Streptomyces isolated from Udhagamandalam, The Nilgiris, Tamilnadu, India, was tested for biocontrol ability and metabolite profiling against the phytopathogen Ralstonia solanacearum. Streptomyces strains were tested in vitro for their ability to promote plant development and antagonistic activity against R. solanacearum. Gas Chromatography-Mass Spectroscopy (GC-MS) analysis was used to investigate the metabolite profile of strain UT4A49. In addition, an in-silico docking research was performed on the discovered lead chemical 2,4-Di-Tert-Butylphenol (2,4-DTBP) to determine its mode of action. Through pot culture studies, the Bio-organic Fertilizer (BOF) augmented potential Streptomyces strain UT4A49 was tested for biocontrol ability against R. solanacearum on tomato seedlings. In vitro, the Streptomyces strain UT4A49 produced Indole Acetic Acid (IAA)
(76.0 2.0 g/ml), siderophore, ammonia, amylase, protease, and cellulase, as well as solubilized phosphate. In vitro, the strain UT4A49 demonstrated high antagonistic activity against R. solanacearum, with a 19.83 0.44 mm inhibitory zone. The identified main chemical, 2,4-Di-tert-butylphenol, inhibited R. solanacearum effectively. According to an in silico docking investigation, the 2,4-DTBP had a lower binding energy score with all of the targeted proteins, indicating that it had greater protein-ligand binding stability. In a pot experiment, BOF modified Streptomyces strain UT4A49 demonstrated substantial biocontrol efficiency against R. solanacearum in tomato seedlings, with a biocontrol efficacy of 78.5 percent. Based on visual and molecular characteristics, the strain UT4A49 was identified as Streptomyces sp. This is the first report on significant bioactive activities of 2,4-DTBP against R. solanacearum, according to a thorough literature review. The results of this study show that a bioorganic fertilizer containing Streptomyces sp. UT4A49 is a promising biocontrol agent for tomato bacterial disease control.
