A yellow-pigmented actinobacterium, designated strain MSL-13T, was isolated from a soil sample collected from Bigeum Island, Republic of Korea, and its taxonomic position was determined by using a polyphasic approach. Strain MSL-13T showed phenotypic and chemotaxonomic properties consistent with its classification in the genus Leifsonia. 16S rRNA gene sequence analysis of strain MSL-13T with sequences from Leifsonia naganoensis DB103T, Leifsonia aquatica DSM 20146T, Leifsonia xyli subsp. cynodontis JCM 9733T, Leifsonia poae VKM Ac-1401T and Leifsonia shinshuensis DB102T revealed similarities of 96.22, 96.19, 95.77, 95.44 and 95.37 %, respectively, with differences of 39–65 nt among 1483 total nucleotides aligned. Based on differences in phenotypic and genotypic characteristics, strain MSL-13T (=KCTC 19267T =DSM 19272T) is designated as the type strain of a novel species of the genus Leifsonia, for which the name Leifsonia kribbensis sp. nov. is proposed.
A coryneform bacterium isolated from a cow with a profound ulceration was characterized by using phenotypic and molecular taxonomic methods. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV and short-chain mycolic acids consistent with the genus Corynebacterium. Comparative 16S rRNA gene sequencing showed that the organism formed a hitherto unknown subline within the genus Corynebacterium. Sequence divergence values of greater than 3.6 % from recognized Corynebacterium species, together with phenotypic differences, showed that the unidentified bacterium represents a new member of this genus. On the basis of phenotypic and phylogenetic considerations, it is proposed that the novel bacterium be classified as representing a novel species of the genus Corynebacterium, with the name Corynebacterium ulceribovis sp. nov. The type strain is IMMIB L-1395T (=DSM 45146T=CCUG 55727T).
A novel Gram-positive, aerobic, short-rod-shaped bacterium, designated strain J112T, was isolated from black sand collected from Soesoggak, Jeju Island, Korea. The strain was found to be oxidase-negative and catalase-positive. Cells grew at 10–37 °C, at pH 5.5–8.0 and with 1–10 % NaCl. Growth occurred on marine agar but not on R2A or trypticase soy agar. A phylogenetic analysis based on 16S rRNA gene sequences showed that the strain belongs to the radiation of the genus Nocardioides. Strain J112T shared the highest 16S rRNA gene sequence similarities with Nocardioides marinisabuli SBS-12T (99.2 %), Nocardioides terrigena DS-17T (97.3 %), Nocardioides kribbensis KCTC 19038T (97.1 %) and type strains of other Nocardioides species with validly published names (<97 %). The DNA–DNA hybridization values between strain J112T and the three most closely related strains were low enough to justify the assignment of this strain to a novel species. On the basis of these phenotypic, phylogenetic and chemotaxonomic data, strain J112T represents a novel species of the genus Nocardioides, for which the name Nocardioides basaltis sp. nov. is proposed. The type strain is J112T (=KCTC 19365T=JCM 14945T).
Two bacterial strains, CP153-3 and CP177-2T, were isolated from biological soil crusts on the Colorado Plateau, USA, and assigned to the genus Patulibacter, according to 16S rRNA gene sequence analysis and phenotypic characteristics. The strains were Gram-positive, aerobic and psychrotolerant and showed positive catalase and negative oxidase reactions. Cells were motile in young cultures, motility consisting of subtle jerking motions, but no flagella could be detected. The strains shared high 16S rRNA gene sequence similarity (99.7 %) and DNA–DNA relatedness (99 %). They contained meso-diaminopimelic acid in the cell wall, the major menaquinone was MK-7(H2) and the predominant fatty acids were C18 : 1 ω9c and iso-C15 : 0. A low DNA–DNA hybridization value of 20 % with the type strain of the type species of the genus Patulibacter, Patulibacter minatonensis, as well as phenotypic differences, indicated that the isolates belong to a novel species, for which the name Patulibacter americanus sp. nov. is proposed. Strain CP177-2T (=ATCC BAA-1038T =DSM 16676T) was chosen as the type strain. An emended description of the genus Patulibacter is also presented. Further, two new orders are created to accommodate several families previously classified in the order Rubrobacterales Rainey et al. 1997. The first, Solirubrobacterales ord. nov., encompasses the families Solirubrobacteraceae, Conexibacteraceae and Patulibacteraceae, and the second, Thermoleophilales ord. nov., includes the family Thermoleophilaceae.
Actinobacteria comprise a substantial fraction of the bacterioplankton in freshwater lakes and streams. Numerous cultivation-independent investigations have retrieved actinobacterial 16S rRNA gene sequences from such habitats. The taxa detected in freshwater habitats are usually absent from terrestrial and marine systems. So far, none of the indigenous freshwater lineages is represented by a taxon with a validly published name. The seven organisms for which Candidatus status is described here were isolated from freshwater lakes and ponds located in tropical, subtropical and temperate climatic zones. Phylogenetic analyses demonstrated that they are affiliated with one of the actinobacterial lineages indigenous to freshwater bacterioplankton. The seven novel taxa could only be cultivated to date as mixed cultures that also contain non-actinobacterial strains. Due to the lack of pure cultures, I propose to establish the candidate species ‘Candidatus Planktoluna difficilis’, ‘Candidatus Aquiluna rubra’, ‘Candidatus Flaviluna lacus’, ‘Candidatus Rhodoluna limnophila’, ‘Candidatus Rhodoluna planktonica’, ‘Candidatus Rhodoluna lacicola’ and ‘Candidatus Limnoluna rubra’ for these taxa.