AH7, a non-polyenic antifungal antibiotic produced by a new strain of Streptosporangium roseum

An antibiotic (AH7) produced by Streptosporangium roseum strain 214 was investigated. This compound was extracted with chloroform from the filtrate culture and purified using thin-layer chromatography and high pressure liquid chromatography procedures. The antibiotic strongly inhibited the growth of several strains of fungi and bacteria known to be plant and human pathogens. This compound differed from all other antibiotics known to be synthesized by Streptosporangium spp. Some of its chemical and physical properties resembled those of maytansines produced by Nocardia but the antibiotic AH7 has only antibacterial and antitumoral activities.     

Complete genome sequence of Streptosporangium roseum type strain (NI 9100)

Streptosporangium roseum Crauch 1955 is the type strain of the species which is the type species of the genus Streptosporangium. The 'pinkish coiled Streptomyces-like organism with a spore case' was isolated from vegetable garden soil in 1955. Here we describe the features of this organism, together with the complete genome sequence and annotation. This is the first completed genome sequence of a member of the family Streptosporangiaceae, and the second largest microbial genome sequence ever deciphered. The 10,369,518 bp long genome with its 9421 protein-coding and 80 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.     

Production and characterization of a thermostable glucoamylase from Streptosporangium sp. endophyte of maize leaves

Thermostable amylolytic enzymes are currently investigated to improve industrial processes of starch degradation. Streptosporangium sp. an endophytic actinomycete isolated from leaves of maize (Zea mays L.) showed glucoamylase production, using starch-Czapek medium, and the highest rate was obtained in the initial growth phase, after incubation for 24 h at pH 8.0. Maximum glucoamylase activity (158 U mg(-1) protein) was obtained at pH 4.5 and 70 degrees C. The isolated enzyme exhibited thermostable properties as indicated by retention of 100% of residual activity at 70 degrees C for 30 min with total inhibition at 100 degrees C. Extracellular enzyme from Streptosporangium sp. was purified by fractionated precipitation with ammonium sulphate. After 60% saturation produced 421 U mg(-1) protein, and yield was 74% with purification 2.7 fold. The enzyme produced by Streptosporangium sp. has potential for industrial applications.     

一株Streptosporangium sp.次生代谢产物研究Ⅰ

通过对Streptosporangium sp．菌株发酵液的初步分离纯化,得到三个化合物,由波谱解析鉴定为：4,6-二甲基-6-羟基-庚烯-2酮(1),2,6-二甲基-2,6-二羟基-庚4酮(2),3,6-二异丙基-2,5-二酮哌嗪(3)。由活体试验证明2和3对粘虫有一定的抑制活性。     

Isolation and partial characterization of pigment-like antibiotics produced by a new strain of Streptosporangium isolated from an Algerian soil

AIMS: Identification of a new actinomycete strain Sg3, belonging to the genus Streptosporangium and partial characterization of the produced antibacterial activities. METHODS AND RESULTS: The strain Sg3 was isolated from an Algerian Saharan soil and identified by morphological, chemotaxonomic and phylogenetic analyses to the genus Streptosporangium. The comparison of its physiological characteristics with those of known species of Streptosporangium showed significant differences with the nearest species Streptosporangium carneum. Analysis of the 16S rDNA sequence of strain Sg3 showed a similarity level ranging between 97% and 98.8% within Streptosporangium species, with S. carneum the most closely related. Strain Sg3 showed a red coloured antibacterial activity against gram-positive bacteria on several culture media. The purification of the red pigment by chromatographic methods led to the isolation of three active products. The (1)H nuclear magnetic resonance (NMR), mass, infrared (IR) and ultraviolet-visible (UV-VIS) data of these molecules strongly suggested that they belonged to the quinone-anthracycline group with three or more rings. CONCLUSIONS: Strain Sg3 represents a distinct phyletic line suggesting a new genomic species. It produces antibacterial activities identified as quinone-anthracycline aromatics. SIGNIFICANCE AND IMPACT OF THE STUDY: The quinone-anthracycline antibiotics are known for their antimicrobial and antineoplastic activities and are used in chemotherapy for the treatment of many cancer diseases. The present work constitutes the first stage of a whole series of studies to be realized on these antibiotics before arriving at a possible application.     

