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dactylocyclines, novel tetracycline derivatives produced by a dactylosporangium sp. i. taxonomy, production, isolation and biological activity.a screen for antibiotics with activity against tetracycline-resistant microorganisms has led to the isolation of dactylosporangium sp. (atcc 53693), a producer of several novel tetracycline derivatives. the major fermentation products, dactylocyclines a and b, were purified and mic values determined against tetracycline-resistant and tetracycline-sensitive gram-positive bacteria. the dactylocyclines represent the first naturally occurring tetracycline c2 amides which lack cross resistance with t ...19921490880
dactylocyclines, novel tetracycline derivatives produced by a dactylosporangium sp. ii. structure elucidation.fermentation of dactylosporangium sp. (atcc 53693) produces a mixture of tetracycline derivatives from which several related tetracycline glycosides, the dactylocyclines, were isolated and their structures determined. the most abundant glycoside in initial fermentations was found to be dactylocycline a. each glycoside proved to be acid sensitive and readily hydrolyzed to a common aglycone, dactylocyclinone. while the aglycone was cross resistant with tetracycline, the dactylocyclines proved acti ...19921490881
dactylocyclines, novel tetracycline derivatives produced by a dactylosporangium sp. iii. absolute stereochemistry of the dactylocyclines.the dactylocycline antibiotics were found through circular dichroism measurements, nmr spectroscopy and chemical transformations to possess the usual tetracycline family absolute configuration at carbons 4, 4a, 5a and 12a. the absolute stereochemistry about the c-6 carbon, however, was the reverse of that found with previously investigated tetracyclines.19921490882
organization and nature of fortimicin a (astromicin) biosynthetic genes studied using a cosmid library of micromonospora olivasterospora dna.the cloning of five dna segments carrying at least seven genes (fms1, fms3, fms4, fms5, fms7, fms11, and fms12) that participate in fortimicin a (astromicin) biosynthesis was described previously. these dna fragments were used to screen a cosmid library of genomic dna in order to examine if these biosynthetic genes are clustered in micromonospora olivasterospora. one cosmid clone (pglm990) was obtained, which hybridized to all the probes. complementation analysis, using mutants blocked at variou ...19921494349
n-formimidoyl fortimicin a synthase, a unique oxidase involved in fortimicin a biosynthesis: purification, characterization and gene cloning.micromonospora olivasterospora, a fortimicin a (ftm a, astromicin) producer, was found to carry an enzyme that converts ftm a to n-formimidoyl ftm a (fi-ftm a). this enzyme (fi-ftmase) was purified to homogeneity and shown to be a flavin adenine dinucleotide (fad) enzyme. tracer experiments proved that the formimidoyl group was derived from c-2 of glycine via oxidation of the amino acid in the presence of ftm a and oxygen. the gene encoding this enzyme, fms 14, was cloned using a 26-mer oligonuc ...19921494350
cloning and analysis of a gene (sms13) encoding sannamycin b-glycyltransferase from streptomyces sannanensis and its distribution among actinomycetes.a gene encoding sannamycin b-glycyltransferase (sms13) of streptomyces sannanensis ifo 14239 was identified by cloning and complementation of s. sannanensis mutant sn13 which is blocked at the interconversion of sannamycins b and a. the cloned dna fragment also permitted the conversion of fortimicin b to a both in s. sannanensis sn13 and streptomyces lividans tk23. dna sequences similar to sms13 were detected in all five producers of the fortimicin-group antibiotics, micromonospora olivasterospo ...19921517162
reverse transcriptase sequencing of 16s ribosomal rna from faenia rectivirgula, pseudonocardia thermophila and saccharopolyspora hirsuta, three wall type iv actinomycetes which lack mycolic acids.the phylogenetic relationships of three mycolateless wall type iv actinomycetes, faenia rectivirgula, pseudonocardia thermophila and saccharopolyspora hirsuta, were examined using reverse transcriptase sequencing of 16s ribosomal rna. the sequences generated were aligned and the level of sequence homology calculated. the homology values were then use to produce a phylogenetic tree and to estimate s(ab) values for the construction of a dendrogram. both analyses show the three taxa to be closely r ...19882460582
