| ecological distribution of spirillum lipoferum beijerinck. | a survey in various countries revealed that the n2-fixing spirillum lipoferum beijerinck is a very common root and soil inhabitant in the tropics. more than half of the grass root and soil samples collected in tropical countries (four african countries and brazil) contained abundant s. lipoferum populations, while less than 10% of the samples collected in temperate south brazil, kenya, and the u.s.a. contained the organism. there is a pronounced vegetation effect. panicum maximum seems the most ... | 1976 | 10062 |
| dependence of the superficial layers of spirillum putridiconchylium on ca2+ or sr2+. | chelating agents disrupted the superficial layers on spirillum putridiconchylium and adsorption of cationized ferritin indicated that both upper and lower surfaces of superficial layer fragments, as well as the outer membrane surface, possessed areas which were negatively charged. growth of the bacterium in 1% casamino acids (vitamin free) resulted in cells which were devoid of the superficial layers, and negative staining of these cells revealed in amorphous precipitate together with a vesicula ... | 1976 | 10067 |
| carbon and ammonia metabolism of spirillum lipoferum. | intact cells and extracts from spirillum lipoferum rapidly oxidized malate, succinate, lactate, and pyruvate. glucose, galactose, fructose, acetate, and citrate did not increase the rate of o2 uptake by cells above the endogenous rate. cells grown on nh+/4 oxidized the various substrates at about the same rate as did cells grown on n2. added oxidized nicotinamide adenine dinucleotide generally enhanced o2 uptake by extracts supplied organic acids, whereas oxidized nicotinamide adenine dinucleoti ... | 1976 | 10278 |
| reassembly in vitro of the superficial cell wall components of spirillum putridiconcyhylium. | | 1976 | 57246 |
| endotoxin-like properties of the peptidoglycan. | peptidoglycan is responsible for the endotoxin-like properties of the streptococcus cell wall. the pyrogenic response of rabbit to group a streptococcus peptidoglycan prepared by hot formamide or tca is dose-dependent and is increased if the material is ultrasonically solubilized. the pyrogenicity can be eliminated by the antiserum to the peptidoglycan or by the degradation of the material by lysozyme. peptidoglycans prepared from cell walls of group b and l streptococci, staphylococcus aureus, ... | 1975 | 126556 |
| the regulation of heme and chlorophyll synthesis in bacteria. | | 1975 | 166593 |
| membrane-bound respiratory of spirillum itersonii. | the membrane-bound respiratory system of the gram-negative bacterium spirillum itersonii was investigated. it contains cytochromes b (558), c (550), and o (558) and beta-dihydro-nicotinamide adenine dinucleotide (nadh) and succinate oxidase activities under all growth conditions. it is also capable of producing d-lactate and alpha-glycerophosphate dehydrogenases when grown with lactate or glycerol as sole carbon source. membrane-bound malate dehydrogenase was not detectable under any conditions, ... | 1976 | 182674 |
| reduction of iron and synthesis of protoheme by spirillum itersonii and other organisms. | membranes from spirillum itersonii reduce ferric iron to ferrous iron with reduced nicotinamide adenine dinucleotide or succinate as a source of reductant. iron reduction was measured spectrophotometrically at 562 nm using ferrozine, which chelates ferrous iron specifically. reduced nicotinamide adenine dinucleotide or succinate was also effective as a source of iron. the effects of respiratory inhibitors suggested that reduction of iron occurs at one or more sites on the respiratory chain befor ... | 1977 | 190208 |
| choice of liquid, semisolid, or soil suspension media: an important factor modifying the effect of pesticides on the nitrogenase (c2h2) activity of clostridium pasteurianum, azotobacter chroococcum, and spirillum lipoferum beijerinck. | | 1979 | 295269 |
| dimethyl sulfoxide as an electron acceptor for anaerobic growth. | the isolation from lake mud of a bacterium which can use dimethyl sulfoxide (dmso) as an electron acceptor for growth is described. the isolate, called strain dl-1, was a small, gram negative, non-motile spiral. the sole product of dmso reduction was dimethyl sulfide (dms). other electron acceptors used by the isolate included sulfite, thiosulfate, elemental sulfur, methionine sulfoxide, tetramethylene sulfoxide, nitrate, and oxygen (microaerophilically). sulfate was not reduced and could not ev ... | 1978 | 414686 |
| isolation of spirillum-like organisms from pig fetuses. | | 1978 | 416554 |
| isolation of azospirullum from diverse geographic regions. | we have isolated azospirillum (spirullum lipoferum) from roots of grasses of several genera collected from a number of tropical and subtropical-temperate locations. pure cultures were obtained from a small percentage of samples; no higher percentage was secured from tropical than from other grasses. acetylene reduction and distinctive growth in n-free soft agar deeps were inadequate to identify this genus, although helpful in initial screening. fluorescent antibody tests with antiserum against c ... | 1979 | 476547 |
| structure determination of frozen, hydrated, crystalline biological specimens. | low temperature transmission electron microscopy can be used to study the structure of biological materials in the hydrated state. spatial averaging techniques are necessary to overcome the radiation damage problems, and for this reason the techniques described are most applicable to crystalline objects. however, with thin, crystalline biological specimens there are no difficulties with preserving periodicity during the freezing process. improved specimen preparation methods are described which ... | 1978 | 641983 |
