Streptomyces jiujiangensis sp. nov., isolated from soil in South China

Modestobacter lacusdianchii sp. nov., a Phosphate-Solubilizing Actinobacterium with Ability to Promote Microcystis Growth

A novel actinobacterium, designated strain JXJ CY 19T, was isolated from a culture mat of Microcystis aeruginosa FACHB-905 collected from Dianchi Lake, South-west China. 16S rRNA gene sequences comparison of strain JXJ CY 19T and the available sequences in the GenBank database showed that the strain was closely related to Modestobacter marinus 42H12-1T (99.1% similarity) and Modestobacter roseus KLBMP 1279T (99.0%). The isolate had meso-diaminopimelic in the cell wall with whole-cell sugars of mannose, rhamnose, ribose, glucose, galactose, and arabinose. The menaquinone detected was MK-9(H4), while the major cellular fatty acids include C17:1 ω8c, C15:0 iso, C15:1 iso G and C16:0 iso. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and an unidentified phospholipid. The DNA-DNA hybridization values between strains JXJ CY 19T and the closely related type strains Modestobacter marinus CGMCC 4.5581T and Modestobacter roseus NBRC 108673T were determined to be 50.8 ± 0.8% and 44.1 ± 1.7%, respectively. The DNA G+C content was 71.9 mol%. On the basis of the above taxonomic data and differences in physiological characters from the closely related type strains, strain JXJ CY 19T was recognized as a novel species of the genus Modestobacter, for which the name Modestobacter lacusdianchii sp. nov. (JXJ CY 19T = KCTC 39600T = CPCC 204352T) is proposed. The type strain JXJ CY 19T can solubilize calcium phosphate tribasic (Ca3(PO4)2), phytin and L-α-phosphatidylcholine. The phosphate-solubilizing property of the novel actinobacterium could be a possible factor for the increase in growth of Microcystis aeruginosa FACHB-905 in ecosystem where the amount of available soluble phosphate is limited such as Dianchi Lake.

Streptomyces humi sp. nov., an actinobacterium isolated from soil of a mangrove forest

A novel Streptomyces strain, MUSC 119(T), was isolated from a soil collected from a mangrove forest. Cells of MUSC 119(T) stained Gram-positive and formed light brownish grey aerial mycelium and grayish yellowish brown substrate mycelium on ISP 2 medium. A polyphasic approach was used to determine the taxonomic status of strain MUSC 119(T), which shows a range of phylogenetic and chemotaxonomic properties consistent with those of the genus Streptomyces. The cell wall peptidoglycan consisted of LL-diaminopimelic acid. The predominant menaquinones were identified as MK-9(H8), MK-9(H6) and MK-9(H4). The polar lipid profile consisted of phosphatidylinositol, phosphatidylethanolamine, glycolipids, diphosphatidylglycerol and four phospholipids. The predominant cellular fatty acids were anteiso-C15:0, iso-C16:0, and anteiso-C17:0. The cell wall sugars were glucose, mannose, ribose and rhamnose. The phylogenetic analysis based on 16S rRNA gene sequence similarity showed that strain MUSC119(T) to be closely related to Streptomyces rhizophilus JR-41(T) (99.0 % sequence similarity), S. panaciradicis 1MR-8(T) (98.9 %), S. gramineus JR-43(T) (98.8 %) and S. graminisoli JR-19(T) (98.7 %). These results suggest that MUSC 119(T) should be placed within the genus Streptomyces. DNA-DNA relatedness values between MUSC 119(T) to closely related strains ranged from 14.5 ± 1.3 to 27.5 ± 0.7 %. The G+C content was determined to be 72.6 mol %. The polyphasic study of MUSC 119(T) showed that this strain represents a novel species, for which the name Streptomyces humi sp. nov. is proposed. The type strain of S. humi is MUSC 119(T) (=DSM 42174(T) = MCCC 1K00505(T)).

L-valine, an antialgal amino acid from Streptomyces jiujiangensis JXJ 0074(T)

An antialgal compound was isolated from the cultured broth of Streptomyces jiujiangensis JXJ 0074(T) by using bioassay methods. Based on the data of (1)H-NMR, (13)C-NMR, ESI-MS, and thin layer chromatography, the active compound was identified as L-valine, which showed antialgal activity mainly against Microcystis. L-valine exhibited greater antialgal activities than both L-lysine and copper sulfate (CuSO4) did on Microcystis aeruginosa lawn. However, M. aeruginosa recovered growth earlier with higher growth rate in L-valine treatment than in L-lysine treatment. L-valine dissipated completely within 2 days, much quicker than L-lysine (6 days), which resulted in the lysing of more than 80 % M. aeruginosa cells and the release of amount of intracellular microcystin-LR (MC-LR) within 2 days. As a resultant, the extracellular MC-LR content was more than twice of the control from day 1 to 5. Exposure to L-valine significantly promoted the synthesis of MC-LR. L-lysine also promoted the release and synthesis of MC-LR with much lesser efficiency than L-valine. L-valine could damage Microcystis severely, causing perforation and collapse of M. aeruginosa cells and decrease of the chlorophyll. The superoxide dismutase (SOD) activity in L-valine-treated cells of M. aeruginosa initially increased with 32.94 ± 3.37 % higher than the control after 36 h and then decreased quickly. However, the increase rate of superoxide anion radical (O2 (-)) was much higher than that of SOD, which resulted in serious lipid peroxidation and accumulation of malondialdehyde (MDA). To our knowledge, this is the first report showing L-valine active against cyanobacteria.