pharmacokinetics of dactimicin in rats.dactimicin is a new pseudo-disaccharidic aminoglycosidic antibiotic produced by dactylosporangium matsuzakiense. the aim of the present research was to evaluate the pharmacokinetics of dactimicin intramuscularly administered, at the dosage of 20 mg/kg, in male sprague-dawley rats with an average b.w. of 200-220 g. dactimicin levels were assessed by using a microbiological method (agar diffusion) employing bacillus subtilis atcc 6633 as test organism. samples were collected immediately before and ...19892637794
microbiological characterization of dactimicin: antibacterial activity towards gram-positive and gram-negative bacteria.dactimicin is the first aminoglycoside antibiotic of dactylosporangium origin, consisting of a pseudo-disaccharide and an amino acid. it has also a formimidoyl moiety instead of the deoxystreptamine found in other aminoglycosides. the authors considered the antibacterial activity of dactimicin compared with amikacin, gentamicin and the fortimicins against gram-positive and gram-negative bacteria. dactimicin showed remarkable antibacterial activity against all strains tested: in particular the mi ...19892752910
in vitro activity of dactimicin and other aminoglycosides against bacteria producing aminoglycoside-modifying enzymes.dactimicin is a new pseudo-disaccharide aminoglycoside, originally isolated from cultures of dactylosporangium matsuzakienzae sp. nov., which is chemically related to astromicin. in this study the in vitro activity of dactimicin has been determined against strains of bacteria producing characterized aminoglycoside-modifying enzymes and has been compared with that of gentamicin, tobramycin, netilmicin and amikacin. minimum inhibitory concentrations were determined using an agar incorporation tech ...19892752913
first microbiological approach to dactimicin, a novel aminoglycoside antibiotic.dactimicin (st 900) is the first aminoglycoside antibiotic of dactylosporangium origin. this drug shows resistance to many enzymes that destroy aminoglycosides. in this first approach, the authors have pointed out the activity of dactimicin against gram-negative rods, particularly klebsiella, enterobacter, serratia and gram-positive bacteria, especially methicillin susceptible and resistant staphylococci. dactimicin showed remarkable antibacterial activity against all strains tested; however thi ...19873447875
tiacumicins, a novel complex of 18-membered macrolide antibiotics. i. taxonomy, fermentation and antibacterial activity.a complex of 18-membered macrolide antibiotics has been discovered in the fermentation broth of strain ab718c-41. the producing culture, isolated from a soil sample collected in hamden, connecticut, was identified as a strain of dactylosporangium aurantiacum and was designated d. aurantiacum subsp. hamdenesis subsp. nov. the antibiotic complex was produced in a new brunswick 150-liter fermentor using a medium consisting of glucose, soybean oil, soybean flour, beef extract and inorganic salts. se ...19873610815
tiacumicins, a novel complex of 18-membered macrolides. ii. isolation and structure determination.a novel complex of gram-positive antibiotics has been isolated from the fermentation broth and mycelium of dactylosporangium aurantiacum subsp. hamdenesis subsp. nov. the structures of these six compounds were deduced employing uv, ms, ir, and extensive 1d and 2d homonuclear and heteronuclear nmr experiments. each component contained a highly unsaturated 18-membered macrolide ring. components differed from one another by minor structural variations in the macrolide ring and by the number and est ...19873610816
a new tetracycline antibiotic from a dactylosporangium species. fermentation, isolation and structure elucidation.an actinomycete identified as a dactylosporangium sp. produces a new tetracycline, 4a-hydroxy-8-methoxychlortetracycline (sch 34164). the addition of magnesium ions to complex fermentation media increased the antibiotic titers. sch 34164 was isolated by solvent extraction and sephadex g-25 column chromatography. the novel structure was proposed based on spectroscopic analysis. the shift of c-4a (35 to 77 ppm) and c-8 (140 to 163 ppm) in the 13c nmr as compared to chlortetracycline was indicative ...19873680006