Streptosporangium nanhuense sp. nov., a novel actinomycete isolated from soil

A novel actinomycete, designated strain NEAU-NH11^T, was isolated from muddy soil collected from a lake and characterized using a polyphasic approach. The 16S rRNA gene sequence analysis showed that strain NEAU-NH11^T belongs to the genus Streptosporangium, and was most closely related to Streptosporangium amethystogenes subsp. amethystogenes DSM 43179^T (99.0 %). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain NEAU-NH11^T formed a monophyletic clade with Streptosporangium purpuratum CY-15110^T (98.3 %) and Streptosporangium yunnanense CY-11007^T (98.0 %), an association that was supported by a bootstrap value of 80 % in the neighbour-joining tree and also recovered with the maximum-likelihood algorithm. However, the low level of DNA–DNA relatedness allowed the strain to be differentiated from S. amethystogenes subsp. amethystogenes DSM 43179^T, S. purpuratum CY-15110^T and S. yunnanense CY-11007^T. Moreover, strain NEAU-NH11^T could also be differentiated from its closest related strains by phenotypic characteristics. Therefore, it is proposed that strain NEAU-NH11^T represents a novel Streptosporangium species, Streptosporangium nanhuense sp. nov. The type strain of S. nanhuense is NEAU-NH11^T. (=CGMCC 4.7131^T = DSM 46674^T).     

Pyrrolo[1,4]benzodiazepine antibiotics. Biosynthesis of the antitumor antibiotic sibiromycin by Streptosporangium sibiricum

The biosynthesis of the antitumor antibiotic sibiromycin by Streptosporangium sibiricum requires the construction of four units: the amino sugar from glucose; the anthranilate ring from DL-tryptophan probably via kynurenine; the aromatic methyl group from methionine; the propylidene proline from L-tyrosine with the loss of two aromatic carbons and addition of a C-1 from methionine. Retention of tritium from DL-[5-3H]tryptophan in sibiromycin suggest an NIH shift during hydroxylation of an intermediate.     

Streptosporangium shengliensis sp. nov., a novel actinomycete isolated from a lake sediment

A novel actinomycete, designated strain NEAU-GH7^T, was isolated from a lake sediment and characterized using a polyphasic approach. Strain NEAU-GH7^T was Gram-stain positive, aerobic, non-spore-forming and produced spherical sporangia. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain NEAU-GH7^T formed a monophyletic clade with the closest relative Streptosporangium longisporum DSM 43180^T (99.0 %), an association that was supported by a bootstrap value of 74 % in the neighbour-joining tree and also recovered with the maximum-likelihood algorithm. However, the low level of DNA–DNA relatedness allowed the strain to be differentiated from its closest relative. Moreover, strain NEAU-GH7^T could also be differentiated from S. longisporum DSM 43180^T and other Streptosporangium species showing high 16S rRNA gene sequence similarity (>98.0 %) by morphological and physiological characteristics. On the basis of phylogenetic analysis, DNA–DNA hybridization and phenotypic characteristics, strain NEAU-GH7^T should be classified as a new species of the genus Streptosporangium, for which the name Streptosporangium shengliensis sp. nov. is proposed. The type strain is NEAU-GH7^T (=CGMCC 4.7105^T=DSM 45881^T).     

Improved secondary metabolite production in the genus Streptosporangium by optimization of the fermentation conditions

The cultivation of strains of the genus Streptosporangium in batch fermentations demonstrated that the optimal conditions for secondary metabolite production are completely different to those of the closely related genus Streptomyces. The dissolved oxygen tension (pO(2)) was identified as an important parameter for optimal production of secondary metabolites in submerged cultures. Extreme variations of this parameter by changes in aeration (gas flow), agitation system and stirrer speed showed a tremendous impact in production yields of all investigated strains. Finally, a 20-fold increase in productivity was observed by conditions of controlled oxygen excess compared to optimal fermentation conditions for Streptomyces strains.     

Collodion membrane secures cells sorted by flow cytofluorometry onto microscope slides

Quantitative microscopic cytology of cells previously sorted by flow cytofluorometry has been hindered by the loss of cells from the microscope slide during staining procedures. The simple application of a semi-permeable membrane of collodion over fixed or unfixed cells sorted directly onto a microscope slide secured virtually 100% of the cells onto the slide. Cells covered with the collodion membrane studied with Papanicolaou's stain as well as routine clinical cervical cytologic preparations. In contrast, fewer than one half of the cells sorted onto uncoated or albumin coated slides were retained after staining.     

Streptosporangium subfuscum sp. nov., isolated from the rhizosphere of marigold (Tagetes erecta L.)

