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At least 19 recordsLinked to original sources

PubMed1976

Study of genetic relationships among marine species of the genera Beneckea and Photobacterium by means of in vitro DNA/DNA hybridization.

Strains representative of species of the marine genera Beneckea and Photobacterium were used as reference standards in in vitro DNA/DNA competition experiments. Within a given species, strains were found to be related by over 80% competition. (Competition was defined as the amount of radioactive DNA displaced by heterologous DNA relative to the amount displaced by homologous DNA.) On the basis of interspecies competition values (expressed as averages), the following groupings could be made: 1. "Photobacterium" fischeri was related to strain ATCC 15382 by a competition of 38% and was distinct from all the other strains tested (competition less than or equal to 11%). 2. The genus Photobacterium consisted of 3 species, P.phosphoreum, P.leiognathi, and a newly designated species, P.angustum (composed of non-luminous strains). The latter species was found to be related to P.leiognathi and P.phosphoreum by 56 and 28% competition, respectively, while P.phosphoreum was related to P.leiognathi by 29%. 3. In the genus Beneckea, 65% competition was detected between B.harveyi and B.campbellii as well as between B.parahaemolytica and B.alginolytica. These pairs of species were related to each other by 51-58% and to B.natriegens by 34-56% competition. A newly designated pathogenic species, B.vulnifica, appeared to have a low but significant relationship to all the above mentioned species of Beneckea. 4. Two biotypes, related by 68% competition, were recognized in the species B.splendida. Similarly, B.pelagia was found to consist of 2 biotypes related by a competition of 67%. The competition values between these species were 38-40%. 5. B.nereida, B.nigrapulchrituda, and "Vibrio" anguillarum had competition values less than or equal to 30% to each other as well as to other species of Beneckea. 6. With Vibrio cholerae as the reference standard, V.albensis was found to be related by a competition of 82%, while V.proteus and V.metschnikovii had competition values of 22 and 12%, respectively. These results suggested that V.albensis should be synonymized with V.cholerae, while the latter two organisms should remain distinct from this species. V.cholerae as well as the other terrestrial organisms tested did not appear to be significantly related to any of the marine strains (competition values less than or equal to 27%). The speciation derived from the results of the DNA/DNA competition experiments was compared to previous speciation based on phenotypic similarities.

DNA, Bacterial↗

PubMed1992

The lux genes in Photobacterium leiognathi are closely linked with genes corresponding in sequence to riboflavin synthesis genes.

Three open reading frames (ORFs) have been found in the region downstream of the luxG gene in the Photobacterium leiognathi lux operon. These genes (ORF I, II, and III) are not only closely linked to the lux operon and transcribed in the same direction but also show the same organization and code for proteins homologous in sequence to the gene products of ribB, ribA, and ribH of Bacillus subtilis, respectively. The Photobacterium leiognathi gene (ORF II) corresponding to ribA was expressed in Escherichia coli in the bacteriophage T7 promoter-RNA polymerase system and a 40 kDa 35S-labeled polypeptide has been detected on SDS-PAGE. Expression of DNA extending from luxBEG to ORF II inserted between a strong promoter and a reporter gene and transferred by conjugation into Vibrio harveyi did not affect the expression of the reporter gene. The results provide evidence that neither promoter nor terminator sites were present in the DNA between the luxG and ORF II indicating that these genes might be part of the lux operon.

Amino Acid Sequence↗

PubMed1975

Enzymes of D-fructose catabolism in species of Beneckea and Photobacterium.

Cell-free extracts of strains representative of the genera Beneckea and Photobacterium catalyzed a P-enolpyruvate dependent phosphorylation of D-fructose. The resulting product, fructose-1-P, was converted to fructose-1,6-P2 by 1-P-fructokinase. Both activities were inducible, being present in D-fructose-grown cells and reduced or absent in D-gluconate-(or succinate-) grown cells.

Adenosine Triphosphate↗

PubMed1977

Control of luciferase synthesis in a newly isolated strain of Photobacterium leiognathi.

In previous studies with luminous bacteria of all different species it has been reported that the synthesis of luciferase is autoinducible: during growth at low cell densities synthesis is effectively repressed while after induction, at higher cell densities, the rate of synthesis of enzyme is up to five times the growth rate. In this paper we report on newly isolated strains of Photobacterium leiognathi which show continued luciferase synthesis irrespective of the cell density. The specific synthesis rate may nevertheless differ from the rate of growth and depends on the luciferase content of the inoculated cells. A ratio of 1 was established for cells having a maximum luciferase content varying to a ratio of about 2 for cells that contained only 1% of the maximum.

