EMENDED DESCRIPTION OF HERBASPIRILLUM - INCLUSION OF [PSEUDOMONAS] RUBRISUBALBICANS, A MILD PLANT PATHOGEN, AS HERBASPIRILLUM-RUBRISUBALBICANS COMB-NOV - AND CLASSIFICATION OF A GROUP OF CLINICAL ISOLATES (EF GROUP-1) AS HERBASPIRILLUM SPECIES-3

[Pseudomonas] rubrisubalbicans, a mild plant pathogen, Herbaspirillum seropedicae, and EF group 1 strains (clustered by an immunological met hod) were investigated by a polyphasic approach with DNA-rRNA and DNA- DNA hybridizations and auxanography on 147 substrates. Our results sho w that they all belong to the genus Herbaspirillum. In addition to H. seropedicae, two other species are described: Herbaspirillum rubrisuba lbicans and a new unnamed species, Herbaspirillum species 3, containin g mainly strains of clinical origin, The three species can be differen tiated on the basis of their auxanographic features and DNA-DNA simila rities, The type strain of H., rubrisubalbicans is NCPPB 1027 (=LMG 22 86); representative strains of the third Herbaspirillum species are st rains CCUG 189 (=LMG 5523), CCUG 10263 (=LMG 5934), and CCUG 11060 (=L MG 5321), It has been confirmed that H. rubrisubalbicans is an endophy tic diazotroph, It colonizes the roots, the stems, and predominantly t he leaves of sugarcane (Saccharum spp,), while Herbaspirillum seropedi cae colonizes in large numbers many different species of the Gramineae , Both diazotrophic Herbaspirillum species could be differentiated wit h meso-erythritol and N-acetylglucosamine, Oligonucleotide probes base d on partial sequences of the 238 rRNA of H. seropedicae and H. rubris ubalbicans (WS and HR probes, respectively), were constructed and used as diagnostic probes.