Brevibacterium sediminis sp. nov., isolated from deep-sea sediments from the Carlsberg and Southwest Indian Ridges.

Three actinobacterial strains, FXJ8.128, FXJ8.269T and FXJ8.309, were isolated from deep-sea sediments collected from the Carlsberg Ridge and Southwest Indian Ridge at depths of 3690, 1800 and 2461 m, respectively. The three strains had highly similar 16S rRNA gene sequences (99.8-99.9 % identities) and formed a monophyletic clade within the Brevibacterium 16S rRNA gene tree, showing 98.2-98.9 % 16S rRNA gene sequence identities with type strains Brevibacterium epidermidis NCIMB 702286T, Brevibacterium iodinum DSM 20626T, Brevibacterium linens DSM 20425T, Brevibacterium oceani BBH7T and Brevibacterium permense VKM Ac-2280T. All three isolates showed activity towards the breakdown of pectin and fluoranthene. They contained MK-8(H2) as the most predominant menaquinone, diphosphatidylglycerol, phosphatidylglycerol and a glycolipd as the main polar lipids, and anteiso-C15 : 0 and anteiso-C17 : 0 as the major cellular fatty acids. Moreover, the three isolates were distinguished readily from the phylogenetically related type strains by DNA-DNA hybridization values, by random amplified polymorphic DNA fingerprint profiles and by a range of physiological and biochemical characteristics. On the basis of the above polyphasic taxonomic data, strains FXJ8.128, FXJ8.269T and FXJ8.309 represent a novel species of the genus Brevibacterium, for which the name Brevibacterium sediminis sp. nov. is proposed. The type strain is FXJ8.269T (=CGMCC 1.15472T=DSM 102229T).

Streptomyces rubrisoli sp. nov., neutrotolerant acidophilic actinomycetes isolated from red soil.

Three neutrotolerant, acidophilic actinomycete strains, designated FXJ1.526, FXJ1.725(T) and FXJ1.726, were isolated from red soil collected from Liujiazhan, Jiangxi Province, China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the three strains clustered together and their closest relative was Streptomyces ferralitis CGMCC 4.1985(T) (98.9-99.0% similarity). Multilocus sequence analysis confirmed their relationship to S. ferralitis and separated these strains as representing a novel species. Mean DNA-DNA hybridization values among strains FXJ1.526, FXJ1.725(T) and FXJ1.726 were 81.6 ± 3.5-87.2 ± 3.8%, and the values between the three strains and S. ferralitis CGMCC 4.1985(T) were well below 70%. The three strains also shared several phenotypic characteristics that were distinct from the closely related species. They grew at 21-50 °C, at pH 4.0-9.0 (with an optimal pH of 5.0) and with 0-3% (w/v) NaCl, and the major cellular fatty acids were anteiso-C15 : 0, iso-C15 : 0 and iso-C16 : 0. On the basis of data from this polyphasic taxonomic study, it is proposed that strains FXJ1.526, FXJ1.725(T) and FXJ1.726 be classified as representatives of a novel species of the genus Streptomyces, with the name Streptomyces rubrisoli sp. nov. The type strain is FXJ1.725(T) ( = CGMCC 4.7025(T)= DSM 42083(T)).

Streptomyces aidingensis sp. nov., an actinomycete isolated from lake sediment.

A novel actinomycete strain, designated TRM 46012(T), was isolated from sediment of Aiding Lake in Tulufan Basin (42° 64' N 89° 26' E), north-west China. The strain was aerobic and Gram-staining-positive with an optimum NaCl concentration for growth of 0-5% (w/v). The isolate had sparse aerial mycelium and produced bud-shaped spores at the end of the aerial mycelium on ISP medium 4. The isolate contained ll-diaminopimelic acid as the diagnostic diamino acid and ribose as the major whole-cell sugar. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol, phosphatidylinositol mannoside, one unidentified phospholipid and three unidentified glycolipids. The predominant menaquinones were MK-9(H6), MK-9(H8) and MK-9(H4). The major fatty acids were iso-C(16:0), anteiso-C(17:0) and anteiso-C(15:0). The G+C content of the DNA was 74.4 mol%. Phylogenetic analysis showed that strain TRM 46012(T) had 16S rRNA gene sequence similarity of 95.7% with the most closely related species with a validly published name, Streptomyces cheonanensis, and it could be distinguished from all species in the genus Streptomyces by using the data from this polyphasic taxonomic study. On the basis of these data, strain TRM 46012(T) should be designated as a representative of a novel species of the genus Streptomyces, for which the name Streptomyces aidingensis sp. nov. is proposed. The type strain is TRM 46012(T) ( =CGMCC 4.5739(T) =NBRC 108211(T)).

