共查询到20条相似文献,搜索用时 15 毫秒
1.
Some of the photosynthetic reactions were measured under aerobic and anaerobic conditions in intact cells of an aerobic photosynthetic bacterium Erythrobacter species strain OCh 114 (ATCC No. 33942). In intact cells, the flash-light induced oxidation of cytochrome c-551, the continuous light-induced oxidation of reaction center bacteriochlorophyll and the continuous light-induced pH change (
) of the suspension decreased on aerobic-anaerobic transition and almost disappeared under anaerobic conditions. These photosynthetic reactions reappeared when the suspension was aerated again. These phenomena were reconciled with the fact that Erythrobacter sp. cannot grow anaerobically even in the light. The incompetence of photoanaerobic growth of this bacterium was explained by the reduction of the primary electron acceptor (QI) before illumination, resulting partly from the relatively high midpoint potential of QI of this bacterium.Abbreviations QI
Primary electron acceptor
- Eh
ambient redox potential
- Em
midpoint redox potential 相似文献
2.
Kazuo Okamura Kazuyasu Kisaichi Ken-ichiro Takamiya Mitsuo Nishimura 《Archives of microbiology》1984,139(2-3):143-146
A soluble cytochrome, cytochrome c-551 was purified from an aerobic photosynthetic bacterium Erythrobacter species strain OCh 114 (ATCC No. 33942) by ammonium sulfate fractionation, ion-exchange chromatography and gel-filtration. The cytochrome had absorption maxima at 277, 410, and 524–525 nm in the oxidized form, and at 415, 522, and 550.5 nm in the reduced form. At 77 K, the -band of the absorption spectrum of the reduced form split in two at 547 and 549 nm. The millimolar absorption coefficient at 550.5 nm was 26.8 mM-1 cm-1 in the reduced form. This cytochrome was an acidic protein with an isoelectric point of 4.9. Its molecular weight was determined to be 15,000 by gel-filtration on Sephadex G-100 and 14,500 by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The midpoint potential of this cytochrome was +250 mV at pH 7.0. This cytochrome did not bind CO. 相似文献
3.
Roseobacter denitrificans, previously named Erythrobacter species OCh 114, synthesized spheroidenone as a major carotenoid under aerobic dark conditions. When the dark-grown cells
were subjected to illumination under anacrobic conditions, many unknown yellow pigments appeared and a considerable amount
of spheroidenone disappeared. Absorption maxima of these pigments were blue-shifted from those of spheroidenone. The most
abundant of the pigments was isolated, and its chemical structure was determined as 3,4-dihydrospheroidenone on spectroscopic
and chemical evidence. Presumably, over-reduction of the photosynthetic apparatus interfered with normal photosynthetic electron
transfer and resulted in photoreduction of C=C double bond at the 3,4-position of spheroidenone. 相似文献
4.
Yukimasa Nishimura Shinichiro Mukasa Hiroshi Iizuka Keizo Shimada 《Archives of microbiology》1989,152(1):1-5
Bacteriochlorophyll(Bchl)-protein complexes were isolated from a strictly aerobic and facultative methylotrophic bacterium Pseudomonas radiora strain MD-1. They were identified as the reaction center (RC)-B870 and the B870 complexes on the basis of their absorption spectra, light induced spectral changes and polypeptide compositions. The RC-B870 complex of this bacterium showed similar properties to those of typical purple photosynthetic bacteria, and contained c-type cytochrome which was oxidized upon illumination.Abbreviations Bchl
bacteriochlorophyll
- RC
reaction center
- SDS
sodium dodecylsulfate
- PAGE
polyacrylamide gel electrophoresis 相似文献
5.
