comparison of spontaneous, uv-induced, and nitrosoguanidine-induced mutability to drug resistance in myxobacteria.the uv survival curves of different strains of myxobacteria exhibited shoulders; in the case of polyangium luteum, an unusual double shoulder appeared. repair inhibitors like acriflavine, caffeine, and coumarin reduced the survival of uv-irradiated cells if the drugs were incorporated in the post-irradiation plating medium. the shoulders were reduced, but the final inactivation slopes were not affected by the repair inhibitors. those strains that were resistant to uv were also more resistant to ...197899434
evidence for repair of ultraviolet-induced damage in cystobacter species (myxobacterales).cystobacter species strain ck 1 does not grow with more than 0.2 microgram/ml acriflavine. spontaneous two-step mutants growing with 2 microgram acriflavine per ml have been selected. one mutant (strain ck3) was used to investigate the effect of repair inhibitors. both strains exhibit pronounced shoulders in their uv dose curves of inactivation. acriflavine (af), coumarin (cu), and caffeine (ca) when incorporated in the post-irradiation plating medium decreased survival of irradiated cells. post ...1978102087
effects of drugs that influence eucaryotic motile processes on motility of cystobacter fuscus (myxobacterales).cytochalasin b, dbcamp and egta were found to inhibit the motility of cystobacter fuscus completely whereas colchicine and camp only reduced velocity of movement.1979232592
the structural elucidation of the two positional isomers of a mono-glucopyranosyl mono-acyl glycerol derivative from cystobacter fuscus (myxobacterales).the structures of two glycolipids produced by cystobacter fuscus cb 685 have been determined by 1h-nmr spectroscopy including 2d-techniques, as the positional isomers 1- and 2-isopentadecanoyl-3-beta-d-glucopyranosyl-x-glycerol. the chain length of the fatty acid residue determined by 13c-nmr spectroscopy has been confirmed by negative ion fab-mass spectrometry.19921627591
5s rrna sequences of myxobacteria and radioresistant bacteria and implications for eubacterial evolution.5s rrna sequences were determined for the myxobacteria cystobacter fuscus, myxococcus coralloides, sorangium cellulosum, and nannocystis exedens and for the radioresistant bacteria deinococcus radiodurans and deinococcus radiophilus. a dendrogram was constructed by using weighted pairwise grouping based on these and all other previously known eubacterial 5s rrna sequences, and this dendrogram showed differences as well as similarities compared with results derived from 16s rrna analyses. in the ...19902125831
distribution of multicopy single-stranded dna among myxobacteria and related species.multicopy single-stranded dna (msdna) is a short single-stranded linear dna originally discovered in myxococcus xanthus and subsequently found in stigmatella aurantiaca. it exists at an estimated 500 to 700 copies per chromosome (t. yee, t. furuichi, s. inouye, and m. inouye, cell 38:203-209, 1984). we found msdna in other myxobacteria, including myxococcus coralloides, cystobacter violaceus, cystobacter ferrugineus (cbfe17), nannocystis exedens, and nine independently isolated strains of m. xan ...19853932332
mutation to acriflavine resistance in some contrast to other gram-negative bacteria, several species of fruiting myxobacteria were found to be extremely sensitive to acriflavine. depending on the species, acriflavine concentrations of 0.05 to 0.5 micrograms affected growth rate and viability. spontaneous first-step mutants resistant to acriflavine were isolated. most of these mutants were cross-resistant to both proflavine and ethidium bromide. some mutants, however, were not cross-resistant to the latter dye. in two species it was po ...19806777638
isolation and identification of althiomycin from cystobacter fuscus (myxobacterales). 19826809724
