Identification of Pyrrole-2-Carboxylic Acid from the Biocontrol Agent Lysobacter Involved in Interactions with Fusarial Fungi

Authors

• Vishakha Jayasekera, University of Nebraska-LincolnFollow
• Yong Han, Ohio UniversityFollow
• Liangcheng Du, University of Nebraska - LincolnFollow

ORCID IDs

Jayasekera https://orcid.org/0000-0002-3915-9938

Han https://orcid.org/0000-0003-3833-1473

Du https://orcid.org/0000-0003-4048-1008

Document Type

Article

Date of this Version

2025

Citation

Microorganisms (2025) 13: 1202

doi: 10.3390/microorganisms13061202

Comments

Open access

License: CC BY 4.0

Abstract

Lysobacter, a genus of Gram-negative bacteria, is known for producing antibiotic compounds, making it a promising biocontrol agent against crop pathogens. As part of the soil microbiome, Lysobacter species cooccur with a variety of microorganisms in the ecosystem. However, little is known about bioactive natural products involved in Lysobacter’s interactions with other organisms. This study investigated interactions between Lysobacter sp. 3655 and two economically important fungal pathogens, Fusarium graminearum and Fusarium verticillioides. We discovered a Lysobacter molecule that is dramatically suppressed when co-culturing with the fungi, and the structure of this molecule was determined to be pyrrole-2-carboxylic acid (P2C). Chitin, a primary component of fungal cell walls, also suppressed P2C production in Lysobacter. Exogenous P2C addition promoted formation of Lysobacter biofilms within a range of concentrations, suggesting its potential role as a signaling molecule. Previously reported result showed that the mutation of the global regulator Clp in Lysobacter enzymogenes led to drastic increase of biofilm formation. Intriguingly, while P2C increased the biofilm formation in the wildtype of L. enzymogenes, it reduced the biofilms in the Clp mutant. Together, these findings reveal P2C as a novel signaling molecule mediating the interaction between Lysobacter and surrounding fungal species, highlighting its role in Lysobacter adaptation in response to environmental conditions.