Biocontrol and other beneficial activities of Bacillus subtilis isolated from cowdung microflora

SummaryBacillus subtilis strains isolated from cowdung (CD) had several beneficial attributes, which included biocontrol, plant growth promotion, sulphur (S) oxidation, phosphorus (P) solubilization and production of industrially important enzymes (amylase and cellulase). The B. subtilis strains from CD inhibited the in vitro growth of fungi, Fusarium oxysporum (25–34%) and Botryodiplodia theobromae (100%), isolated from the postharvest rots of yam (Dioscorea rotundata) tubers. Other than biocontrol, B. subtilis strains were able to promote root elongation in seedlings of Cicer arietinum up to 70–74% as compared to untreated seeds (control). B. subtilis strains had also the ability to oxidize elemental S to sulphate (2–15 μg ml−1) and showed distinct P-solubilization activity in vitro. In addition, the cultures showed cellulase activity in carboxy methyl cellulose medium (1.5–1.8 mg of reducing sugar 24 h−1 ml−1) and amylase activity in vitro.