| [vertical distribution and the characteristics of the species composition of the microorganisms of some stratified lakes in estonia]. | the total number, vertical distribution, and special composition of microorganisms from three stratified lakes in the south-eastern estonia containing hydrogen sulfide and ferrous iron were studied in march, 1976. the number of bacteria was lowest in surface water samples (1.2-1.9 x 10(6) cells/ml). it increased first in the zone where oxygen disappeared (2.4-7.6 x 10(6) cells/ml), then slightly decreased, and again increased near the bottom where it became maximal (3.7-14.0 x 10(6) cells/ml). t ... | 1979 | 440169 |
| light microscopy observations of tetrazolium-reducing bacteria in the endorhizosphere of maize and other grasses in brazil. | roots of field-grown tropical maize, panicum maximum jacq. and digitaria decumbens stent., and of sorghum and wheat grown in monoxenic culture with the diazotroph spirillum lipoferum (syn. azospirillum spp.) were examined for tetrazolium-reducing bacteria following incubation of roots in a malate-phosphate buffer-2,3,5-triphenyltetrazolium chloride medium. bacteria were observed between and in cells of the cortex, in intercellular spaces between the cortex and endodermis, in xylem cells, and in ... | 1978 | 667740 |
| structure of the surface layer protein of the outer membrane of spirillum serpens. | | 1979 | 439191 |
| deoxyribonucleic acid-mediated transformation of spirillum lipoferum. | the methodology for deoxyribonucleic acid-mediated transformation of spirillum lipoferum to resistance to various antimicrobial agents is reported. | 1979 | 438124 |
| physiological studies of spirillum lipoferum. | | 1977 | 411476 |
| motility of flagellated bacteria in viscous environments. | the lowest viscosity that immobilized flagellated bacteria such as psedomonas aeruginosa, spirillum serpens, and escherichia coli was 60 centipoise (cp). much higher viscosities (1,000 cp and higher) were required to immobilize two flagellated bacteria selectively isolated from nature by methods based on their ability to migrate through agar gels. the latter finding indicates that certain flagellated bacteria have the ability to swim through environments of relatively high viscosity. it is sugge ... | 1977 | 410784 |
| nitrogen fixation, denitrification, and pleomorphic growth in a highly pigmented spirillum lipoferum. | a strain of spirillum lipoferum with intense red pigmentation was isolated from the roots of cynodon dactylon "coastal." this isolate vigorously reduced acetylene when grown in n-free, na-malate, semisolid agar, and it was identical to s. lipoferum strain sp7 by standard taxonomic tests. both s. lipoferum sp7 and the c. dactylon root isolate displayed the unique features of being denitrifiers as well as n2 fixers. the n2-dependent growth curve was biphasic: cells in younger cultures showed the c ... | 1977 | 22311 |
| the taxonomy of the chemoheterotrophic spirilla. | | 1976 | 791070 |
| relationship between cell coiling and motility of spirochetes in viscous environments. | the lowest viscosity that stops translational motility of cells (minimum immobilizing viscosity [miv] was determined for various spirochetes. the viscous agent used was polyvinylpyrrolidone, the miv for either spirochaeta halophila p1 or spirochaeta aurantia j4t was approximately 1,000 centipoise (cp), and for leptospira interrogans (biflexa) b16 the miv was greater than 500 cp. in comparison, the miv for the flagellated bacteria escherichia coli and spirillum serpens was 60 cp. miv values for t ... | 1977 | 330506 |
| [studies on flagella of the anaerobic motile vibrio-like bacteria (s-form organism) (author's transl)]. | | 1978 | 285193 |
| spirillum-like organism isolated from pig and bovine fetuses. | | 1979 | 116417 |
| [physiology of xerophytic microorganisms that grow under very dry conditions]. | the biology of xerophytic microorganisms surviving and growing under conditions imitating martian ones was studied, as well as the zone of tolerance of several microorganisms towards the activity of water. the xerophytic nature of microorganisms is suggested to be evaluated by means of quantitative determination, using gas chromatography, of carbon dioxide which is evolved when microorganisms are cultivated on media with different values of aw. | 1978 | 418315 |
| [ulcus gangraenosum s. phagedaenicum with window-like perforation of the preputium]. | | 1977 | 860565 |
| studies on the biodegradation of nonionic surfactants applied in the polyester fiber industry. ii. effect of activated sludge load on microorganisms. | the effect of selected nonionic surfactants cirrasol fp, cirrasol sf 200 and cirrasol tcs on activated sludge organisms purifying wastes from the polyestre fibre industry was studied. the toxic effect of the mentioned surfactants towards bacteria, protozoa, rotifera and nematoda occurred at loads exceeding 0.32 mg surfactant/mg d.w./day and in periods of large fluctuations of the employed loads. morphological changes of activated sludge flocs are also observed in similar conditions. | 1976 | 62498 |
