Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| [myxobacteria of the myxococcus family as indirect indicators of fecal matter in surface water. 1. communication (author's transl)]. | the fruiting-body-forming myxobacteria of the myxococcus order are coprophilic, i.e., they accumulate in biotopes that contain faecal substances. therefore, a special detection of myxococcus in water, based on the membrane-filter method, has been worked-out. field studies, undertaken in the region of a mechanico-biological clarifying plant, above a certain stretch of a stream (the regnitz) laden with waste-water, and on the bodensee (=lake constance) have revealed a clear correlation between the ... | 1975 | 808923 |
| on the utilization in vivo of lycopene and phytoene as precursors for the formation of carotenoid glucoside ester and on the regulation of carotenoid biosynthesis in myxococcus fulvus. | during th logarithmic phase of growth of the myxobacterium myxococcus fulvus the specific carotenoid content and the molar ratio of the two main carotenoids keto-torulene (3',4'-didehydro-beta,psi-caroten-4-one, 15%) and myxobacton ester (1'-glucosyloxy-3',4'-didehydro-1',2'-dihydro-beta,psi-caroten-4-one ester, 80%) are highly constant. when the formation of these carotenoids was prevented by an inhibitory block at the level of phytoene desaturation, the normal specific content is rapidly reach ... | 1975 | 809283 |
| coats from myxococcus xanthus: characterization and synthesis during myxospore differentiation. | an extracellular coat from glycerol-induced myxospores of myxococcus xanthus has been isolated and characterized. coats were examined chemically and by using both transmission and scanning electron microscopy. on a dry weight basis, approximately 75% of the coat is polysaccharide composed entirely of galactosamine and glucose. the remainder of the coat is protein (14%), glycine (8%), and organic phosphorus (less than 1%). coats remained morphologically intact despite boiling in 10 m urea, sodium ... | 1975 | 809426 |
| carbohydrate accumulation during myxospore formation in myxococcus xanthus. | during glycerol-induced myxospore formation in myxococcus xanthus, cellular neutral polysaccharide increases by approximately 200%, respiration decreases by 80%, and net phospholipid synthesis ceases. | 1975 | 811652 |
| regulation of development in myxococcus xanthus: effect of 3':5'-cyclic amp, adp, and nutrition. | an assay was developed to study the regulation of fruiting in myxococcus xanthus. the nucleotides, adenosine 3':5'-cyclic monophosphate (cyclic amp) and adenosine diphosphate (adp), were found to greatly stimulate fruiting under the assay conditions. very sharp concentration optima were observed. even under conditions of starvation, these nucleotides greatly increased the number of aggregation sites. nutrition was found to influence fruiting body morphology. the effect of amino acids on the nucl ... | 1975 | 164657 |
| aspartokinase isoenzymes of the fruiting myxobacterium myxoccus xanthus. | two isoenzymes of aspartokinase can be found in extracts of the differentiating bacterium myxococcus xanthus. aspartokinase i is repressed by l-lysine and feedback is inhibited by meso-diaminopimelate and by low concentrations of l-lysine. however, the inhibition by l-lysine is no longer observed at high concentration of this amino acid. aspartokinase ii is repressed and feedback inhibited specifically by l-threonine. both enzymes are stimulated significantly by l-methionine and l-isoleucine; th ... | 1975 | 170969 |
| carotenoid pigments of facultatively anaerobic spirochetes. | carotenoid pigments were purified from a previously undescribed, red, halophilic spirochete (spirochete rs1), and from spirochaeta aurantia strain j1. both spirochetes are facultative anaerobes and produce pigments when growing aerobically. the major pigments of the two spirochetes were identified by means of chromatographic analysis, absorption spectroscopy, hydride reduction, acetylation and silylation experiments, and mass spectrometry. it was concluded that the major pigment from spirochete ... | 1975 | 1158846 |
| [investigations on the structure of the sphingolipids of the genus bacteroides (author's transl)]. | in 1972 fritsche and thelen have described the difference between the structure of the komplex lipids of the genus bacteroides and the genus sphaerophorus. further investigations of fritsche demonstrated the possibility of grouping gramnegative anaerobes into the genus bacteroides in spite of the fact, that one of the final products of metabolism of these strains is butyric acid. these strains are the so-called butyric acid producing bacteroides. this paper describes the structure of the still u ... | 1975 | 1202872 |
| mutants of myxococcus xanthus insensitive to glycerol-induced myxospore formation. | mutants of myxococcus xanthus fbt unable to form myxospores in response to 0.5 m glycerol arise spontaneously with a frequency of 1--3 x 10(-5). these mutants are designated glc. ultraviolet mutagenesis increases the frequency to a maximum of 7% of the survivors. the reversion frequency following ultraviolet irradiation of spontaneous glc mutants is less than 10(-3). of four glc mutants examined, none form myxospores in response to the alternative inducers, ethylene glycol and dimethyl sulphoxid ... | 1975 | 53038 |
| morphogenesis in myxococcus xanthus and myxococcus virescens myxobacterales. | 1. myxococcus xanthus b and m. virescens v2 were compared with a view to establishing the control of their morphogenetic cycles. both organisms are typical myxococci and on solid media with low concentrations of nutrient they form fruiting bodies, within which vegetative cells convert to myxospores. ultrathin sections of vegetative m. virescens resembled those of m. xanthus and contained prominent heavily stained bodies, presumed to be polyphosphate granules. shadowed preparations showed fimbria ... | 1976 | 58646 |
| bacteriophage mx-1: properties of the phage and its structural proteins. | bacteriophage mx-1 is a virulent dna phage for myxococcus. the host range includes strains of myxococcus xanthus, m. fulvus and m. virescens. the phage has a sedimentation coefficient (s degrees 20,w) of 1145s and a density of 1-531 g/ml. by using sds-polyacrylamide gel electrophoresis, 23 phage proteins with apparent mol. wt. between 10000 and 150000 were resolved. gel filtration in the presence of non-ionic detergent partially resolved the proteins. the fraction excluded from sephadex g-100, f ... | 1976 | 812957 |
