rhizobium

rhi·zo·bi·um

noun \rī-ˈzō-bē-əm\

Definition of RHIZOBIUM

1

capitalized : a genus (family Rhizobiaceae) of small heterotrophic soil bacteria capable of forming symbiotic nodules on the roots of leguminous plants where they fix atmospheric nitrogen

2

plural -bia \-bē-ə\ : any bacterium of the genus Rhizobium