Sphingobacterium canadense sp. nov., an isolate from corn roots

Abstract

A free-living Gram-negative bacterial strain CR11(T) was isolated from corn roots. Polyphasic taxonomy was performed, including API20 NE and API50 CH bacterial identification kits, Biolog analysis, lipids and fatty acid analysis, DNA-DNA hybridization, 16S rRNA and cpn60 gene sequence analyses. 16S rRNA gene sequence analysis indicated that strain CR11(T) belonged to the genus Sphingobacterium and was closely related to Sphingobacterium multivorum IFO 14947(T) (98% similarity) and Sphingobacterium. thalpophilum ATCC 43320(T) (97% similarity). DNA-DNA hybridization showed 11% and 13% DNA re-association with S. multivorum LMG 8342(T) and S. thalpophilum LMG 11520(T), respectively. Major fatty acids (16:0, 15:0 iso and 17:0 iso 3-OH) and the G+C content of the DNA (40.5 mol%), were also similar to those of the genus Sphingobacterium. The predominant respiratory quinone was MK-7. In all analyses, including phenotypic characterization, this isolate was found to be different from the closely related species, S. multivorum and S. thalpophilum. On the basis of these results, this strain represents a new species within the genus Sphingobacterium. The name Sphingobacterium canadense sp. nov. is suggested and the type strain is CR11(T) (=NCCB 100125(T)=LMG 23727(T)).