| electron microscopy of malachite green--glutaraldehyde fixed bacteria. | malachite green combined with glutaraldehyde has been used recently as a fixative for preserving and revaling lipid complexes in thin sections of eukaryotic cells examined by electron microscopy. when bacteria were prefixed with the above mixture granular electron dense inclusions were revealed in all cultures tested. these inclusions were replaced by electron transparent areas in cells fixed with glutaraldehyde alone. the structures were frequently located near to or within the nucleoid and adj ... | 1979 | 94953 |
| micromorphology of gram-negative hydrogen bacteria. ii. cell envelope, membranes, and cytoplasmic inclusions. | the fine structure of the cell envelope, of membrane systems and of cytoplasmic inclusions of gram-negative aerobic hydrogen bacteria has been studied. the results have been tabulated, and three main groups could be recognized: group 1: alcaligenes eutrophus, a.paradoxus, a.ruhlandii, pseudomonas facilis, p.flava, p.pseudoflava, p.palleronii, and aquaspirillum autotrophicum; group 2: "corynebacterium" autotrophicum and strains ma 2 and sa 35; group 3: paracoccus denitrificans. special structur ... | 1977 | 199126 |
| micromorphology of gram-negative hydrogen bacteria. i. cell morphology and flagellation. | the cell morphology, the arrangement and fine structure of flagella and the piliation of the following gram-negative aerobic hydrogen bacteria have been studied: alcaligenes eutrophus, alcaligenes paradoxus, alcaligenes ruhlandii, pseudomonas flava, pseudomonas pseudoflava, pseudomonas palleronii, pseudomonas facilis, aquaspirillum autotrophicum, paracoccus denitrificans, corynebacterium autotrophicum, and strains ma 2 and sa 35. the identity of the bacteria was examined by their substrate spect ... | 1977 | 410385 |
| 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 |
| 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 |
| a chemically defined medium for aquaspirillum aquaticum atcc 11330. | | 1975 | 1201522 |
| 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 |
| linear growth and poly(beta-hydroxybutyrate) synthesis in response to pulse-wise addition of the growth-limiting substrate to steady-state heterotrophic continuous cultures of aquaspirillum autotrophicum. | heterotrophic pyruvate-limited steady-state continuous cultures of the bacterium aquaspirillum autotrophicum were perturbed with a pulse injection of a small volume of concentrated pyruvate solution. these cultures exhibited an instantaneous change in the growth dynamics, turning from steady state to apparently linear growth. these transient growth-responses had no lag phase and were clearly distinct from unlimited exponential growth according to the initial rates of increase of biomass and subs ... | 1992 | 1593258 |
| cloning of a sequence of aquaspirillum magnetotacticum that complements the arod gene of escherichia coli. | a 2 kb dna fragment isolated from a cosmid library of aquaspirillum magnetotacticum strain ms-1 complements the aromatic-metabolite requirements and iron-uptake deficiencies of escherichia coli and salmonella typhimurium strains that lack a functional arod (biosynthetic dehydrodquinase) sequence. all recombinant cosmids selected for their arod complementation property carry this sequence. no dna sequence homology has, however, been detected by southern hybridization between the cloned fragment a ... | 1991 | 1766390 |
| 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 |
| effect of paracrystalline protein surface layers on predation by bdellovibrio bacteriovorus. | we determined that paracrystalline protein surface arrays (s layers) protected gram-negative eubacteria from predation by bdellovibrio bacteriovorus. aquaspirillum serpens vha and mw5 and aquaspirillum sinuosum were resistant to predation by b. bacteriovorus 6-5-s when fully covered by their s layers. the s layer of aeromonas salmonicida a449 protected the cells from predication by b. bacteriovorus 109j. a predacious, plaque-forming vibrio that lysed an s-layer- variant of caulobacter crescentus ... | 1991 | 2007549 |
| nucleotide sequence of reca gene of aquaspirillum magnetotacticum. | | 1990 | 2106674 |
| the structure and associations of the double s layer on the cell wall of aquaspirillum sinuosum. | aquaspirillum sinuosum cell walls bear two paracrystalline, proteinaceous surface layers (s layers). each shows a different symmetry: the inner layer is closely apposed to the outer membrane and is a tetragonal array (90 degrees axes; 5-nm units; repeat frequency 8 nm); the outer layer is a hexagonal array on the external surface (14-nm units; repeat frequency 18 nm) and, although the units have a six-pointed stellate form, the linkage between units is not resolved. the outer layer consists of a ... | 1990 | 2117993 |
| nucleotide sequence, secondary structure and evolution of the 5s ribosomal rna from five bacterial species. | the nucleotide sequences of the 5s ribosomal rnas of the bacteria agrobacterium tumefaciens, alcaligenes faecalis, pseudomonas cepacia, aquaspirillum serpens and acinetobacter calcoaceticus have been determined. the sequences fit in a generally accepted model for 5s rna secondary structure. however, a closer comparative examination of these and other bacterial 5s rna primary structures reveals the potential of additional base pairing and of multiple equilibria between a set of slightly different ... | 1985 | 2408888 |
| pneumonia and meningitis caused by a new nonfermentative unknown gram-negative bacterium. | seven isolates of an unclassified bacterium resembling flavobacterium spp. were characterized by growth requirements, microscopic examination, biochemical characteristics, antimicrobial susceptibility tests, protein profile analysis, and serologic data. the unclassified isolates were differentiated from flavobacterium meningosepticum, flavobacterium odoratum, flavobacterium balustinum, flavobacterium strain iib, chromobacterium violaceum, aquaspirillum serpens, and pseudomonas spp. the bacterium ... | 1989 | 2504766 |
| cloning and characterization of the reca gene of aquaspirillum magnetotacticum. | the reca gene of aquaspirillum magnetotacticum has been isolated from a genomic library and introduced into a reca mutant strain of escherichia coli k12. the cloned gene complemented both the recombination and dna repair deficiency of the host and its protein product promoted the proteolytic cleavage of the lexa protein. a protein whose molecular weight is similar to that of the reca protein of e. coli was associated with the cloned sequence. | 1989 | 2511817 |