《BBA》1987,890(2):127-133
A photosynthetic reaction center complex has been purified from an aerobic photosynthetic bacterium, Erythrobacter species OCh 114. The reaction center was solubilized with 0.45% lauryldimethylamine N-oxide and purified by DEAE-Sephacel column chromatography. Absorption spectra of both reduced and oxidized forms of the reaction center were very similar to those of the reaction center from Rhodopseudomonas sphaeroides R-26 except for the contributions due to cytochrome and carotenoid. 1 mol reaction center contained 4 mol bacteriochlorophyll a, 2 mol bacteriopheophytin a, 4 mol cytochrome c-554, 2 mol ubiquinone-10, and carotenoid. The reaction center consisted of four different polypeptides of 26, 30, 32 and 42 kDa. The last one retained heme c. Absorbance at 450 nm oscillated with the period of two on consecutive flashes. The light-minus-dark difference spectrum had two peaks at 450 nm and 420 nm, indicating that odd flashes generated a stable ubisemiquinone anion and even flashes generated quinol. o-Phenanthroline accelerated the re-reduction of flash-oxidized reaction centers, indicating that o-phenanthroline inhibited the electron transfer between QA and QB. The cytochrome (cytochrome c-554) in the reaction center was oxidized on flash activation. The midpoint potential of the primary electron acceptor (QA) was determined by measuring the extent of oxidation of cytochrome c-554 at various ambient potentials. The mid-point potential of QA was −44 mV, irrespective of pH between 5.5 and 5.9. 相似文献
6.
Takumi Noguchi Hidenori Hayashi Keizo Shimada Shinichi Takaichi Mitsuo Tasumi 《Photosynthesis research》1992,31(1):21-30
In vivo states and functions of carotenoids in the membranes and the isolated RC-B865 pigment-protein complexes from an aerobic photosynthetic bacterium, Erythrobacter longus, are investigated by means of fluorescence excitation and resonance Raman (RR) spectra. Erythroxanthin sulfate, a dominant carotenoid species in the membranes (>70%), is found not to transfer the absorbed light energy to bacteriochlorophyll (Bchl), and its RR spectra are similar between the in vivo and in vitro states. These observations indicate that erythroxanthin sulfate does not interact with either Bchl or proteins in the membranes, and suggest that its function may be limited to photoprotection by quenching the harmful singlet oxygen. On the other hand, two other carotenoid species contained in the isolated RC-B865 complexes, zeaxanthin and bacteriorubixanthinal, have a high efficiency of energy transfer to Bchl (88±5%). The RR spectra of these two carotenoids, each of which can be selectively obtained by choosing the excitation wavelength, show some characteristics of interactions with proteins or Bchl.Abbreviations Bchl
bacteriochlorophyll a
- FWHM
full width at half maximum
- PAGE
polyacrylamide gel electrophoresis
- RC
reaction center
- RR
resonance Raman
- SDS
sodium dodecyl sulfate 相似文献
7.
Reversible photo-oxidation of cytochromes and reversible photobleachingof bacteriochlorophyll were observed in aerobically grown cellsof the aerobic heterotroph, the Erythrobacter species (OCh 114).Light inhibited O2-uptake by cells of this bacterium and Erythrobacterlongus (OCh 101). A vesicular structure of intracytoplasmicmembrane systems was observed in sections of aerobically growncells of OCh 114. These bacteria may be called aerobic photosyntheticbacteria (i.e., photosynthetic bacteria which can utilize lightenergy under aerobic conditions but not under anaerobic conditions). (Received September 9, 1981; Accepted December 2, 1981) 相似文献
8.
Rathgeber C Lince MT Alric J Lang AS Humphrey E Blankenship RE Verméglio A Plumley FG Van Dover CL Beatty JT Yurkov V 《Photosynthesis research》2008,97(3):235-244
The vertical distribution of culturable anoxygenic phototrophic bacteria was investigated at five sites at or near the Juan de Fuca Ridge in the Pacific Ocean. Twelve similar strains of obligately aerobic phototrophic bacteria were isolated in pure culture, from depths ranging from 500 to 2,379 m below the surface. These strains appear morphologically, physiologically, biochemically, and phylogenetically similar to Citromicrobium bathyomarinum strain JF-1, a bacterium previously isolated from hydrothermal vent plume waters. Only one aerobic phototrophic strain was isolated from surface waters. This strain is morphologically and physiologically distinct from the strains isolated at deeper sampling locations, and phylogenetic analysis indicates that it is most closely related to the genus Erythrobacter. Phototrophs were cultivated from three water casts taken above vents but not from two casts taken away from active vent sites. No culturable anaerobic anoxygenic phototrophs were detected. The photosynthetic apparatus was investigated in strain JF-1 and contains light-harvesting I and reaction center complexes, which are functional under aerobic conditions. 相似文献
9.