| novel surface polymer changes in development of myxococcus spp. | 1976 | 814464 | |
| extrachromosomal dna in chloramphenicol resistant myxococcus strains. | the presence of extrachromosomal dna in strains of myxococcus xanthus and m fulvus was examined by rate-zonal centrifugation of radioactively-labelled dna in 'cleared lysates'. all the strains examined contained extrachromosomal dna, with the exception of m. xanthus fbt. chloramphenicol resistance is inducible in m. xanthus fbt. a peak of extrachromosomal dna, containing covalently closed molecules, was found in one of the induced strains, implying that induction of chloramphenicol resistance is ... | 1976 | 816990 |
| dna of myxococcus bacteriophage mx-1: macromolecular properties and restriction fragments. | 1. bacteriophage mx-1 is a virulent dna phage whose hosts include strains of myxococcus xanthus, m. fulvus and m. virescens. dna was extracted from purified phage preparations. the molecular weight of phage dna was measured by sedimentation-velocity and by rate-zonal ultracentrifugation. the apparent molecular weight was found to vary for reasons discussed in the text. from rate-zonal ultracentrifugation, using calibrated sucrose gradients, the molecular weight was calculated to be 149 (+/-22) x ... | 1976 | 818975 |
| restriction in myxococcus virescens. | 1. the plating efficiency of bacteriophage mx-1 on myxococcus xanthus strains a and b and m. virescens v2 were compared. comparison of strains v2 and a suggest that v2 is restrictive and a is not (restriction coefficient was approximately 8). a derivative of m. virescens v2 (strain v2-9) was obtained by repeated exposure of strain v2 to ultraviolet radiation. strain v2-9 was also unrestrictive. strain b is apparently unrestrictive too but analysis of phenotypic changes in phage derived from host ... | 1976 | 818976 |
| phage and defective phage of strains of myxococcus. | 1. phage-like particles were found in the supernatants of cultures of strains of myxococcus xanthus, m. virescens and m. fulvus. the largest number of such particles was associated with m. virescens v2. most of the particles were similar in morphology to the virulent myxococcus phage, mx-1. 2. several new phages were isolated from soil and animal droppings. a new phage was isolated from cultures of m. virescens v2. all resembled phage mx-1 in morphology and were related to phage mx-1 serological ... | 1976 | 821449 |
| dna of myxococcus phage mx-1. pyrimidine isostichs and the recognition of a minor pyrimidine. | dna was isolated from bacteriophage mx-1 and was hydrolysed with acids. hydrolysis with 90% formic acid produced several interconvertable fluorescent artefacts. these substances were produced in greater quantity following hydrolysis with h2so4. in the course of the course of the study it was found that dna extracted from phage by 4-aminosalicylate and phenol contained 4-aminosalicylate and breakdown products derived from 4-aminosalicylate following acid hydrolysis. pyrimidine oligonucleotides re ... | 1976 | 821537 |
| fructification & antagonistic effect of myxobacteria on eubacteria: lytic effect & fruiting body formation of myxococcus, chondrococcus & angiococcus spp. | 1976 | 821856 | |
| evidence for motility-related fimbriae in the gliding microorganism myxococcus xanthus. | an electron-microscopic examination of negatively stained preparations from cell lysates of myxococcus xanthus and in situ samples of myxococcus xanthus, myxococcus virescens, and myxococcus fulvus has demonstrated the presence of polar fimbriae, about 8.5 nm in diameter, on motile but not nonmotile cells. | 1976 | 824039 |
| the isolation and characterization of gliding motility mutants of myxococcus xanthus. | nonmotile and motility-altered mutants of myxococcus xanthus have been obtained by the use of chemical mutagens, ultraviolet irradiation, and a procedure for selective spontaneous mutants. as judged by their behaviour on a variety of growth media, in both plate and slide culture, the mutants were divided into four groups. one group contains mutants which are truly nonmotile. myxococcus xanthus nm, previously described as a nonmotile mutant, may be similar to type 3 mutants (described in text). | 1976 | 824040 |
| linkages between deoxyribonucleic acid synthesis and cell division in myxococcus xanthus. | addition of chloramphenicol or 0.5 m glycerol to growing myxococcus xanthus resulted in an immediate cessation of cell division and 40% net increase in deoxyribonucleic acid (dna). although the chloramphenicol-treated cells divided in the presence of nalidixic acid after chloramphenicol was removed, glycerol-induced myxospores required dna synthesis for subsequent cell division. myxospores prepared from chloramphenicol-treated cells lost this potential to divide in the presence of nalidixic acid ... | 1976 | 824278 |
| nuclear activity and cell division in the microcysts of myxococcus fulvus demonstrated by electron micrography of sections. | electron micrographs of sectioned fruiting bodies confirm that, in myxococcus fulvus, approximately 10% of mature microcysts show appearances interpretable as typical bacterial nuclear activity and cell division. this suggests a simple mechanism for fruiting body development, and its existence bears upon the validity of the classical descriptions of microcyst maturation in myxobacteria. | 1976 | 827459 |
| 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. | 1976 | 16345178 |
| cell-to-cell stimulation of movement in nonmotile mutants of myxococcus. | a large number of nonmotile mutants of the gliding bacterium myxococcus xanthus have been isolated and partly characterized. about [unk] of these mutants are conditional mutants of a novel kind: mutant cells become transiently motile after contact with nonmutant cells or with cells of a different mutant type. these "stimulatable" mutants fall into five phenotypic classes (types b, c, d, e, and f). most mutants are nonstimulatable (type a) and never become motile, but type a cells (and wild-type ... | 1977 | 16592422 |
| myxospore coat synthesis in myxococcus xanthus: enzymes associated with uridine 5'-diphosphate-n-acetylgalactosamine formation during myxospore development. | activities of the enzymes glutamine synthetase (ec 6.3.1.2.), glucosamine 6-phosphate acetyltransferase (ec 2.3.1.4.), uridine 5'-diphosphate (udp)-n-acetylglucosamine pyrophosphorylase (ec 2.7.23.), udp-n-acetylglucosamine 4-epimerase (ec 5.1.3.7.), fructose 1,6-diphosphate phosphatase (ec 3.13.11.), l-glutamine-fructose 6-phosphate transamidase (ec 5.3.1.19.), alkaline phosphatase (ec 3.1.3.1.), and malic dehydrogenase (ec 1.1.1.37) were assayed in partially purified extracts prepared at diffe ... | 1977 | 19417 |