| immunological identification and distribution of dissimilatory heme cd1 and nonheme copper nitrite reductases in denitrifying bacteria. | polyclonal antibodies were used to identify heme or copper nitrite reductases in the following groups: 23 taxonomically diverse denitrifiers from culture collections, 100 numerically dominant denitrifiers from geographically diverse environments, and 51 denitrifiers from a culture collection not selected for denitrification. antisera were raised against heme nitrite reductases from pseudomonas aeruginosa and pseudomonas stutzeri and against copper nitrite reductase from achromobacter cycloclaste ... | 1989 | 2624465 |
| 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 |
| basal-body-associated disks are additional structural elements of the flagellar apparatus isolated from wolinella succinogenes. | the intact flagella of wolinella succinogenes, a gram-negative, anaerobic bacterium with a single polar flagellum, were obtained by an improved procedure, introduced recently by aizawa et al. (s.-j. aizawa, g. e. dean, c. j. jones, r. m. macnab, and s. yamaguchi, j. bacteriol. 161:836-849, 1985) for the flagellum of salmonella typhimurium. disks with a diameter of 130 +/- 30 nm, which were attached to the basal body of the isolated intact flagella, could be identified by electron microscopy as a ... | 1989 | 2708319 |
| hydroxamate production by aquaspirillum magnetotacticum. | spent culture fluids from aquaspirillum magnetotacticum ms-1 grown at high (20 microm) but not low (5 microm) iron concentration contained material yielding a positive hydroxamate test. cells possessed six major outer membrane proteins. three outer membrane proteins ranging from 72,000 to 85,000 daltons were coordinately produced at iron concentrations conducive to hydroxamate production. a 55,000-dalton iron-repressible outer membrane protein was also present in strain ms-1 cultured at low but ... | 1986 | 2941414 |
| the ultrastructure and atpase nature of polar membrane in campylobacter jejuni. | polar membrane in campylobacter jejuni has been visualized on membrane vesicles. it was composed of doughnut-shaped particles 5-6 nm in diameter, with stalks, arranged in a hexagonal array. this structure was stabilized on the membrane by a high ionic strength buffer in the presence of 2-mercaptoethanol. histochemical staining indicated localized atpase activity at the poles of the cells. an atpase with distinctive properties has been isolated and purified from this organism; it gives a specific ... | 1988 | 2974756 |
| iron respiration-driven proton translocation in aerobic bacteria. | washed cell suspensions of aquaspirillum magnetotacticum ms-1, a. itersonii e12639, bacillus subtilis 6633, and escherichia coli csh27 translocated protons in response to the added oxidant o2 or no3-, with triphenylmethylphosphonium bromide as the permeant ion. iron respiration-driven proton translocation was observed in a. magnetotacticum ms-1, b. subtilis, and e. coli but not in a nonmagnetic strain of a. magnetotacticum (strain nm-1a) or with a. itersonii. proton translocation to fe3+ was tot ... | 1986 | 3015890 |
| purification and properties of the soluble cytochromes c-550 and c-556 from the bacterium aquaspirillum itersonii. | two c-type cytochromes were isolated from cells of the gram-negative bacterium aquaspirillum itersonii grown under low aeration in the presence of nitrate. the major component, cytochrome c-550, was equated with the (single) c-type cytochrome previously reported to be present in this organism [clark-walker, g. d. & lascelles, j. (1970) arch. biochem. biophys. 136, 153-159], although a significantly higher molecular mass was apparent in the present work. the complete amino acid sequence of this c ... | 1987 | 3036516 |
| the soluble c-type cytochromes from the bacterium aquaspirillum itersonii. the complete amino acid sequence of the cytochrome c-550. | a complete amino acid sequence is proposed for the cytochrome c-550 isolated from the gram-negative chemo-organotrophic bacterium aquaspirillum itersonii. the sequence, a single polypeptide chain of 111 residues, was deduced from the sequences of peptides obtained by tryptic, thermolytic or chymotryptic digestion. the cytochrome shows a high degree of sequence homology with the cytochrome c2 from the photosynthetic bacterium rhodospirillum rubrum, and the evolutionary implications of this are co ... | 1987 | 3036517 |
| characterization of the bacterial magnetosome membrane. | intact magnetosomes of aquaspirillum magnetotacticum were purified from broken cells by a magnetic separation technique. electron microscopic and chemical analyses revealed the magnetite to be enclosed by a lipid bilayer admixed with proteins. lipids were recovered in fractions expected to contain (i) neutral lipids and free fatty acids, (ii) glycolipids and sulfolipids, and (iii) phospholipids (in a weight ratio of 1:4:6). phospholipids included phosphatidylserine and phosphatidylethanolamine. ... | 1988 | 3123464 |
| functional expression of aquaspirillum magnetotacticum genes in escherichia coli k12. | gene libraries from the magnetotactic bacterium, aquaspirillum magnetotacticum were constructed in escherichia coli with cosmids plafr3 and c2rb as vectors. recombinant cosmids able to complement the thr-1, leub, and proa mutations of the host were identified. the pro+ recombinant cosmid restored wild-type phenotype in proa and prob but not in the proc mutants of e. coli. the results of restriction endonuclease digestion and southern hybridization analysis indicate that the relevent leu and pro ... | 1988 | 3146020 |
| asei, a restriction endonuclease from aquaspirillum serpens which recognizes 5'at--taat3'. | | 1988 | 3264065 |
| determination of the spiral conformation of aquaspirillum spp. by scanning electron microscopy of elongated cells induced by cephalexin treatment. | the effect of the beta-lactam antibiotic cephalexin on the spiral conformation of cells of aquaspirillum spp. was examined by scanning electron microscopy. a. itersonii and a. peregrinum, which are known to have a left-handed spiral shape, elongated and still showed left-handed spirals in medium containing cephalexin. the spiral conformation of the elongated cells is therefore considered to represent the natural condition. the spiral conformations of a. metamorphum and a. psychrophilum grown in ... | 1986 | 3531396 |
| three-dimensional structure of the surface layer protein of aquaspirillum serpens vha determined by electron crystallography. | the three-dimensional structure of the protein which forms the s layer of aquaspirillum serpens strain vha has been determined by electron microscopy. structures have been reconstructed to a resolution of about 1.6 nm for single-layered specimens and about 4 nm for two-layered specimens. the structure, which has hexagonal symmetry, consists of a core in the shape of a cup, with six projections arising from the rim of the cup to join adjacent subunits at the threefold symmetry axes. the model is ... | 1986 | 3745114 |