Two types of cytochrome cd1 in the aerobic photosynthetic bacterium, Erythrobacter sp. OCh 114 总被引:1,自引:0,他引:1
Components I and II of cytochrome cd1 which had different spectral features were purified from the aerobic photosynthetic bacterium, Erythrobacter sp. strain OCh 114. Component I showed an absorption maxima at 700 and 406 nm in the oxidized form, and at 621, 552.5, 548 and 416 nm in the reduced form. Component II showed an absorption maxima at 635 and 410 nm in the oxidized form and at 628, 552.5, 548 and 417 nm in the reduced form. The relative molecular mass, Mr, of both cytochromes was determined to be 135,000 with two identical subunits. Components I and II showed pI values of 7.6 and 6.8, respectively. The redox potential of hemes ranged from +234 mV to +242 mV, except for the heme d1 of component I (Em7 = +134 mV). Components I and II showed both cytochrome c oxidase and nitrite reductase activities. Cytochrome c oxidase activity was strongly inhibited by a low concentration of nitrite and cyanide. Erythrobacter cytochromes c-551 and c-552 were utilized as electron donors for the cytochrome c oxidase reaction. The high affinity of cytochrome c-552 to component II (Km = 1.27 microM) suggested a physiological significance for this cytochrome. Erythrobacter cytochromes cd1 are unique in their presence in cells grown under aerobic conditions as compared to other bacterial cytochromes cd1 which are formed only under denitrifying conditions. 相似文献
10.
Control of bacteriochlorophyll accumulation by light in an aerobic photosynthetic bacterium, Erythrobacter sp. OCh 114 总被引:2,自引:0,他引:2
The effect of light on bacteriochlorophyll (Bchl) accumulation as well as the activity of two enzymes in the initial step of the tetrapyrrole biosynthetic pathway was examined in an aerobic photosynthetic bacterium, Erythrobacter sp. strain OCh 114. Light clearly regulated the Bchl and carotenoid accumulation, completely suppressing their levels at high light intensity. However, porphyrin and Bchl precursors were not found in either the cells or the growth medium of lighted culture. The level of Bchl showed an inverse relationship to the light energy flux. Kinetic studies showed a Hill coefficient of n = 3.3 (r = 0.973), indicating a positive cooperativity. Bchl accumulation was stopped immediately upon illumination without any lag or overshoot. Despite low Bchl content, the activities of 5-aminolevulinic acid synthetase and porphobilinogen synthase were rather stimulated, but not suppressed by light. The high activity of enzymes coincided with the results that heme contents, particularly cytochrome c and catalase activity, were increased in light-grown cells. These results suggest that light regulated Bchl accumulation, but not Bchl biosynthesis and that the effect of light is to render newly formed pigment molecules unstable. 相似文献
11.
Abstract An acid phosphatase highly spcific for pyridoxal 5'-phosphate (PLP) was found and partially purified from the aerobic photosynthetic bacterium, Erythrobacter sp. OCh 114. The enzyme showed a pH optimum at 5.5; its activity was stimulated by magnesium ions. This enzyme also hydrolyzed p -nitrophenyl phosphate (NPP) and flavin mononucleotide (FMN). The enzyme level varied depending on growth conditions. Supplementing the growth medium with glycerol, glucose, xylose or mannitol increased the level of phosphatase activity. An inverse relationship between free phosphate content in the cells and enzyme level was observed. 相似文献
12.