| purification and characterization of the membrane-bound ferrochelatase from spirillum itersonii. | the membrane-bound enzyme ferrochelatase (protoheme ferro-lyase, ec 4.99.1.1) was purified from isolated membrane fragments of spirillum itersonii approximately 490-fold. purification was achieved by solubilization with chaotropic salts followed by ammonium sulfate fractionation, diethylaminoethyl-cellulose chromatography, and gel filtration on sephadex g-200. the purified enzyme has an apparent minimum molecular weight of approximately 50,000, as determined by gel filtration in the presence of ... | 1977 | 21163 |
| growth of spirillum lipoferum at constant partial pressures of oxygen, and the properties of its nitrogenase in cell-free extracts. | spirillum lipoferum, an n2-fixing organism, was grown at constant concentrations of dissolved o2. when supplied with nh4+ aerobically, its doubling time was 1 h; when it fixed n2 microaerophilically, its doubling time was 5-5 to 7 h and the optimal po2 for growth was 0-005 to 0-007 atm. at its optimal po2 for growth on n2, s. lipoferum assimilated 8 to 10 mg nitrogen/g carbon substrate used; its efficiency was less at higher po2 levels. nitrogenase in cell-free extracts required mg2+ and mn2+, a ... | 1977 | 13147 |
| stimulatory effect of dihydroxyphenyl compounds on the aerotolerance of spirillum volutans and campylobacter fetus subspecies jejuni. | the aerotolerance of the microaerophilic bacterium spirillum volutans was greatly stimulated in a defined medium by the presence of dihydroxyphenyl ferric iron-binding compounds such as nor-epinephrine at 10(-5) to 10(-6) m. dihydroxyphenyl compounds at 2 x 10(-4) m, or iron salts (ferrous or ferric) at high concentration, greatly increased the aerotolerance of a strain of campylobacter fetus subsp. jejuni when grown on streak plates of brucella agar. the results suggest that the microaerophilis ... | 1976 | 942201 |
| factors affecting growth and nitrogen fixation of spirillum lipoferum. | spirillum lipoferum grows vigorously on malate, succinate, lactate, or pyruvate, moderately on galactose or acetate, and poorly on glucose or citrate. it reduces 15n2. acetylene reduction rates decrease rapidly when the ph of the culture rises above 7.8. the organism is highly aerobic and had doubling times as low as 2 h when grown on nh4+. however, s. lipoferum reduces n2 well only under microaerophilic conditions. the optimal po2 for acetylene reduction by stagnant cultures was 0.006 to 0.02 a ... | 1976 | 8430 |
| superficial cell-wall layers on spirillum "ordal" and their in vitro reassembly. | the cell envelope of sporillum sp. strain "ordal" (possibly a variety of s. anulus) demonstrated multiple superficial wall layers which were diverse in their macromolecular arrays. negative staining and freeze-etching techniques revealed an outer hexagonally packed layer and an inner tetragonally packed layer. however, both thin sections and freeze-etched cleavages of the wall showed that each of these regular structures rested upon a backing layer, and that there was a delicate amorphous layer ... | 1976 | 4216 |
| cleavage planes in the envelope of aquaspirillum bengal. | the cell surface of aquaspirillum bengal was devoid of superficial wall structure. when cells were freeze-cleaved and etched, multiple fracture planes through the cell envelope were exposed, which was unusual for an aquaspirillum. these included both convex and concave surfaces and they are compared with those of other gram-negative bacteria. | 1978 | 647474 |
| inducing effect of plant cells on nitrogenase activity by spirillum and rhizobium in vitro. | eleven different plant cell tissue cultures of both legume and non-legume origin have been grown in direct association, and in separate but close proximal association with both spirillum lipoferum and rhizobium sp. 32h1. basic similarities were found in the nutritional requirement for the induction of nitrogenase activity (c2h2) in both organisms. in the absence of plant cell cultures both organisms need to be provided with a pentose sugar and a tricarboxylic acid to induce high levels of nitrog ... | 1978 | 647472 |
| physiological basis of the selective advantage of a spirillum sp. in a carbon-limited environment. | a spirillum sp. and a pseudomonas sp. possessing crossing substrate saturation curves for l-lactate were isolated from fresh water by chemostat enrichment. their ks and mumax values for l-lactate were: spirillum sp., 23 micrometer and 0.35 h-1, respectively; pseudomonas sp., 91 micrometer and 0.64 h-1, respectively. under l-lactate limitation, pseudomonas sp. outgrew spirillum s. at dilution rates (d) above 0.29 h-1, but the converse occurred at lower d values. the advantage of spirillum sp. inc ... | 1978 | 641523 |
| protein-lipid-lipopolysaccharide association in the superficial layer of spirillum serpens cell walls. | the backing layer of the spirillum serpens vha cell wall, which supports and is bonded to the outer, structured protein layer, was isolated and shown to be similar in composition to the same elements of the outer membrane. it contained a lipopolysaccharide that was similar, but not identical, to that of the intact wall and the same phospholipids. the interaction of the isolated wall lipopolysaccharide with the loosely bound wall lipids provided lamellae, whose surfaces were an effective template ... | 1978 | 627537 |
