Runella zeae sp. nov., a novel gram-negative bacterium from the stems of surface-sterilized Zea mays

Abstract

A Gram-negative bacterium, designated NS12(T), was previously isolated from duplicate treatments of surface-sterilized Zea mays stems. The plants were grown in synthetic soil under greenhouse conditions and watered with fertilizer containing no nitrogen. Strain NS12(T) was not isolated from plants watered with the standard level or 20% (w/v) of the standard level of nitrogen. Cells were bent rods that formed chains of irregular shapes in R2A broth. Unlike its closest described relative Runella slithyformis, strain NS12(T) fermented glucose and sucrose. The G+C content was 49 mol%. Phylogenetic analysis of the 16S rRNA gene showed that the strain was a member of the domain Bacteria and is most closely related to R. slithyformis, a member of the Flexibacter group within the Cytophaga-Flexibacter-Bacteroides phylum. Phenotypic and genotypic analyses indicated that strain NS12(T) could not be assigned to any recognized species; therefore a new species designated Runella zeae sp. nov. is proposed, for which NS12(T) ( = ATCC BAA-293(T) = LMG 21438(T)) is the type strain.