Long-standing marine mystery solved: How algae get nitrogen to grow

Scientists shed light on an unexpected partnership: A marine diatom and a bacterium that can account for a large share of nitrogen fixation in vast regions of the ocean. This symbiosis likely plays a key role for global marine nitrogen fixation and productivity, and thus uptake of carbon dioxide. The newly-discovered bacterial symbiont is closely related to the nitrogen-fixing Rhizobia which live in partnership with many crop plants and may also open up new avenues for engineering nitrogen-fixing plants.