Rhodopseudomonas palustris, shown in this photomicrograph, is a type of bacteria that can use iron-only nitrogenase to convert nitrogen and carbon dioxide into methane as well as ammonia and hydrogen gas in a single enzymatic step. (UW / Harwood Lab)
Every year, microbes produce hundreds of millions of tons of methane, a greenhouse gas that’s more potent than carbon dioxide. Scientists had thought the job was done exclusively through methanogenesis. But in the journal Nature Microbiology, a research team led by the University of Washington’s Caroline Harwood lays out an alternate method that makes use of a backup enzyme called iron-only nitrogenase.