| [aquaspirillum in mineral waters of castellammare di stabia]. | | 1985 | 3939628 |
| sugar catabolism in aquaspirillum gracile. | aquaspirillum (spirillum) gracile is one of the few spirilla that cause acidification of the medium when cultured with sugars. acidic reactions have been reported only for d-glucose, d-galactose, and l-arabinose, and the mode of attack of these sugars has not been previously investigated. the soluble portion of extracts of glucose-cultured cells of a. gracile atcc 19624 was found by spectrophotometric methods to contain enzyme activities characteristic of the entner-doudoroff and embden-meyerhof ... | 1974 | 4369249 |
| the membrane-bound hydrogenase of alcaligenes eutrophus: ii. localization and immunological comparison with other hydrogenase systems. | immunological comparison of the soluble and the membrane-bound hydrogenase of alcaligenes eutrophus revealed no common antigenic determinants shared by the native proteins, however, a small amount of cross-reacting material was detected after freezing and thawing. immune precipitation assays supported previous observations indicating the membrane-bound hydrogenase to be localized in the outer surface of the cytoplasmic membrane. the membrane-bound hydrogenases of a. eutrophus and pseudomonas pse ... | 1980 | 6156647 |
| structure and cell envelope associations of flagellar basal complexes of vibrio cholerae and campylobacter fetus. | to isolate intact flagella with basal complexes from vibrio cholerae, a rhamnolipid hemolysin from pseudomonas aeruginosa was used to disrupt the cell envelope and flagellar sheath. the nonionic detergent, triton x-100, provided similar results for campylobacter fetus. each of these basal complexes possessed, in addition to the four classical rings, concentric membrane rings (cmr's) similar to those found in aquaspirillum serpens. through the use of stereo imaging (which allows structures to be ... | 1984 | 6426766 |
| [taxonomic study of free nitrogen-fixing bacteria isolated from the endorhizosphere of rice]. | twenty strains of free-living n2-fixing bacteria, isolated from the endorhizosphere of rice in rice soils of senegal, were studied on the basis of 259 morphological, physiological, biochemical and nutritional characters. half of them were gram-negative small rods with polar flagella and showing a strictly respiratory metabolism; they were characteristic of the genus pseudomonas. a first group of 6 strains was related to the p. cepacia-p. marginata group characterized by lophotrichous flagella; t ... | 1983 | 6651126 |
| presence of a new cytochrome b - like pigment with a peak at 567 nm in various aerobic bacteria. | several physiological groups of bacteria were examined for the presence of a cytochrome b - like pigment which is demonstrable in dithionite-reduced minus substrate-reduced difference spectra. this pigment is characterized by an unusually high alpha band at 567 nm, a low concentration relative to conventional cytochromes, and an inability to be fully reduced by endogenous substrates or nadh. previous studies with one denitrifying and nondenitrifying species of the genus pseudomonas, in paracoccu ... | 1983 | 6652580 |
| components of the regular surface array of aquaspirillum serpens mw5 and their assembly in vitro. | the two-layered regular surface array of aquaspirillum serpens mw5 was removed from cell envelopes and dissociated into subunits by treatment with 6 m urea. the surface components reassembled onto an outer membrane surface and self-assembled into planar sheets in vitro in the presence of ca2+ or sr2+. the two layers were removed sequentially from cell envelopes by a two-step extraction procedure involving initial treatment with a high-ph buffer to remove the outermost surface layer and subsequen ... | 1984 | 6693353 |
| magnetosome dynamics in magnetotactic bacteria. | diffusive motions of the magnetosomes (enveloped fe3o4 particles) in the magnetotactic bacterium aquaspirillum magnetotacticum result in a very broad-line mössbauer spectrum (t approximately 100 mm/s) above freezing temperatures. the line width increases with increasing temperature. the data are analyzed using a bounded diffusion model to yield the rotational and translational motions of the magnetosomes as well as the effective viscosity of the material surrounding the magnetosomes. the results ... | 1984 | 6743757 |
| defined medium for aquaspirillum serpens vhl effective in batch and continuous culture. | a defined medium for aquaspirillum serpens vhl allows the replacement of the complex media now in use. it was developed by batch culture methods but supports growth in continuous culture. a basal salts medium supplemented with l-aspartic acid, l-alanine, and l-glutamic acid provided the best growth (turbidity), as long as ammonium chloride was omitted. ammonium chloride caused either a lag or a reduction or a complete inhibition of the growth of a. serpens vhl on the above amino acids and other ... | 1980 | 6766700 |
| cell wall proteins of aquaspirillum serpens. | the triton x-100-insoluble wall fraction of aquaspirillum serpens vha contained three major proteins: the regularly structured (rs) superficial protein (molecular weight 140,000) and two peptidoglycan-associated proteins (molecular weights, 32,000 and 33,000). the molecular arrangement and interactions of the outer membrane and rs proteins were examined with the use of bifunctional cross-linking reagents. the peptidoglycan-associated and rs proteins were not readily cross-linked in either homo- ... | 1981 | 6787011 |
| oxygen tolerance of strictly aerobic hydrogen-oxidizing bacteria. | growth of various bacteria, especially aerobic hydrogen-oxidizing bacteria, in the presence of 2 to 100% (v/v) oxygen in the gas atmosphere was evaluated. the bacterial strains included alcaligenes eutrophus, a. paradoxus, aquaspirillum autotrophicum, arthrobacter spec. strain 11 x, escherichia coli, arthrobacter globiformis, nocardia opaca, n. autotrophica, paracoccus denitrificans, pseudomonas facilis, p. putida, and xanthobacter autotrophicus. under heterotrophic conditions with fructose or g ... | 1982 | 7049081 |
