mesorhizobium calcicola mesorhizobium calcicola mesorhizobium calcicola is a gram-negative and rod-shaped bacterium from the genus of mesorhizobium which has been isolated from the root nodules of the tree sophora in new zealand. mesorhizobium calcicola scientific classification domain: bacteria phylum: pseudomonadota class: alphaproteobacteria order: hyphomicrobiales family: phyllobacteriaceae genus: mesorhizobium species: m. calcicola binomial name mesorhizobium calcicolade meyer et al. 2016 type strain hambi 3609, lmg 28224, icmp 19559, icmp 19560, icmp 19561, icmp 19562, icmp 19563