Leifsonia gen. nov., a genus for 2,4-diaminobutyric acid-containing actinomycetes to accommodate "Corynebacterium aquaticum" Leifson 1962 and Clavibacter xyli subsp cynodontis Davis et al. 1984

"Corynebacterium aquaticum" was first proposed by Leifson in 1962 but not i ncluded in the approved lists of bacterial names in 1980, This species has been left from reclassification of the genus Corynebacterium because of the unusual chemotaxonomic characteristics such as 2,4-diaminobutyric acid (DA B) in the peptidoglycan and menaquinones of MK-10 and MK-11. A close relati onship of "C. aquaticum" to the genera Agromyces and Rathayibacter has been pointed out from the viewpoint of chemotaxonomic profiles and phylogeny ba sed on the 16S rDNA sequences. An analysis of DAB isomers of the peptidogly can distinguished "C. aquaticum" clearly from these genera by possessing bo th L-DAB and D-DAB. We also found that the type strain of Clavibacter xyli subsp, cynodontis and two strains of amine-decomposing bacteria showed the similar chemotaxonomic features and formed a cluster with "C. aquaticum" in the phylogenetic tree based on 16S rDNA sequences in the family Microbacte riaceae. Considering these results, we propose a new genus Leifsonia to acc ommodate the four strains. The four species, Leifsonia aquatica sp. nov., n om, rev., comb. nov. (type species, type strain = JCM 1368), Leifsonia shin shuensis sp. nov. (type strain = DB102 = JCM 10591), Leifsonia naganoensis sp. nov. (type strain = DB103 = JCM 10592), and Leifsonia cynodontis comb. nov. (type strain = JCM 9733 = ICMP 8790), were proposed here for the strai ns.