| gliding motility and actinomycin d sensitivity of fusobacterium nucleatum and other gram-negative rods. | six strains of gram-negative anaerobic fusiform rods (fusobacterium and bacteroides spp.), isolated from deep subgingival locations in humans, were examined for (i) gliding motility in slide cultures, (iii) cell densities on nutrient agar surfaces, and (iii) sensitivity to actinomycin d. known gliding (fbt) and nonmotile (nm) strains of myxococcus xanthus served as controls for the gliding and cell density experiments. in the present study, three strains of gram-negative fusiforms from the oral ... | 1977 | 332633 |
| glucan common to the microcyst walls of cyst-forming bacteria. | chemical analysis indicated that d-glucose is tha major neutral monosaccharide present in the microcysts of a range of gram-negative bacteria. varying amounts of other neutral sugars were found. the glucose was mainly present as a glucan that could be extracted from microcysts of representative strains with alkali or mild acid treatment. the glucan could be identified as an alpha-1,3-linked polymer on the basis of (i) periodate resistance of the extracted polymer and the material present in micr ... | 1977 | 402353 |
| cell density-dependent growth of myxococcus xanthus on casein. | when myxococcus xanthus fb was grown on 0.2% casein it exhibited a phenomenon we call cooperative growth. that is, above 104 cells per ml, both strains that were studied exhibited increasing growth rates as a function of increasing cell numbers. between 104 and 107 cells per ml, the mean doubling times of strains ys and tns decreased from 15.2 to 8 h and 26 to 8.5 h, respectively. the extracellular proteinase activity of the two strains was equivalent and directly proportional to cell number. co ... | 1977 | 402357 |
| developmentally induced autolysis during fruiting body formation by myxococcus xanthus. | the developmental events during fruiting body construction by the myxobacterium m. xanthus is an orderly process characterized by several sequential stages: growth leads to aggregation leads to formation of raised, darkened mounds of cells leads to autolysis leads to myxospore induction. the temporal sequence of autolysis followed by myxospore induction is consistent with the interpretation that developmental autolysis provides essential requirements for the surviving cells to induce to myxospor ... | 1977 | 402359 |
| effect of temperature on the growth of myxococcus xanthus. | the cardinal growth characteristics of myxococcus xanthus were examined from 14 to 40 degree c, and the examinations indicated that the organism is mesophilic in character. the maximum growth rate (0,3 doublings per h) was between 34 and 36 degree c and the temperature characteristic (micron) is 17,000 cal/mol (71,162 j/mol). | 1977 | 404288 |
| isolation of sporopollenin from four myxobacteria. | sporopollenin, a resistance material previously found only in algae, fungi, pollen grains, and in some plant spores, has been found in four species of myxococcus. sporopollenin was isolated from vegetative cells and myxospores of the myxobacteria tested but it was not detected in any of the other bacteria tested. | 1977 | 407993 |
| myxospore coat synthesis in myxococcus xanthus: in vivo incorporation of acetate and glycine. | myxospore coat synthesis in myxococcus xanthus was studied by incorporation of [(14)c]acetate into intermediates in the biosynthesis of coat polysaccharide and into acid-insoluble material during vegetative growth and after glycerol induction of myxospores. during short labeling periods at 27 degrees c, the radioactivity was shown to be located primarily in n-acetyl groups rather than sugar moieties. two hours after glycerol induction, the pools of n-acetylglucosamine 6-phosphate and uridine 5'- ... | 1977 | 408325 |
| a quantitative assay to study cell movement in the myxobacteria. | a simple quantitative assay has been developed to test the rate of cell movement of myxobacteria. the assay employs an agar surface and at no time are the cells cultured in a liquid environment. isolation of a rate-increasing substance(s) from fruiting myxococcus xanthus is reported. the understanding of the aggregative process in these bacteria will be aided by characterization of the chemotactic system. | 1977 | 408365 |
| intracellular, periodic structures in the gliding bacterium myxococcus xanthus. | electron microscopic observations of thin sections of myxococcus xanthus vegetative cells revealed the presence of cytoplasmic bundles of 4- to 5-nm-diameter filaments running longtitudinally below the cell membrane and terminating in association with the envelope near one pole. part of each bundle demonstrated a herringbone-like periodicity (approximately 12-nm spacing). this structure was observed in cells from shake cultures and in gliding cells fixed by several methods. it is proposed that t ... | 1977 | 410797 |
| bacteriocins from myxococcus fulvus (myxobacterales). | bacteriocin-like activities were found in several myxococcus fulvus strains. one strain, mx f16, exerted strong inhibitory effects on several myxobacterial strains. synthesis of its bacteriocinic activity could not be induced by mitomycin. electrophoresis and molecular sieve chromatography revealed at least three different bacteriocinic substances of low molecular weight. | 1977 | 412477 |
| pigmentation phenotype instability in myxococcus xanthus. | cells of myxococcus xanthus fb2 produce tan or yellow colonies. subcultures of tan colonies yielded tan and yellow colonies and subcultures of most yellow colonies yielded only yellow colonies. strain fb2 variants in which the color type is more stable were obtained. yellow cells were distinguishable from tan by the presence of pigment(s) with an absorption maximum at 379 nm. fluctuation test experiments and the presence of this pigment(s) in liquid cultures of fb2 indicated that tan phenotype c ... | 1977 | 413617 |
| bacteriolytic myxobacteria: parasites or scavengers? | the activity range of an enzymatic preparation from myxococcus xanthus was assayed against some soil and rhizospheric bacteria. the lysis of unequally aged sensitive eubacterial populations, as related to their viability, was investigated and, at last, the often used streak method was checked and the relationship between cell viability and susceptibility to lysis is discussed. | 1977 | 414478 |