| structure of the regular surface layer of aquaspirillum serpens mw5. | the structure of the regular surface layer of aquaspirillum serpens mw5 has been investigated by electon microscopy supplemented by computer image processing and least-squares analysis. the layer has a ribbed appearance, both on the bacterium and in isolated, negatively stained fragments. however, detailed analysis indicated that the layer was composed of two hexagonal sheets having p6mm symmetry and a = 16 nm. one sheet was staggered by one half repeat along a (1,0) line of the p6nm lattice rel ... | 1982 | 7061396 |
| the comparison of rhapidosomes and defective bacteriophage particles from aquaspirillum intersonii. | aquaspirillum itersonii spontaneously produces rhapidosomes. these structures, which are found throughout the cell cycle, are compared with the defective bacteriophage particles that can be induced by mitomycin c treatment (0.5 microgram/ml). the rhapidosomes are composed of three proteins (mw 63 000, 23 500, and 15 000). the defective bacteriophage particles are composed of two proteins (mw 50 000 and 17 500). the defective bacteriophage particles do not react with anti-rhapidosomal protein ant ... | 1980 | 7214221 |
| buffering capacity and h+ membrane conductance of gram-negative bacteria. | buffering capacity and membrane h+ conductance were examined in seven gram-negative species: aquaspirillum serpens, pseudomonas aeruginosa, alcaligenes faecalis, escherichia coli, salmonella typhimurium, proteus mirabilis and aeromonas hydrophila. all strains of enterobacteriaceae studied here showed a decrease in both parameters as the external ph increased, over the ph range studied. the other four species presented an increase in buffering capacity and membrane conductance to protons as the e ... | 1995 | 7557289 |
| nitrite reductase from the magnetotactic bacterium magnetospirillum magnetotacticum. a novel cytochrome cd1 with fe(ii):nitrite oxidoreductase activity. | cytochrome cd1 nitrite reductase was isolated from magnetite-containing cells of the magnetotactic bacterium magnetospirillum (formerly aquaspirillum) magnetotacticum, which was microaerobically cultivated under denitrifying conditions. the enzyme showed absorption maxima at 643 nm and 409 nm in the oxidized form, and at 663, 551, 522, and 418 nm in the reduced form. a distinctive split absorption band did not occur at about 550 nm. the pyridine ferrohemochrome spectra suggested the presence of ... | 1995 | 7588814 |
| purification and properties of a 'cytochrome a1'-like hemoprotein from a magnetotactic bacterium, aquaspirillum magnetotacticum. | a novel hemoprotein was purified from a magnetotactic bacterium, aquaspirillum magnetotacticum ms-1. the protein showed absorption peaks at 437 nm in the oxidized form, and 592, 550 and 450 nm in the reduced form. although the spectral properties of the hemoprotein were very similar to those of 'cytochrome a1', the hemoprotein contained no molecules of heme a. the protein contained two kinds of hemes; one was extracted with hcl-acetone and the other was covalently bound to the protein. the pyrid ... | 1993 | 8251522 |
| protein composition of rhapidosomes isolated from aquaspirillum itersonii. | rhapidosomes are tubular microstructures composed of proteins that are found in a variety of bacteria and algae. these structures, which are resistant to disruption by many denaturing agents, have potential application as a biomaterial and may serve as a new model for the study of self assembly. when rhapidosomes were purified and analysed by sds-page the presence of three proteins with molecular masses of 53, 29 and 18 kda was revealed. however, lysozyme treatment of the rhapidosome preparation ... | 1993 | 8515241 |
| the relationship between kinetics of substrate-limited transitions and steady-state growth in continuous cultures of aquaspirillum autotrophicum limited by pyruvate. | heterotrophic growth at steady state and during transient states caused by the sudden change of the concentration of the limiting factor in the feed medium was investigated experimentally for continuous cultures of aquaspirillum autotrophicum limited by pyruvate. a model for describing the growth at steady state was selected from three unstructured models after statistical tests of the data. this model postulates that the growth yield increases linearly with the growth rate. growth during transi ... | 1995 | 8572674 |
| characterization of a novel spirillum-like bacterium that degrades ferrioxamine-type siderophores. | a novel gram-negative spirillum-like bacterium (asp-1) was isolated from lake water by enrichment culture on desferrioxamine b as sole source of carbon and energy. asp-1 was able to degrade the siderophores desferrioxamine b and e. the property of siderophore degradation was inducible in the presence of desferrioxamine b. the ferric complexes, however, were not measurably degraded but served as an iron source. degradation of desferrioxamines in culture was followed by measuring the residual ferr ... | 1996 | 8574095 |
| nitrogen-fixing aerobic bacteria have higher genomic gc content than non-fixing species within the same genus. | the genomic gc contents of both nitrogen-fixing and non-fixing members of eight genera of bacteria are investigated. analysis by t-tests showed that in the two aerobic general investigated (aquaspirillum and vibrio) there is a significantly higher gc content in the nitrogen-fixing members of the genus than in those unable to fix nitrogen, whilst in aerobic genera there is either no gc bias, or in the case of two genera (rhodospirillum and clostridium) there is a significantly higher gc content i ... | 1998 | 9687237 |
| polyphosphate-accumulating and denitrifying bacteria isolated from anaerobic-anoxic and anaerobic-aerobic sequencing batch reactors | in this study, phosphate-accumulating bacteria achieved complete phosphate removal in two different systems: an anaerobic-anoxic sequencing batch reactor and an anaerobic-aerobic sequencing batch reactor. this result shows that phosphate-accumulating bacteria in the a2 sbr can use nitrate as terminal electron acceptor instead of oxygen. phosphate-accumulating bacteria accumulated phosphate with a rates between 30 and 70 mg p/l/h in the a/o sbr and between 15 and 32 mg p/l/h in the a2 sbr. twenty ... | 1999 | 9841775 |
| iron reductase for magnetite synthesis in the magnetotactic bacterium magnetospirillum magnetotacticum. | ferric iron reductase was purified from magnetotactic bacterium magnetospirillum (formerly aquaspirillum) magnetotacticum (atcc 31632) to an electrophoretically homogeneous state. the enzyme was loosely bound on the cytoplasmic face of the cytoplasmic membrane and was found more frequently in magnetic cells than in nonmagnetic cells. the molecular mass of the purified enzyme was calculated upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be about 36 kda, almost the same as that ... | 1999 | 10094692 |
