Genome Analysis ofEndobacterium cerealis, a Novel Genus and Species Isolated fromZea maysRoots in North Spain

In the present work, we analyse the genomic and phenotypic characteristics of a strain named RZME27(T)isolated from roots of aZea maysplant grown in Spain. The phylogenetic analyses of 16S rRNA gene and whole genome sequences showed that the strain RZME27(T)clustered with the type strains ofNeorhizobium galegaeandPseudorhizobium pelagicumfrom the familyRhizobiaceae. This family encompasses several genera establishing symbiosis with legumes, but the genes involved in nodulation and nitrogen fixation are absent in its genome. Nevertheless, genes related to plant colonization, such as those involved in motility, chemotaxis, quorum sensing, exopolysaccharide biosynthesis and hydrolytic enzymes production were found. The comparative pangenomic analyses showed that 78 protein clusters present in the strain RZME27(T)were not found in the type strains of its closest relativesN. galegaeandP. pelagicum. The calculated average nucleotide identity (ANI) values between the strain RZME27(T)and the type strains ofN. galegaeandP. pelagicumwere 75.61% and 75.1%, respectively, similar or lower than those found for other genera from familyRhizobiaceae. Several phenotypic differences were also found, highlighting the absence of the fatty acid C(19:0)cyclo omega 8c and propionate assimilation. These results support the definition of a novel genus and species namedEndobacterium cerealisgen. nov. sp. nov. whose type strain is RZME27(T).