| myxobacterial slime and proteolytic activity. | an extracellular protein-polysaccharide-lipide (ppl) complex from exponentially growing cultures of myxococcus virescens was purified by phosphate precipitation and gel chromatography. the high molecular weight slime polymer appeared homogenous upon isoelectric focusing. the ppl complex exhibited proteolytic activity against gelatin and the activity was only partly reduced by heat treatment. the function of the slime polymer as protein denatured was studied. the complex formed micelles similar t ... | 1978 | 414687 |
| nutrition of myxococcus xanthus, a fruiting myxobacterium. | the minimal requirements for vegetative growth of myxococcus xanthus have been sought. isoleucine, leucine, and valine were required, and vitamin b12 was needed for the synthesis of methionine. pyruvate was an excellent energy source and an efficient source of cellular carbon. acetate, aspartate, glutamate, and most tricarboxylic acid cycle intermediates could also be utilized, but were less efficient sources of carbon and energy than was pyruvate. many mono- and disaccharides were tested, but, ... | 1978 | 415048 |
| isolation of bacteriophage mx4, a generalized transducing phage for myxococcus xanthus. | 1978 | 416222 | |
| physical characterization of bacteriophage mx4, a generalized transducing phage for myxococcus xanthus. | 1978 | 416223 | |
| changes in cyclic amp levels during development in myxococcus xanthus. | cyclic amp levels doubled in myxococcus xanthus under conditions in which cells aggregate and form fruiting bodies. in liquid medium, glycerol- or dimethyl sulfoxide-induced sporulating cultures exhibited a sharp but transient rise in cyclic amp concentration after 45 min. | 1978 | 205533 |
| cyclic nucleotides, cyclic nucleotide phosphodiesterase, and development in myxococcus xanthus. | exogenous cyclic nucleotide phosphodiesterase (pd) accelerated fruiting body (fb) formation and increased territory size of aggregates in myxococcus xanthus. both guanosine 3'5'-monophosphate (cgmp) and guanosine 5'-monophosphate (gmp) were antagonistic to the pd effect. adenosine 3'5'-monophosphate (camp) increases fb numbers twofold in the absence but not in the presence of pd. pd induction is not affected by methionine or isoleucine, which inhibit, or by threonine, which stimulates, fb format ... | 1978 | 218712 |
| chromosome replication in myxococcus xanthus. | the rates of dna synthesis during the cell-division cycle were measured in myxococcus xanthus growing in three different media permitting a twofold variation in doubling time. in all three media, simple dna cycles were observed. synthesis of dna occurred during 85% of the cell-division cycle, independent of generation time, from 5 to 11 h. cells were observed to contain one bacterial nucleoid at birth that later divided synchronously midway through the cell cycle. nucleoid segregation appeared t ... | 1978 | 412830 |
| purification and properties of an extracellular protease from myxococcus virescens. | an extracellular protease from myxococcus virescens was purified by phosphate precipitation, gel exclusion, and ion-exchange chromatography. the enzyme appeared homogeneous upon disc electrophoresis. the molecular weight of the protease was estimated to be 26,000. the enzyme was rapidly inactivated by ethylenediaminetetraacetate, but the activity could be partially restored by divalent cations. diisopropylphosphorofluoridate inhibited enzyme activity completely. michaelis-menten kinetics were ob ... | 1978 | 22536 |
| stimulation of fruiting body formation of myxococcus virescens thaxter (myxobacterales) in crude culture by addition of salt. | 1978 | 25514 | |
| on the distribution of myxobacteria in the temperate south america (author's transl). | 60 soil samples from southern chile, mainly from forests and grassland, yielded six species of myxobacteria. in forest soils myxococcus coralloides and myxococcus fulvus occur frequently, in grassland soils myxococcus coralloides and archangium gephyra are predominating. myxococcus virescens, melittangium lichenicola, and cytobacter fuscus have been observed rarely. it is pointed out that due to climate factors a high soil acidity causes the low nuber of myxobacter species. a comparison with the ... | 1978 | 27046 |
| systematic isolation of transducing phages for myxococcus xanthus. | 1978 | 97862 | |
| synergism between morphogenetic mutants of myxococcus xanthus. | 1978 | 98366 | |
| 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 ... | 1978 | 99434 |
| synthesis and salvage of purines during cellular morphogenesis of myxococcus xanthus. | intact cells of myxococcus xanthus were examined for de novo purine synthesis and salvage utilization. the cellular uptake rates of radioactive glycine (de novo purine precursor), adenine, and guanine were measured, and thin-layer chromatography and radioautography were used to examine cell extracts for de novo synthesized purine nucleotides. intact vegatative cells, glycerol-induced myxospores, and germinating cells of m. xanthus cw-1 were able to carry out de novo purine and salvage synthesis. ... | 1978 | 101526 |
| incorporation of 32pi into nucleotides, polyphosphates, and other acid-soluble compounds by myxococcus xanthus during myxospore formation. | when glycerol was used to induce myxospore formation in myxococcu xanthus in the presence of 32pi, the label was incorporated into a variety of acid-soluble compounds. incorporation into ribonucleotides was approximately fivefold greater than in vegetative cells or noninducible mutants grown in glycerol. the label was also incorporated into some unknown compounds and material tentatively identified as guanosine tetraphosphate. marked accumulation into polyphosphates, which were present mainly in ... | 1978 | 102632 |
| transduction of myxococcus virescens by coliphage p1cm: generation of plasmids containing both phage and myxococcus genes. | chloramphenicol-resistant myxococcus virescens were obtained by infecting myxococci with escherichia coli specialized transducing phage p1cm. the drug-resistant myxococci were phenotypically unstable. they contained more than one type of plasmid; these plasmids were not found in the parent strain. chloramphenicol-resistant e. coli were obtained by transformation with either a fraction of myxococcal dna containing the plasmids or with p1cm prophage dna. these transformants contained plasmids. esc ... | 1978 | 103996 |