Photophosphorylation and oxidative phosphorylation in intact cells and chromatophores of an aerobic photosynthetic bacterium, Erythrobacter sp. strain OCh114. 总被引:2,自引:1,他引:1
下载免费PDF全文
![点击此处可从《Journal of bacteriology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Light-induced ATP synthesis was studied in intact cells and chromatophores of Erythrobacter sp. strain OCh114. ATP synthesis was measured by both the pH method and the luciferin-luciferase luminescence method. The rate of ATP synthesis was moderate (a typical value of 0.65 mol of ATP per mol of bacteriochlorophyll per min), and synthesis was inhibited by antimycin A. ATP was synthesized under illumination only under aerobic conditions and not under anaerobic conditions. This characteristic was similar to that of other light-induced energy transduction processes in this bacterial species, such as oxidation of reaction center, oxidation of cytochrome c551, and translocation of H+, which were not observed under anaerobic conditions. This phenomenon was reconciled with the fact that the Erythrobacter sp. could not grow anaerobically even in the light. The characteristics of oxidative phosphorylation and ATP hydrolysis were also investigated. The respiratory ratio of chromatophores was 2.3. Typical rates of oxidative phosphorylation by NADH and by succinate were 2.9 mol of ATP per mol of bacteriochlorophyll per min (P/O = 0.22) and 1.1 mol of ATP per mol of bacteriochlorophyll per min (P/O = 0.19), respectively. A typical rate of ATP hydrolysis was 0.25 mol of ATP per mol of bacteriochlorophyll per min in chromatophores. ATPase and adenylate kinase are also involved in the metabolism of adenine nucleotides in this bacterium. 相似文献
13.
Koblízek M Béjà O Bidigare RR Christensen S Benitez-Nelson B Vetriani C Kolber MK Falkowski PG Kolber ZS 《Archives of microbiology》2003,180(5):327-338
Seven strains of marine aerobic anoxygenic phototrophs belonging to the genus Erythrobacter were isolated. The strains were characterized regarding their physiological and biochemical properties, 16S rDNA and pufM gene sequences, morphological features, substrate preference, as well as pigment and lipid composition. All strains had functional type-2 reaction centers containing bacteriochlorophyll, served by small, light-harvesting complex 1, and were photosynthetically competent. In addition, large pools of carotenoids were found, but only some of the accessory pigments transfer energy to the reaction centers. All of the isolates were facultative photoheterotrophs. They required an organic carbon substrate for growth; however, they are able to supplement a significant fraction of their metabolic requirements with photosynthetically derived energy.Abbreviations BChl Bacteriochlorophyll - Chl Chlorophyll - Erb. Erythrobacter - Erm. Erythromicrobium - FAMEs Fatty acid methyl esters - IRFRR Infrared fast repetition rate - LH1, LH2 Light-harvesting complex 1 and 2, respectively - Por. Porphyrobacter - PUFAs Polyunsaturated fatty acids - Rsb. Roseobacter - RubisCO Ribulose-1,5-bisphosphate carboxylase/oxygenase - µ Growth rate - 470 Functional cross-section of the photosynthetic unit at 470 nm 相似文献
14.
Exogenously administered 5-aminolevulinic acid (ALA) inhibited the formation of bacteriochlorophyll a (Bchl a) in a dose-dependent manner in the aerobic photosynthetic bacterium, Erythrobacter sp. strain OCh 114, under dark growth conditions. The ALA concentration required for half-inhibition after 24-h growth was estimated to be about 3.0 mM. Porphyrin and Bchl precursors were not found in either the cells or the growth medium. The same inhibition was also observed with cytochrome c formation. When ALA was incubated with intact cells, a large amount of ALA was converted to an unknown metabolite. The pH optimum of the conversion was 7.8. The metabolite did not react with Ehrlich's reagent, but did so with ninhydrin, giving a yellow color. Based on analyses by several techniques including mass spectrometry, ir spectrometry, and paper electrophoresis, it was identified as 4-hydroxy-5-aminovaleric acid (HAVA). Authentic HAVA prepared from ALA was a competitive inhibitor of the enzyme, porphobilinogen synthase of Erythrobacter. The Ki value for authentic HAVA was calculated to be 2.4 mM from a Dixon plot and the HAVA concentration required for half-inhibition was 17 mM. It is concluded that in Erythrobacter cells, exogenous ALA is converted to the metabolite, HAVA, which is responsible for the inhibition of porphobilinogen synthase as well as that of Bchl a and cytochrome formation. 相似文献
15.