| nitrogen fixation by spirillum sp. from rice roots. | nitrogen fixation by spirillum sp. obtained from the roots of rice plants grown at different levels of combined nitrogen was studied. the roots of rice plants exposed to low levels of combined nitrogen (20--40 kg n/ha) harboured spirillum sp. possessing higher nitrogen-fixing efficiency as compared to the cultures from plants receiving 60--100 kg n/ha. moreover, the nitrogen-fixing efficiency of these spirillum spp. varied with age of the plant, irrespective of the dosage of combined nitrogen. | 1977 | 603343 |
| aldolase and dehydrogenase activities in spirillum bengal. | spirillum bengal is unable to grow on sugars, but can utilize different organic acids as carbon sources. dehydrogenase activities were tested with different substrates and were found highest with lactate, glutamate, acetate, succinate and malate. a low aldolase activity was also detectable. | 1979 | 421815 |
| surface arrays on the cell wall of spirillum metamorphum. | a complex and easily disrupted arrangement of macromolecules was present on the outer (lipopolysaccharide) membrane of the cell wall of spirillum metamorphum. separation of the arrays from the cell and spontaneous reassembly into regularly structured complexes usually occurred during preparation for electron microscopy. freeze etchings, thin sections, and optical diffraction analysis of negatively stained fragments indicated that they consisted of two sets of a thin layer which was studied with ... | 1975 | 1194243 |
| cell morphology and flagellation of nitrogen-fixing spirilla. | twenty isolates of n2-fixing spirilla were isolated from the rhizosphere of maize and sugar cane grown in egyptian and belgian soils. electron microscopy distinguished two morphological groups. the first includes short and thick curved rods with an unipolar flagellum while cells of the second group are much longer with the typical appearance of spiral cells and most probably possess a bipolar tuft of flagella. | 1979 | 527912 |
| isolation and pure culture of a freshwater magnetic spirillum in chemically defined medium. | a bipolarly flagellated magnetotactic spirillum containing intracellular chains of single domain-sized magnetite crystals was isolated by applying a magnetic field to sediments from a freshwater swamp. the organism was cultured in a chemically defined medium containing ferric quinate and succinate as sources of iron and carbon, respectively. nonmagnetic variants of this isolate were maintained in chemically defined medium lacking ferric quinate. in contrast to magnetic cells, these had less iron ... | 1979 | 500569 |
| nitrate and nitrite reductase negative mutants of n2-fixing azospirillum spp. | chlorate resistant spontaneous mutants of azospirillum spp. (syn. spirillum lipoferum) were selected in oxygen limited, deep agar tubes with chlorate. among 20 mutants from a. brasilense and 13 from a. lipoferum all retained their functional nitrogenase and 11 from each species were nitrate reductase negative (nr-). most of the mutants were also nitrite reductase negative (nir-), only 3 remaining nir+. two mutants from nr+ nir+ parent strains lost only nir and became like the nr+ nir- parent str ... | 1978 | 697499 |
| the nitrogenase system of spirillum lipoferum. | the nitrogenase system of spirillum lipoferum was separated into three components, the normal mo-fe and fe proteins as well as an activating factor for the fe protein. the rate of activation is increased by mn2+ or by an excess of mg2+, and the process requires atp. | 1978 | 708367 |
| a taxonomic study of the spirillum lipoferum group, with descriptions of a new genus, azospirillum gen. nov. and two species, azospirillum lipoferum (beijerinck) comb. nov. and azospirillum brasilense sp. nov. | sixty-one strains of the root-associated nitrogen fixer spirillum lipoferum exhibited a similar morphology in peptone--succinate salts medium: vibrioid cells having a diameter of 1.0 micrometer. when grown in broth the cells had a single polar flagellum, but when grown on agar at 30 degrees c lateral flagella of shorter wavelength were also formed. the dna base composition was 69--71 mol% guanine + cytosine when determined by thermal denaturation. dna homology experiments indicated the occurrenc ... | 1978 | 356945 |
| microcapsule of campylobacter fetus: chemical and physical characterization. | the antiphagocytic antigen (antigen [a]) comprising the microcapsule of a strain of campylobacter fetus subsp. intestinalis has been purified from culture supernatants by ammonium sulfate fractionation and free-flow electrophoresis. antigen [a] is a glycoprotein containing about 4% carbohydrate consisting of hexose, pentose, and methylpentose. the composition of the protein was typical of bacterial extramural structural proteins in its low content of basic, aromatic, and sulfur-containing amino ... | 1978 | 730387 |
| effect of oxygen and nitrate on nitrogen fixation and denitrification by azospirillum brasilense grown in continuous culture. | azospirillum brasilense was grown continuously at various levels of dissolved oxygen (o2) in a nitrogen-free medium containing malates as the carbon source. steady-state cultures were established only at o2 concentrations less than 0.0150 atm (1 atm = 101.325 pa) and rates of acetylene reduction (n2 fixation) and efficiencies of n2 fixation were maximal between 0.0050-0.0075 atm dissolved o2. these cultures appeared to be o2- or n2-limited. there was no evidence of a respiratory protective mecha ... | 1978 | 743647 |
| biology of the chemoheterotrophic spirilla. | | 1976 | 773367 |