a new antibiotic sf-2185 produced by dactylosporangium. i. taxonomy, fermentation and biological properties.a new antibiotic sf-2185 was found active against plant pathogen, particularly the causal organisms of cucumber downy mildew and rice blast. the producing organism, strain sf-2185, is a novel actinomycete and has been identified as dactylosporangium aurantiacum subsp. gifuense.19854077728
fine structure of the globose bodies of dactylosporangium thailandense (actinomycetales). 19744436644
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 t ...19705437730
poorly lytic bacteriophage from dactylosporangium thailandensis (actinomycetales).dactylosporangiophage a1 has a polygonal head (75 nm) with spherical capsomeres (3 nm) and a noncontractile tail (200 by 10 nm) with cross-striations which is terminated with at least three prongs which are used for attachment. it contains double-stranded deoxyribonucleic acid and produces very little lysis. intracellular phage multiplication leads to the formation of crystalline aggregates of apparently complete virions. plaques are formed only on certain substrains of dactylosporangium thailan ...19695774140
a new aminoglycoside antibiotic g-367 s1, 2'-n-formylsisomicin fermentation, isolation and characterization.a new aminoglycoside antibiotic, g-367 s1 (2'-n-formylsisomicin, c20h37n5o8) produced by a rare actinomycetes, dactylosporangium thailandense g-367 (ferm-p 4840) has been isolated by column chromatography on a cation-exchange resin. g-367 s1 is active against gram-positive and gram-negative bacteria.19836432760
studies on a new aminoglycoside antibiotic, dactimicin. i. producing organism and fermentation.the producing organism of a new antibiotic, dactimicin, is described. the presence of finger-shaped sporangia bearing motile spores, the absence of aerial mycelium and its cell wall of type ii, ascribe this organism to the genus dactylosporangium. the cultural and physiological features distinguish this organism from all the described dactylosporangium species. therefore, it is considered to be a new species for which the name dactylosporangium matsuzakiense sp. nov. is proposed. fermentation of ...19807192278
cell wall composition of micromonospora olivoasterospora, micromonospora sagamiensis, and related organisms.cell walls of 19 micromonospora species were analyzed for their components. all the cell walls had xylose and arabinose, but the presence of glucose, galactose, mannose, or rhamnose depended on the strain. amino acids present in the walls consisted of glycine, glutamic acid, diaminopimelic acid, and alanine, in a molar ratio of approximately 1:1:1:0.6--0.8. 3-hydroxydiaminopimelic acid, together with meso-diaminopimelic acid, was found in many species and was isolated from micromonospora olivoas ...19817217010
studies on a new aminoglycoside antibiotic, dactimicin. ii. isolation, structure and chemical degradation.a new aminoglycoside antibiotic, dactimicin produced by a dactylosporangium matsuzakiense sf-2052 has been isolated by column chromatography on a cation-exchange resin and cm-sephadex. the structure of dactimicin was determined to be 4-amino-1,4-dideoxy-3-o-(2,6-diamino-2,3,4,6,7-pentadeoxy-beta-l-lyxo- heptopyranosyl)-1-[(n-formimidoylglycyl)-methylamino]-6-o-methyl-l-chiro-inosit ol. alkaline hydrolysis of dactimicin afforded 1-n-(n-formylglycyl)fortimicin b, fortimicin b, fortimicin a and an ...19817328051
characterization of two different types of resistance genes among producers of fortimicin-group antibiotics.fortimicin-a (ftm-a; astromicin)-resistance genes (fmr genes) isolated from six producers of the ftm-group of antibiotics were analysed. these genes could be classified into two types by the resistance profiles to aminoglycoside antibiotics and by their dna homologies. three genes, fmrt from the istamycin producer streptomyces tenjimariensis atcc 31603, fmrs from the sannamycin producer streptomyces sannanensis ifo 14239 and fmrh from the sporaricin producer saccharopolyspora hirsuta atcc 20501, ...19938473864