Luciferases↗

PubMed1979

The terminal oxidase of Photobacterium phosphoreum. A novel cytochrome.

The terminal oxidase of Photobacterium phosphoreum has been purified to the electrophoretically homogeneous state and some of its properties have been studied. The enzyme catalyses oxidation of ascorbate in the presence of phenazine methosulphate or N,N,N',N'-tetramethyl-p-phenylenediamine. The reaction is inhibited by cyanide. Nitrite at comparatively high concentrations inhibits the enzyme, but the enzyme does not catalyse nitrite reduction with ascorbate plus the electron mediator as the electron donor. The enzyme shows the absorption peaks at 632, 565, 534 and 436 nm in the reduced form. It has two kinds of haems: protohaem and haem d. Namely, the enzyme is a 'cytochrome bd'-type oxidase; a novel cytochrome.

Cytochromes↗

PubMed1992

Crystallization of Photobacterium leiognathi non-fluorescent flavoprotein, an unusual flavoprotein with limited sequence identity to bacterial luciferase.

Single crystals of the non-fluorescent flavoprotein (NFP) purified from Photobacterium leiognathi strain S1 have been grown from ammonium sulphate solutions using the hanging drop vapour diffusion technique. The crystals grow as thin (0.06 mm) plates and belong to the orthorhombic space group C222(1): a = 57.06(3) A, b = 92.41(6) A, c = 99.52(6) A. There is one NFP monomer per asymmetric unit and crystals diffract to 2.2 A spacings on film. A complete native data set to 2.5 A resolution has been collected on a San Diego Multiwire Detector system at the University of Alberta and a heavy-atom derivative search is presently in progress.

Bacterial Proteins↗

PubMed1977

A calorimetric investigation of the growth of the luminescent bacteria Beneckea harveyi and Photobacterium leiognathi.

Direct calorimetric determinations of the rate of heat production along with simultaneous determinations of the rate of photon emission and the number of viable cells have provided insight into the growth of Beneckea harveyi and Photobacterium leiognathi. These experiments were performed with a Tronac isothermal microcalorimeter modified with a fiber optic light guide to allow in situ detection of light. Escherichia coli and a dark variant of P. leiognathi were also examined to provide points of reference. It is demonstrated that B. harveyi seems to pause in the rate of metabolic heat production at the same point in time that the enzyme luciferase begins to be synthesized. This effect is not removed if B. harveyi is grown in conditioned medium. The thermograms for all species are correlated with cell generation time. The heat production per cell indicates that uncrowded cultures produce more heat than older, more crowded cultures, supporting the original observation of Bayne-Jones and Rhees (1929). These observations reopen for examination the suggestion that living systems tend toward a state of minimum metabolism per unit mass.

Calorimetry↗

PubMed1977

A pulse-radiolysis study of the catalytic mechanism of the iron-containing superoxide dismutase from Photobacterium leiognathi.

The mechanism of the enzymic reaction of an iron-containing superoxide dismutase purified from the marine bacterium Photobacterium leiognathi was studied by using pulse radiolysis. Measurements of activity were done with two different preparations of enzyme containing either 1.6 or 1.15 g-atom of iron/mol. In both cases, identical values of the second-order rate constant for reaction between superoxide dismutase and the superoxide ion in the pH range 6.2-9.0 (k=5.5 X 10(8) M-1-S-1 at pH 8.0) were found. As with the bovine erythrocuprein, there was no evidence for substrate saturation. The effects of reducing agents (H2O2, sodium ascorbate or CO2 radicals) on the visible and the electron-paramagnetic-resonance spectra of the superoxide dismutase containing 1.6 g-atom of ferric iron/mol indicate that this enzyme contains two different types of iron. Turnover experiments demonstrate that only that fraction of the ferric iron that is reduced by H2O2 is involved in the catalysis, being alternately oxidized and reduced by O2; both the oxidation and the reduction steps have a rate constant equal to that measured under turnover conditions. These results are interpreted by assuming that the superoxide dismutase isolated from the organism contains 1 g-atom of catalytic iron/mol and a variable amount of non-catalytic iron. This interpretation is discused in relation to the stoicheiometry reported for iron-containing superoxide dismutases prepared from several other organisms.

Ascorbic Acid↗

PubMed1976

Studies on luciferase from Photobacterium phosphoreum. VIII. FMN-H2O2 initiated bioluminescence and the thermodynamics of the elementary steps of the luciferase reaction.