| phylogenetic relationships among members of the comamonadaceae, and description of delftia acidovorans (den dooren de jong 1926 and tamaoka et al. 1987) gen. nov., comb. nov. | the phylogenetic relationships among members of the family comamonadaceae and several unclassified strains were studied by direct sequencing of their pcr-amplified 16s rrna genes. based on the 16s rrna gene sequence analysis, members of the family formed a coherent group. the closest relatives are species of the rubrivivax sub-group: leptothrix discophora, ideonella dechloratans and rubrivivax gelatinosus. the genus hydrogenophaga formed two subclusters, as did the species of acidovorax, whereas ... | 1999 | 10319477 |
| kinetic behavior of some polyphosphate-accumulating bacteria isolates in the presence of nitrate and oxygen. | this paper studies the phosphate uptake by pure cultures of aeromonas hydrophila, klebsiella oxytoca, agrobacterium tumefaciens, and aquaspirillum dispar in the presence of both nitrate and oxygen. it is shown that species were able to respire both electron acceptors for phosphate accumulation. a. tumefaciens and a. dispar accumulated overall phosphate both in oxic and anoxic culture conditions, whereas a. hydrophila and k. oxytoca eliminated overall phosphate only in oxic conditions. a. dispar ... | 1999 | 10355118 |
| sequence analysis of the gluconobacter oxydans reca protein and construction of a reca-deficient mutant. | the deduced amino acid sequence of gluconobacter oxydans reca protein shows 75.2, 69.4, and 66.2% homology with those from aquaspirillum magnetotacticum, escherichia coli, and pseudomonas aeruginosa, respectively. the amino acid residues essential for function of the recombinase, protease, and atpase in e. coli reca protein are conserved in g. oxydans. of 24 amino acid residues believed to be the atp binding domain of e. coli reca, 17 are found to be identical in g. oxydans reca. interestingly, ... | 1999 | 10420585 |
| the phylogeny of purple bacteria: the alpha subdivision. | the technique of oligonucleotide cataloging shows the purple photosynthetic eubacteria to comprise three major subdivisions, temporarily called alpha, beta, and gamma--previously designated groups i-iii by gibson et al. (1979). each subdivision contains a number of non-photosynthetic genera in addition to the photosynthetic ones. the alpha subdivision, the subject of the present report, contains most but not all of the species that fall into the classically defined genera rhodospirillum, rhodo ... | 1984 | 11541974 |
| phylogenetic analysis of the genus aquaspirillum based on 16s rrna gene sequences. | phylogenetic analysis of 15 species of the genus aquaspirillum based on 16s rrna gene (rdna) sequences indicated that the genus aquaspirillum is phylogenetically heterogeneous and the species could be divided into four groups as follows: aquaspirillum serpens, the type species of this genus, a. dispar and a. putridiconchylium are situated in the family neisseriaceae; members of the second group, a. gracile, a. delicatum, a. anulus, a. giesbergeri, a. sinuosum, a. metamorphum and a. psychrophilum ... | 2002 | 12113929 |
| thalassospira lucentensis gen. nov., sp. nov., a new marine member of the alpha-proteobacteria. | a novel bacterium from the mediterranean sea was isolated under oligotrophic conditions at in situ temperature after prolonged continuous culture. the isolates were initially characterized by partial 16s rrna gene sequencing. similarity searches of one of the isolates, qmt2t, indicated high sequence identity to the well-characterized rhodospirillum rubrum, [aquaspirillum] itersonii and [oceanospirillum] pusillum micro-organisms, which are representatives of the alpha-subclass of the proteobacter ... | 2002 | 12148640 |
| phylogenetic relationships of the helical-shaped bacteria in the alpha proteobacteria inferred from 16s rdna sequences. | 16s ribosomal rna gene sequences from seven strains of aquaspirillum peregrinum, aqu. itersonii, aqu. polymorphum, and oceanospirillum pusillum were compared with homologous sequences from other members of helical-shaped bacteria. the bootstrapped neighbor-joining tree, inferred from 887 aligned sites, placed the spirillum taxa assigned to aquaspirillum, oceanospirillum, azospirillum, magnetospirillum, rhodospirillum, and rhodocista of the proteobacteria in seven clusters of alpha proteobacteria ... | 1997 | 12501339 |
| anaerobic mineralization of quaternary carbon atoms: isolation of denitrifying bacteria on pivalic acid (2,2-dimethylpropionic acid). | the degradability of pivalic acid was established by the isolation of several facultative denitrifying strains belonging to zoogloea resiniphila, to thauera and herbaspirillum, and to comamonadaceae, related to [aquaspirillum] and acidovorax, and of a nitrate-reducing bacterium affiliated with moraxella osloensis. pivalic acid was completely mineralized to carbon dioxide. the catabolic pathways may involve an oxidation to dimethylmalonate or a carbon skeleton rearrangement, a putative 2,2-dimeth ... | 2003 | 12620885 |
| investigations into the life cycle of the bacterial predator bdellovibrio bacteriovorus 109j at an interface by atomic force microscopy. | atomic force microscopy was used to image bdellovibrio bacteriovorus 109j, a gram-negative bacterial predator that consumes a variety of other gram-negative bacteria. in predator-prey communities grown on filters at hydrated air-solid interfaces, repeated cycles of hunting, invasion, growth, and lysis occurred readily even though the cells were limited to near two-dimensional movement. this system allowed us to image the bacteria directly without extensive preparation or modification, and many o ... | 2003 | 12719266 |
| description of comamonas aquatica comb. nov. and comamonas kerstersii sp. nov. for two subgroups of comamonas terrigena and emended description of comamonas terrigena. | three clusters of isolates have previously been defined within the species comamonas terrigena, on the basis of dna-rrna and dna-dna hybridization data, and of protein electrophoretic patterns and immunotyping. more detailed characterization in the current study shows that representatives of these three groups can also be differentiated phenotypically from each other. strains of c. terrigena sensu stricto (c. terrigena dna group 1) are pyrrolidone aminopeptidase-positive, do not grow at 40 degre ... | 2003 | 12807213 |