| alterations in the cell wall of spirillum serpens vhl early in its association with bdellovibrio bacteriovorus 109d. | in both freeze-etched and critical-point dried preparations examined by transmission and scanning electron microscopy, respectively, the outer surfaces of the cells of spirillum serpens vhl assume a wrinkled appearance 10-15 min after challenge by bdellovibrion bacteriovorus 109d. this wrinkling effect is believed (on circumstantial evidence) to be caused by the bdellovibrio's disruption of the cell wall lipoprotein of the spirillum. with the exception of those topological changes caused by wrin ... | 1976 | 818972 |
| rat-bite fever. | | 1992 | 1560927 |
| reduction of sulfur by spirillum 5175 and syntrophism with chlorobium. | a small spirillum, designated 5175, was isolated from an anaerobic enrichment culture for desulfuromonas in which the major medium constituents were acetate and elemental sulfur. the organisms grew only under anaerobic or microaerophilic conditions. elemental sulfur was formed anaerobically in a malate-sulfide medium, and cell densities of 10(8) cells/ml were obtained. hydrogen and formate were actively oxidized as substrates for growth under anaerobic conditions; s0, s032-, or s2o32-, but not s ... | 1977 | 848960 |
| isolation of spirillum/vibrio-like organisms from bovine fetuses. | | 1977 | 560078 |
| selective advantage of a spirillum sp. in a carbon-limited environment. accumulation of poly-beta-hydroxybutyric acid and its role in starvation. | a freshwater spirillum sp., which apparently belongs to a niche of low nutritional status (matin & veldkamp, 1978), accumulated poly-beta-hydroxybutyric acid (phb) during lactate-limited growth in continuous culture. the phb content varied in a complex manner with the dilution rate (d), but was greatest at the lowest d value examined: about 18% (w/w) at d = 0.025 h-1. it is not known what mechanism accounted for phb accumulation during carbon-limited growth. the resistance of cultures of spirill ... | 1979 | 225410 |
| nitrate reduction nitrogenase activity in spirillum lipoferum1. | nitrate and nitrite reduction under aerobic, microaerophillic, and anaerobic conditions was demonstrated in spirillum lipoferum (atcc 29145). nitrite did not accumulated during assimilatory nitrate reduction in air. the nitrite produced during dissimilatory nitrate reduction accumulated in the medium but not in the cells. on exposure of the bacteria to nitrate and anaerobiosis, a low initial rate (lag) was followed by accelerated rates of nitrite accumulation. a 3-h anaerobic pretreatment, in th ... | 1977 | 856423 |
| cell envelope associations of aquaspirillum serpens flagella. | specific regions of the cell envelope associated with the flagellar basal complex of the gram-negative bacterium aquaspirillum (spirillum) serpens were identified by studying each of the envelope layers: outer membrane, mucopeptide, and plasma membrane. the outer membrane around the flagella insertion site was differentiated by concentric membrane rings and central perforations surrounded by a closely set collar. the perforations in both the outer membrane and the isolated mucopeptide layer were ... | 1978 | 721774 |
| localization and stability of hydrogenases from aerobic hydrogen bacteria. | alcaligenes eutrophus strains h 16, b 19, g 27 and n9a contained two different hydrogenases. one enzyme catalyzed the reduction of nad by hydrogen and was strictly localized in the soluble cell fraction. while the second enzyme was found to be particulate and unable to react with nad. all other tested strains, alcaligenes paradoxus sa 29, pseudomonas facilis, p. palleronii rh 2, pseudomonas sp. strain ga 3, paracoccus denitrificans, aquaspirillum autotrophicum sa 32, and corynebacterium autotrop ... | 1977 | 871226 |
| n2 fixation associated with non-leguminous plants. | | 1977 | 921696 |
| identification of a promoter dependent on nifa and sigma 54 upstream of nifh in azospirillum lipoferum. | southern hybridization experiments strongly indicate that the regulatory region of the azospirillum lipoferum nifh gene is located on a cloned 1.1 kb bamhi-xhoi restriction fragment. by cloning this fragment into a promoter-probe plasmid in escherichia coli, a promoter was identified oriented towards the nifh gene. using a set of several bacterial strains and plasmids, both nifa and the alternative sigma factor, sigma 54, from klebsiella pneumoniae were shown to be required for the induction of ... | 1991 | 2046661 |
| taxonomic studies of spirillum lipoferum. | | 1977 | 921697 |
| isolation of spirillum-like organisms from pig and bovine fetuses. | | 1979 | 112758 |
| acetylene reduction (nitrogen fixation) associated with corn inoculated with spirillum. | sorghum and corn breeding lines were grown in soil in field and greenhouse experiments with and without an inoculum of n2-fixing in spirillum strains from brazil. estimated rates of n2 fixation associated with field-grown corn and sorghum plants were less than 4 g of n2/ha per day. the mean estimated n2-fixation rates determined on segments of roots from corn inoculated with spirillum and grown in the greenhouse at 24 to 27 degrees c were 15 g of n2/ha per day (16 inbreds), 25 g of n2/ha per day ... | 1976 | 970933 |
| gastrospirillum hominis. | | 1989 | 2569058 |
| spirillum swimming: theory and observations of propulsion by the flagellar bundle. | the hydrodynamics and energetics of helical swimming by the bacterium spirillum sp. is analysed using observations from medium speed cine photomicrography and theory. the photographic records show that the swimming organism's flagellar bundles beat in a helical fashion just as other bacterial flagella do. the data are analysed according to the rotational resistive theory of chwang & wu (1971) in a simple-to-use parametric form with the viscous coefficients cs and cn calculated according to the m ... | 1976 | 1018163 |
