Saccharothrix obliqua sp. nov., isolated from soil of Sichang Island, Thailand

During an investigation of rare actinobacteria, isolate SC076T was isolated from a soil sample collected from Sichang Island, Chonburi Province, Thailand. The strain showed the highest 16S rRNA gene similarity to Saccharothrix australiensis DSM 43800T (98.6%) and Saccharothrix espanaensis DSM 44229T (98.6%). The zigzag morphology of the spore chain was observed on the aerial mycelia. meso-Diaminopimelic acid was detected in the peptidoglycan. Whole-cell sugars contained rhamnose, ribose, mannose glucose and galactose. Polar lipids were phosphatidylethanolamine, hydroxyphosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol mannoside, phosphatidylinositol, unidentified ninhydrin-positive glycolipid, unidentified glycolipid and four unidentified lipids. The menaquinones were MK-9(H8), MK-9(H4), MK-9(H2) and MK-9(H0). The predominant fatty acids were iso-C16 : 0, iso-C15 : 0 and anteiso-C17 : 0. The draft genome of SC076T was 8040245 bp with a G+C content of 72.5 mol%. The results of genomic analysis between strain SC076T and the related type strains showed that the digital DNA–DNA hybridization and average nucleotide identity values among the strains were 23.6-32.8% and 77.7–86.8 %, respectively, which are lower than the thresholds used to distinguish strains from others of the same species. Based on the taxonomic evidence, strain SC076T represents a novel species of the genus Saccharothrix for which the name Saccharothrix obliqua sp. nov. is proposed. The type strain is SC076T (=TBRC 14540T=NBRC 115117T).

Saccharothrix lopnurensis sp. nov., a filamentous actinomycete isolated from sediment of Lop Nur

A novel actinomycete strain, designated YIM LPA2h(T), was isolated from a sediment sample collected from Lop Nur, Xinjiang Uygur Autonomous Region, North-West China. The taxonomic position of strain YIM LPA2h(T) was investigated by a polyphasic approach. The morphological and chemotaxonomic properties of the isolate were in accordance with the members of the genus Saccharothrix. The 16S rRNA gene sequence of the strain showed highest similarities to Saccharothrix yanglingensis (98.6 %), Saccharothrix longispora (98.4 %) and Saccharothrix hoggarensis (98.3 %). However, the DNA-DNA hybridization values between the new isolate YIM LPA2h(T) and S. yanglingensis, S. longispora and S. hoggarensis were significantly below 70 %. Strain YIM LPA2h(T) was found to contain meso-diaminopimelic acid as diagnostic diamino acid. The major sugars in whole-cell hydrolysates were rhamnose, galactose, mannose, glucose and fructose. The major polar lipids were identified as phosphatidylethanolamine, phosphatidylhydroxylethanolamine, diphosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside. The predominant respiratory menaquinones were MK-9 (H4) and MK-10 (H4). The major fatty acids were C17:1 ω8c (15 %), iso-C15:0 (12 %), anteiso-C15:0 (12 %) and summed feature 3 (C16:1 ω6c/C16:1 ω7c, 10 %). The genomic DNA G+C content of strain YIM LPA2h(T) was determined to be 75 mol %. The genotypic and phenotypic results suggest that strain YIM LPA2h(T) represents a novel species of the genus Saccharothrix, for which the name Saccharothrix lopnurensis sp. nov. is proposed. The type strain is YIM LPA2h(T) (=CGMCC 4.7246(T)=KCTC 39545(T)).

Reclassification of ‘Dactylosporangium variesporum’ as Saccharothrix variisporea corrig. (ex Tomita et al. 1977) sp. nov., nom. rev

In the course of a polyphasic study it was observed that ‘Dactylosporangium variesporum’ NRRL B-16296 is misclassified in the genus Dactylosporangium as it exhibits properties consistent with its assignment to the genus Saccharothrix. Phylogenetic analyses based on 16S rRNA gene sequences show that the strain falls within the evolutionary radiation of the genus Saccharothrix, a result which is supported by corresponding chemotaxonomic and morphological markers. The strain is phylogenetically most closely, albeit loosely, related to Saccharothrix espanaensis, but can be readily distinguished from this and other species of the genus Saccharothrix with validly described names by using a range of phenotypic properties. The combined genotypic and phenotypic data demonstrate conclusively that this strain should be classified as a new species in the genus Saccharothrix for which the name Saccharothrix variisporea sp. nov. is proposed. The type strain is NRRL B-16296T (=ATCC 31203T =DSM 43911T =JCM 3273T =NBRC 14104T).