| diversity and seasonal variability of beta-proteobacteria in biofilms of polluted rivers: analysis by temperature gradient gel electrophoresis and cloning. | the beta-subgroup of the proteobacteria has been shown to be important in aquatic habitats and was investigated in depth here by molecular 16s rrna techniques in biofilms of the elbe river and its polluted tributary, the spittelwasser river. the bacterial 16s rrna genes were cloned from each site, screened for beta-proteobacterial clones and sequenced. river biofilm clones from both rivers grouped into 9 clusters (rbfs). rbfs 1, 2, and 3 fell into the recently described betai cluster of cosmopol ... | 2003 | 12902230 |
| aquaspirillum dispar hylemon et al. 1973 and microvirgula aerodenitrificans patureau et al. 1998 are subjective synonyms. | the 16s rdna sequences of [aquaspirillum] dispar lmg 4329(t) and microvirgula aerodenitrificans sgly2(t) (=lmg 18919(t)) were found to be very similar (>99 %). dna-dna hybridizations between the two strains revealed a high level of dna-dna binding (84 %), showing that they represent a single species. m. aerodenitrificans and [a.] dispar were also phenotypically very similar. it is concluded that [a.] dispar and m. aerodenitrificans are subjective synonyms. as [a.] dispar was wrongly assigned to ... | 2003 | 13130033 |
| microbial characterization of the mars odyssey spacecraft and its encapsulation facility. | microbial characterization of the mars odyssey spacecraft and the kennedy space center spacecraft assembly and encapsulation facility ii (saef-ii) was carried out by both culture-based and molecular methods. the most dominant cultivable microbes were species of bacillus, with comamonads, microbacteria and actinomycetales also represented. several spore-forming isolates were resistant to gamma-radiation, uv, h2o2 and desiccation, and one acinetobacter radioresistens isolate and several aureobasid ... | 2003 | 14510851 |
| effects of gypsophila saponins on bacterial growth kinetics and on selection of subterranean clover rhizosphere bacteria. | plant secondary metabolites, such as saponins, have a considerable impact in agriculture because of their allelopathic effects. they also affect the growth of soil microorganisms, especially fungi. we investigated the influence of saponins on rhizosphere bacteria in vitro and in soil conditions. the effects of gypsophila saponins on the growth kinetics of rhizosphere bacteria were studied by monitoring the absorbance of the cultures in microtiter plates. gypsophila saponins (1%) increased the la ... | 2003 | 14569290 |
| ottowia thiooxydans gen. nov., sp. nov., a novel facultatively anaerobic, n2o-producing bacterium isolated from activated sludge, and transfer of aquaspirillum gracile to hylemonella gracilis gen. nov., comb. nov. | strain k11t was isolated from activated sludge of a municipal wastewater-treatment plant. phylogenetic analysis of the 16s rrna gene sequence revealed that it represents a distinct line of descent within the comamonadaceae. the novel strain was a gram-negative, catalase- and oxidase-positive, non-motile, straight to slightly curved rod. polyhydroxyalkanoate granules were stored intracellularly as reserve material. colonies on agar plates were small, regular and characterized by a water-insoluble ... | 2004 | 14742465 |
| micromanipulation and further identification of fish-labelled microcolonies of a dominant denitrifying bacterium in activated sludge. | the activated sludge process relies on the formation of strong microbial flocs. the knowledge about dominant floc-forming bacteria is at present very limited, especially from a phylogenetic perspective. in this study, numerous microcolonies in the activated sludge flocs were found to be targeted by a betaproteobacteria-group-specific oligonucleotide probe using fluorescence in situ hybridization (fish). some of these were micromanipulated and further identified by reverse transcriptase polymeras ... | 2004 | 15049920 |
| emended description of the species lampropedia hyalina. | three lampropedia hyalina strains from different habitats were compared by phenotypic, chemotaxonomic and molecular characteristics. all strains form coccoid cells and have been reported to grow as square tablets of eight to 64 cells. however, two of these strains (atcc 11041t and atcc 43383) have apparently lost this ability, and the third strain may temporarily lose this capacity under certain cultivation conditions. the three strains showed only minor differences in metabolic characteristics: ... | 2004 | 15388733 |
| proposals of curvibacter gracilis gen. nov., sp. nov. and herbaspirillum putei sp. nov. for bacterial strains isolated from well water and reclassification of [pseudomonas] huttiensis, [pseudomonas] lanceolata, [aquaspirillum] delicatum and [aquaspirillum] autotrophicum as herbaspirillum huttiense comb. nov., curvibacter lanceolatus comb. nov., curvibacter delicatus comb. nov. and herbaspirillum autotrophicum comb. nov. | two strains of curved bacteria, 7-1(t) and 7-2(t), isolated from well water, were phylogenetically examined to determine their taxonomic position. strain 7-1(t) is a gram-negative, slightly curved rod. analysis of the 16s rrna gene sequence showed that strain 7-1(t) formed a cluster with [aquaspirillum] delicatum and [pseudomonas] lanceolata. it has some similar characteristics to [a.] delicatum and [p.] lanceolata, but has sufficient distance to separate it from other genera. dna-dna hybridizat ... | 2004 | 15545462 |
| bacterial population dynamics and community structure in a pharmaceutical manufacturing water supply system determined by real-time pcr and pcr-denaturing gradient gel electrophoresis. | to control bacteria in the pharmaceutical water supply system. | 2004 | 15546402 |
| adaptation to extreme environments: macromolecular dynamics in complex systems. | what we previously thought of as insurmountable physical and chemical barriers to life, we now see as yet another niche harbouring 'extremophiles'. extremophiles and their macromolecules had to develop molecular mechanisms of adaptation to extreme physico-chemical conditions. using neutron spectroscopy, we have demonstrated that molecular dynamics represents one of these molecular mechanisms of adaptation. to which extent do hyper-saline conditions and extreme temperatures influence molecular dy ... | 2005 | 15951115 |
| microbial community in a geothermal aquifer associated with the subsurface of the great artesian basin, australia. | to investigate the biomass and phylogenetic diversity of the microbial community inhabiting the deep aquifer of the great artesian basin (gab), geothermal groundwater gushing out from the aquifer was sampled and analyzed. microbial cells in the groundwater were stained with acridine orange and directly counted by epifluorescence microscopy. microbial cells were present at a density of 10(8)-10(9) cells per liter of groundwater. archaeal and bacterial small-subunit rrna genes (rdnas) were amplifi ... | 2005 | 15980939 |
