Bubble-mediated hydrogen degassing in the rumen: a theoretical hypothesis with potential implications for methane mitigation

The rumen is a fluidic system in which dissolved gases routinely exceed their Henry's Law equilibrium concentrations and are ultimately eructed, implying the existence of physical degassing processes. However, the mechanisms governing intraruminal degassing are poorly characterized. In this study, a theoretical hypothesis is proposed based on thermodynamic and mechanistic considerations, in which bubble-mediated degassing competes with methanogenesis for dissolved hydrogen (H 2 ). This hypothesis further contemplates intraruminal devices incorporating engineered surfaces that could promote bubble formation and potentially augment natural degassing pathways and inhibitor-based methane (CH 4 ) mitigants that elevate dissolved hydrogen. This approach integrates physical chemistry, interfacial science, and rumen microbiology and is amenable to evaluation using established methods. Accelerating the transition of excess dissolved hydrogen into the gas phase may provide a new physical mechanism for enteric methane mitigation.