Faecalibacterium duncaniae A2-165 regulates the expression of butyrate synthesis, ferrous iron uptake, and stress-response genes based on acetate level in early-stationary cultures - CNRS - Centre national de la recherche scientifique Accéder directement au contenu
Pré-Publication, Document De Travail (Preprint/Prepublication) Année : 2023

Faecalibacterium duncaniae A2-165 regulates the expression of butyrate synthesis, ferrous iron uptake, and stress-response genes based on acetate level in early-stationary cultures

Résumé

Background : Faecalibacterium prausnitzii , a promising next-generation probiotic, is one of the most abundant acetate-consuming, butyrate-producing bacteria in the healthy human gut. However, little is known about the gene expression strategies used by this bacterium to adapt to the availability of acetate in the human gut. Result : We first established a growth model of F. duncaniae A2-165 (previously known as F. prausnitzii A2-165) using batch cultures, under high- and low-acetate conditions. Over late exponential and early stationary phases, the bacteria displayed a growth deficiency and a low butyrate production in low- compared with high-acetate conditions. Using RNA-seq, we compared expression patterns between early stationary and late exponential phases in high- and low-acetate conditions and between high- and low-acetate conditions in the early stationary phase. Functional classification of the low-acetate transcriptome revealed the specific activation of a general stress response, including upregulation of chaperones, toxin-antitoxin type II systems and downregulation of numerous protein synthesis genes. We observed two distinct import system transcriptomes, under low and high-acetate conditions, suggesting major adaptation responses to nutrient-deprived conditions of the early-stationary growth phase. Specifically, in high-acetate conditions, the feoAABC operon encoding one FeoB ferrous iron transporter was strongly activated but not the feoAB gene encoding the second FeoB transporter of F. duncaniae A2-165. This strong activation in early-stationary phase under high-acetate conditions suggested that (i) the level of extracellular ferrous iron is low (ii) FeoAABC system is required for ferrous iron uptake, in this iron-poor environment. Using RT-PCR, we demonstrated that excess ferrous iron represses feoB expression (i.e feoAABC operon) but not feoAB expression in high-acetate conditions. Finally, we conducted an integrated analysis of a healthy human fecal metaproteome, in which we were able to detect FeoB peptides from both genus Faecalibacterium and strain A2-165. Conclusion : We characterized two early-stationary lifestyles of F. duncaniae A2-165 at the transcriptional level, related to acetate consumption and butyrate production. We characterized the regulation of feoAABC operon encoding an high-affinity ferrous iron transporter that may play a major role in iron homeostasis and butyrate synthesis in iron-poor and acetate-rich conditions in F. duncaniae A2-165.

Dates et versions

hal-04443517 , version 1 (20-03-2023)
hal-04443517 , version 2 (07-02-2024)

Identifiants

Citer

Sophie Verstraeten, Séverine Layec, Sandrine S. Auger, Catherine Juste, Céline Henry, et al.. Faecalibacterium duncaniae A2-165 regulates the expression of butyrate synthesis, ferrous iron uptake, and stress-response genes based on acetate level in early-stationary cultures. 2023. ⟨hal-04443517v1⟩
103 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More