Roles of bacteriochlorophyll and carotenoid synthesis in formation of intracytoplasmic membrane systems and pigment-protein complexes in an aerobic photosynthetic bacterium, Erythrobacter sp. strain OCh114. 总被引:2,自引:0,他引:2
下载免费PDF全文
![点击此处可从《Journal of bacteriology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Synthesis of bacteriochlorophyll and carotenoids was inhibited in an aerobic photosynthetic bacterium, Erythrobacter sp. strain OCh114, by alpha, alpha'-dipyridyl and diphenylamine. Formation of two pigment-protein complexes, reaction center-B870 (RC-B870) and B806, and development of the intracytoplasmic membranes of the cells were studied by spectral analysis and electron microscopy. Inhibition of bacteriochlorophyll synthesis by alpha, alpha'-dipyridyl, which was accompanied by a decrease in carotenoid synthesis, suppressed formation of intracytoplasmic membranes in the cells. Growth under illumination had a similar effect on formation of pigments and membranes. On the other hand, inhibition of carotenoid synthesis by diphenylamine did not suppress either development of the membrane system or bacteriochlorophyll synthesis. Formation of RC-B870 and B806 complexes, however, was differentially affected by blockage of carotenoid synthesis. In the presence of diphenylamine, the B806 complex was formed in a much smaller amount than the RC-B870 complex. These results suggest that, in Erythrobacter sp. strain OCh114, bacteriochlorophyll plays an essential role in intracytoplasmic membrane development, and carotenoids are important for assembly of pigment-protein complexes. 相似文献
16.
David B. Knaff 《Photosynthesis research》1993,35(2):117-133
Complete nucleotide sequences are now available for the pet (fbc) operons coding for the three electron carrying protein subunits of the cytochrome bc
1 complexes of four photosynthetic purple non-sulfur bacteria. It has been demonstrated that, although the complex from one of these bacteria may contain a fourth subunit, three subunit complexes appear to be fully functional. The ligands to the three hemes and the one [2Fe-2S] cluster in the complex have been identified and considerable progress has been made in mapping the two quinone-binding sites present in the complex, as well as the binding sites for quinone analog inhibitors. Hydropathy analyses and alkaline phosphatase fusion experiments have provided considerable insight into the likely folding pattern of the cytochrome b peptide of the complex and identification of the electrogenic steps associated with electron transport through the complex has allowed the orientation within the membrane of the electron-carrying groups of the complex to be modeled. 相似文献
17.
Woo JH Hwang YO Kang SG Lee HS Cho JC Kim SJ 《Applied microbiology and biotechnology》2007,76(2):365-375
Previously, we reported that ten strains belonging to Erythrobacter showed epoxide hydrolase (EHase) activities toward various epoxide substrates. Three genes encoding putative EHases were
identified by analyzing open reading frames of Erythrobacter litoralis HTCC2594. Despite low similarities to reported EHases, the phylogenetic analysis of the three genes showed that eeh1 was similar to microsomal EHase, while eeh2 and eeh3 could be grouped with soluble EHases. The three EHase genes were cloned, and the recombinant proteins (rEEH1, rEEH2, and
rEEH3) were purified. The functionality of purified proteins was proved by hydrolytic activities toward styrene oxide. EEH1
preferentially hydrolyzed (R)-styrene oxide, whereas EEH3 preferred to hydrolyze (S)-styrene oxide, representing enantioselective hydrolysis of styrene oxide. On the other hand, EEH2 could hydrolyze (R)- and (S)-styrene oxide at an equal rate. The optimal pH and temperature for the EHases occurred largely at neutral pHs and 40–55
°C. The substrate selectivity of rEEH1, rEEH2, and rEEH3 toward various epoxide substrates were also investigated. This is
the first representation that a strict marine microorganism possessed three EHases with different enantioselectivity toward
styrene oxide. 相似文献
18.