cystothiazoles a and b, new bithiazole-type antibiotics from the myxobacterium cystobacter bithiazole-type antibiotics, cystothiazoles a (c20h26n2o4s2) and b (c20h26n2o5s2), have been isolated from a culture broth of the myxobacterium, cystobacter fuscus. the gross structures of these compounds were elucidated by spectroscopic analysis, and their absolute stereochemistry was determined by chemical degradation of cystothiazole a. cystothiazole a inhibits fungi and human tumor cells, whereas it is inactive against bacteria. the antifungal activity appears to result from the inhibiti ...19989589062
the correlation between morphological and phylogenetic classification of order to determine whether morphological criteria are suitable to affiliate myxobacterial strains to species, a phylogenetic analysis of 16s rdnas was performed on 54 myxobacterial strains that represented morphologically 21 species of the genera angiococcus, archangium, chondromyces, cystobacter, melittangium, myxococcus, polyangium and stigmatella, five invalid species and three unclassified isolates. the analysis included 12 previously published sequences. the branching pattern confirmed t ...199910425789
[isolation and identification of myxobacteria].this paper reported that the authors isolated large numbers of myxobacteria from more than 100 samples collected in many places of china. more than 400 pure strains were obtained. these strains belonged to 10 genera of myxococcales. the most frequent genera isolated were myxococcus, sorangium, corallococcus, and cystobacter. melittangium was seldom isolated. no chondromyces and haploangium were found.200012549062
improved methods of isolation and purification of myxobacteria and development of fruiting body formation of two using baiting techniques and different purification methods, a high number of myxobacterial strains have been isolated as pure cultures from soil of different regions of china. because myxobacterial cells do not disperse easily in liquid media, a medium containing an enzymatic hydrolysate of casein (ceh) medium have been used for purification and purity tests combined in a single step. the key method, in which isolates are reintroduced to sterile rabbit dung to induce fruiting bodies formatio ...200312732418
biosynthetic studies on a myxobacterial antibiotic, cystothiazole a: biosynthetic precursors of the carbon skeleton.biosynthetic studies on cystothiazole a (1), a beta-methoxyacrylate-type antifungal compound from a myxobacterium, were performed by feeding the producing organism, cystobacter fuscus, with stable-isotope-labeled compounds including [2-(13)c]acetate, [1,2-(13)c2]acetate, [1-(13)c]propionate, l-[1-(13)c]serine, l-[methyl-(13)c]methionine, and dl-valine-d8. the polyketide moiety of 1 was found to be derived from acetate and propionate, the bithiazole moiety from l-serine, the o-methyl groups from ...200312817811
archazolids, new cytotoxic macrolactones from archangium gephyra (myxobacteria). production, isolation, physico-chemical and biological properties.novel cytotoxic compounds, archazolid a and b, were isolated from the culture broth of strains of the myxobacteria archangium gephyra and cystobacter sp. archazolids consist of a macrocyclic lactone ring with a thiazole side chain and showed high activity against mammalian cells. the ic50 values with different cell lines ranged from 0.1 to 1 ng/ml. an incubation of ptk2 potoroo cells with archazolid a (5 ng/ml) led to the formation of vacuoles in the er, a phenomenon that is typical for inhibito ...200312931860
cyrmenins, new beta-methoxyacrylate inhibitors of the electron transport. production, isolation, physico-chemical and biological antibiotic compounds, named cyrmenins, were isolated from the culture broth of strains of the myxobacteria cystobacter armeniaca and archangium gephyra. the compounds belong to the group of beta-methoxyacrylate (moa) inhibitors and are the first naturally occuring nitrogen-linked moas. the cyrmenins show nearly the same antifungal activity as strobilurin a, but are less toxic in a growth inhibition assay with l929 mouse cells. cyrmenins inhibit nadh oxidation by submitochondrial particles fr ...200314700275
