inhibiting capabilities could arise from mechanisms such as competitive exclusion, the production of antimicrobial substances. Additionally, its resilience to salt suggests that it could thrive in saline soils, offering a natural alternative to chemical pesticides and supporting sustainable farming practices. The annotated genomic data analysed using KEGG database indicated the existence of antimicrobial compounds secreted by the strain. Metabolomics analysis indicated the existence of the metabolites which have potentially inhibitory secreted by KB25 on the pathogen growth. The metabolomics profile of bacteria and fungus interaction indicated a biological state characterized by upregulated energy production and cofactor biosynthesis involving quinone, thiamine and CoA coupled with active nucleotide synthesis. These findings have proved the reason for the stress regulation and inhibitory effect against P. infestans. Molecular docking and dynamics analysis indicated to have a strong binding affinity of a metabolite of KB25 with RXLR virulence protein and cell wall membrane protein phosphatidylinositol 3-kinase of P. infestans. These data eventually have also proved the biocontrol properties of KB25 and adaptive response to high osmotic pressure which could be subsidised the stress regulator protein of the plants under abiotic stress conditions.