Evaluation of Biocontrol Potentiality of Bacillus subtilis on Aflatoxins Production in Grains

Aims: This study aimed to isolate Aspergillus species from peanut (Arachis hypogaea) and toor dhal (Cajanus cajan), extraction and characterize of aflatoxin, assessment of its degradation by Bacillus subtilis metabolites. Study Design: The study was conducted involving sample collection, fungal isolation, toxin extraction, and bacterial degradation analysis. Place and Duration of Study: The study was carried out at Centre for Bioscience and Nanoscience Research, Coimbatore District from December 2024 to February 2025. Methodology: Peanut and Toor dhal samples were collected from the local market in Pappampatti, Coimbatore. Aspergillus spp. was isolated using standard plate method using Potato Dextrose Agar (PDA) and their growth was observed in Potato Dextrose Broth (PDB). Aflatoxin was extracted using acetone and dichloromethane solvent partitioning methods. Aflatoxin characterization involved TLC, UV-Visible spectroscopy), FTIR, and HPLC.   Molecular identification was performed using 18sRNA sequencing. Bacillus subtilis culture was used and its secondary metabolites were extracted using ammonium sulfate precipitation.  Aflatoxin degradation by bacterial metabolites was confirmed through UV-visible spectroscopy,  Results: Aspergillus versicolor was isolated from peanut and Toor dhal produced aflatoxin, characterized as Aflatoxin B1 (AFB1). TLC, UV-Visible spectroscopy (maximum absorption at 360 nm with peaks at 224, 266, and 363 nm, FTIR, and HPLC confirmed the presence of aflatoxin (7.132ug/ml).  Degradation studies indicated that bacterial metabolites from Bacillus subtilis effectively degraded aflatoxin as confirmed by the absence of characteristic absorption peaks. The level of degradation was also observed and found to be 72.0%. Conclusion: The study demonstrates the successful isolation of Aspergillus versicolor aflatoxin characterization, and effective degradation of aflatoxin using Bacillus subtilis metabolites, highlighting its potential as a biocontrol agent for aflatoxin contamination.