biotransformation of cystothiazole a, a myxobacterial antibiotic, into novel derivatives by the mother producer, cystobacter fuscus.the bioconversion of the myxobacterial antibiotic, cystothiazole a, by the antibiotic producer, cystobacter fuscus, was investigated. in our previous study, an adsorbent resin was added to the fermentation mixture to achieve high productivity of cystothiazole a, the major and most active component. on the other hand, a relative increase in the metabolic derivatives of cystothiazole a was observed when cultured without the resin. furthermore, when cystothiazole a was externally added to the cultu ...200414981303
construction of a bacterial artificial chromosome library for a myxobacterium of the genus cystobacter and characterization of an antibiotic biosynthetic gene cluster.a bacterial artificial chromosome (bac) library was constructed to isolate the biosynthetic gene cluster for the polyketide/peptide hybrid-type antibiotic cystothiazole a from the myxobacterium cystobacter fuscus strain aj-13278. sequence analysis of a 63.9 kb contiguous region that encompasses the biosynthetic gene cluster (cta) led to the identification of a polyketide synthase (pks)/nonribosomal peptide synthetase (nrps) hybrid gene cluster 32.1 kb in size, which consists of six open reading ...200516041144
exploring the diversity of myxobacteria in a soil niche by myxobacteria-specific primers and probes.the diversity of myxobacteria in a soil niche was explored using culture-dependent and -independent methods. conventional cultivation for bacteriolytic myxobacteria produced six types of myxobacteria, which were identified as two myxococcus spp., two corallococcus spp., a cystobacter sp. and a nannocysts sp. hybridization analysis of the soil bacterial 16s rrna gene library with myxobacteria-specific probes revealed that myxobacteria accounted for less than 1% in the bacterial community. a cysto ...200516156733
identification of stir, the first regulator of secondary metabolite formation in the myxobacterium cystobacter fuscus cb f17.1.myxobacteria are well established as proficient producers of natural products with numerous biological activities. although some knowledge has been gained regarding the biosynthesis of secondary metabolites in this class of bacteria, almost nothing is known about the underlying regulatory mechanisms. in order to identify regulatory elements, we submitted the argyrin and stigmatellin producer cystobacter fuscus to a random transposon mutagenesis strategy and screened 1,000 mutants for the occurre ...200616221500
myxobacters from arid mexican soil.myxobacters were found to be common inhabitants of the arid soils from the monterrey, nuevo leon, mexico, area. thirteen species of the genera myxococcus, archangium, cystobacter, stigmatella, polyangium, and chondromyces were isolated on a mineral salts agar supplemented with bakers' yeast and filter paper. greater species diversity per soil sample was found in the region receiving 400 to 800 mm of annual rainfall as compared with soils from an area having only 200 to 400 mm of rainfall.197616345178
biosynthesis of 2'-o-methylmyxalamide d in the myxobacterium cystobacter fuscus: a polyketide synthase-nonribosomal peptide synthetase system for the myxalamide d skeleton and a methyltransferase for the final o-methylation.the biosynthetic gene cluster for the polyene antifungal antibiotic, 2'-o-methylmyxalamide d, was cloned from myxobacterium cystobacter fuscus aj-13278. a sequence analysis of the 12.8-kb region in the gene cluster revealed the presence of two type i polyketide synthase genes, mmxb and mmxc. the involvement of these two genes in the biosynthesis of 2'-o-methylmyxalamide d was confirmed by a gene disruption experiments. in addition, an s-adenosylmethionine-dependent methyltransferase gene (mmxm) ...200616556988
evolutionary diversity of ketoacyl synthases in cellulolytic myxobacterium sorangium.the diversity of type i polyketide synthases (pkss) in cellulolytic myxobacterium sorangium was explored by assaying the ketoacyl synthases (kss) in 10 sorangium strains with two degenerate primer sets and 64 different ks fragments were obtained. for their deduced amino acid sequences, eight were identical to three known kss from sorangium and magnetospirillum, while the others showed 54-83% identities to the modular ks domains reported from various microorganisms. parts of the sorangium kss tig ...200716899349
