Biology subjects

Rigolet, A.

Publications and source records attributed to Rigolet, A..

4 recordsLinked to original sources

bioRxiv2026

A global regulatory atlas of Streptomyces reveals conserved and diversified transcriptional networks across actinomycetes

Transcriptional regulatory networks determine how bacteria integrate environmental signals with growth, metabolism and stress adaptation. Actinomycetes encode exceptionally large repertoires of transcription factors (TFs) coordinating morphological development, environmental adaptation and specialized metabolism, yet their regulatory networks remain poorly defined. Here, we apply DNA affinity purification sequencing (DAP-seq) to 789 predicted TFs of Streptomyces coelicolor, generating genome-wide binding maps for 393 regulators and expanding the experimentally supported regulome from [~]8% to [~]50%. Integration with ChIP-seq reveals pleiotropic regulators and hierarchical network architecture linking primary metabolism, development and biosynthetic gene clusters (BGCs). Multiplexed DAP-seq (multiDAP) across 16 additional actinomycetes uncovered deeply conserved regulatory circuits alongside widespread divergence in TF-target interactions. Together, these data establish a regulatory atlas for Streptomyces and related actinomycetes, enabling researchers to explore control of genes, pathways, BGCs and conserved network modules. This provides a foundation for predictive analysis and engineering of complex bacterial phenotypes in biotechnology and medicine.

microbiology↗

bioRxiv2023

Nitrogen sources enhance siderophore-mediated competition for iron between potato common scab and late blight causative agents

Withdrawal StatementThe authors have withdrawn their manuscript owing to the fact that the P. infestans strain received from third parties is not the one referred in the manuscript despite having the certificate from the providing collection. All the experiments and data are correct but not included into a proper research context. A new version of this work will be published in near future. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

microbiology↗

bioRxiv2023

The fate of bacterial secondary metabolites in the rhizosphere: Streptomyces degrades and feeds on cyclic lipopeptides produced by competitors

Cyclic lipopeptides are key bioactive secondary metabolites produced by some plant beneficial rhizobacteria such as Pseudomonas and Bacillus. They exhibit antimicrobial properties, promote induced systemic resistance in plants and support key developmental traits including motility, biofilm formation and root colonization. However, our knowledge about the fate of lipopeptides once released in the environment and especially upon contact with neighboring rhizobacteria remains limited. Here, we investigated the enzymatic degradation of Bacillus and Pseudomonas cyclic lipopeptides by Streptomyces venezuelae. We observed that Streptomyces is able to degrade the three lipopeptides surfactin, iturin and fengycin upon confrontation with of B. velezensis in vitro and in planta according to specific mechanisms. S. venezuelae was also able to degrade the structurally diverse sessilin, tolaasin, orfamide, xantholisin and putisolvin-type lipopeptides produced by Pseudomonas, indicating that this trait is likely engage in the interaction with various competitors.Furthermore, the degradation of CLPs is associated with the release of free amino and fatty acids and was found to enhance Streptomyces growth, indicating a possible nutritional utilization. Thereby, this work stresses on how the enzymatic arsenal of S. venezuelae may contribute to its adaptation to BSMs-driven interactions with microbial competitors. The ability of Streptomyces to degrade exogenous lipopeptides and feed on them adds a new facet to the implications of the degradation of those compounds by Streptomyces, where linearization of surfactin was previously reported as a detoxification mechanism. Additionally, we hypothesize that lipopeptide-producing rhizobacteria and their biocontrol potential are impacted by the degradation of their lipopeptides as observed with the polarized motility of B. velezensis, avoiding the confrontation zone with Streptomyces and the loss of antifungal properties of degraded iturin. This work illustrates how CLPs, once released in the environment, may rapidly be remodeled or degraded by members of the bacterial community, with potential impacts on CLP-producing rhizobacteria and the biocontrol products derived from them.

microbiology↗

bioRxiv2021

Chelator sensing and lipopeptide interplay mediates molecular interspecies interactions between soil bacilli and pseudomonads

AbstractSome bacterial species are important members of the rhizosphere microbiome and confer protection to the host plant against pathogens. However, our knowledge of the multitrophic interactions determining the ecological fitness of these biocontrol bacteria in their highly competitive natural niche is still limited. In this work, we investigated the molecular mechanisms underlying interactions between B. velezensis, considered as model plant-associated and beneficial species in the Bacillus genus, and Pseudomonas as a rhizosphere-dwelling competitor. Our data show that B. velezensis boosts its arsenal of specialized antibacterials upon the perception of the secondary siderophore enantio-pyochelin produced by phylogenetically distinct pseudomonads and some other genera. We postulate that B. velezensis has developed some chelator sensing systems to learn about the identity of its surrounding competitors. Illustrating the multifaceted molecular response of Bacillus, surfactin is another crucial component of the secondary metabolome mobilized in interbacteria competition. Its accumulation not only enhances motility but, unexpectedly, the lipopeptide also acts as a chemical trap that reduces the toxicity of other lipopeptides released by Pseudomonas challengers. This in turn favors the persistence of Bacillus populations upon competitive root colonization. Our work thus highlights new ecological roles for bacterial secondary metabolites acting as key drivers of social interactions.

microbiology↗