Six-legged cows? Cockroaches unlock the secrets of hydrogenosomes, the culprit of ruminant methane emission.

Enteric fermentation in ruminants produces 32% of global anthropogenic methane emission and remains a major obstacle to achieving sustainable livestock production. Discovered only 50 years ago, hydrogenosomes of ciliates are associated with endosymbiotic methanogens and have been hypothesized to be a potential powerhouse for methanogenesis. However, their role remains poorly studied due to difficulties in producing anaerobic in vitro cultivation relevant to real life applications. The project may provide a breakthrough opportunity to investigate fundamental interactions between ciliate hydrogenosomes and rumen biome interactions and, in turn, use this knowledge to develop biotechnological solutions to mitigate methane emission from ruminants. The cockroach model hosting the transplanted rumen biome provides a novel platform to investigate other anaerobic eukaryotes (protists and fungi) and their role in methane emission and potential in biofuel production.