Cellulomonas marina sp. nov., isolated from deep-sea water.

A bacterial strain FXJ8.089(T) was isolated from deep-sea water collected from the southwest Indian Ocean (49° 39' E 37° 47' S) at a depth of 2800 m, and its taxonomic position was investigated by a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain FXJ8.089(T) belonged to the genus Cellulomonas and had the highest similarities with Cellulomonas oligotrophica (96.9 %) and Cellulomonas aerilata (96.6 %). It contained MK-9(H4) as the predominant menaquinone. The polar lipids were diphosphatidylglycerol and phosphatidylinositol mannosides. The cell-wall peptidoglycan type was A4ß with an interpeptide bridge L-Orn-D-Glu. The cell-wall sugars were glucose, mannose and ribose. The DNA G+C content was 70.3 mol%. The strain also showed a number of physiological and biochemical characteristics that were distinct from the closely related species. Based on phenotypic and genotypic data, strain FXJ8.089(T) (= CGMCC 4.6945(T) = DSM 24960(T)) represents a novel species of the genus Cellulomonas, for which the name Cellulomonas marina sp. nov. is proposed.

Longimycelium tulufanense gen. nov., sp. nov., a filamentous actinomycete of the family Pseudonocardiaceae.

A novel filamentous actinomycete strain, designated TRM 46004(T), was isolated from sediment of Aiding Lake in Tulufan Basin (42° 64' N 89° 26' E), north-west China. The isolate was characterized using a polyphasic approach. The isolate formed abundant aerial mycelium with few branches and vegetative mycelium, occasionally twisted and coiled; spherical sporangia containing one to several spherical spores developed at the ends of short sporangiophores on aerial mycelium. The G+C content of the DNA was 65.2 mol%. The isolate contained meso-diaminopimelic acid as the diagnostic diamino acid and xylose, galactose and ribose as the major whole-cell sugars. The diagnostic phospholipids were phosphatidylethanolamine, phosphatidylcholine and phosphatidylglycerol. The predominant menaquinones were MK-9(H4), MK-9(H6) and MK-9(H10). The major fatty acids were iso-C16 : 0 and anteiso-C17 : 0. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain TRM 46004(T) formed a distinct lineage within the family Pseudonocardiaceae and showed 91.7-96.1 % 16S rRNA gene sequence similarity with members of the family Pseudonocardiaceae. On the basis of the evidence from this polyphasic study, a novel genus and species, Longimycelium tulufanense gen. nov., sp. nov., are proposed. The type strain of Longimycelium tulufanense is TRM 46004(T) (= CGMCC 4.5737(T) = NBRC 107726(T)).

Saccharopolyspora lacisalsi sp. nov., a novel halophilic actinomycete isolated from a salt lake in Xinjiang, China.

A novel actinomycete strain, designated TRM 40133(T), was isolated from a hypersaline habitat of Tarim basin in Xinjiang Province, north-west China. Its taxonomic status was determined using a polyphasic approach. Phylogenetic analysis based on an almost-complete 16S rRNA gene sequence of the strain showed that it formed a well-seperated sub-branch within the radiation of the genus Saccharopolyspora. The highest levels of 16S rRNA gene sequence similarity was found between the strain TRM 40133(T) and Saccharopolyspora qijiaojingensis YIM 91168(T) (96.5%). The chemotaxonomic characteristics of the isolate are typical for the genus Saccharopolyspora. It contained meso-DAP as the diagnostic diamino acid. Whole cell hydrolysate contained arabinose, xylose, ribose and glucose. The diagnostic phospholipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol and two unknown phospholipids. The main menaquinone was MK-9(H(6)) and MK-9(H(4)). No mycolic acid was detected. The predominant cellular fatty acids were iso-C(16:0) and anteiso-C(17:0). The G+C content of the genomic DNA was 68.2 mol%. In addition, the strain TRM 40133(T) had a phenotypic profile that readily distinguished it from the recognized representatives of the genus Saccharopolyspora. The strain TRM 40133(T) therefore represents a novel species of the genus Saccharopolyspora, for which the name Saccharopolyspora lacisalsi sp. nov. is proposed. The type strain is TRM 40133(T) (=KCTC 19987(T) =CCTCC AA 2010012(T)).