| membrane damage and incorporation of escherichia coli components into bdellovibrio bacteriovorus. | cytoplasmic membrane of e. coli is degraded within 20 min following infection with bdellovibrio. 50% of cellular 42-k is lost during the first 10 min. the cytoplasmic membrane, 20 min after infection, centrifugated on a sucrose gradient produces a wide band containing the main enzyme activities (succinic dehydrogenase and lactic dehydrogenase) bound to the membrane. the incorporation into bdellovibrio of labelled host cell constituents during intracellular growth has been studied at successive i ... | 1975 | 1096504 |
| outer cell envelope membrane and shape of spirillum serpens. | | 1975 | 1152044 |
| [production of magnetic material by magnetic bacteria]. | | 1991 | 1875093 |
| analysis of the cell wall and lipopolysaccharide of spirillum serpens. | isolated walls of spirillum serpens vha contained lipid, lipopolysaccharide, and protein in amounts similar to those of other gram-negative organisms. the loosely bound lipids consisted mainly of phosphatidylethanolamine, lyso-phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol. lipopolysaccharide was tightly bound to the wall and could only be removed in a substantial amount after digestion of the wall with pronase. the lipopolysaccharide contained l-glycero-d-mannoheptos ... | 1975 | 1194232 |
| periplasmic superoxide dismutases in aquaspirillum magnetotacticum. | aquaspirillum magnetotacticum ms-1 cells cultured microaerobically (dissolved o2 tension 1% of saturation), expressed proteins with superoxide dismutase (sod) activity. the majority (roughly 95%) of total cell superoxide dismutase activity was located in the cell periplasm with little or no activity in the cell cytoplasm. iron-type sod (fesod) contributed 88% of the total activity activity detected, although a manganese-type sod (mnsod) was present in the periplasm as well. cells cultured at a h ... | 1989 | 2684080 |
| construction of a gene library from azospirillum brasilense and characterization of a recombinant containing the nif structural genes. | 1. we have constructed a gene library, from azospirillum brasilense using the vector embl4. 2. a recombinant containing the nif structural genes from a. brasilense was isolated and characterized. this recombinant contains a dna insert of about 15 kilobases (kb) which gives rise to five fragments after cleavage with ecori. only one of the dna fragments (6.5 kb) hybridized to the nifhdk genes of klebsiella pneumoniae. 3. the organization of the nif genes in this dna fragment was determined using d ... | 1987 | 2837298 |
| spirillum endocarditis. | | 1975 | 1197164 |
| cloning and characterization of the glna gene of azospirillum brasilense sp7. | a plasmid which, by complementation, restored a gln+nif+ phenotype to the gln-nif- azospirillum brasilense mutant 7029, was isolated from a gene bank of total dna of a. brasilense sp7 (atcc 29145) constructed in the broad host range vector pvk100. this plasmid contained the structural gene (glna) for glutamine synthetase. the glna gene was mapped by tn5 insertion and dna hybridization with a klebsiella pneumoniae glna probe. the direction of transcription of glna was determined. the glna product ... | 1986 | 2893582 |
| a chemically defined medium for aquaspirillum aquaticum atcc 11330. | | 1975 | 1201522 |
| influence of dilution rate on enzymes of intermediary metabolism in two freshwater bacteria grown in continuous culture. | two freshwater bacteria, a pseudomonas sp. and a spirillum sp., were grown in continuous culture under steady-state conditions in l-lactate-, succinate-, ammonium- or phosphate-limited media. in pseudomonas sp., nad-independent and nad-dependent l-lactate dehydrogenases, aconitase, isocitrate dehydrogenase and glucose 6-phosphate dehydrogenase activities increased up to 10-fold as the dilution rate (d) was decreased from 0.5 to 0.02 h-1, regardless of whether the growth-limiting nutrient was car ... | 1976 | 950555 |
| rat bite fever: a case report of a kenyan. | rat bite fever has not been reported from kenya previously. a case of 17 year old kenyan male who was diagnosed to have rat bite fever after a bite of domestic rat is described. the history, clinical features and demonstration of spirillum like organisms from a thick blood film suggest infection due to spirillum minus. the patient recovered completely after a course of penicillin and gentamicin. | 1992 | 1286642 |
| [sodoku--a case report]. | rat-bite fever results from an infection with the organism spirillum minus. the authors report a symptomatic patient with fever, malaise, and ulcer in forehead after a rodent exposure. the organism was identified in darkfield examination of the ulcer exudate. penicillin was the drug used with clinical improvement of symptoms. | 1992 | 1308939 |
| gene transfer in magnetic bacteria: transposon mutagenesis and cloning of genomic dna fragments required for magnetosome synthesis. | broad-host-range incp and incq plasmids have been transferred to the aerobic magnetic bacterium aquaspirillum sp. strain amb-1. conjugal matings with escherichia coli s17-1 allowed high-frequency transfer of the rk2 derivative prk415 (4.5 x 10(-3) transconjugant per recipient cell) and the rsf1010 derivative pkt230 (3.0 x 10(-3) transconjugant per recipient). these plasmids successfully formed autonomous replicons in transconjugants and could be isolated and transformed back into e. coli, illust ... | 1992 | 1314800 |
