Characterization of antagonistic streptomyces as potential biocontrol agent against fungal pathogens of chickpea and sorghum

Twenty-seven actinomycetes isolated from vermicompost and rhizosphere soils were screened for their antagonistic potential against fungal pathogens of chickpea and sorghum. Eight isolates (BCA-657, BCA-671, BCA-679, BCA-687, BCA-690, CAI-67, CAI-70 and CAI-98) showed broad-spectrum antagonistic activity in dual-culture assay and metabolite inhibition assay. The isolates exhibited growth at pH 7−11, up to 10% saline (except BCA-687, CAI-67 and CAI-70) at 20−40 °C (BCA-679 and BCA-690 exhibited growth even at 50 °C) and produced siderophore, chitinase, cellulase, lipase, and protease with some exceptions, including hydrocyanic acid and indole acetic acid. At field application level, all the isolates tolerated the fungicide Bavistin. The sequences of 16S rDNA gene of the isolates matched with Streptomyces but with different species in the BLAST analysis. This study indicates that the selected actinomycetes have broad-spectrum biocontrol and plant growth promotion potentia