the first hydroxylated archazolid from the myxobacterium cystobacter violaceus: isolation, structural elucidation and v-atpase inhibition.the novel macrocyclic polyketide, 10-hydroxymethyl-archazolid-7-o-beta-d-glucopyranoside (archazolid d), was obtained from the myxobacterium cystobacter violaceus. the structure of this first hydroxylated archazolid was determined by spectroscopic analysis, in particular by hmbc, hmqc, and roesy nmr investigations, and by degradation. this novel metabolite was evaluated for growth inhibition of murine connective tissue cells and v-atpase inhibition in comparison to other known archazolids.200717551213
first total synthesis of cyrmenin b1.a short and efficient synthesis of cyrmenin b(1), an antifungal metabolite of myxobacteria cystobacter armeniaca and archangium gephyra, is described. the crucial steps of the synthesis included the formation of the dehydroalanine moiety from the corresponding serine acetate and the formation of the beta-methoxyacrylate system via trimethylsilyldiazomethane methylation of the corresponding beta-hydroxy enamide.200919035819
discovery of 23 natural tubulysins from angiococcus disciformis an d48 and cystobacter sbcb004.the tubulysins are a family of complex peptides with promising cytotoxic activity against multi-drug-resistant tumors. to date, ten tubulysins have been described from the myxobacterial strains angiococcus disciformis an d48 and archangium gephyra ar 315. we report here a third producing strain, cystobacter sp. sbcb004. comparison of the tubulysin biosynthetic gene clusters in sbcb004 and an d48 reveals a conserved architecture, allowing the assignment of cluster boundaries. a sbcb004 strain con ...201020338521
expanded phylogeny of myxobacteria and evidence for cultivation of the 'unculturables'.an expanded neighbour-joining tree of myxobacteria is presented based on the analysis of 16s rrna gene sequences of 101 strains (including types) representing 3 suborders, 6 families, 20 genera, 46 species, and 12 other novel taxa. the distinctions amongst members of the three suborders (sorangiineae, cytobacterineae and nannocystineae) are reaffirmed. the positions of anaerobic myxobacteria, novel groups (pyxidicoccus and several cystobacter species) in cystobacterineae, the marine genera (ples ...201020807581
archazolid a-15-o-β-d-glucopyranoside and iso-archazolid b: potent v-atpase inhibitory polyketides from the myxobacteria cystobacter violaceus and archangium gephyra.two structurally novel analogues of the macrolides archazolids a and b, archazolid a-15-o-β-d-glucopyranoside (archazolid e, 5) and iso-archazolid b (archazolid f, 6), were isolated from the myxobacterium cystobacter violaceus and archangium gephyra, respectively. macrolactone 5 represents the first 15-o-glycoside of the archazolids. iso-archazolid b (6) incorporates a c-3 alkene and presents the first constitutional isomer reported for this natural product class. the structures of these polyket ...201121513292
p-hydroxyacetophenone amides from cystobacter ferrugineus, strain cb g35.a family of six novel p-hydroxyacetophenone amides, 1-6, was isolated from cystobacter ferrugineus, strain cb g35. their structures were elucidated by esi-tof mass spectrometry and nmr spectroscopy. feeding experiments with labeled [(13)c(9),(15)n]-tyrosine and [d(10)]-leucine identified the biosynthetic precursors of 1.201121591808
roimatacene: an antibiotic against gram-negative bacteria isolated from cystobacter ferrugineus cb g35 (myxobacteria).roimatacene (1) was isolated from the myxobacterium cystobacter ferrugineus strain cb g35 in a bioactivity-guided process, by following the antimicrobial activity against escherichia coli. since 1 was extremely sensitive to oxygen, a protective isolation and handling protocol was developed, by utilizing the free radical scavenger 4-ethoxyphenol. the structure of 1 was determined by hrms, 1d and 2d nmr spectroscopy and chemical derivatization to acetonides and mosher esters to finally establish t ...201121618624
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