We describe the ability of carboxydotrophic bacteria for nitrate respiration or denitrification. Four out of fourteen strains examined could denitrify heterotrophically forming N2 (Pseudomonas carboxydoflava) or N2O (Pseudomonas carboxydohydrogena, Pseudomonas compransoris, and Pseudomonas gazotropha). Three carried out a heterotrophic nitrate respiration (Arthrobacter 11/x, Azomonas B1, and Azomonas C2). P. carboxydohydrogena could use H2 as electron donor for nitrate respiration under chemolithoautotrophic growth conditions. CO did not support denitrification or nitrate respiration of carboxydotrophic bacteria, although the free energy changes of the reactions would be sufficiently negative to allow growth. CO at 50 kPa was a weak inhibitor of N2O-reduction in carboxydotrophic and non-carboxydotrophic bacteria and decelerated denitrifying growth. Carboxydotrophic bacteria could utilize a wide range of N-sources. Results obtained with a plasmid-cured mutant of Pseudomonas carboxydovorans OM5 showed, that genes involved in nitrogen assimilation entirely reside on the chromosome. In the presence of an suitable electron donor, most carboxydotrophic bacteria could carry out a reduction of nitrate to nitrite that did not support growth and did not lead to the formation of ammonia.This article is dedicated to Professor Hans G. Schlegel on the occasion of his 65th birthday and in admiration for his élan and eternal idealism 相似文献
19.
Growth Characteristics and Substrate Specificity of Aerobic Photosynthetic Bacterium, Erythrobacter Sp. (OCh 114) 总被引:1,自引:0,他引:1
Optimal growth conditions and substrate specificity of the aerobicphotosynthetic bacterium, Erythrobacter sp. (OCh 114), wereinvestigated. Erythrobacter utilized 19 out of 26 substratestested, including several sugars and amino acids. Glycerol andlactate were the most effective as electron donors or carbonsources. Maximum growth was obtained at a salinity of about25, pH 89 and temperature 28°C in a glycerol-enrichedmedium. A suitable growth medium for Erythrobacter sp. (OCh114) is proposed. (Received October 18, 1985; Accepted January 10, 1986) 相似文献
20.
R. Max Wynn Dale F. Gaul Won-Ki Choi Robert W. Shaw David B. Knaff 《Photosynthesis research》1986,9(1-2):181-195
Cytochrome bc
1 complexes have been isolated from wild type Rhodopseudomonas viridis and Rhodospirillum rubrum and purified by affinity chromatography on cytochrome c-Sepharose 4B. Both complexes are largely free of bacteriochlorophyll and carotenoids and contain cytochromes b and c
1 in a 2:1 molar ratio. For the Rps. viridis complex, evidence has been obtained for two spectrally distinct b-cytochromes. The R. rubrum complex contains a Rieske iron-sulfur protein (present in approximately 1:1 molar ratio to cytochrome c
1) and catalyzes an antimycin A- and myxothiazol-sensitive electron transfer from duroquinol to equine cytochrome c or R. rubrum cytochrome c
2. Although an attempt to prepare a cytochrome bc
1 complex from the gliding green bacterium Chloroflexus aurantiacus was not successful, membranes isolated from phototrophically grown Cfl. aurantiacus were shown to contain a Rieske iron-sulfur protein and protoheme (the prosthetic group of b-type cytochromes).Dedicated to Prof. L.N.M. Duysens on the occasion of his retirement. 相似文献