Bacterial luciferase from Photobacterium phosohoreum was found to produce bioluminescence on reaction with FMN and H2O2 in the presence of aldehyde. This luminescence is presumably produced by the same X1 intermediate as that found in FMNH2-O2 initiated luminescence. From the ratio of the light intensities of the FMN-H2O2 initiated reactions, we calculated the association constant of the reaction, luciferase+FMN+H2O2in equilibriumX1, and estimated its temperature dependence. From these results we calculated the thermodynamic parameters of the reaction, luciferase+FMNH2+O2in equilibriumX1. We found that the free energy level of X1 is only 3.2 kcal below that of fr-e FMN and H2O2. We also estimated the thermodynamic parameters of other steps of the luminescent reaction. The values obtained showed that the formation of X1 from luciferase, FMNH2 and O2 involves a positive entropy change, but the intermediate is in a state stabilized against decomposition. Results also suggest a considerable degree of electronic rearrangement on formation of the excited-state molecule from the X1-aldehyde complex.

Aldehydes↗

PubMed1977

Luminescence and respiratory activities of Photobacterium phosphoreum. II. Control by monovalent cations.

Luminescent activity of spheroplasts of the cells of Photobacterium phosphoreum was stimulated by Rb+ and K+ and inhibited by Na+ in the medium. Opposite effects of these ions were observed on the rate of O2 consumption of the spheroplasts through the cytochrome and luciferase electron transfer systems. In vitro activities of NADH-FMN reductase and luciferase were only slightly stimulated by Rb+, K+, and Na+, while Na+ exhibited significant activation of the NADH-oxidizing activity of the cells. The redox level of cytochrome b in the spheroplasts during steady-state respiration in an Na+ medium was more reduced, while that of NAD(P) was more oxidized, than those in an Rb+ or K+ medium. Na+ activates the cytochrome electron transfer system at a point between NADH and cytochrome b, and thus has a stimulative effect on cellular O2 consumption. Rb+ and K+ do not show similar activation, but the cellular NAD(P) was brought to a more reduced level, so that in vivo luminescence is stimulated in an Rb+ or K+ medium.

Cations, Monovalent↗

PubMed1978

Properties and kinetics of salt activation of a membrane-bound NADH dehydrogenase from a marine bacterium Photobacterium phosphoreum.

A membrane-bound NADH dehydrogenase, solubilized and partially purified from a marine bacterium Photobacterium phosphoreum, contains FAD as the prosthetic group, and is specific for NADH. Ferricyanide, various other redox dyes and cytochrome c can act as electron acceptors. The enzymatic activity when assayed with electron acceptors other than cytochrome c, is activated by monovalent cations (Na+ and K+) and deactivated by high concentrations of monovalent anions (SCN-, NO3-, and Cl-) but not by phosphate ions. The enzymatic reaction follows a ping-pong mechanism and kinetic analysis of the enzyme showed that the activation by monovalent cations is due to increase of affinity of the enzyme for substrates; Vm was not affected. The increase of affinity was 62- and 46-fold for NADH and 57- and 31-fold for 2,6-dichlorophenol indophenol in the presence of Na+ and K+, respectively. On the other hand, NADH-cytochrome c reductase activity of the enzyme was strongly inhibited by these cations.

Anions↗

PubMed1978

Studies on luciferase from Photobacterium phosphoreum. XI. Interaction of 8-substituted FMNH2 with luciferase.

The interaction of bacterial luciferase from Photobacterium phosphoreum with reduced flavin was investigated using various 8-substituted FMNH2 analogs. Flavins tested were FMNH2 and FMNH2 substituted at the 8 position with HO-, CH3O-, C2H5O-, Cl-, Br-, I-, H2N-, (CH3)HN-, and (ch3)2n. 8-ch30-, c2h5o-, cl-, and Br-FMNH2 showed luminescent activity in the luciferase reaction with emission peaks at various wavelengths. 8-HO- and I-FMNH2 were competitive inhibitors toward FMNH2 in the luminescent reaction. 8-Amino analogs of FMNH2 showed no luminescent or inhibitor activity. The dissociation constant of the luciferase-FMNH2 analog complex was determined kinetically as a substrate or inhibitor constant. A contribution of the imino group at position 5 in the isoalloxazine ring to the FMNH2 binding to luciferase was suggested by a Hammett plot of the dissociation constants.

Flavin Mononucleotide↗

PubMed1976

Symbiotic association of Photobacterium fischeri with the marine luminous fish Monocentris japonica; a model of symbiosis based on bacterial studies.