A Gram-stain positive, filamentous bacterial strain, designated strain NEAU-TWSJ13^T, was isolated from the rhizosphere of a marigold (Tagetes erecta L.) plant collected in Heilongjiang Province, northeast China, and characterized using a polyphasic approach. The strain was observed to form abundant aerial hyphae differentiated into spherical sporangia. 16S rRNA gene sequence similarity studies showed that strain NEAU-TWSJ13^T belongs to the genus Streptosporangium, being most closely related to Streptosporangium fragile DSM 43847^T (98.6 %). Phylogenetic analysis of the 16S rRNA gene sequence indicated that it formed a phyletic line with S. fragile DSM 43847^T, Streptosporangium jomthongense NBRC 110047^T (98.4 % 16S rRNA gene similarity) and Streptosporangium violaceochromogenes DSM 43849^T (97.6 % 16S rRNA gene similarity). A combination of DNA–DNA hybridization results and some phenotypic characteristics indicated that strain NEAU-TWSJ13^T can be distinguished from S. fragile DSM 43847^T and S. jomthongense NBRC 110047^T. Moreover, strain NEAU-TWSJ13^T can also be differentiated from S. violaceochromogenes DSM 43849^T and other Streptosporangium species showing high 16S rRNA gene sequence similarity (>98.0 %) by morphological and physiological characteristics. Therefore, it is proposed that strain NEAU-TWSJ13^T represents a novel species of the genus Streptosporangium, for which the name Streptosporangium subfuscum sp. nov. is proposed. The type strain is NEAU-TWSJ13^T ( = CGMCC 4.7146^T = DSM = 46724^T).     

Rapid assessment of the effect of ciprofloxacin on chromosomal DNA from Escherichia coli using an in situ DNA fragmentation assay

Background  

Fluoroquinolones are extensively used antibiotics that induce DNA double-strand breaks (DSBs) by trapping DNA gyrase and topoisomerase IV on DNA. This effect is usually evaluated using biochemical or molecular procedures, but these are not effective at the single-cell level. We assessed ciprofloxacin (CIP)-induced chromosomal DNA breakage in single-cell Escherichia coli by direct visualization of the DNA fragments that diffused from the nucleoid obtained after bacterial lysis in an agarose microgel on a slide.     

Streptosporangium anatoliense sp. nov., isolated from soil in Turkey

A novel actinobacterium, strain N9999^T, was isolated from soil and its taxonomic position determined using a polyphasic approach. The organism formed abundant aerial hyphae that differentiated into spherical spore vesicles. The cell wall contained meso-diaminopimelic acid; the whole-cell sugars were galactose, glucose, mannose, madurose and ribose; the predominant menaquinones MK-9 (H₂) and MK-9 (H₄); the major phospholipids phosphatidylethanolamine, diphosphatidylglycerol, a phosphaglycolipid and phosphatidylinositol mannosides; while the cellular fatty acids were rich in iso-C_14:0, C_15:0, cis-9-C_17:1, iso-C_16:0 and 10-methyl C_17:0 components. Phylogenetic analyses based on an almost complete 16S rRNA gene sequence indicated that strain N9999^T was closely related to a group that consisted of Streptosporangium pseudovulgare DSM 43181^T and Streptosporangium nondiastaticum DSM 43848^T. However, DNA–DNA relatedness and phenotypic data demonstrated that strain N9999^T was clearly distinguished from all closely related Streptosporangium species. The combined genotypic and phenotypic data demonstrate conclusively that the isolate should be classified as a new species of Streptosporangium.     

链孢囊菌属3种分子分类方法的对比

链孢囊菌属（Streptosporangium）是链孢囊菌科（Streptosporangiaceae）的模式属,包含13个种．种的鉴别通常是多相分类方法,其中尤以DNA同源性分析为国际公认的定种标准;全基因组杂交同源性在70%以下的为不同种．但在进行大量菌株的比对时操作比较复杂．本实验以链孢囊菌属15株标准菌株为实验菌株,选择适宜引物,对其基因组DNA的16S-23S rDNA 间隔区序列（ITS）和REP序列进行了扩增,分别获得了两种基因指纹图谱,并通过UPGMA聚类法构建了相应的进化距离树图．结果表明,对于链孢囊菌属中不同种的区分,两种基因图谱技术的分辨力相当,且两种方法呈现的菌株间同源性与DNA-DNA杂交的结果吻合,有望为链孢囊菌属分类学的研究提供简单、准确、快速的标准程序．     

Distribution of the Escherichia coli structural maintenance of chromosomes (SMC)-like protein MukB in the cell

Fluorescent polyclonal antibodies specific for MukB have been used to study its localization in Escherichia coli. In wild-type cells, the MukB protein appeared as a limited number of oblong shapes embracing the nucleoid. MukB remained associated with the nucleoid in the absence of DNA replication. The centre of gravity of the dispersed MukB signal initially localized near mid-cell, but moved to approximately quarter positions well before the termination of DNA replication and its subsequent reinitiation. Because MukB had been reported to bind to FtsZ and to its eukaryotic homologue tubulin in vitro, cells were co-labelled with MukB- and FtsZ-specific fluorophores. No co-localization of MukB with polymerized FtsZ (the FtsZ ring) was observed at any time during the cell cycle. A possible role for MukB in preventing premature FtsZ polymerization and in DNA folding that might assist DNA segregation is discussed.     