16s ribosomal dna analysis of the genera micromonospora, actinoplanes, catellatospora, catenuloplanes, couchioplanes, dactylosporangium, and pilimelia and emendation of the family micromonosporaceae.in order to determine the phylogenetic structure of the actinomycete family micromonosporaceae, the 16s ribosomal dna sequences of 17 type species of the genera actinoplanes, dactylosporangium, and pilimelia were compared with the 16s ribosomal dna sequences of species of the genera catellatospora, catenuloplanes, and couchioplanes and with those of species of the genus micromonospora and other actinomycete genera for which the sequences have been previously determined. all genera of the family, ...19968782687
microbial conversion of em574 and em523, gastrointestinal motor stimulating agents.em574 exerts gastrointestinal motor stimulating (gms) activity even after being converted to its metabolites p1 and p2 in dogs. these metabolites were isolated from dog liver using a series of chromatographic procedures. their structures were determined to be the 15- and 14-hydroxyl derivatives of em574, respectively, by spectral analysis. large scale preparation by microbial transformation was investigated for further evaluation of the metabolites, because the amounts obtained by oxidation with ...19968823514
flagellar proteins of motile spores of actinomycetes.flagella of some of the actinoplanete genera were purified and the molecular sizes of their flagellin subunits compared by sds-page analysis to flagellins of cells of other bacteria. several species of actinoplanes have a major flagellar protein of subunit sizes of 42-43 kda and a lesser amount of a second protein, possibly a minor flagellin subunit, of 60 kda. the flagellar protein sizes of other actinoplanetes ranged from 32-43 kda (major) and 48-58 kda (minor). antibodies formed against the 4 ...19968987497
production of brominated tiacumicin derivatives.several novel tiacumicin derivatives containing bromine have been produced by the addition of inorganic bromine to the fermentation both of dactylosporangium aurantiacum subsp, hamdenensis. structures were elucidated employing mass spectrometry and nmr spectroscopy. antibacterial activity of the bromotiacumicins is comparable to that of the parent compounds.19979127190
bacterial degradation of natural rubber: a privilege of actinomycetes?using natural rubber latex as the sole source of carbon and energy 50 rubber-degrading bacteria were isolated. out of those 50 isolates, 33 were identified as streptomyces species and 8 as micromonospora species. screening of 1220 bacteria obtained from different culture collections revealed 46 additional rubber-degrading bacteria (streptomyces 31 strains, micromonospora 5, actinoplanes 3, nocardia 2, dactylosporangium 1, actinomadura 1, unidentified 3). all rubber-degrading isolates were identi ...19979170260
production of brominated tiacumicin derivativesseveral novel tiacumicin derivatives containing bromine have been produced by the addition of inorganic bromine to the fermentation broth of dactylosporangium aurantiacum subsp. hamdenesis. structures were elucidated employing mass spectrometry and nmr spectroscopy. antibacterial activity of the bromotiacumicins is comparable to that of the parent compounds.19979439690
microbial proline 4-hydroxylase screening and gene cloning.microbial proline 4-hydroxylases, which hydroxylate free l-proline to trans-4-hydroxy-l-proline, were screened in order to establish an industrial system for biotransformation of l-proline to trans-4-hydroxy-l-proline. enzyme activities were detected in eight strains, including strains of dactylosporangium spp. and amycolatopsis spp. the dactylosporangium sp. strain rh1 enzyme was partially purified 3,300-fold and was estimated to be a monomer polypeptide with an apparent molecular mass of 31 kd ...199910473412
enzymatic production of trans-4-hydroxy-l-proline by regio- and stereospecific hydroxylation of l-proline.a proline 4-hydroxylase gene, which was cloned from dactylosporangium sp. rh1, was overexpressed in escherichia coli w1485 on a plasmid under a tryptophan tandem promoter after the codon usage of the 5' end of the gene was optimized. the proline 4-hydroxylase activity was l600-fold higher than that in dactylosporangium sp. rh1. trans-4-hydroxy-l-proline(hyp) was produced and accumulated to 41 g/l (87% yield from l-proline) in 100 h when the recombinant e. coli was cultivated in a medium containi ...200010830487