Isolation of bacteria from the luminous organ of the fish Monocentris japonica has revealed that the organ contains a pure culture of luminous bacteria. For the four fish examined, all contained Photobacterium fischeri as their luminous bacterial symbiont. This is the first time that P. fischeri has been identified in a symbiotic association. A representative isolate (MJl) of the light organ population was selected for in vivo studies of its luminous system. Several physiological features suggest adaptation for symbiotic existence. First, MJl has been shown to produce and respond to an inducer of luciferase that could accumulate in the light organ. Secondly, the specific activity of light production was seen to be maximal under low, growth-limiting concentrations of oxygen. Thirdly, unlike another luminous species (Beneckea harveyi), synthesis of the light production system of these bacteria is not catabolite repressed by glucose--a possible source of nutrition in the light organ. Fourthly, when grown aerobically on glucose these bacteria excrete pyruvic acid into the medium. This production of pyruvate is a major process, accounting for 30-40% of the glucose utilized and may serve as a form of regulatory and nutritional communication with the host.

Animals↗

PubMed1979

[Genetic studies of Photobacterium mandapamensis. II. The classification of mutants with an altered luminescence intensity according to their sensitivity to exogenous aldehyde].

The collection of 157 dark and dim Photobacterium mandapamensis strains was divided into four groups using the addition of 0.2 ml of 0.15% myristis aldehyde to cell suspension. The luminescence did not change in the presence of the aldehyde in 76 mutants, it decreased in 30 mutants, it was 2--8-fold increased in 35 mutants, and it was increased more than 10-fold in 16 mutant strains. 19 strains of those having luminescence in the presence of the aldehyde have mutations in genes controlling the biosynthesis of the aldehyde factor. Among them mutants are chosen which can be used as indicators for the aldehyde presence in the medium.

Aldehydes↗

PubMed1975

Luminescence and respiratory activities of Photobacterium phosphoreum. Competition for cellular reducing power.

Changes in the in vivo luminescence, respiratory activities, contents of cytochromes, extractable luciferase and NAD(P)H-FMN reductase during growth of the wild (bright) strain of Photobacterium phosphoreum and its dim mutant were determined. The intensity of the in vivo luminescence per cell increased 10 times in the wild strain and 750 times in the dim strain during logarithmic growth, while the contents of luciferase and NAD(P)H-FMN reductase remained almost constant. It is suggested that a characteristic change in the mode of competition of the luminescence reaction system with another electron transfer chain involving cytochromes for NAD(P)H take place during the growth of this bacterium.

Cell Division↗

PubMedDate not supplied

[Luminescence and growth of Photobacterium mandapamensis in periodic culture].

The luminescent Photobacterium mandapamensis, strain 54 (the collection of the Institute of Physics, Siberian Branch of the USSR Academy of Sciences), was isolated from the water of the Pacific Ocean in the equatorial zone and studied in the course of periodic cultivation. The dynamics of changes in the main parameters of the culture, such as luminescence, growth, respiration, heat emission etc., was investigated. The data obtained were used to establish a correlation between changes in these parameters and in the cell metabolism when one energy substrate was substituted by another.

Culture Media↗

PubMed1978

[Isolation of bacterial luminescence reaction inhibitor from Photobacterium sp. cells].

The factor having a strong inhibitory effect on bacterial luminescence was isolated from the luminous bacteria species Photobacterium sp. The inhibitor purified by gel filtration on the biogel and by DEAE chromatography was homogenous (single bound during electrophoresis in polyacrylamide gel), it reacted with coomassie brilliant blue and gave a positive Lowry reaction on protein. Molecular weight was about 30,000 as determined by SDS-polyacrylamide gel electrophoresis. The absorption spectrum was characterised by the maximum at 209 nm and unexpressed maximum in the region of 260 nm. It was shown that the inhibitor had an efficient inhibitory effect on both partially- and highly purified luciferase preparations from different species of luminous bacteria, but it produced no effect on the activity of specific NADH: FMN-oxidoreductase.

Bacterial Proteins↗

PubMed1975

The nucleotide sequence of the 5S ribosomal RNA from a photobacterium.

Comparative sequencing studies provide powerful insights into molecular function and evolution. The sequence for 5S ribosomal RNA from Photobacter strain 8265 is eighteen base replacements removed from that of Escherichia coli. Of these, the vast majority involve a G or C becoming an A or U. These variations also define unequivocally a hexanucleotide base paired region, which appears to be a universal feature of the 5S RNA molecule. The base composition of this helix seems to be under rather stringent, and so unusual, energetic constraints. The possible implications of this are discussed - in particular the prospect of a 5S RNA molecule that undergoes conformational transitions as a part of the overall state changes that constitute the function of the ribosome.

Base Sequence↗