| spiral bacterium associated with gastric, ileal and caecal mucosa of mice. | a spiral shaped bacterium was seen in smears and histological sections (stained by carbolfuchsin) of gastric, ileal and caecal mucosa as well as in stool smears from mice. a significant correlation between the presence of the spiral bacterium and the occurrence of gastritis was observed but the ileal and caecal mucosa seemed unaffected. the bacterium was gram negative and grew on bhm and skirrow's medium, under microaerophilic conditions, at 37 degrees c. its major biochemical characteristics in ... | 1992 | 1447907 |
| denitrification by n2-fixing sprillum lipoferum. | forty-nine n2-fixing strains of spirillum lipoferum isolated from a wide range of plant roots and soils were examined for reduction of no3-. all strains reduced no3-to no2-. thirty of the strains further reduced no2-with production of gas. examiniation of representative strains of the putative denitrifiers showed that they produced both n2o and c2h4 in the presence of 0.1 atm of c2h2. strains which did not reduce no2-with production of gas produced c2h4 but ont n2o in the presence of c2h2. this ... | 1977 | 851911 |
| production of a dark field motion photomicrograph exhibiting flagella in motile bacteria. | | 1992 | 1517190 |
| 'gastrospirillum hominis', another gastric spiral bacterium. | 'gastrospirillum hominis' is a 'new' tightly coiled gram-negative bacterium carrying bundles of sheathed polar flagella. it has been rather infrequently detected in antral and, even more rarely, in fundic mucosa samples removed at endoscopy from patients investigated for helicobacter pylori colonization. until now, it has remained noncultivable but has successfully been maintained in laboratory mice. its identity with similar bacteria found in the stomachs of cats, dogs, monkeys, pigs, and other ... | 1992 | 1611710 |
| spiral organisms: what are they? a microbiologic introduction to helicobacter pylori. | the stomach provides a hostile environment to most microorganisms owing to the antibacterial effect of gastric acidity. however, over the period of mammalian evolution a highly specialized group of bacteria has evolved to inhabit the gastric mucosa. the common features of these bacteria that allow survival in the stomach and colonization of their natural ecologic niche, mucus, are a specialized form of motility, microaerophilism, and very high activity of the enzyme urease. other important adapt ... | 1991 | 1775930 |
| investigations on microbial sulfur respiration. isolation, purification, and characterization of cellular components from spirillum 5175. | the sulfur-reducing bacterium spirillum 5175 was investigated with regard to membrane constituents that might be part of the sulfur oxidoreductase which converts elemental sulfur to hydrogen sulfide. regardless of the electron acceptor used for cultivation of the bacteria, i.e. elemental sulfur, fumarate, or nitrate (sp. 5175s,f,n), the qualitative pattern of cytochromes and fe-s proteins did not change significantly, as documented by ultraviolet/visible and electron paramagnetic resonance spect ... | 1991 | 1847872 |
| phylogenetic analysis of aquaspirillum magnetotacticum using polymerase chain reaction-amplified 16s rrna-specific dna. | the 16s rrna gene of the magnetotactic magnetogen aquaspirillum magnetotacticum ms1 was amplified by a polymerase chain reaction, using two eubacterial consensus oligodeoxynucleotide primers flanking the majority of the 16s rrna gene, cloned, and sequenced. phylogenetic analysis revealed that a. magnetotacticum ms1 belongs to the alpha-group of proteobacteria. this assignment offers perspective on the biochemical properties of a. magnetotacticum, since this organism is expected to have the gener ... | 1991 | 1854644 |
| electroporation and conjugal plasmid transfer to members of the genus aquaspirillum. | electroporation methods and conjugal matings were used to transfer several plasmid vectors to aquaspirillum dispar and aquaspirillum itersonii. the incompatibility p class plasmid rp4 was conjugally transferred from escherichia coli hb101 to these spirilla, and the transconjugants subsequently donated the molecule to plasmid-free e. coli and a. dispar strains via conjugal matings. high-voltage electrotransformation was used to transfer plasmids pucd2, psa151 and rp4 to a. dispar and a. itersonii ... | 1991 | 1907445 |
| helicobacter felis gastritis in gnotobiotic rats: an animal model of helicobacter pylori gastritis. | the gastric spirillum helicobacter felis, originally isolated from the cat stomach, colonizes the stomachs of germfree rats. studies were designed to examine the pathological and serological responses of germfree rats inoculated orally with h. felis. at 2 weeks postinoculation, the gastric mucosa of germfree rats had lymphocytes and eosinophils scattered in small foci throughout the subglandular region of the antrum. small numbers of lymphocytes were present in the subglandular portion of the an ... | 1991 | 1997430 |
| isolation of acetylene-reducing spirilla from the roots of potamogeton filiformis from loch leven (kinross). | | 1976 | 993784 |
