Reassociation of Deoxyribonucleic Acids from Actinoplanes and Other Actinomycetes

The ability of deoxyribonucleic acid (DNA) isolated from a number of actinomycetes to reassociate with reference DNA from Actinoplanes philippinensis or Streptomyces venezuelae has been measured. All of the DNA preparations except for those from Nocardia erythropolis and Thermomonospora viridis contained 70 to 73 moles per cent guanine and cytosine. DNA from two species of Actinoplanes, two species of Dactylosporangium, and Ampullariella digitata formed extensive thermally stable duplexes with the Actinoplanes philippinensis reference. DNA from streptomycetes formed duplexes with the A. philippinensis reference, but these duplexes possessed low thermal stability. DNA from N. erythropolis and T. viridis did not bind significant amounts of this reference DNA. Only DNA from Streptomyces albus, Streptoverticillium baldaccii, and Microellobosporia flavea appreciably bound the Streptomyces venezuelae reference. Our results separate the actinomycetes forming sporangia into two groups: the first group contained Actinoplanes, Dactylosporangium, and Ampullariella; the second group contained Planomonospora, Spirillospora, and Streptosporangium.     

Mechanism of natural resistance to kirromycin-type antibiotics in actinomycetes

Abstract The sensitivity of intact cells and subcellular fractions of actinomycetes to kirromycin and pulvomycin was examined. These antibiotics block bacterial protein synthesis by acting on elongation factor Tu (EF-Tu). Two types of natural resistance were encountered in actinomycetes. Some strains were resistant to kirromycin and pulvomycin by virtue of inefficient cellular uptake of these drugs. In 3 strains, kirromycin resistance was attributable to a drug-insensitive EF-Tu. These 3 organisms produce kirromycin-type antibiotics: Streptomyces cinnamomeus, Streptomyces lactamdurans and Streptoverticillium mobaraense synthesize kirrothricin, efrotomycin and pulvomycin, respectively. In S. cinnamomeus and S. lactamdurans resistance to their own antibiotic is due to possession of a nonresponding EF-Tu factor, whereas pulvomycin resistance in Sv. mobaraense is more likely derived from the permeability properties of the cell envelope.     

嗜酸丝状放线菌的选择性分离与多样性

摘要:【目的】针对酸性土壤中的嗜酸丝状放线菌,建立有效的选择性分离方法,并了解其多样性。【方法】用不同的样品预处理方式和分离培养基,并添加不同的抑制剂进行分离;根据放线菌的菌落数和出菌率确定最佳分离方法组合。采用最佳分离方法对从江西采集的17份酸性土壤样品进行分离;根据培养特征对分离菌株进行分群,进一步通过对各类群的显微形态观察和pH梯度生长实验确定代表菌株;对代表菌株进行16S rRNA基因序列分析研究其多样性。【结果】嗜酸丝状放线菌的最佳分离方法为：土壤样品经分散差速离心预处理后,涂布添加了放线菌酮、制霉菌素和萘啶酮酸（各50 mg/L）的GTV培养基。用此方法共分离到放线菌369株,归为10个不同的颜色类群,其中6.6%为严格嗜酸放线菌,72.4%为中度嗜酸放线菌,21.0%为耐酸放线菌。52株嗜酸放线菌代表菌株分布于放线菌目中的12个属：链霉菌属(Streptomyces)、小单孢菌属(Micromonospora) 、诺卡氏菌属(Nocardia)、野野村菌属(Nonomuraea) 、韩国生工属(Kribbella) 、小双孢菌属(Microbispora)、马杜拉菌属(Actinomadura)、拟无枝菌酸菌属(Amycolatopsis)、指孢囊菌属(Dactylosporangium)、伦茨氏菌属(Lentzea)、游动四孢菌属(Planotetraspora) 和链嗜酸菌属(Streptacidiphilus),其中链霉菌分离菌株在系统发育树上形成12个不同的进化类群。【结论】所建立的选择性分离方法可用于土壤嗜酸丝状放线菌的高效分离;江西酸性土壤含有丰富多样的嗜酸丝状放线菌种属。     

Streptacidiphilus jiangxiensis sp. nov., a novel actinomycete isolated from acidic rhizosphere soil in China

The taxonomic position of three acidophilic actinomycetes isolated from acidic rhizosphere soil was established using a polyphasic approach. The morphological and chemical properties of the isolates were found to be consistent with their assignment to the genus Streptacidiphilus. Almost complete 16S rRNA gene sequences determined for the strains were aligned with corresponding sequences of representatives of the genera Kitasatospora, Streptacidiphilus and Streptomyces and phylogenetic trees inferred using three tree-making algorithms. The organisms formed a distinct subclade within the Streptacidiphilus 16S rRNA gene tree. They also shared nearly identical phenotypic profiles and rep-PCR fingerprint patterns that readily distinguished them from representatives of the established species of Streptacidiphilus. It is evident from the genotypic and phenotypic data that the three isolates form a new species in the genus Streptacidiphilus. The name proposed for this new species is Streptacidiphilus jiangxiensis, the type strain is isolate 33214T (= AS 4.1857T = JCM 12277T).     

