Reaction center complex from an aerobic photosynthetic bacterium, Erythrobacter species OCh 114

Takamiya, Ken Ichiro; Iba, Koh; Okamura, Kazuo

doi:10.1016/0005-2728(87)90013-2

Cited by 33 publications

(25 citation statements)

References 21 publications

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“…While typical photosynthetic bacteria can grow under continuous light and anaerobiosis, the synthesis of the photosynthetic apparatus of ORS278 occurs only under cyclic illumination, and its photosynthetic activity requires aerobic conditions. The inability of aerobic photosynthetic bacteria to grow at the expense of light under anaerobic conditions has been related to the reduction of the primary electron acceptor because of the more positive value of its midpoint potential compared with those of the purple photosynthetic bacteria (29)(30)(31). However, in a recent report, Scharze et al (32) cast doubt on this interpretation, since they observed that the high value for the midpoint potential of the primary electron acceptor obtained for Roseobacter denitrificans (29) was due to lack of equilibration during the redox titration.…”

Section: Discussionmentioning

confidence: 99%

Effect of Bradyrhizobium photosynthesis on stem nodulation of Aeschynomene sensitiva

Giraud

Hannibal

Fardoux

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

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Some leguminous species of the genus Aeschynomene are specifically stem-nodulated by photosynthetic bradyrhizobia. To study the effect of bacterial photosynthesis during symbiosis, we generated a photosynthesis-negative mutant of the Bradyrhizobium sp. strain ORS278 symbiont of Aeschynomene sensitiva. The presence of a functional photosynthetic unit in bacteroids and the high expression of the photosynthetic genes observed in stem nodules demonstrate that the bacteria are photosynthetically active during stem symbiosis. Stem inoculation by the photosynthetic mutant gave a 50% decrease in stem-nodule number, which reduced nitrogen fixation activity and plant growth in the same proportion. These results indicate an important role of bacterial photosynthesis in the efficiency of stem nodulation.R hizobia interact symbiotically with leguminous plants by inducing nitrogen-fixing nodules on the roots. Some plants of the genus Aeschynomene, encountered in waterlogged soils or riverbanks, have the peculiar property of forming stem nodules. This very unusual behavior among leguminous plants is shared only with a few species of the genera Sesbania, Neptunia, and Discolobium (1). Rhizobia isolated from Aeschynomene stem nodules exhibit a property uncommon among other rhizobia of developing a photosynthetic system (2, 3). This was first demonstrated in the case of a strain isolated from Aeschynomene indica stem nodules and designated BTAi 1 (2). In ex planta culture, BTAi 1 required a photoperiod for production and accumulation of bacteriochlorophyll a and exhibited a photoheterotrophic and strictly aerobic photosynthesis (4, 5). In this respect, the photosynthetic activity of the bacteriochlorophyll-containing rhizobia most closely resembles that of the aerobic anoxygenic photosynthetic bacteria (6, 7).Since the discovery of BTAi 1, several other rhizobia isolated from Aeschynomene stem nodules have been reported to produce bacteriochlorophyll a (8 -13). These photosynthetic Aeschynomene rhizobia were shown to form a separate subbranch of the Bradyrhizobium rRNA lineage, distinct from Bradyrhizobium japonicum and Bradyrhizobium elkanii (13). All photosynthetic strains were shown to nodulate stem-nodulating Aeschynomene species specifically (13), indicating that the photosynthetic character of these rhizobia could play an important role during this unusual symbiosis. The demonstration by Evans et al. (4) that illumination of the stem nodules of A. indica by far-red light consistently accelerated acetylene reduction and the report of Fleischman and Kramer (3) on the presence of bacteriochlorophyll a in bacteroids isolated from stem nodules of Aeschynomene aspera provide further evidence for the importance of the photochemical activity of the endophytes in the stem nodules. However, no genetic study has determined the real contribution of the bacterial photosynthesis in the symbiotic interaction and its impact on plant growth.In purple bacteria, most of the genes required for the formation of the photosystem are clustered in...

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Section: Discussionmentioning

confidence: 99%

Effect of Bradyrhizobium photosynthesis on stem nodulation of Aeschynomene sensitiva

Giraud

Hannibal

Fardoux

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

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“…In addition to these traits, the ABC bacteria share a number of common characteristics, such as aerobic chemoorganotrophy as the preferred mode of growth, low levels of BChls, and strong inhibition by light of BChl synthesis under normal growth conditions. Moreover, fully active reaction center and LH 1 complexes with BChl are present in all the species studied so far (Nishimura et al, 1996;Takamiya et al, 1987;. Peripheral antenna (LH 2) complexes are absent in most species.…”

Section: Overview Of Aerobic Bacteriochlorophyll-containing (Abc) Bacmentioning

confidence: 94%

Aerobic anoxygenic photosynthetic bacteria with zinc-bacteriochlorophyll.

