runella zeae runella zeae runella zeae is a gram-negative bacterium from the genus of runella which has been isolated from the stem of the mais plant zea mays in madison in the united states. runella zeae scientific classification domain: bacteria phylum: bacteroidota class: cytophagia order: cytophagales family: spirosomaceae genus: runella species: r. zeae binomial name runella zeaechelius et al. 2002 type strain atcc baa-293, dsm 19591, kctc 12164, lmg 21438, m. chelius, ns12