| hemolysin of myxococcus fulvus nk 35 i. production and isolation. | myxococcus fulvus nk 35 has been shown to produce a soluble hemolysin which lysed rabbit, human, horse, and sheep erythrocytes. a medium (varghese's medium) was devised in which a maximum of hemolysin was produced in 6 days at 28 degrees c under static conditions. the lysin was precipitated by complete saturation of the culture filtrate with ammonium sulphate, followed by dialysis against saline. other enzyme systems were destroyed by heating at 100 degrees c. further purification was achieved b ... | 1978 | 104473 |
| purification and effects of fulvocin c, a bacteriocin from myxococcus fulvus mx f16. | fulvocin c is a bacteriocin from myxococcus fulvus mx f16. it has a molecular weight of 4672 and is one of the smallest bacteriocins known. four disulfide bonds give the molecule a tight structure, so that its native form was not attacked by chymotrypsin or pronase. fulvocin c was stable in various organic solvents and could tolerate 80 degrees c in aqueous solution without loss of activity. the killing effect of fulvocin c was observed only at concentrations higher than 0.25 mumol/1. macromolec ... | 1978 | 104692 |
| site of atpase activity in myxococcus xanthus: lipid requirement for enzyme activity. dedicated to professor dr. w. schwartz on his 80th birthday. | treatment of cells with lysophosphatidylcholine, lysozyme, and phospholipase d removed most of their phospholipids and reduced atpase activity to near zero. addition of a microdispersion of phospholipids restored enzyme activity to various degrees. phosphatidylcholine was most effective in reconstitution experiments, less effective were phosphatidylethanolamine and phosphatidylserine. lipid analyses of cell fractions were possible through separation of cell wall and cell membrane in a sucrose gr ... | 1978 | 151387 |
| rifampin-resistant mutants of myxococcus xanthus defective in development. | rifampin, an antibiotic which is known to bind to and inhibit rna polymerase, was used to probe the molecular regulation of development in myxococcus xanthus. rifampin-resistant mutants were screened for defects in fruiting-body formation. about 20% of the isolates in the initial screenings showed major defects in developmental aggregation or sporulation. eleven independent mutants with wild-type growth rates and stable phenotypes were analyzed by transduction. in these strains, the rifampin-res ... | 1979 | 104962 |
| homology of the gene coding for outer membrane lipoprotein within various gram-negative bacteria. | the mrna for a major outer membrane lipoprotein from escherichia coli was found to hybridize specifically with one of the ecori and one of the hindiii restriction endonuclease-generated fragments of total dna from nine bacteria in the family enterobacteriaceae: e. coli, shigella dysenteriae, salmonella typhimurium, citrobacter freundii, klebsiella aerogenes, enterobacter aerogenes, edwardsiella tarda, serratia marcescens, and erwinia amylovora. however, among the enterobacteriaceae, dna from two ... | 1979 | 104972 |
| gene expression during development of myxococcus xanthus: pattern of protein synthesis. | 1979 | 108160 | |
| developmental induction of myxococcus xanthus myxospores. | myxospore differentiation during the developmental cycle of myxococcus xanthus is characterized by several distinguishable morphological stages. two experimentally useful criteria of myxospore induction are the conversion of vegetative rods to optically refractile short rods or ovoids and the development of resistance to sonic lysis. the use of optical refractility as the first morphological criterion of myxospore induction has facilitated an analysis of induction on developmental plates. the ti ... | 1979 | 115838 |
| myxococcus xanthus mutants with temperature-sensitive, stage-specific defects: evidence for independent pathways in development. | fruiting-body formation in the bacterium myxococcus xanthus consists of a temporal sequence of cellular aggregation and sporulation. to examine the developmental stages more closely, we established synchronous and reproducible conditions for fruiting-body formation. mutants that are temperature sensitive for fruiting-body formation were isolated and analyzed under these conditions. the terminal morphologies of the mutant strains at the nonpermissive temperature were found to resemble intermediat ... | 1979 | 118153 |
| iso-branched 2- and 3-hydroxy fatty acids as characteristic lipid constituents of some gliding bacteria. | the fatty acids present in the total hydrolysates of several gliding bacteria (myxococcus fulvus, stigmatella aurantiaca, cytophaga johnsonae, cytophaga sp. strain samoa and flexibacter elegans) were analyzed by combined gas-liquid chromatography and mass spectrometry. in addition to 13-methyl-tetradecanoic acid, 15-methyl-hexadecanoic acid, hexadecanoic acid, and hexadecenoic acid, 2- and 3-hydroxy fatty acids comprised up to 50% of the total fatty acids. the majority was odd-numbered and iso-b ... | 1979 | 118159 |
| two methods of large-scale extraction of an antibiotic produced by myxococcus coralloides. | two methods for the isolation of an antibiotic produced by myxococcus coralloides have been developed: the chloroform extraction method and the charcoal adsorption method. the recovery of antibiotic in each case was 25% and 30%, respectively, by the two methods. although the two methods yield a relative low recovery, the charcoal adsorption method seems more attractive and promising due to its simplicity and economic advantages. | 1979 | 119135 |
| biological activity of an antibiotic produced by myxococcus coralloides. | a strain of myxococcus coralloides was isolated which produced an antibiotic active against gram-positive bacteria and also against neisseria sp at high levels of antibiotic. the antibiotic was bactericidal on sensitive growing bacteria. it was inactive on non-growing cells and also on cells whose growth has been stopped by addition of chloramphenicol. strains of s. aureus resistant to several antibiotics, including penicillin and ampicillin, were also sensitive to this antibiotic. | 1979 | 120482 |
| [aquatic myxobacteria (sporocytophaga cauliformis) and the order "myxobacterales" (author's transl)]. | the indicator function of aquatic myxobacteria for the purpose of evaluating drinking water quality as well as their occurrence in sewage effluent make it desirable to describe these hitherto little known organisms in more detail. to this end, a comparative investigation of anaerobic myxobacteria of the genus sphaerocytophaga, two typical representatives of the order myxobacterales (myxococcus fulvus, sporocytophage cauliformis), and a strain ov vitrepscilla (vitroescilla proteolytica) was under ... | 1979 | 120650 |
