摘要：AbstractObjectivesEvaluation ofStreptomycesisolated from Udhagamandalam, The Nilgiris, Tamilnadu, India for the biocontrol potential against the phytopathogenRalstonia solanacearumand its metabolite profiling.MethodsStreptomycesstrains were screened for plant growth promotion and antagonistic activity againstR. solanacearuminin-vitro. The metabolite profiling of strain UT4A49 was studied through gas chromatography coupled with mass spectroscopy (GC–MS) analysis. Further, the identified lead compound 2,4-Di-tert-butylphenol (2,4-DTBP) was analyzed for its mechanism of action throughin-silicodocking study. The bioorganic fertilizer (BOF) amended potentialStreptomycesstrain UT4A49 was studied for biocontrol activity againstR. solanacearumon tomato seedlings through pot culture experiments.ResultsTheStreptomycesstrain UT4A49 showed the promising production of indole acetic acid (IAA) (76.0 ± 2.0 µg/ml), siderophore, ammonia, amylase, protease, cellulase as well as it solubilized the phosphatein-vitro. The strain UT4A49 showed strongin vitroantagonistic activity againstR. solanacearumwith the inhibition zone of 19.83 ± 0.44 mm in diameter. The isolated major compound, 2,4-Di-tert-butylphenol was showed strong inhibition againstR. solanacearum.In silicodocking study revealed that the 2,4-DTBP showed lower binding energy score with all targeted proteins which found better protein–ligand binding stability. In the pot experiment, biocontrol activity of BOF amendedStreptomycesstrain UT4A49 showed significant biocontrol efficacy was 78.5% againstR. solanacearumin tomato seedlings. The strain UT4A49 was identified asStreptomycessp. based on its morphological and molecular properties.ConclusionsThe detailed literature survey revealed that this is the first report on strong bioactive properties of 2,4-DTBP againstR. solanacearum. This present study proved that bioorganic fertilizer amended withStreptomycessp. UT4A49 is a promising biocontrol agent for tomato bacterial disease control.