Factors influencing odour production by actinomycetes

Odour production by actinomycete (Streptomyces spp.) strains isolated from hypereutrophic natural waters in which muddy odours in fish have occurred, were studied by the ISP (International Streptomyces Project) carbon utilization method. The streptomycete strains were isolated from water, bottom mud and aquatic plants. Nine different carbon sources were used. Odour character was determined by sniffing the cultures. Odour production varied depending on the strain and the carbon source used. Some of the strains produced similar odours in all media regardless of the carbon source. In other strains, the odour varied depending on the carbohydrate used. The total colony counts of actinomycetes may not necessarily indicate the role of actinomycetes in odour problems in the aquatic environment because the odour production by actinomycetes depends on environmental factors.     

Bacterial colony screening with a Streptomyces DNA probe

Restriction fragments of 1.5 kb-3.5 kb length were selected from a SalI digest of Streptomyces coriofaciens ISP5485 DNA. After radiolabelling, these fragments were used as a molecular probe. A number of actinomycetes was screened in colony hybridization. Streptomyces and Streptoverticillium strains were recognized by the probe and the hybridization sensitivity was high with isolated DNA.     

Antagonistic activity of soil acidophilic actinomycetes

It has been shown that soil acidophilic actinomycetes (mycelial prokaryotes with a growth optinum between pH 3 and 7) markedly differ from neutrophilic actinomycetes in antimicrobial activity: the former are more active against fungi and yeasts, whereas the latter effectively suppress Gram-positive bacteria. Acidophilic streptomycetes actively inhibit the growth of phytopathogenic fungi, especially on acidic media.     

Phenotypic variation in Streptomyces sp. DSM 40537, a lipoteichoic acid producing actinomycete

Aims:  To reinvestigate the production of lipoteichoic acid (LTA) by the actinomycete strain Streptomyces sp. DSM 40537 (=ATCC 3351).
Methods and Results:  LTA was extracted and purified from strain Streptomyces sp. DSM 40537. The identification of the LTA was confirmed by Western blotting with a monoclonal antibody. During these studies, two stable phenotypic variants of DSM 40537 were obtained, one of which released a distinctive orange pigment. 16S rRNA gene sequencing of each variant yielded identical sequences and allowed phylogenetic analysis to be performed.
Conclusions:  Streptomyces sp. DSM 40537 was shown to exhibit stable morphological variation. The strain was confirmed to be a LTA-producing actinomycete and to belong to the Streptomyces albidoflavus cluster within the genus Streptomyces .
Significance and Impact of the Study:  These data provide important support for the hypothesis that the distribution of LTA is linked to that of wall teichoic acids and emphasizes the need to reinvestigate LTA distribution in actinomycetes.     

Production of a Naphthoquinone Pigment by a Species of Streptoverticillium and Its Accumulation by a Streptomycete

A naphthoquinone pigment produced by a species of Streptoverticillium was accumulated by a Streptomyces sp. when the two organisms were grown in mixed cultures.     

Differential Growth Inhibition of Diaporthe and Phomopsis Isolates by the Metabolic Activity of Five Actinomycetes

Fifty-five cultures derived from Diaporthe perithecia and Phomopsis pycnidia found on diverse host plant species collected at different times and sites in Vojvodina, Yugoslavia, showed distinguishing quantitative reactions to the fungistatic activity of five actinomycetes obtained as fortuitous laboratory contaminants coming from field material. Streptomyces albidoflavus , S. albus , S. diastaticus , Streptomyces sp., and Streptoverticillium sp. could be ranked by their growth-inhibitory potential, with S. albus showing the strongest, and Streptomyces sp. the lowest. The responses of the fungi varied depending on the tested actinomycetes, but two major groups could be distinguished: A, which encompased the isolates that were less affected by the proximity of the actinomycetes; and B, with those which exhibited high sensitivity in all the experiments. Group A was typically represented by Diaporthe arctii , Phomopsis longicolla, and the Phomopsis type-1 cultures from Xanthium italicum; group B was typically represented by Diaporthe/Phomopsis helianthi, Phomopsis type-2 cultures from X. italicum , and isolates from Lactuca serriola . The results obtained underscore the dissimilarities between D. arctii and D. helianthi , and corroborate the value of the physiological aspects of congeneric isolates in considering taxonomic problems in the coelomicete genus Phomopsis.     

