A Gram-negative, strictly aerobic bacterium, comprising non-endospore-forming motile rods (1.2-2.0 microm x 0.4-0.6 microm) with polar flagellae was isolated from root nodules of the leguminous plant Pueraria lobata (Willd.) Ohwi growing on the coast of Yakushima Island, Kagoshima Prefecture, Japan. The novel strain, designated Yak96B(T), grew at an optimum pH of 7.0 and an optimum temperature of 28 degrees C. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that the new strain was closely related to Devosia neptuniae J1(T) and Devosia chinhatensis IPL18(T), with sequence similarities of 98.1 % and 97.8 %, respectively. However, the DNA-DNA relatedness values of strain Yak96B(T) with D. neptuniae LMG 21357(T) and D. chinhatensis CCM 7426(T) were 53.6 % and 34 %, respectively. The DNA G+C content of strain Yak96B(T) was 65.3 mol%, the predominant isoprenoid quinone was Q10 (85 %) and the polar lipids were phosphatidylglycerol and diphosphatidylglycerol. The major fatty acids (>5 %) were 11-methyl C(18 : 1)omega7c (35.0 %), C(16 : 0) (22.4 %), C(18 : 1)omega7c (21.8 %), C(19 : 0) cyclo omega8c (6.8 %) and C(18 : 0) (5.4 %). The infection/nodulation test was negative and nifH and nodD genes were not detected. Based on its chemotaxonomic and physiological characteristics, strain Yak96B(T) represents a novel species of the genus Devosia, for which the name Devosia yakushimensis sp. nov. is proposed. The type strain is Yak96B(T) (=KCTC 22147(T)=NBRC 103855(T)=LMG 24299(T)).