application of a method incorporating differential centrifugation for selective isolation of motile actinomycetes in soil and plant litter.the present paper describes a simple enrichment technique which enables rapid and selective isolation of diverse zoosporic actinomycete genera directly from soil and plant litter. this technique, designated the rehydration and centrifugation (rc) method, consists of immersing the air-dried source material in 10 mm phosphate buffer containing 10% soil extract, letting the preparation stand at 30 degrees c for 90 min, followed by centrifugation of the fluid at 1,500 x g for 20 min. portions of the ...200011204769
diversity of antifungal actinomycetes in various vegetative soils of korea.diversity of actinomycetes and their antifungal activities against some plant pathogenic fungi were examined in various vegetative soils from 14 different sites in the western part of korea. actinomycete counts ranged from 1.17 x 10(6) to 4.20 x 10(6) cfu x g(-1) dried soil. a total of 1510 actinomycetes were isolated from the soil samples. streptomyces was predominant in soils with a ph range of 5.1-6.5, 9.1-13.0% moisture, and 9.1-11.0% organic matter. most micromonospora, dactylosporangium, a ...200212109880
sf2809 compounds, novel chymase inhibitors from dactylosporangium sp. 1. taxonomy, fermentation, isolation and biological properties.six novel chymase inhibitors, sf2809-i, sf2809-ii, sf2809-iii, sf2809-iv, sf2809-v and sf2809-vi, were isolated from the fermentation broth of an actinomycete strain sf2809. the strain was identified as dactylosporangium sp. by morphological, chemotaxonomical and phylogenetic studies. these six novel compounds inhibited recombinant human chymase in the range between ic50 of 0.014 and 7.3 microm. however, they showed little or no inhibitory activity against chymotrypsin or cathepsin g, even thoug ...200415112955
sf2809 compounds, novel chymase inhibitors from dactylosporangium sp. 2. structural elucidation.novel chymase inhibitors, sf2809-i, ii, iii, iv, v and vi, were isolated from the fermentation broth of dactylosporangium sp. sf2809, and their structures were determined by spectroscopic analyses. sf2809 compounds commonly contain a substituted indole moiety and a quinolinone moiety. the two moieties are connected to a methylene carbon in sf2809-i and iii. the other compounds, sf2809-ii, iv, v and vi, have an additional moiety, a p-hydroxyphenyl group or a phenyl group. in these compounds, all ...200415112956
production of human metabolites of cyclosporin a, am1, am 4 n and am 9, by microbial conversion.in humans, cyclosporin a (cya) is primarily metabolized to two hydroxylated (am1 and am 9) and one n-demethylated (am 4 n) derivative. to produce these derivatives, 1237 actinomycetes were screened for their ability to convert cya. among them, 89 strains (7.2%) produced these derivatives from cya. finally, dactylosporangium variesporum ifo 14104, actinoplanes sp. atcc 53771 and streptosporangium sp. af 935 were selected for the production of am1, am 4 n, and am 9, respectively. composition of th ...200516233807
drug evaluation: opt-80, a narrow-spectrum macrocyclic antibiotic.optimer pharmaceuticals inc, in collaboration with par pharmaceutical companies inc, is developing opt-80, a narrow-spectrum macrocyclic antibiotic secreted by the actinomycete dactylosporangium aurantiacum, for the potential treatment of clostridium difficile-associated diarrhea (cdad) and vancomycin-resistant enterococcus infection. a phase iib/iii clinical trial of opt-80 in patients with cdad is underway.200717328233
diversity of cultivated and uncultivated actinobacterial endophytes in the stems and roots of rice.a dual approach consisting of cultivation and molecular retrieval of actinobacterial 16s rrna genes was used to characterize the diversity of actinobacterial community inhabiting interior of rice stems and roots. streptomyces is the most frequently isolated genus from rice stems and roots. forty-five clones chosen randomly among 250 clones in the 16s rrna gene clone library from roots were affiliated with nine genera of actinobacteria and uncultured actinobacteria (mycobacterium, streptomyces, m ...200717334856