Biosynthesis of a natural polyketide-isoprenoid hybrid compound, furaquinocin A: identification and heterologous expression of the gene cluster

Furaquinocin (FQ) A, produced by Streptomyces sp. strain KO-3988, is a natural polyketide-isoprenoid hybrid compound that exhibits a potent antitumor activity. As a first step toward understanding the biosynthetic machinery of this unique and pharmaceutically useful compound, we have cloned an FQ A biosynthetic gene cluster by taking advantage of the fact that an isoprenoid biosynthetic gene cluster generally exists in flanking regions of the mevalonate (MV) pathway gene cluster in actinomycetes. Interestingly, Streptomyces sp. strain KO-3988 was the first example of a microorganism equipped with two distinct mevalonate pathway gene clusters. We were able to localize a 25-kb DNA region that harbored FQ A biosynthetic genes (fur genes) in both the upstream and downstream regions of one of the MV pathway gene clusters (MV2) by using heterologous expression in Streptomyces lividans TK23. This was the first example of a gene cluster responsible for the biosynthesis of a polyketide-isoprenoid hybrid compound. We have also confirmed that four genes responsible for viguiepinol [3-hydroxypimara-9(11),15-diene] biosynthesis exist in the upstream region of the other MV pathway gene cluster (MV1), which had previously been cloned from strain KO-3988. This was the first example of prokaryotic enzymes with these biosynthetic functions. By phylogenetic analysis, these two MV pathway clusters were identified as probably being independently distributed in strain KO-3988 (orthologs), rather than one cluster being generated by the duplication of the other cluster (paralogs).     

Intergeneric hydridization of the actinomycetes Streptoverticillium mycoheptinicum and Streptomyces coelicolor

Intergeneric crossing of the actinomycetes Streptoverticillium mycoheptinicum and Streptomyces coelicolor yielded recombinants which were mostly nonviable and unstable despite a relatively high frequency (10(-2)-10(-4)) at which their colonies appeared. The rare viable and stable recombinants were prototrophs. The structure of antibiotics in the hybrid cell may be modified as follows from the differences in the antibiotic activity of the LIA-973 hybrid and the parent strains.     

Cystathionine gamma-lyase of Streptomyces phaeochromogenes. The occurrence of cystathionine gamma-lyase in filamentous bacteria and its purification and characterization

Cystathionine gamma-lyase (EC 4.4.1.1) is widely distributed in actinomycetes, e.g. genera Streptomyces, Micromonospora, Micropolyspora, Mycobacterium, Nocardia, Streptosporangium, and Streptoverticillium. The enzyme was purified from Streptomyces phaeochromogenes (IFO 3105) in nine steps. After the last steps, the enzyme appeared to be homogenous by the criteria of polyacrylamide gel electrophoresis, analytical centrifugation, and double diffusion in agarose. The enzyme crystallized in the apo form with the addition of ammonium sulfate. The enzyme has a molecular weight of about 166,000 and consists of four subunits identical in molecular weight. The enzyme exhibits absorption maxima at 278 and 421 nm and contains 4 mol of pyridoxal 5'-phosphate/mol of enzyme. L-Cystathionine, L-homoserine, DL-lanthionine, L-djenkolic acid, and L-cystine are cleaved as preferred substrates by the Streptomyces enzyme. The alpha, beta-elimination reaction of L-cystathionine is also catalyzed by the enzyme at a ratio of about one-seventh of the alpha, gamma-elimination reaction. Cystathionine beta-synthase (EC 4.2.1.22) and cystathionine gamma-synthase (EC 4.2.99.9) activities were also detected in crude extracts of S. phaeochromogenes, but cystathionine beta-lyase (EC 4.4.1.8) was not. Consequently, the reverse transsulfuration pathway in actinomycetes may be similar to that in yeast and molds.     

Taxonomic status of Kitasatosporia, and proposed unification with Streptomyces on the basis of phenotypic and 16S rRNA analysis and emendation of Streptomyces Waksman and Henrici 1943, 339AL.

Species classified within the genus Kitasatosporia share many of the phenotypic characteristics typical of streptomycetes. By using a probabilistic identification scheme, they were identified with Streptomyces exfoliatus cluster 5, a species group within Streptomyces. The four species studied hybridized with a 16S rRNA genus probe for Streptomyces spp., indicating a close relationship between the two genera. The kitasatosporias were resistant to selected polyvalent streptomycete phages tested. Quantitative analysis showed that meso-diaminopimelic acid varied from 49 to 89% in Kitasatosporia species and from 1 to 16% in Streptomyces species depending on growth conditions. On the basis of 16S rRNA analysis, it is proposed to reduce Kitasatosporia to synonymy with Streptomyces. As a result, the new names proposed are Streptomyces mediocidicus comb. nov., Streptomyces phosalacineus comb. nov., Streptomyces setae comb. nov., and Streptomyces griseolosporeus comb. nov., nom. nov.     

