Bacillus atrophaeus NX-12 Utilizes Exosmotic Glycerol from Fusarium oxysporum f. sp. cucumerinum for Fengycin Production

Abstract

Bacillus strains are widely used as biological control agents to protect plants from fungal pathogens. However, whether Bacillus can exploit fungal pathogens to increase its biocontrol efficacy remains largely unexplored. Here, Bacillus atrophaeus NX-12 showed a high inhibition efficacy against Fusarium oxysporum f. sp. cucumerinum (FOC). The primary extracellular antifungal component of B. atrophaeus NX-12 was identified as fengycin by matrix-assisted laser desorption/ionization–time-of-flight-mass spectrometry (MALDI-TOF-MS) analysis. NX-12-secreted fengycin not only inhibited the germination of FOC spores but also induced the production of reactive oxygen species (ROS) in FOC cells, leading to oxidative stress and the accumulation of glycerol. Additionally, NX-12-secreted fengycin increased FOC cell wall hydrolase activity, leading to cell splitting and the exosmose of accumulated glycerol. The increased exosmose of glycerol further promoted the production of fengycin. Our results showed that in addition to the direct inhibition of FOC, NX-12 can indirectly strengthen its antagonistic efficacy against the pathogen by exploiting the exosmotic glycerol from FOC.

Antifungal Peptide P852 Effectively Controls Fusarium oxysporum, a Wilt-Causing Fungus, by Affecting the Glucose Metabolism and Amino Acid Metabolism as well as Damaging Mitochondrial Function

“…Xue et al found that the lipopeptide fengycin was also able to oxidative stress F. oxysporum, which is the same as our findings …”

“…Xue et al found that the lipopeptide fengycin was also able to oxidative stress F. oxysporum, which is the same as our findings. 43 Disruption of the Mitochondrial Structure and Membrane Potential by the Antifungal Peptide P852. Transmission electron microscopy was utilized to observe the structural changes in the mitochondria of F. oxysporum after 12 h of P852 treatment.…”