[haloalkaliphilic actinomycetes in soils of mongolian desert steppes].the abundance of actinomycetes isolated from the soils of mongolian desert steppes varies from several thousand to hundreds of thousands of cfu/g soil, depending on soil type and isolation medium. eight actinomycete genera have been found in these soils: streptomyces, micromonospora, saccharopolyspora, actinomadura, microtetraspora, thermomonospora, nocardia, and dactylosporangium. the streptomycete complexes of brown desert-steppe and gray-brown desert alkaline soils include halophilic, alkalip ...200717966911
[diversity of actinomycetes in wuling mountain].to isolate new actinomycetes for discovering compounds of pharmaceutical importance.200818837376
isolation, diversity, and antimicrobial activity of rare actinobacteria from medicinal plants of tropical rain forests in xishuangbanna, china.endophytic actinobacteria are relatively unexplored as potential sources of novel species and novel natural products for medical and commercial exploitation. xishuangbanna is recognized throughout the world for its diverse flora, especially the rain forest plants, many of which have indigenous pharmaceutical histories. however, little is known about the endophytic actinobacteria of this tropical area. in this work, we studied the diversity of actinobacteria isolated from medicinal plants collect ...200919648362
dactylosporangium darangshiense sp. nov., isolated from rock soil.a novel actinomycete was isolated from soil of a rock surface collected from the peak of darangshi oreum (small mountain) in jeju, republic of korea. phylogenetic analyses based on 16s rrna gene sequences demonstrated that strain dls-44(t) belonged to the genus dactylosporangium, with the type strains of dactylosporangium roseum (99.1 % sequence similarity) and dactylosporangium fulvum (99.0 %) as the nearest phylogenetic relatives. substrate mycelium was abundant, irregularly branched, twisted ...201019666791
dactylosporangium maewongense sp. nov., isolated from soil.morphological and chemotaxonomic characterization of actinomycete strain mw2-25(t), isolated from tropical forest soil in nakhon sawan province, thailand, clearly demonstrated that this strain belongs to the genus dactylosporangium. phylogenetic analysis using 16s rrna gene sequences also indicated that this strain should be classified in the genus dactylosporangium and showed that the closest relative was dactylosporangium aurantiacum ifo 12592(t) (99.3 % sequence similarity). dna-dna hybridiza ...201019667384
[selective isolation and diversity of acidophilic filamentous actinomycetes from acidic soils].to establish effective methods for selective isolation of acidophilic filamentous actinomycetes from acidic soils, and to investigate their genus and species diversity.200919673405
new pcr primers for the selective amplification of 16s rdna from different groups of actinomycetes.actinomycetes play a relevant role in soil ecology and are also of important biotechnological interest as they produce several bioactive metabolites. within the filamentous actinomycetes, it would be desirable to recognize and characterize environmental samples containing unusual genera. to this end, we have developed selective primer sets for polymerase chain reaction (pcr) amplification of 16s rdna from the actinomycetales families micromonosporaceae, streptomycetaceae, streptosporangiaceae an ...200219709301
three new species of dactylosporangium isolated from soil: dactylosporangium luridum sp. nov., dactylosporangium luteum sp. nov. and dactylosporangium salmoneum sp. nov.forty strains isolated from soil taken from a hay meadow were assigned to the genus dactylosporangium on the basis of colonial properties. 16s rrna gene sequencing showed that the isolates formed a group that was most closely related to the type strain of dactylosporangium aurantiacum, but well separated from other dactylosporangium type strains and from 'dactylosporangium salmoneum' nrrl b-16294. twelve out of thirteen representative isolates had identical 16s rrna gene sequences and formed a s ...200919767364
reclassification of 'dactylosporangium variesporum' as saccharothrix variisporea corrig. (ex tomita et al. 1977) sp. nov., nom. rev.in the course of a polyphasic study it was observed that 'dactylosporangium variesporum' nrrl b-16296 is misclassified in the genus dactylosporangium as it exhibits properties consistent with its assignment to the genus saccharothrix. phylogenetic analyses based on 16s rrna gene sequences show that the strain falls within the evolutionary radiation of the genus saccharothrix, a result which is supported by corresponding chemotaxonomic and morphological markers. the strain is phylogenetically mos ...201120305067