| impact of flooding on soil bacterial communities associated with poplar (populus sp.) trees. | soil bacterial communities were analyzed in different habitats (bulk soil, rhizosphere, rhizoplane) of poplar tree microcosms (populus tremulaxp. alba) using cultivation-independent methods. the roots of poplar trees regularly experience flooded and anoxic conditions. therefore, we also determined the effect of flooding on microbial communities in microcosm experiments. total community dna was extracted and bacterial 16s rrna genes were amplified by pcr and analyzed by terminal restriction fragm ... | 2005 | 16329959 |
| denitrification and assimilatory nitrate reduction in aquaspirillum magnetotacticum. | aquaspirillum magnetotacticum ms-1 grew microaerobically but not anaerobically with no(3) or nh(4) as the sole nitrogen source. nevertheless, cell yields varied directly with no(3) concentration under microaerobic conditions. products of no(3) reduction included nh(4), n(2)o, no, and n(2). no(2) and nh(2)oh, each toxic to cells at 0.2 mm, were not detected as products of cells growing on no(3). no(3) reduction to nh(4) was completely repressed by the addition of 2 mm nh(4) to the growth medium, ... | 1983 | 16346418 |
| freeze-thawing of aquaspirillum magnetotacticum cells selectively releases periplasmic proteins. | cells of the gram-negative bacterium aquaspirillum magnetotacticum, when suspended in buffer and freeze-thawed, produced pinkish orange supernatant fluid. the fluid contained </=2.0% of total extractable outer membrane component 2-keto-3-deoxyoctonate or of the cytoplasmic membrane marker succinic dehydrogenase. electrophoretic banding patterns and difference spectra of proteins and hemoproteins released by freeze-thawing cells were distinct from those of membrane-associated substances and simil ... | 1987 | 16347475 |
| alteration of the magnetic properties of aquaspirillum magnetotacticum by a pulse magnetization technique. | the presence of a narrow shape and size distribution for magnetite crystals within magnetotactic organisms suggests strongly that there are species-specific mechanisms that control the process of biomineralization. in order to explore the extent of this control, cultures of aquaspirillum magnetotacticum in the exponential growth phase were exposed to increasing magnetic pulses with the aim of separating cell populations on the basis of their magnetic coercivities. isothermal remanent magnetizati ... | 1991 | 16348587 |
| redox cycling of iron supports growth and magnetite synthesis by aquaspirillum magnetotacticum. | under anaerobic conditions and in the absence of alternative electron acceptors, growth of the magnetic bacterium aquaspirillum magnetotacticum msi was iron concentration dependent. weak chelation of the iron (with quinate, oxalate, or 2,3-dihydroxybenzoate) enhanced growth, whereas strong chelation (with edta, citrate, or nitrilotriacetic acid) retarded the growth of strain msi relative to that of controls lacking chelators. growth was proportional to the percentage of unchelated iron in medium ... | 1992 | 16348681 |
| proposal of giesbergeria voronezhensis gen. nov., sp. nov. and g. kuznetsovii sp. nov. and reclassification of [aquaspirillum] anulus, [a.] sinuosum and [a.] giesbergeri as giesbergeria anulus comb. nov., g. sinuosa comb. nov. and g. giesbergeri comb. nov., and [aquaspirillum] metamorphum and [a.] psychrophilum as simplicispira metamorpha gen. nov., comb. nov. and s. psychrophila comb. nov. | five gram-negative, motile, spiral-shaped strains were isolated from a sulfide spring (d-412t), active sludge of wastewater (d-419t, d-420, d-424) and industrial wastewater (d-416). comparative 16s rrna gene sequence analysis showed that the isolates belong to the family comamonadaceae, within the class betaproteobacteria, but fall into a distinct cluster. on the basis of phenotypic, chemotaxonomic and phylogenetic data, a new genus, giesbergeria gen. nov., is proposed, including five species. t ... | 2006 | 16514029 |
| criteria and methodology for identifying respiratory denitrifiers. | respiratory denitrification is not always adequately established when bacteria are characterized. we have tested a simple method that allows one to evaluate whether the two necessary criteria to claim denitrification have been met, namely, that n(inf2) or n(inf2)o is produced from nitrate or nitrite and that this reduction is coupled to a growth yield increase. microorganisms were cultured in sealed tubes under a helium headspace and in the presence of 0, 2, 4, 7, and 10 mm nitrate or nitrite. a ... | 1995 | 16534960 |
| identity, abundance and physiology of aquaspirillum-related filamentous bacteria in activated sludge. | microcolony-forming bacteria closely related to the genus aquaspirillum in the betaproteobacteria were recently observed to be abundant in many nutrient removal wastewater treatment plants. the developed oligonucleotide probe, aqs997, however, occasionally also targeted some filamentous bacteria in activated sludge samples when fluorescence in situ hybridization was performed. in this study, the identity, abundance, and ecophysiology of these aqs997-positive filamentous bacteria were studied in ... | 2006 | 16898157 |
| alkylphenol polyethoxylate removal in a pilot-scale reed bed and phenotypic characterization of the aerobic heterotrophic community. | the removal of the non-ionic surfactant triton x-100, dosed at 30 and 300 mg/l in a pilot-scale subsurface horizontal flow reed bed, and the aerobic heterotrophic cultivable community associated with the roots and with the substrate gravel in both absence and presence of triton x-100 were investigated. t-octylphenol (op) and its mono-, di- and tri-ethoxyl derivatives, among others, were found in the outlet. a mass balance allowed us to calculate that approximately 40% of the triton x-100 metabol ... | 2006 | 16929647 |
| hrt and nutrients affect bacterial communities grown on recirculation aquaculture system effluents. | in a recirculation aquaculture system the drumfilter effluent can be used as substrate for heterotrophic bacterial production, which can be recycled as feed. because the bacteria might contain pathogens, which could reduce its suitability as feed, it is important to characterize these communities. bacteria were produced in growth reactors under different conditions: 7 h hydraulic retention time (hrt) vs. 2 h, sodium acetate vs. molasses, and ammonia vs. nitrate. the community of the drumfilter e ... | 2007 | 17371322 |