Hiraishi

Shimada

2001

J. Gen. Appl. Microbiol.

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IntroductionChlorophylls (Chls) and bacteriochlorophylls (BChls) are porphyrin derivatives chelated with magnesium, and represent a class of lipophilic pigments involved in natural photosynthesis. There has been no rational explanation for why extant phototrophic organisms have used Mg exclusively as the central metal with which the chlorophyllous pigments are complexed. Apart from this question, phototrophic organisms that use Chls or BChls containing metals other than Mg were unknown for a long time. Recently, this common understanding of natural photosynthesis was unexpectedly modified by the new finding that a novel purple pigment, zinc-chelated-BChl (Zn-BChl) (for abbreviations, see Takaichi et al. (1999)), was discovered in a specific group of obligately aerobic bacteria (Hiraishi et al., 1998;Wakao et al., 1996Wakao et al., , 1999.It has been satisfactorily demonstrated that BChls are present not only in facultatively and obligately anaerobic anoxygenic phototrophic bacteria but also in large numbers of species of obligately aerobic bacteria Naturally occurring chlorophyllous pigments, which function as the cofactor in the early photochemical reaction of photosynthesis, have been proven beyond question to be magnesium-complexed porphyrin derivatives. Phototrophic organisms that use (bacterio)chlorophylls ([B]Chls)containing metals other than Mg were unknown for a long time. This common knowledge of natural photosynthesis has recently been modified by the striking finding that a novel purple pigment, zinc-chelated-BChl (Zn-BChl) a, is present as the major and functional pigment in species of the genus Acidiphilium. Acidiphilium species are obligately acidophilic chemoorganotrophic bacteria that grow and produce photopigments only under aerobic conditions. Although the mechanism of photosynthesis with Zn-BChl a in Acidiphilium species is similar to that seen in common purple bacteria, some characteristic photosynthetic features of the acidophilic bacteria are also found. The discovery of natural photosynthesis with Zn-BChl has not only provided a new insight into our understanding of bacterial photosynthesis but also raised some interesting questions to be clarified. The major questions are why the acidophilic bacteria have selected ZnBChl for their photosynthesis and how they synthesize Zn-BChl and express photosynthetic activity with it in their natural habitats. In this article we review the current knowledge of the biology of Acidiphilium as aerobic photosynthetic bacteria with Zn-BChl a and discuss the interesting topics noted above.

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“…Photoautotrophic growth under anaerobic or aerobic conditions has not been shown in these organisms, although some organisms may be photoheterotrophic under a limited range of cultivation conditions (Takamiya et al, 1987). Many of these organisms are exclusively chemoorganotrophic, leading to the view that the organisms are photoheterotrophic under unknown growth conditions.…”

Section: Introductionmentioning

confidence: 99%

Porphyrobacter cryptus sp. nov., a novel slightly thermophilic, aerobic, bacteriochlorophyll a-containing species

Rainey

Silva

Nobre

et al. 2003

International Journal of Systematic and Evolutionary Microbiology

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Two strains of a novel aerobic, bacteriochlorophyll a-containing species of the a-4 subclass of the Proteobacteria were isolated from the hot spring at Alcafache in central Portugal. 16S rRNA gene sequence-based phylogenetic analyses showed the two novel isolates to be phylogenetically related to members of the genera Erythrobacter, Erythromicrobium and Porphyrobacter. The strains produce reddish-orange-pigmented colonies, have an optimum growth temperature of about 50˚C and could be distinguished from the species Porphyrobacter tepidarius, which also has a high growth temperature, primarily on the basis of the fatty acid composition. The novel species does not grow anaerobically in the presence or absence of a light source. The strains of the novel species utilize several single carbon sources for growth, most of which are also used by P. tepidarius. The species status of strains ALC-2 T and ALC-3 was confirmed by low reassociation values of the DNA with species of the genera Erythrobacter, Erythromicrobium and Porphyrobacter. Phenotypic characteristics and 16S rRNA gene sequence analyses also show that strains ALC-2 T (=DSM 12079 T =ATCC BAA-386 T ) and ALC-3 (=DSM 12080) represent a novel species, for which the name Porphyrobacter cryptus sp. nov. is proposed. INTRODUCTIONMany species within the a-subclass of the Proteobacteria synthesize bacteriochlorophyll a (Bchl a) under aerobic conditions. Photoautotrophic growth under anaerobic or aerobic conditions has not been shown in these organisms, although some organisms may be photoheterotrophic under a limited range of cultivation conditions (Takamiya et al., 1987). Many of these organisms are exclusively chemoorganotrophic, leading to the view that the organisms are photoheterotrophic under unknown growth conditions. The a-4 subclass of the Proteobacteria comprises the Bchl a-containing species of the genera Erythrobacter , 1997). The species Erythrobacter longus and Erythrobacter litoralis originate from marine samples, are slightly halophilic and multiply by binary fission. The species Erythromicrobium ramosum also grows by binary fission, but, as the name implies, this organism can form slightly branching cells. The species Porphyrobacter neustonensis, unlike the other Bchl a-synthesizing bacteria of the a-4 subclass of the Proteobacteria, produces unusual pleomorphic cells, some of which have stalk-like structures and reproduce by budding. The other species of this genus, Porphyrobacter tepidarius, produces short, ovoid, rod-shaped cells, divides by binary fission and has an optimum growth temperature of about 45-50˚C. Another species, invalidly described as 'Citromicrobium bathyomarinum', was isolated from an abyssal hot-spring plume, is mesophilic, yellow-pigmented, contains Bchl a under aerobic growth and forms pleomorphic cells that resemble those of Erythromicrobium ramosum (Yurkov et al., 1999). Other strains closely related to the genera Erythrobacter, Erythromicrobium and Porphyrobacter Abbreviation: Bchl a, bacteriochlorophyll a.The GenBank/EMBL/...

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Reaction center complex from an aerobic photosynthetic bacterium, Erythrobacter species OCh 114

Cited by 33 publications

References 21 publications

Effect of Bradyrhizobium photosynthesis on stem nodulation of Aeschynomene sensitiva

Effect of Bradyrhizobium photosynthesis on stem nodulation of Aeschynomene sensitiva

Aerobic anoxygenic photosynthetic bacteria with zinc-bacteriochlorophyll.

Porphyrobacter cryptus sp. nov., a novel slightly thermophilic, aerobic, bacteriochlorophyll a-containing species

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