dactylosporangium luridum sp. nov., dactylosporangium luteum sp. nov. and dactylosporangium salmoneum sp. nov., nom. rev., isolated from soil.forty strains isolated from soil taken from a hay meadow were assigned to the genus dactylosporangium on the basis of colonial properties. 16s rrna gene sequence analysis showed that the isolates formed a group that was most closely related to the type strain of dactylosporangium aurantiacum, but well separated from other dactylosporangium type strains and from 'dactylosporangium salmoneum' nrrl b-16294. twelve of 13 representative isolates had identical 16s rrna gene sequences and formed a subc ...201020688750
[genetic manipulation system for tiacumicin producer dactylosporangium aurantiacum nrrl 18085].to optimize the production of tiacumicin b in dactylosporangium aurantiacum nrrl 18085, we developed a genetic manipulation system for disrupting genes involved in tiacumicin biosynthesis.201020931868
dactylosporangium tropicum sp. nov., isolated from a thai soil.two novel actinomycete strains were isolated from soil samples. both formed finger-shaped sporangia on short sporangiophores that emerged directly from substrate hyphae. the cell-wall peptidoglycan of both strains contained glutamic acid, glycine, alanine and meso-diaminopimelic acid; galactose, glucose, mannose, rhamnose, ribose and xylose were found as whole-cell sugars. the diagnostic phospholipids were phosphatidylethanolamine. the predominant menaquinone was mk-9(h8). mycolic acids were not ...201021037030
characterization of tiacumicin b biosynthetic gene cluster affording diversified tiacumicin analogues and revealing a tailoring dihalogenase.the rna polymerase inhibitor tiacumicin b is currently undergoing phase iii clinical trial for treatment of clostridium difficile associated diarrhea with great promise. to understand the biosynthetic logic and to lay a foundation for generating structural analogues via pathway engineering, the tiacumicin b biosynthetic gene cluster was identified and characterized from the producer dactylosporangium aurantiacum subsp. hamdenensis nrrl 18085. sequence analysis of a 110,633 bp dna region revealed ...201021186805
detection, selective isolation and characterisation of dactylosporangium strains from diverse environmental samples.a culture-independent, nested pcr procedure based on genus-specific oligonucleotide primers detected the presence of members of the genus dactylosporangium in 14 out of 21 diverse environmental samples. clones generated from the 14 positive environmental samples formed distinct phyletic lines in the dactylosporangial 16s rrna gene tree. presumptive dactylosporangiae were isolated from 7 of these samples using a medium designed to be selective for members of the genus dactylosporangium, namely st ...201121596505
characterization of a sugar-o-methyltransferase tias5 affords new tiacumicin analogues with improved antibacterial properties and reveals substrate promiscuity.the 18-membered macrocyclic glycoside tiacumicin b, an rna polymerase inhibitor, is of great therapeutic significance in treating clostridium difficile infections. the recent characterization of the tiacumicin b biosynthetic gene cluster from dactylosporangium aurantiacum subsp. hamdenensis nrrl 18085 revealed the functions of two glycosyltransferases, a c-methyltransferase, an acyltransferase, two cytochrome p450s, and a tailoring dihalogenase in tiacumicin biosynthesis. here we report the gene ...201121633995
fidaxomicin: a macrocyclic antibiotic for the treatment of clostridium difficile infection.clostridium difficile is an emerging pathogen in certain health care systems and community-based populations that is associated with high rates of morbidity and mortality, as well as increased costs for the health care system. as recurrence rates increase, new pharmacologic agents to treat c. difficile infection are needed. fidaxomicin, a novel macrocyclic antibiotic, was recently approved by the united states food and drug administration for the treatment of c. difficile-associated diarrhea. or ...201121923589
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