| ecophysiology of abundant denitrifying bacteria in activated sludge. | the abundance of potential denitrifiers in full-scale wastewater treatment plants with biological nitrogen and phosphorus removal was investigated by fish and various oligonucleotide probes. the potential denitrifiers were characterized as probe-defined populations that were able to consume radiolabelled substrate with oxygen, nitrate and nitrite as electron acceptor as determined by microautoradiography. the most abundant potential denitrifiers were related to the genera aquaspirillum, azoarcus ... | 2007 | 17391331 |
| membrane bioreactor process for removing biodegradable organic matter from water. | this research investigated a membrane bioreactor (mbr) process for removing biodegradable organic matter (bom) and trihalomethane (thm) precursors from pre-ozonated water. bench-scale and mini-pilot-scale mbr experiments were conducted using powdered activated carbon (pac) and acclimated biomass. dissolved organic carbon (doc) was removed through a combination of adsorption and biodegradation mechanisms, and the initial doc removals depended on carbon dose, while steady-state removals were in th ... | 2007 | 17643469 |
| reclassification of aquaspirillum itersonii and aquaspirillum peregrinum as novispirillum itersonii gen. nov., comb. nov. and insolitispirillum peregrinum gen. nov., comb. nov. | phylogenetic analysis based on 16s rrna gene sequences showed that aquaspirillum itersonii and aquaspirillum peregrinum form distinct phylogenetic lineages within the alphaproteobacteria, whereas aquaspirillum serpens, the type species of the genus aquaspirillum, belongs to the betaproteobacteria. a. itersonii and a. peregrinum exhibited 16s rrna gene sequence similarity values of 82.0-82.4 % to the type strain of a. serpens and of 91.8-92.0 % to each other. a. itersonii and a. peregrinum were c ... | 2007 | 18048733 |
| paludibacterium yongneupense gen. nov., sp. nov., isolated from a wetland, yongneup, in korea. | a cream-coloured bacterial strain, 5yn8-15(t), was isolated from a wetland, yongneup, in the inje region of the republic of korea. the bacterium was facultatively anaerobic, gram-negative, motile with a single polar flagellum and curved-rod-shaped. based on 16s rrna gene sequence analysis, strain 5yn8-15(t) is a member of the betaproteobacteria. closely related taxa were gulbenkiania mobilis e4fc31(t) (94.9% sequence similarity), chromobacterium species (94.1-94.4%), aquitalea magnusonii tro-001 ... | 2008 | 18175708 |
| amyloid-like adhesins produced by floc-forming and filamentous bacteria in activated sludge. | amyloid proteins (fimbriae or other microbial surface-associated structures) are expressed by many types of bacteria, not yet identified, in biofilms from various habitats, where they likely are of key importance to biofilm formation and biofilm properties. as these amyloids are potentially of great importance to the floc properties in activated sludge wastewater treatment plants (wwtp), the abundance of amyloid adhesins in activated sludge flocs from different wwtp and the identity of bacteria ... | 2008 | 18192426 |
| substrate-dependent denitrification of abundant probe-defined denitrifying bacteria in activated sludge. | the denitrification capacity of different phylogenetic bacterial groups was investigated on addition of different substrates in activated sludge from two nutrient-removal plants. nitrate/nitrite consumption rates (crs) were calculated from nitrate and nitrite biosensor, in situ measurements. the nitrate/nitrite crs depended on the substrate added, and acetate alone or combined with other substrates yielded the highest rates (3-6 mg n gvss(-1) h(-1)). the nitrate crs were similar to the nitrite c ... | 2008 | 18811652 |
| bacterial community and biological nitrate removal: comparisons of autotrophic and heterotrophic reactors for denitrification with raw sewage. | an autotrophic denitrification reactor (adr-1) and a heterotrophic denitrification reactor (hdr-2) were operated to remove nitrate and nitrite in an anoxic environment in raw sewage. the no3-n removal rate of adr-1 was shown to range from 52.8% to 78.7%, which was higher than the no3-n removal rate of hdr-2. specific denitrification rates (sdnr) of adr-1 and hdr-2 were 3.0 to 4.0 and 1.1 to 1.2mgno3- n/gvss/h, respectively. from results of restriction fragment length polymorphism (rflp) of the 1 ... | 2008 | 19047828 |
| a birefringence relaxation determination of rotational diffusion of magnetotactic bacteria. | the orientational relaxation of the magnetotactic bacterium aquaspirillum magnetotacticum is observed by the decay of the optical birefringence upon switching off an aligning magnetic field. the data yield a rotational diffusion constant d(r) [unk] 0.13 s(-1) and information about cell sizes that is consistent with optical microscopy data. | 1985 | 19431585 |
| effects of compost addition and simulated solarisation on the fate of ralstonia solanacearum biovar 2 and indigenous bacteria in soil. | abstract the effects of compost addition and simulated solarisation of soil on the survival of ralstonia solanacearum biovar 2 strain 1609, as well as on the structure of indigenous soil bacterial communities, were analysed. in addition, effects on the invasion of susceptible test plants by strain 1609 were assessed. in untreated soil in microcosms and the field, strain 1609 showed slow progressive declines, from 10(6)-10(7) to roughly 10(4)-10(5) cfu per g dry soil in around 60 days. when these ... | 2003 | 19719697 |
| construction of river model biofilm for assessing pesticide effects. | due to the high importance of biofilms on river ecosystems, assessment of pesticides' adverse effects is necessary but is impaired by high variability and poor reproducibility of both natural biofilms and those developed in the laboratory. we constructed a model biofilm to evaluate the effects of pesticides, consisting in cultured microbial strains, pedobacter sp. 7-11, aquaspirillum sp. t-5, stenotrophomonas sp. 3-7, achnanthes minutissima n71, nitzschia palea n489, and/or cyclotella meneghinia ... | 2011 | 20422166 |
| Quantification of polyphenols during retting and characterization of bacteria from the Kadinamkulam Backwaters, Kerala. | The retting environment which provides a competitive niche for specialized microbes is speculated to harbour a variety of microbes with high biodegradation potential. In this context, an effort has been made to isolate and identify bacterial species having high tolerance to phenol In vitro. Maximum polyphenol (1.897 mg l(-1)) as observed during the initial period of retting, which decreased as retting proceeded. Based on biochemical characterization, the isolated bacterial strains were identifie ... | 2011 | 21888245 |