As key players in anoxic environments, methanogenic archaea account for the vast majority of biogenic methane emissions and play important roles during organic matter mineralization. Growing evidence indicates potential for broader ecological roles beyond methanogenesis. This review summarizes the physiology of biogeochemically relevant transformations of iron minerals, humic acid, biochar, and toxic heavy metals/metalloids. We examine how methanogenic archaea couple carbon cycling with other element cycles through methanogenic pathways and electron transfer processes. We also discuss known and potential molecular mechanisms that underlie these interactions. Furthermore, we highlight the discovery of the reversal of methanogenesis driven by extracellular electron transfer and its potential for methane bioconversion technologies. This work underscores the physiological versatility of methanogenic archaea, suggesting their diverse roles in biogeochemical cycles.

The anaerobic conversion of organic matter to methane and carbon dioxide typically relies on obligate syntrophic interactions between bacteria and ...

Abstract. Methanogenic archaea research is challenged by limited strain resources, fragmented genomic data, inconsistent genome quality, substantial uncult

Key questions about the early evolution of archaea remain unanswered. Here, Huang et al. use improved methods of genome evolution to propose a euryarchaeal root for archaea, a methanogenic ancestor, a...

Microorganisms employ inorganic polyphosphate (polyP) as an ancient strategy for energy and phosphate storage, yet its physiological roles in metha...

Methanogenic archaea play a critical role in methane (CH4) production and the global carbon cycle, yet accurately monitoring their gas metabolism unde…