H2Rumen: Hydrogen metabolism in the rumen at the crossroads between reducing methane emissions and improving rumen fermentation

News

Reducing methane (CH₄) emissions from ruminants is a major challenge for the livestock sector. An optimal CH₄ mitigation strategy should also induce co-benefits such as enhanced animal productivity and health. CH₄ is produced during the fermentation of feeds in the rumen. This process is carried out by a complex microbial community (rumen microbiota) and mediated by hydrogen (H₂) in the rumen ecosystem. Our knowledge on the drivers that shape H₂ flows is still incomplete. H₂Rumen aims to generate fundamental knowledge on H₂ flows in the rumen ecosystem and to translate this knowledge into predictive mathematical models of rumen fermentation. Our scientific outputs will be of high value for the optimal design of CH₄ mitigation strategies with co-benefit for the animal. Our hypothesis is that thermodynamics and microbial interactions jointly control hydrogen transactions in the rumen ecosystem. H2Rumen addresses the following fundamental scientific question: Where does H₂ go? We will answer this question with an integrative approach that combines in vitro experiments, in silico modelling and omics approaches. In addition to the impact on ruminant livestock, our methods might be applicable to other ecosystems such as the human gut, engineering bioreactors and fermented food ecosystems.

H2Rumen is an ANR project (2025-2029) coordinated by Rafael Muñoz-Tamayo.

Who we are: H2Rumen brings together an interdisciplinary consortium covering expertise on rumen fermentation and dynamic modeling (MoSAR), rumen microbiology (UMRH) and computational biology (PLEIADE).

MoSAR (INRAE, AgroParisTech, Université Paris-Saclay) conducts research to understand, characterize and predict the relationships between livestock and their feeding environment to develop tools that increase the feed efficiency whilst optimising performance, adaptive capacity and wellbeing. Staff: Valérie Berthelot, Anaïs Roger, Rafael Muñoz-Tamayo

UMRH (INRAE, Theix) conducts research to understand the ingestion, microbial digestion and metabolic mechanisms controlling ruminant nutrition. Staff: Milka Popova, Arthur Bourguet, Aurélie Dehornoy, Diego Morgavi

PLEIADE (Inria, INRAE, Bordeaux) explores the diversity of organisms and the diversity of their functions and, as a fundamental challenge, seeks to formalize the links between them using mathematical and computational biology methods. Staff: David James Sherman, Clémence Frioux, Simon Labarthe

H2Rumen concept

Our project will study H₂ transactions and metabolic fluxes in in vitro systems at increasing microbial complexity levels starting with batch experiments using mono-culture, co-culture, and mini-consortia (i). Batch and continuous cultivation experiments in dual outflow fermenters will be carried out with complex rumen microbial consortium (ii). The experimental data produced will be used for the construction of a mathematical model of rumen microbial fermentation integrating H₂ dynamics, thermodynamic control and microbial genomic information. This will allow the production of a model with capabilities for designing microbial strategies for sustainable ruminant production. The model will be developed using the framework of genome-scale metabolic models (GEMs) (iii).

H2Rumen tasks