Taxonomic study on nonpathogenic streptomycetes isolated from common scab lesions on potato tubers

Numerical analysis was carried out to compare sixteen nonpathogenic actinomycetes isolated from common scab lesions on potato tubers with Streptomyces scabiei type strain as well as with other streptomycete groups. These isolates were divided into two classes according to their level of similarity with S. scabiei. Isolates resembling S. scabiei were associated with S. griseoruber or with S. violaceusniger while isolates exhibiting less than 61% of similarity with S. scabiei were phenotypically related to S. albidoflavus or to S. atroolivaceus. Sequence of the 16S rRNA gene of each isolate was obtained and compared against the GenBank nucleotide database. No significant match could be established between the sequences of two potato isolates and the ones available in the GenBank database. The other isolates were closely related with S. setonii (S. griseus), S. mirabilis, S. fimbriatus, S. violaceoruber, S. melanosporofaciens and S. thermocarboxydus.     

药用植物内生放线菌的分离、筛选及活性菌株YIM 61470鉴定

从云南西双版纳热带雨林多种药用植物中分离到272株内生放线菌,活性筛选表明 146株菌的发酵产物具有抗菌活性,其中94株菌具有拮抗病原细菌活性,127株菌具有抑制病原真菌的功能.分离菌株YIM 61470具有广谱抗菌活性,通过形态特征、培养特征、生理生化特征、细胞化学分类特征和基于16S rRNA基因序列的相似性分析等研究,菌株YIM 61470被鉴定为链霉菌属(Streptomyces)氢化链霉菌(S.llydrogenans)的一个菌株.     

Description of <Emphasis Type="Italic">Streptomyces neopeptinius</Emphasis> sp. nov., an actinobacterium with broad spectrum antifungal activities

A streptomycete strain producing broad-spectrum antifungal substances was taxonomically characterized. The strain, designated KNF 2047(T) (= SH-09(T) = KCTC 10586BP(T)), was found to form extensively branching aerial and substrate mycelia, and produce spiny-ornamented spores with loose spiral chains. The whole cell hydrolyzates contained major amount of LL-diaminopimelic acid. The major fatty acids of the phospholipids were saturated and branched fatty acids containing 14~17 carbons, and the major isoprenoid quinones were hexa-and octa-hydrogenated menaquinones with 9 isoprene units. The phylogenetic analysis using the 16S rRNA gene indicated that the strain belongs to the genus Streptomyces but forms an independent phyletic line. These results clearly demonstrate that strain KNF2047(T) forms a new center of taxonomic variation within Streptomyces, for which the name Streptomyces neopeptinius sp. nov. is proposed.     

云南酸性土壤中度嗜酸链霉菌的多样性

[目的]了解酸性土壤环境里中度嗜酸链霉菌的多样性,调查其物种资源.[方法]用分散和差速离心法及选择性分离培养基从14份云南酸性土壤样品中分离到367株具有链霉菌培养特征的放线菌,并进行了颜色分群.从各颜色类群中选取代表菌株共97株,通过显微形态观察和pH梯度生长实验确定其中的中度嗜酸链霉菌.进一步从中筛选出16株中度嗜酸链霉菌代表菌株,进行16SrRNA基因序列的相似性和系统发育分析,并结合基因组DNA-DNA相关性数据.[结果]分离菌株归为12同的颜色类群,其中80%属于中度嗜酸链霉菌,其代表菌株在系统发育树上形成了8个距离较远且与已知种不同的进化分枝,可能代表链霉菌属内至少8个不同的新基因种.[结论]用以上方法筛选出的中度嗜酸链霉菌可归为8个不同于已知种的进化群,说明云南酸性土壤含有丰富多样的中度嗜酸链霉菌新物种.     

邳州银杏内生放线菌分离、筛选及活性菌株鉴定

【目的】从银杏中分离、筛选得到具有抑菌作用的内生放线菌,为放线菌在生物防治上的应用提供新的菌种资源。【方法】采用组织贴片培养法进行分离,生长对峙法进行筛选。【结果】从银杏的根、茎、叶中分离得到98株、50株、8株内生放线菌(共计156株),47株放线菌具有拮抗植物病原真菌活性。菌株KLBMP 5501抗菌活性最好且具有广谱性,基于形态特征、培养特征、生理生化特征和16S rRNA基因序列的相似性分析等多项分类特征表明,菌株KLBMP 5501是一株浅紫链霉菌(Streptomyces violascens)。【结论】筛选得到了具有应用潜力的高活性菌株,并进行了菌种鉴定。