Pseudacidovorax intermedius gen. nov., sp. nov., a novel nitrogen-fixing betaproteobacterium isolated from soil.

A Gram-negative, short rod-shaped, nitrogen-fixing bacterium (CC-21(T)) was isolated from a soil sample collected from the regional agricultural research station in Kaohsiung County (Taiwan). Using 16S rRNA gene sequence analysis, it could be clearly demonstrated that this isolate was novel: it showed <97 % similarity to species of the genera Acidovorax, Alicycliphilus, Giesbergeria, Simplicispira and Diaphorobacter. The organism used several organic acids, but only a few sugars as substrates. The fatty acid profile differed from those reported for members of the genera Acidovorax, Alicycliphilus, Giesbergeria, Simplicispira and Diaphorobacter. On the basis of 16S rRNA gene sequence analysis in combination with physiological data, strain CC-21(T) represents a novel species in a new genus, for which the name Pseudacidovorax intermedius gen. nov., sp. nov. is proposed; the type strain is CC-21(T) (=CCUG 54492(T)=CIP 109510(T)).