Genetic screening strategy for rapid access to polyether ionophore producers and products in actinomycetes.

Polyether ionophores are a unique class of polyketides with broad-spectrum activity and outstanding potency for the control of drug-resistant bacteria and parasites, and they are produced exclusively by actinomycetes. A special epoxidase gene encoding a critical tailoring enzyme involved in the biosynthesis of these compounds has been found in all five of the complete gene clusters of polyether ionophores published so far. To detect potential producer strains of these antibiotics, a pair of degenerate primers was designed according to the conserved regions of the five known polyether epoxidases. A total of 44 putative polyether epoxidase gene-positive strains were obtained by the PCR-based screening of 1,068 actinomycetes isolated from eight different habitats and 236 reference strains encompassing eight major families of Actinomycetales. The isolates spanned a wide taxonomic diversity based on 16S rRNA gene analysis, and actinomycetes isolated from acidic soils seemed to be a promising source of polyether ionophores. Four genera were detected to contain putative polyether epoxidases, including Micromonospora, which has not previously been reported to produce polyether ionophores. The designed primers also detected putative epoxidase genes from diverse known producer strains that produce polyether ionophores unrelated to the five published gene clusters. Moreover, phylogenetic and chemical analyses showed a strong correlation between the sequence of polyether epoxidases and the structure of encoded polyethers. Thirteen positive isolates were proven to be polyether ionophore producers as expected, and two new analogues were found. These results demonstrate the feasibility of using this epoxidase gene screening strategy to aid the rapid identification of known products and the discovery of unknown polyethers in actinomycetes.

Actinopolyspora alba sp. nov. and Actinopolyspora erythraea sp. nov., isolated from a salt field, and reclassification of Actinopolyspora iraqiensis Ruan et al. 1994 as a heterotypic synonym of Saccharomonospora halophila.

Three actinomycetal strains, designated YIM 90479, YIM 90480(T) and YIM 90600(T), were isolated from a salt field in Xinjiang province, North-west China and subjected to polyphasic taxonomic study. All three strains were moderately halophilic and were able to grow on agar at NaCl concentrations of up to 20-25 % (w/v). No growth was observed in the absence of NaCl. Good growth occurred at 37 °C and 15 % (w/v) NaCl. The cell walls of the three strains were of the type IV variety and their phospholipid patterns were type PIII. MK-9 (H(4)) and MK-10 (H(4)) or MK-9 (H(4)) and MK-9 (H(2)) were the predominant menaquinones. iso-C(16 : 0) and anteiso-C(17 : 0) or anteiso-C(15 : 0) and anteiso-C(17 : 0) were the major fatty acids. The G+C contents of the genomic DNA were 66.4-68.3 mol%. Based on differential phenotypic, chemotaxonomic and phylogenetic characteristics and the results of DNA-DNA hybridization tests, the three novel stains represent two novel species, for which the names Actinopolyspora alba sp. nov. and Actinopolyspora erythraea sp. nov. are proposed. The type strains of the species are YIM 90480(T) ( = DSM 45004(T)  = KCTC 19119(T)) and YIM 90600(T) ( = CCTCC M 208247(T)  = KCTC 19372(T)). In addition, we propose that Actinopolyspora iraqiensis (Ruan et al., 1994) be transferred to the genus Saccharomonospora as a heterotypic synonym of Saccharomonospora halophila based on present research results.

Streptomyces sanyensis sp. nov., isolated from mangrove sediment.

A novel strain, 219820(T), whose metabolites were found to be active against tumour cells, was isolated and characterized. The isolate belonged to the genus Streptomyces and had white to grey aerial mycelium and long chains of smooth spores in the aerial mycelium. A phylogenetic tree based on 16S rRNA gene sequences showed that strain 219820(T) had highest similarity to members of the genus Streptomyces and was most closely, albeit loosely, associated with Streptomyces crystallinus NBRC 15401(T) (98.624 % similarity), Streptomyces melanogenes NBRC 12890(T) (98.565 %) and Streptomyces noboritoensis NBRC 13065(T) (98.564 %). However, DNA-DNA relatedness and phenotypic data readily distinguished strain 219820(T) from these phylogenetically related type strains. It is evident from the combination of genotypic and phenotypic data that strain 219820(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces sanyensis sp. nov. is proposed; the type strain is 219820(T) ( = CGMCC 4.5626(T)  = DSM 42014(T)).

