Scientists have discovered an antibiotic produced by a symbiotic nitrogen-fixing bacterium from a tropical forest in Mexico that may help lead to a ‘plant prebiotic.’ Rhizobium sp. forms nodules on bean plant roots, resulting in a more robust plant (right) than on the left. Image credit: Dmitrii Y. Travin. The bacterium that produces phazolicin is an unidentified species of Rhizobium. It was isolated in a tropical forest in Los Tuxtlas, Mexico,...