Received: 03-10-2023 / Accepted: 07-03-2024
Rhizobacterium Bacillus subtilisRB.CJ41 isolated from black pepper hasantifungal activity against Fusariumsp. under in vitroand ex vitroconditions. The objective of the study was to select the appropriate culture conditions of the strain B. subtilisRB.CJ41. The single effect of environmental factors including C/N source, carbon sources, (NH4)2SO4and MgSO4sourceswas investigated on the density and Fusariumsp antifungal activity of the strain RB.CJ41. The results showed that bean residue, mannitol and MgSO4had the greatest impact on density and antifungal activity of strain RB.CJ41. Using Response Surface Methodology (RSM) - Central Composite Design (CCD), a quadratic equation describing the dependence of Fusariumsp. antifungal activity with three survey variableswas determined in the form “Antifungal activity (%) = 11.66 – 0.9452A + 1.00B + 0.2713C – 0.5625AB – 0.5625AC – 0.0625BC – 2.28A2 – 2.73B2– 1.84C2.Analytical results showed theoptimal range forhigh antifungal activity of rhizobacteriumB. subtilisRB.CJ41 was7 g/lto 8 g/lfor bean residue, 6g/lto 7g/lfor mannitol and 4 g/lto 5 g/lfor MgSO4.