| [occurrence and distribution of fruiting body-forming myxobacteria in siebengebirge. comparative studies with special reference to characteristic biotypes]. | in the region of the "siebengebirge" near bonn, six characteristic biotopes were studied with respect to the occurrence of fruiting body forming myxobacteria. 23 different species, belonging to the 8 known genera, were found. the number of species in the respective biotopes varied between 6 and 17, the average numbers of species per sampling area were between 2.1 and 10.0. 15 species were found on dung pellets of wild living herbivorous mammals. deciduous forest soils contained 13 species in spr ... | 1979 | 121178 |
| purification and partial characterization of an antibiotic produced by myxococcus coralloides. | a strain of myxococcus coralloides producing an antibiotic capable of inhibiting growth of gram-positive bacteria was isolated. antibiotic production occurred during vegetative growth but not during myxospore formation. the antibiotic was extracted from the growth medium with chloroform and purified by adsorption on silicic acid and by preparative silica gel thin-layer chromatography. the purified antibiotic showed a resistance to heat, acid, alkali and proteolytic enzymes. chromatographic and e ... | 1979 | 37227 |
| social gliding is correlated with the presence of pili in myxococcus xanthus. | myxococcus xanthus, an organism whose motility involves cell interactions, normally bears pili. myxococcal pili are found only at cell poles, are less than 10 nm in diameter, and may be longer than a cell. myxococcus has two basic patterns of cell movement, adventurous (a-motility) and social (s-motility). pili are found to be completely correlated with the presence of s-motility. (the s-motility pattern has many groups of cells, almost no single cells, and is governed by a set of genes called s ... | 1979 | 42906 |
| the function of fimbriae in myxococcus xanthus. i. purification and properties of m. xanthus fimbriae. | myxococcus xanthus fimbriae have been purified and characterized as part of a study of the function of fimbriae in this prokaryote. myxococcus xanthus produced two types of fimbriae, termed flaccid (f) and rigid (r) on the basis of electron microscopy. f and r fimbriae differed slightly in their response to ph and freeze-thaw regimes but were similar in their resistance to hydrolytic enzymes, amino acid composition, molecular weight, carbohydrate content, and antigenic determinants. although the ... | 1979 | 43765 |
| the function of fimbriae in myxococcus xanthus. ii. the role of fimbriae in cell-cell interactions. | anti-fimbriae antiserum specifically inhibited swarming but no gliding motility per se in myxococcus xanthus. however, formation of motile aggregates on agar and clumps in liquid media correlated with the presence of fimbriae. ethylenediaminetetraacetic acid which inhibited swarming also inhibited fimbriae formation. direct electron-microscopic observations revealed that fimbriae establish contact with apposing cell surfaces. intact but not depolymerized fimbriae exhibited hemagglutination activ ... | 1979 | 43768 |
| demonstration of positive chemotaxis to cyclic gmp and 5'-amp in myxococcus xanthus by means of a simple apparatus for generating practically stable concentration gradients. | 1979 | 231479 | |
| biosynthesis and self-assembly of protein s, a development-specific protein of myxococcus xanthus. | myxococcus xanthus is a gram-negative bacterium that has a complex life cycle including a temporal sequence of cellular aggregation, mound formation, and myxosporulation. during development, protein s (molecuar weight 23,000) is induced and accumulates in very large amounts. protein s was found in the soluble fraction of early developmental extracts and in the insoluble fraction in later extracts. this insoluble form of protein s can be solubilized by the addition of 1 m nacl at 0 degrees c to e ... | 1979 | 284334 |
| myxobacterial hemagglutinin: a development-specific lectin of myxococcus xanthus. | fruiting body formation in the bacterium myxococcus xanthus consists of a temporal sequence of cellular aggregation and sporulation. during the period of cellular aggregation, a major new development-specific protein that has lectin-like activity is synthesized. this protein, called myxobacterial hemagglutinin (mbha), was able to agglutinate sheep or guinea pig erythrocytes but not horse, ox, chicken, or human erythrocytes. mbha was undetectable in extracts of vegetative cells, cells starved in ... | 1979 | 93278 |
| patterns of protein production in myxococcus xanthus during spore formation induced by glycerol, dimethyl sulfoxide, and phenethyl alcohol. | spore formation of myxococcus xanthus can occur not only on agar plates during fruiting body formation, but also in a liquid culture by simply adding glycerol, dimethyl sulfoxide, or phenethyl alcohol to the culture. this chemically-induced spore formation occurs synchronously and much faster than that occurring during fruiting body formation. dramatic changes in patterns of protein synthesis were observed during chemically-induced spore formation, as had previously been observed during fruiting ... | 1980 | 6160140 |
| purine-containing compounds, including cyclic adenosine 3',5'-monophosphate, induce fruiting of myxococcus xanthus by nutritional imbalance. | induction of myxococcus xanthus fruiting by a number of different purine-containing compounds, including cyclic adenosine 3',5'-monophosphate, is defective in a mutant resistant to 2,6-diaminopurine. furthermore, the purine-induced fruiting of wild-type cultures is uniquely blocked by a low concentration of added glycine. these results imply that different purine-containing compounds induce fruiting through a single mechanism involving nutritional imbalance. | 1980 | 6243625 |
| recovery of quenched radioactivity from thin-layer chromatographic plates. an improved assay for cgmp phosphodiesterase in myxococcus xanthus. | ammonium bicarbonate was found useful in extracting a variety of radiolabeled compounds from thin-layer chromatographic plates. the technique significantly increased the sensitivity of the assay for cyclic nucleotide phosphodiesterases. this method was used to show unequivocally, the presence of cgmp phosphodiesterase in vegetative cells of myxococcus xanthus. | 1980 | 6252204 |
