Bacterial Compounds That Fight Harmful Plant Fungi

Jim Crocker
28th June, 2024

Bacterial Compounds That Fight Harmful Plant Fungi

Lipopeptides extracted from Bacillus velezensis strains GB03 (a) and FZB42 (b) most effectively inhibited the mycelial growth of Fusarium oxysporum f.sp. strigae, with weaker inhibition from B. subtilis BSn5 (c) and no effect from other tested bacteria (dā€“g), demonstrating the potent antagonistic activity of these specific Bacillus metabolites.

Image adapted from: Assena et al. / CC BY (Source)

Key Findings

  • The study from the University of Hohenheim focused on how bacterial metabolites, specifically lipopeptides (LPs), affect fungal growth
  • Bacillus strains GB03, FZB42, and BSn5 significantly inhibited the growth of the fungus Fusarium oxysporum f.sp. strigae (Fos)
  • The presence of Fos triggered an increase in the production of bacillomycin D, a type of LP, by the Bacillus strains, highlighting dynamic microbial interactions
The University of Hohenheim recently conducted a study investigating the influence of bacterial cyclic lipopeptides (LPs) on microbial interactions, specifically focusing on how these bacterial metabolites affect fungal growth[1]. The study aimed to determine whether the presence of bacteria inhibits fungal growth through the release of LPs, a group of compounds known for their antimicrobial properties. Bacterial LPs include surfactins, iturins, and fengycins, which are produced by various bacterial strains. These compounds have been noted for their potential in promoting plant growth and protecting plants against pathogens. The researchers selected several endophytic bacterial strains with known plant-growth-promoting capabilities and cultured them in the presence of Fusarium oxysporum f.sp. strigae (Fos), a model fungal organism. The study focused on characterizing the extracellular metabolome of these bacteria, particularly the LPs, and investigating their inhibitory effects on fungal growth. The results revealed that Bacillus velezensis strains GB03 and FZB42, as well as Bacillus subtilis BSn5, exhibited strong antagonism against Fos. This antagonism was evident through significant inhibition of spore germination and damage to the hyphal structure of the fungus. Liquid chromatography tandem mass spectrometry identified several variants of iturin, fengycin, and surfactin LP families produced by these strains, with varying intensities. Interestingly, the presence of Fos in dual plate cultures triggered an increase in bacillomycin D production from the Bacillus strains, highlighting the dynamic nature of microbial interactions. The findings from this study emphasize the crucial role of microbial interactions in shaping the coexistence of microbial assemblages. This aligns with previous research indicating that plants host diverse microbial communities internally, which play essential roles in plant development, growth, and fitness[2]. The interactions between these microorganisms, driven by chemical communication, are vital for community development in various environments, including agricultural settings[3]. Moreover, the study's results support the concept that plants can recruit protective microorganisms to enhance microbial activity and suppress pathogens in the rhizosphere, as evidenced by previous research[4]. By understanding the mechanisms governing the selection and activity of microbial communities by plant roots, new opportunities arise to increase crop production and improve plant health. This research provides valuable insights into the potential of harnessing bacterial LPs for agricultural applications. The potent antagonistic effects of specific Bacillus strains on fungal pathogens like Fos suggest that these bacteria could be utilized as biocontrol agents to protect crops from fungal infections. The study also highlights the importance of further exploring microbial interactions and the production of antimicrobial compounds to develop sustainable agricultural practices. In conclusion, the University of Hohenheim's study underscores the significance of bacterial LPs in inhibiting fungal growth and shaping microbial interactions. By building on previous findings, this research contributes to a deeper understanding of plant-microbe interactions and offers promising avenues for enhancing crop protection and productivity through natural microbial solutions.

BiotechBiochemPlant Science

References

Main Study

1) Inhibitory activity of bacterial lipopeptides against Fusarium oxysporum f.sp. Strigae

Published 27th June, 2024

https://doi.org/10.1186/s12866-024-03386-2

Related Studies

2) The Hidden World within Plants: Ecological and Evolutionary Considerations for Defining Functioning of Microbial Endophytes.

https://doi.org/10.1128/MMBR.00050-14

3) Chemical signals driving bacterial-fungal interactions.

https://doi.org/10.1111/1462-2920.15410

4) The rhizosphere microbiome and plant health.

https://doi.org/10.1016/j.tplants.2012.04.001


Related Articles

An unhandled error has occurred. Reload šŸ—™