A spore-forming streptomycete designated strain SUK12(T) was isolated from a Malaysian ethnomedicinal plant. Its taxonomic position, established using a polyphasic approach, indicates that it is a novel species of the genus Streptomyces. Morphological and chemical characteristics of the strain were consistent with those of members of the genus Streptomyces. Analysis of the almost complete 16S rRNA gene sequence placed strain SUK12(T) in the genus Streptomyces where it formed a distinct phyletic line with recognized species of this genus. The strain exhibited highest sequence similarity to Streptomyces corchorusii DSM 40340(T) (98.2 %) followed by Streptomyces chrestomyceticus NRRL B-3310(T) (98.1 %). The G+C content of the genomic DNA was 74 mol%. Chemotaxonomic data [MK-9(H8) as the major menaquinone; LL-diaminopimelic acid as a component of cell-wall peptidoglycan; C12 : 0, C14 : 0, C15 : 0 and C17 : 1 as the major fatty acids; phospholipid type II] supported the affiliation of strain SUK12(T) to the genus Streptomyces. The results of the phylogenetic analysis and phenotypic data derived from this and previous studies allowed the genotypic and phenotypic differentiation of strain SUK12(T) from the related species of the genus Streptomyces. The DNA-DNA relatedness value between strain SUK12(T) and S. corchorusii DSM 40340(T) is 18.85±4.55 %. Strain SUK12(T) produces phenazine-1-carboxylic acid, known as tubermycin B, an antibacterial agent. It is proposed, therefore, that strain SUK12(T) ( = DSM 42048(T) = NRRL B-24860(T)) be classified in the genus Streptomyces as the type strain of Streptomyces kebangsaanensis sp. nov.
Three novel actinobacteria, strains 39(T), 40 and 41, were isolated from soil collected from Barrientos Island in the Antarctic. The taxonomic status of these strains was determined using a polyphasic approach. Comparison of 16S rRNA gene sequences revealed that strain 39(T) represented a novel lineage within the family Dermacoccaceae and was most closely related to members of the genera Demetria (96.9 % 16S rRNA gene sequence similarity), Branchiibius (95.7 %), Dermacoccus (94.4-95.3 %), Calidifontibacter (94.6 %), Luteipulveratus (94.3 %), Yimella (94.2 %) and Kytococcus (93.1 %). Cells were irregular cocci and short rods. The peptidoglycan type was A4α with an L-Lys-L-Ser-D-Asp interpeptide bridge. The cell-wall sugars were galactose and glucose. The major menaquinone was MK-8(H(4)). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphoglycolipid, two glycolipids and one unknown phospholipid. The acyl type of the cell-wall polysaccharide was N-acetyl. The major cellular fatty acids were anteiso-C(17 : 0) (41.97 %), anteiso-C(17 : 1)ω9c (32.16 %) and iso-C(16 : 0) (7.68 %). The DNA G+C content of strain 39(T) was 68.4 mol%. On the basis of phylogenetic and phenotypic differences from other genera of the family Dermacoccaceae, a novel genus and species, Barrientosiimonas humi gen. nov., sp. nov., is proposed; the type strain of the type species is 39(T) (=CGMCC 4.6864(T) = DSM 24617(T)).
A novel Streptomyces, strain MUSC 26(T), was isolated from mangrove soil at Tanjung Lumpur, Malaysia. The bacterium was observed to be Gram-positive and to form grayish yellow aerial and substrate mycelium on ISP 7 agar. A polyphasic approach was used to study the taxonomy of strain MUSC 26(T), which shows a range of phylogenetic and chemotaxonomic properties consistent with those of the members of the genus Streptomyces. The cell wall peptidoglycan was determined to contain LL-diaminopimelic acid. The predominant menaquinones were identified as MK-9 (H8) and MK-9(H6). The polar lipids detected were identified as diphosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylmethylethanolamine and hydroxyphosphatidylmethylethanolamine. The predominant cellular fatty acids (>10.0 %) were identified as anteiso-C15:0 (31.4 %), iso-C16:0 (16.3 %), iso-C15:0 (13.9 %) and anteiso-C17:0 (12.6 %). The cell wall sugars were found to be galactose, glucose, mannose, ribose and rhamnose. These results suggest that MUSC 26(T) should be placed within the genus Streptomyces. Phylogenetic analysis indicated that closely related strains include Streptomyces qinglanensis 172205(T) (96.5 % sequence similarity), S. sodiiphilus YIM 80305(T) (96.5 %) and S. rimosus subsp. rimosus ATCC 10970(T) (96.4 %). DNA-DNA relatedness values between MUSC 26(T) and closely related type strains ranged from 17.0 ± 2.2 to 33.2 ± 5.3 %. Comparison of BOX-PCR fingerprints indicated MUSC 26(T) presents a unique DNA profile. The DNA G+C content was determined to be 74.6 mol%. Based on this polyphasic study of MUSC 26(T), it is concluded that this strain represents a novel species, for which the name Streptomyces gilvigriseus sp. nov. is proposed. The type strain is MUSC 26(T) (=DSMZ 42173(T) = MCCC 1K00504(T)).