| cyclic adenosine 3',5'-monophosphate binding protein in developing myxospores of myxococcus xanthus. | the interaction of cyclic adenosine 3',5'-monophosphate (camp) with specific protein molecules was examined in the high-speed supernatant fraction of extracts made at stages throughout glycerol-induced myxospore development in myxococcus xanthus. experiments using 8-azido[32p]camp, a photoaffinity analogue of camp, and sds - polyacrylamide gel electrophoresis showed that the nucleotide interacts with only a single protein band of 12 500 molecular weight. both the identiy and amount of this prote ... | 1980 | 6257359 |
| accumulation of guanosine tetraphosphate and guanosine pentaphosphate in myxococcus xanthus during starvation and myxospore formation. | cultures of myxococcus xanthus develop multicellular fruiting bodies when starved for carbon and nitrogen sources on an agar surface. under these conditions of severe starvation, cultures rapidly accumulated a compound identified as guanosine tetraphosphate by chromatographic migration of the compound and of its major acid and alkali breakdown products. the accumulation of guanosine tetraphosphate was reduced in the presence of tetracycline, indicating that it may be synthesized by mechanisms si ... | 1980 | 6766441 |
| guanosine pentaphosphate and guanosine tetraphosphate accumulation and induction of myxococcus xanthus fruiting body development. | development of multicellular fruiting bodies of myxococcus xanthus can be induced by limitation of any of a number of different classes of amino acids. investigated were amino acids that wild-type strains of m. xanthus are unable to synthesize (isoleucine, leucine, and valine), can synthesize at a low rate (phenylalanine), or can normally synthesize at an adequate rate (tryptophan and serine). in general, gradual rather than abrupt starvation for an essential amino acid was required for the indu ... | 1980 | 6766442 |
| separation and properties of the cytoplasmic and outer membranes of vegetative cells of myxococcus xanthus. | we have developed methods for separating the cytoplasmic and outer membranes of vegetative cells of myxococcus xanthus. the total membrane fraction from ethylenediaminetetraacetic acid-lysozyme-treated cells was resolved into three major fractions by isopycnic density centrifugation. between 85 and 90% of the succinate dehydrogenase and cyanide-sensitive reduced nicotinamide adenine dinucleotide oxidase activity was found in the first (i) fraction (rho = 1.221 g/ml) and 80% of the membrane-assoc ... | 1980 | 6767694 |
| preliminary crystallographic data for protein s, a development-specific protein of myxococcus xanthus. | protein s, which is produced only during the developmental cycle of myxococcus xanthus, has been crystallized using 2-methyl-2,4-pentanediol as a precipitating agent. the crystals were very stable in the x-ray beam for up to 150 h and diffracted to a resolution of 2.2 a. the crystals belong to the orthorhombic space group p212121 with unit cell dimensions a = 52.99 a, b = 60.10 a, and c = 102.16 a. each asymmetric unit consists of two monomers of protein s, each having a molecular weight of 23,0 ... | 1980 | 6767725 |
| adenylate energy charge during fruiting body formation by myxococcus xanthus. | the adenylate energy charge of developing myxococcus xanthus cells was measured. the energy charge of vegetative cells (0.81) does not change significantly during the course of fruiting body formation. furthermore, myxospores, which are resistant, resting cells present in the fruiting body, have a relatively high energy charge (0.73). | 1980 | 6769905 |
| s-adenosylmethionine biosynthesis in myxococcus xanthus. | 1980 | 6773804 | |
| myxothiazol, an antibiotic from myxococcus fulvus (myxobacterales). i. cultivation, isolation, physico-chemical and biological properties. | myxothiazol (ab-mx f16-1), a new antifungal antibiotic, is produced by the myxobacterium myxococcus fulvus strain mx f16. it is active against many filamentous fungi, and completely inhibits growth of mucor hiemalis at a concentration of 2 micrograms/ml. the molecular formula of myxothiazol was determined to e c25h33n3o3s2. | 1980 | 6788741 |
| evolutionary relationship between halobacterium cutirubrum and eukaryotes determined by use of aminoacyl-trna synthetases as phylogenetic probes. | the cross-species reactivities between trnas and aminoacyl-trna synthetases have been employed as a basis to estimate the relatedness of various prokaryotes to the eukaryotes. the trna of halobacterium cutirubrum, unlike that of other prokaryotes tested, including agrobacterium tumefaciens, arthrobacter luteus, bacillus subtilis, bacillus stearothermophilus, escherichia coli, micrococcus luteus, myxococcus xanthus, rhodopseudomonas spheroides, and thermus aquaticus, was found to share with yeast ... | 1980 | 6989454 |
| bacteriophage k7, a double stranded dna phage that infects strains of escherichia coli harbouring drug resistance factors of incompatability group w. | bacteriophage k7 is specific for escherichia coli strains harbouring r factors of incompatability group w, including hybrid coliphage p1-myxococcus virescens plasmids. the phage has an unusual morphology with an isometric head and long tail of variable length. the tail lengths appear to fall into classes corresoonsing to simple multimers of a unit length. partially purified lysates of the phage include material that may represent phage particles in the process of biogenesis and other material de ... | 1980 | 6996631 |
| myxothiazol, an antibiotic from myxococcus fulvus (myxobacterales). ii. structure elucidation. | myxothiazol is shown to be 4-(6-carbamoyl-3,5-dimethoxy-4-methylhexa-1e,5e-dienyl)-2'-(1,6-dimethylhepta-2 e,4e-dienyl)-2,4'-bithiazole by spectroscopic (mainly 1h nmr, 15c nmr and mass spectroscopic) and chemical methods. | 1980 | 7271921 |
| myxothiazol, a new antibiotic interfering with respiration. | myxothiazol, a new antibiotic from the myxobacterium myxococcus fulvus, inhibited the growth of many yeasts and fungi at concentrations between 0.01 and 3 micrograms/ml. it was generally inactive against bacteria. the inhibitory effect was cytostatic. with candida albicans, saccharomyces cerevisiae, and mucor hiemalis, the growth inhibition was neutralized by glucose. soon after being added to a cell suspension, the compound almost completely blocked oxygen consumption. | 1981 | 7247372 |
