Selection of Bacillus sp. from biofertilizer and biodynamic preparations to control of Fusarium oxysporum

Fusarium species constitute a limiting factor for chickpeas (Cicer arietinum L.) production, with organic products based on Bacillus being an alternative for managing fusariosis. This study aimed to evaluate the potential of Bacillus isolates from biofertilizers and biodynamic preparations in controlling Fusarium oxysporum in chickpeas. Bacillus isolates were obtained from a commercial biodynamic preparation (PB500), a biodynamic preparation (PBG500), and a liquid biofertilizer (BioL) produced in-house. Experiments were conducted to evaluate the efficiency of Bacillus isolates in controlling F. oxysporum CML 2878 through direct antagonism, culture pairing, and production of volatile organic compounds (VOC’s). These experiments evaluated the diameter of fungal mycelial growth and the percentage of fungal mycelial growth inhibition at 3, 6, and 9 days of incubation. Biofertilizers and biodynamic preparations made from manure allowed for the isolation of 40 bacterial strains. Three bacterial species were identified by MALDI-TOF: two Bacillus species (B. cereus and B. subtilis), Rhodococcus hoagii, and nine bacteria belonging to the genus Bacillus. Isolates from BioL caused greater inhibition of F. oxysporum mycelial growth (54% and 88%), as determined by culture pairing and direct antagonism tests, respectively. This study demonstrates that the methodology for isolating Bacillus sp. from BioL and biodynamic preparations is auspicious for selecting Bacillus sp. with potential to control F. oxysporum in chickpeas.