| substructure and in vitro assembly of the outer, structured layer of spirillum serpens. | electron micrographs of disintegrating units of the outer, structured (hp) layer of spirillum serpens and of the isolated protein obtained from the hp layer revealed v- and y-shaped and linear profiles. interpretation of these forms, influenced by the seemingly trimeric form of the isolated protein and by biochemical data, suggested that the protein subunits were identical and y shaped. a model is proposed for the assembly of the y-shaped subunits to form a hexagon composed of two triads (three ... | 1976 | 1245458 |
| azospirillum irakense sp. nov., a nitrogen-fixing bacterium associated with rice roots and rhizosphere soil. | a new species of nitrogen-fixing bacteria, azospirillum irakense, was found associated with roots and the rhizosphere of rice in the region of diwaniyah (qadisya), iraq. the seven isolates, on which the species description is based, have vibrioid to s-shaped cells with one polar flagellum in liquid medium. additional lateral flagella are seen on cells grown on nutrient agar. poly-beta-hydroxybutyrate granules are present in cells. nitrogen fixation occurs in microaerobic conditions. the phenotyp ... | 1989 | 2626596 |
| membrane protein patterns of three azospirillum species and herbaspirillum seropedicae. | membrane protein patterns in sds-page clearly characterized azospirillum amazonense, a. brasilense, a. lipoferum, and herbaspirillum seropedicae. each species showed also a typical major band with approximate molecular weights (amws) of 44, 39.5, 35.5, and 37.5 kdaltons for the four species respectively. characteristic lighter bands with amws of 63.5 and 19 kdaltons were shown by a. amazonense. similar bands of 54, 24 and 24.5 kdaltons were typical of a. brazilense, a. lipoferum and h. seropedic ... | 1989 | 2629550 |
| cloning of histidine genes of azospirillum brasilense: organization of the abfh gene cluster and nucleotide sequence of the hisb gene. | a cluster of four azospirillum brasilense histidine biosynthetic genes, hisa, hisb, hisf and hish, was identified on a 4.5 kb dna fragment and its organization studied by complementation analysis of escherichia coli mutations and nucleotide sequence. the nucleotide sequence of a 1.3 kb fragment that complemented the e. coli hisb mutation was determined and an orf of 624 nucleotides which can code for a protein of 207 amino acids was identified. a significant base sequence homology with the carbo ... | 1989 | 2664449 |
| antiparasitic mechanisms in parasitic infections. | | 1970 | 4098297 |
| specific staining for electron microscopy of murein sacculi of bacterial cell walls. | | 1970 | 4098764 |
| structural properties and features of parasitic bdellovibrio bacteriovorus. | the structure of five parasitic strains of bdellovibrio bacteriovorus was studied by electron microscope after negative staining and in shadow-case and etched freeze-fractured preparations. special attention was paid to the cell wall and the flagellar sheath which is continuous with the wall or part of it. these structural components reveal distinct features which are induced by certain staining substances; they are exceedingly susceptible to disruption by physical treatments, and in old cells o ... | 1970 | 4099101 |
| studies on the cell wall of spirillum serpens. ii. chemical characterization of the outer structured layer. | | 1973 | 4119519 |
| location and description of spiral-shaped microorganisms in the normal rat cecum. | some indigenous microorganisms have been shown to localize in certain anatomical sites of the digestive tract of mammals. we studied the ceca of normal adult rats by light and electron microscopy to determine whether any specific bacterial population localizes in this area. all rats studied showed that the crypt was packed with organisms whose morphological character differs from those of the cecal lumen. organisms localized in the crypt were often identified topographically close to the microvi ... | 1972 | 4120246 |
| localization of adenosine triphosphatase activity in motile bacteria. | | 1973 | 4128469 |
| evolution of the regulatory isozymes of 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase present in the escherichia coli genealogy. | the evolutionary history of isozymes for 3-deoxy-d-arabino-heptulosonate 7-phosphate (dahp) synthase has been constructed in a phylogenetic cluster of procaryotes (superfamily b) that includes escherichia coli. members of superfamily b that have been positioned on a phylogenetic tree by oligonucleotide cataloging possess one or more of four distinct isozymes of dahp synthase. dahp synthase-0 is insensitive to feedback inhibition, while dahp synthase-tyr, dahp synthase-trp, and dahp synthase-phe ... | 1986 | 2867085 |
| superficial macromolecular arrays on the cell wall of spirillum putridiconchylium. | electron microscopy of the cell envelope of spirillum putridiconchylium, using negatively stained, thin-sectioned, and replicated freeze-etched preparations, showed two superficial wall layers forming a complex macromolecular pattern on the external surface. the outer structured layer was a linear array of particles overlying an inner tetragonal array of larger subunits. they were associated in a very regular fashion, and the complex was bonded to the outer, pitted surface of the lipopolysacchar ... | 1974 | 4137219 |
| [selenomonas in the caecum of rats]. | | 1972 | 4144943 |
| abnormally low activities of fumarate hydratase and malate dehydrogenase in oxygen-sensitive cultures of spirillum volutans. | | 1973 | 4148677 |
| structure and assembly of bacterial surface layers composed of regular arrays of subunits. | | 1974 | 4152594 |