Streptomyces avicenniae sp. nov., a novel actinomycete isolated from the rhizosphere of the mangrove plant Avicennia mariana.

A novel isolate, designated strain MCCC 1A01535(T), belonging to the genus Streptomyces was isolated from the rhizosphere of the mangrove plant Avicennia mariana from Fujian Province, south China. Characterization of the isolate was based on a polyphasic approach. Pairwise comparison of 16S rRNA gene sequences revealed that strain MCCC 1A01535(T) shared 97.7 and 97.5 % sequence similarities to Streptomyces specialis GW41-1564(T) and Streptomyces hainanensis YIM47672(T), respectively, its most closely related neighbours, whereas the DNA-DNA relatedness value between strains MCCC 1A01535(T) and GW41-1564(T) was 50.2 %. The major fatty acids of strain MCCC 1A01535(T) were iso-C(16 : 0), C(16 : 0) and anteiso-C(15 : 0). These differed from the fatty acid compositions of related strains. Strain MCCC 1A01535(T) exhibited an unusual menaquinone system that comprised MK-10(H(6)) as the predominant component and moderate amounts of MK-9(H(6)), MK-9(H(8)) and MK-10(H(8)); minor amounts of MK-9(H(4)), MK-10(H(4)), MK-9(H(10)) and MK-10(H(10)) were also present. Based on its chemotaxonomic, phenotypic and genotypic characteristics, strain MCCC 1A01535(T) is considered to represent a novel species of the genus Streptomyces, for which the name Streptomyces avicenniae sp. nov. is proposed. The type strain is MCCC 1A01535(T) (=DSM 41943(T)=CGMCC 4.5510(T)).

Actinomycetes for marine drug discovery isolated from mangrove soils and plants in China.

The mangrove ecosystem is a largely unexplored source for actinomycetes with the potential to produce biologically active secondary metabolites. Consequently, we set out to isolate, characterize and screen actinomycetes from soil and plant material collected from eight mangrove sites in China. Over 2,000 actinomycetes were isolated and of these approximately 20%, 5%, and 10% inhibited the growth of Human Colon Tumor 116 cells, Candida albicans and Staphylococcus aureus, respectively, while 3% inhibited protein tyrosine phosphatase 1B (PTP1B), a protein related to diabetes. In addition, nine isolates inhibited aurora kinase A, an anti-cancer related protein, and three inhibited caspase 3, a protein related to neurodegenerative diseases. Representative bioactive isolates were characterized using genotypic and phenotypic procedures and classified to thirteen genera, notably to the genera Micromonospora and Streptomyces. Actinomycetes showing cytotoxic activity were assigned to seven genera whereas only Micromonospora and Streptomyces strains showed anti-PTP1B activity. We conclude that actinomycetes isolated from mangrove habitats are a potentially rich source for the discovery of anti-infection and anti-tumor compounds, and of agents for treating neurodegenerative diseases and diabetes.

Streptomyces xiamenensis sp. nov., isolated from mangrove sediment.

Actinomycete strain MCCC 1A01550(T), isolated from the national mangrove reserve in Fujian Province, China, was determined to belong to the genus Streptomyces based on a polyphasic approach. The cell wall of the novel strain contained ll-diaminopimelic acid and galactose. The predominant menaquinones were MK-9(H(4)) and MK-9(H(6)) and the major fatty acids were iso-C(16 : 0), cis9-C(16 : 1) and C(16 : 0). The diagnostic phospholipid was phosphatidylethanolamine. The DNA G+C content of the novel strain was 71.6 mol%. Phylogenetic analysis of 16S rRNA gene sequences confirmed the separation of the novel strain from recognized members of the genus Streptomyces available in public databases. DNA-DNA relatedness values between strain MCCC 1A01550(T) and the type strains of three related species ranged from 21.29 % to 43.38 %. Based on its phenotypic and genotypic characteristics, strain MCCC 1A01550(T) (=DSM 41903(T)=CGMCC 4.3534(T)) represents the type strain of a novel species, for which the name Streptomyces xiamenensis sp. nov. is proposed.