A bacterial strain, designated MS4(T), was isolated from soil in the Ryukyu Archipelago, Japan. The bacterium grew with 3-methyl sulfolane as sole sulfur source. Phylogenetic analysis based on 16S rRNA gene sequences suggested that strain MS4(T) belonged to the genus Shinella; it was closely related to the type strains of Shinella granuli and Shinella zoogloeoides (16S rRNA gene sequence similarities of 98.2 and 96.7 %, respectively). Strain MS4(T) was a Gram-negative, non-motile, rod-shaped, aerobic bacterium. The major respiratory quinone was ubiquinone-10 and the predominant cellular fatty acid was C(18 : 1)omega7c. The DNA G+C content was 66.4 mol%. Based on phylogenetic and phenotypic traits, it was concluded that the organism represents a novel species in the genus Shinella for which the name Shinella yambaruensis sp. nov. is proposed; the type strain is MS4(T) (=NBRC 102122(T)=DSM 18801(T)).