Biocontrol and plant-growth-promoting capacities of actinobacterial strains from the Algerian Sahara and characterisation of Streptosporangium becharense SG1 as a promising biocontrol agent

Sixteen actinobacterial strains isolated from various ecological niches in the Algerian Sahara were screened for their biocontrol potential in root rot disease caused by Fusarium culmorum and their promotion of durum wheat growth. All actinobacteria were studied for in vitro antagonistic activity and plant-growth-promotion traits, for the production of cyanhydric acid, siderophores, chitinases and indole-3-acetic acid, and for the solubilisation of inorganic phosphate. Strongly antagonistic actinobacteria were selected for the biocontrol of F. culmorum in vivo and for the growth promotion of durum wheat plants in autoclaved and non-autoclaved soils. The Streptosporangium becharense strain SG1 exhibited remarkable positive results in all trials. Compared to untreated wheat seeds, the root rot severity index was decreased significantly (P?相似文献   

Techniques for studying adipocytes

Various fixatives as well as tissue and slide handling procedures have been evaluated in attempts to demonstrate adipocytes histochemically while maintaining cell and tissue integrity. The optimal procedure for analysis of immature adipose depots consists of the following steps: 1) fresh, unfixed tissues are rapidly in isopentane quenched in a liquid nitrogen bath; 2) cryostat sections are cut, removed from the knife with a room temperature slide, and then air dried for 5-10 minutes; 3) slides can be stained directly with picro-Ponceau or toluidine blue procedures or with oil red O following fixation for 30 minutes in cold (4 C) 10% formalin-CaCl2 (1.25%). For analysis of mature rat adipose depots steps 2 and 3 are modified as follows: 2) cryostat sections are removed from the knife with a cold slide (-20 C) and dried for 30 minutes at 4 C; 3) the mounted sections are stained with oil red O following fixation for 30 minutes in cold (4 C) 10% formalin-HgCl2 (2.5%). When procedures described above for immature adipose depots are combined with esterase staining, adipocyte cytoplasm is clearly demonstrated. These procedures allow the routine use of fresh frozen, unfixed cryostat sections in studies of adipose cellularity.     

A particular structure associated to the nucleoid of cyanobacteria

Regressive staining as well as beta-radiations or trypsin treatment on Synechocystis PCC6803 and Spirulina platensis (Gom,-Geilteri.) whole cells or permeaplasts, respectively, have demonstrated the presence of a particular structure associated to the nucleoid of cyanobacteria. This structure with a tridimensional network aspect has been called scaffold-like. We presume that it represents the cellular-molecular support for the supercoiling of the nucleoid of cyanobacteria.     

Serological relationships among flagella of Erwinia carotovor var. atroseptica and some E. carotovora var. carotovora serogorups

The 2 Erwinia carotovora var. atroseptica serogroups and 2 out of 16 E. carotovora var. carotovora serogroups previously established on the basis of diffusible somatic antigens were shown to be serologically related by agglutination procedures using whole cells. The common agglutinating antigen in serogroups I, III, V, and XVIII was heat labile and identified as the bacterial flagella by the fluorescent antibody staining procedure. A few strains in serogorups I and III apparently lacked flagella altogether. Fluorescent antibody staining of whole cells also confirmed that the cell wall antigens of serogroups I, II, and XVIII were related and that the cell wall antigens of serogroups III and V were not related to each other or to the other serogroups.     

三株杀粘虫放线菌的分类鉴定

菌株YIM31331、YIM31333、YIM31355是从云南省丽江、中甸采集的土壤样品中分离得到的具有产杀粘虫活性物质菌株。根据其形态学特征、生理生化特性及16S rDNA序列分析结果,认为菌株YIM 31331属于链霉菌属的Streptomyces subrutilus,YIM31333属于指孢囊菌属Dactylosporangium aurantiacum,YIM31355属于链孢囊菌属Streptosporangium vulgare。