Metagenomic analysis of fecal microbiomes reveals genetic potential for diverse hydrogen management strategies in marsupials

Abstract

Herbivorous marsupials such as kangaroos and wallabies have been reported to produce significantly lower methane emissions than ruminant livestock despite eating a similar diet, yet the microbial mechanisms underlying this difference remain poorly understood. Here, we conduct a comparative study of fecal microbiomes of 14 marsupial species to provide the first investigation of hydrogen-cycling genetic capacity across these animals. Through comparative analysis with fecal microbiomes of high- and low-methane-producing animals, we identify enrichment of bacterial genes for alternative hydrogen uptake and disposal pathways in some marsupials, supporting competition for hydrogen playing a role in the level of methane production. These data also indicate variation in hydrogen management between marsupials, including within species, suggesting methane emission capacity may vary at the level of the individual.