Streptomyces hyaluromycini sp. nov., isolated from a tunicate (Molgula manhattensis)

A novel Gram-stain-positive actinomycete, designated MB-PO13(T), was isolated from a tunicate (Molgula manhattensis) collected in Tokyo Bay, Japan, and its taxonomic position was studied by a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain MB-PO13(T) was closely related to Streptomyces graminisoli JR-12(T) (99.72% 16S rRNA gene sequence similarity) and Streptomyces shenzhenensis 172115(T) (99.23%). The strain contained LL-diaminopimelic acid in the whole-cell hydrolysate. The predominant menaquinones were MK-9(H8) and MK-9(H6) and the major fatty acids were anteiso-C15:0, iso-C16:0, iso-C14:0 and C16:0. These data supported the affiliation of the novel strain to the genus Streptomyces. Meanwhile, results of DNA-DNA hybridization and physiological and biochemical tests indicated that strain MB-PO13(T) was distinguished from known Streptomyces type strains. Therefore, strain MB-PO13(T) represents a novel species of the genus Streptomyces for which the name Streptomyces hyaluromycini sp. nov. is proposed; the type strain is MB-PO13(T) (=NBRC 110483(T) =DSM 100105(T)).

An antialgal compound produced by Streptomyces jiujiangensis JXJ 0074(T)

Previous investigations suggested that Streptomyces jiujiangensis JXJ 0074(T) can secrete antialgal compounds. In this study, an antialgal compound was isolated from the cultured broth of S. jiujiangensis JXJ 0074(T) by using bioassay methods. Based on spectroscopic data, the active compound was identified as 2'-deoxyadenosine, which exhibited a greater antialgal activity against cyanobacteria than its analogues such as adenosine, guanosine, and 2'-deoxyguanosine. The antialgal activity of 2'-deoxyadenosine increased with the content and time. 2'-Deoxyadenosine severely damaged the vegetative cells of cyanobacteria, causing crumpling, collapse, expanding, perforation, breakage of filamentous cyanobacteria, and decrease of the chlorophyll. However, 2'-deoxyadenosine seemed to have less impact on the morphology of heterocysts of filamentous cyanobacteria. The superoxide dismutase (SOD) activity in the treated cells of M. aeruginosa FACHB-905 initially increased with 31.14 ± 2.00% higher than that of the control after 36 h and then decreased quickly. On the same time, there were rapid increases in superoxide anion radical (O2 (-)) and malondialdehyde (MDA) contents with 315.53 ± 12.81 and 84.72 ± 6.15% higher than these of the controls at 60 h, respectively. The intracellular microcystin-LR (MC-LR) content in the treated cells of M. aeruginosa FACHB-905 increased by 36.34 ± 7.35% 1 day later, followed by a rapid decrease with a rate of 90.50 ± 1.08% 8 days later, while the extracellular MC-LR content showed no significant difference with the control. Five days after adding 15 μg/ml of 2'-deoxyadenosine to the culture of M. aeruginosa FACHB-905, there was no 2'-deoxyadenosine detected by HPLC, suggesting that 2'-deoxyadenosine completely degraded. This study provides a new clue to screen natural-based antialgal compounds from nucleoside analogues.

List of new names and new combinations previously effectively, but not validly, published

The purpose of this announcement is to effect the valid publication of the following effectively published new names and new combinations under the procedure described in the Bacteriological Code (1990 Revision). Authors and other individuals wishing to have new names and/or combinations included in future lists should send three copies of the pertinent reprint or photocopies thereof, or an electronic copy of the published paper to the IJSEM Editorial Office for confirmation that all of the other requirements for valid publication have been met. It is also a requirement of IJSEM and the ICSP that authors of new species, new subspecies and new combinations provide evidence that types are deposited in two recognized culture collections in two different countries. It should be noted that the date of valid publication of these new names and combinations is the date of publication of this list, not the date of the original publication of the names and combinations. The authors of the new names and combinations are as given below. Inclusion of a name on these lists validates the publication of the name and thereby makes it available in the nomenclature of prokaryotes. The inclusion of a name on this list is not to be construed as taxonomic acceptance of the taxon to which the name is applied. Indeed, some of these names may, in time, be shown to be synonyms, or the organisms may be transferred to another genus, thus necessitating the creation of a new combination.