| mode of action of myxococcus xanthus antibiotic ta. | antibiotic ta inhibited incorporation of diaminopimelic acid and uridine diphosphate-n-acetylglucosamine into escherichia coli cell walls without altering the ratio of cross-linked to uncross-linked peptidoglycan. formation of the lipid intermediate was not blocked by ta, suggesting that ta interferes with polymerization of the lipid-disaccharide-pentapeptide. | 1981 | 6812494 |
| plasmid-mediated uv-protection in myxococcus xanthus. | plasmid r46 was successfully transferred from escherichia coli k=12 into myxococcus xanthus strain md-1 but not into m. xanthus strain xk. plasmid r68.45 was transferred from e. coli k-12 into both strains of m. xanthus. the effects of these plasmids on survival of m. xanthus after ultraviolet (uv)-244 nm irradiation, the ability of m. xanthus to reactivate irradiated myxophages, and weigle reactivation of uv-irradiated effect on uv survival of m. xanthus, but increased the host's ability to rea ... | 1981 | 6790909 |
| misrepair mutagenesis in myxococcus xanthus: induction of rifampicin-resistant mutants by n-methyl-n'-nitro-n-nitrosoguanidine and ultraviolet-irradiation. | in the ultraviolet (uv)-mutable bacterium, myxococcus xanthus, dose response curves for the induction of rifampicin-resistant (rifr) mutants were compared with dose response curves for weigle(w)-reactivation of the uv-irradiated phage mx4 at a phage survival of 5 x 10(-6). in most strains examined, including a uvr mutant, these curves are largely similar. unexpectedly the uv-sensitive strain m. xanthus bt, which is unable to perform w-reactivation, is nevertheless uv-mutable. this result may ind ... | 1981 | 6793809 |
| development-specific protein s of myxococcus xanthus: purification and characterization. | protein s, a development-specific protein of myxococcus xanthus, was purified from the cells of a late stage of development and crystallized. its circular dichroism spectra indicated that protein s had a high content of beta-structure in both the presence and absence of calcium ion, which is required for self-assembly of protein s on the myxospore surface. its amino and carboxyl terminal sequences were determined to be alanine-aspartic acid-isoleucine-glycine-valine-alanine-methionine-asparagine ... | 1981 | 6795183 |
| purification and characterization of myxobacterial hemagglutinin, a development-specific lectin of myxococcus xanthus. | myxococcus xanthus is a gram-negative bacterium that has a complex life cycle which includes cellular aggregation and sporulation. during the period of cellular aggregation, a lectin-like protein called myxobacterial hemagglutinin (mbha) is synthesized. a four-step purification procedure for mbha is described. it consists of chromatography on deae-cellulose, cm-cellulose, and hydroxyapatite, followed by gel filtration on bio-gel p-30. this procedure gives good yields of mbha (40-50%) free of con ... | 1981 | 6795208 |
| localization of myxobacterial hemagglutinin in the periplasmic space and on the cell surface of myxococcus xanthus during developmental aggregation. | during the period of developmental aggregation which precedes fruiting body formation, the bacterium myxococcus xanthus produces a large amount of a lectin called myxobacterial hemagglutinin (mbha). sequential cell washing, osmotic shock, and disruption of developmental cells showed that as much as 90% of the total hemagglutinating activity can be recovered in the wash and shock fractions. analysis of the wash and shock fluids by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed t ... | 1981 | 6795209 |
| beta-lactamase activity and resistance to penicillins in myxococcus xanthus. | several mutants and other variants of myxococcus xanthus hp100 were obtained with differences in their sensitivity to carbenicillin and other penicillin derivatives. the specific activities of beta-lactamase in different resistant organisms varied from strain to strain but were consistently higher than in hp100. the relative molecular mass (mr) of the enzyme in m. xanthus hp100 was found to be 22,300. in certain carbenicillin resistant strains a second fraction of beta-lactamase activity of mole ... | 1981 | 6797377 |
| [myxobacteria (myxobacteriales) on leaf surfaces]. | 140 leaf samples were examined, 73 of which (= 52.1%) contained myxobacteria. three species of the genus myxococcus, m. virescens, m. fulvus and m. coralloides, could be found more or less frequently in the phyllosphere of woody plants and annuals. archangium gephyra was observed only once. there was no significant difference in the occurrence of myxobacteria between evergreen leaves and leaves from deciduous trees and shrubs. fruit-trees yielded the best results. | 1981 | 6801873 |
| the primary structure of fulvocin c from myxococcus fulvus. | the primary structure of fulvocin c, a bacteriocin produced by myxococcus fulvus strain mx f16, has been determined. this new bactericidal protein is composed of 45 amino acid residues and has a molecular weight of 4672. it contains no lipids or carbohydrates, indicating that only the protein molecule is responsible for its biological activity. | 1981 | 6783114 |
| excreted adenosine is a cell density signal for the initiation of fruiting body formation in myxococcus xanthus. | 1981 | 6788625 | |
| reexamination of the genome size of myxobacteria, including the use of a new method for genome size analysis. | the genome sizes of two myxobacteria, myxococcus xanthus and stigmatella aurantiaca, were measured by renaturation analysis and also by a new method involving the quantitation of individual restriction fragments. in contrast to several previous reports, which indicate that m. xanthus has a genome size which is three to four times that of escherichia coli, the present measurements indicated that the m. xanthus genome is only about 24 to 53% larger than that of e. coli. s. aurantiaca had a genome ... | 1981 | 6259127 |
| genetic characterization of aggregation-defective developmental mutants of myxococcus xanthus. | the transposon tn5 was used to map temperature-sensitive mutants of myxococcus xanthus defective in aggregation (c. e. morrison and d. r. zusman, j. bacteriol. 140:1036-1042, 1979). seven of the eight mutants showing a similar terminal phenotype (rough) were found to be tightly linked. these mapped in a group of loci which we have designated aggr1, aggr2, aggr3, and aggr4. temperature-sensitive mutants having a different terminal phenotype were not liked to aggr. a search through a group of nonc ... | 1981 | 6268606 |