Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| isolation and characterization of biliprotein aggregates from acaryochloris marina, a prochloron-like prokaryote containing mainly chlorophyll d. | phycobiliprotein aggregates were isolated from the prokaryote acaryochloris marina, containing chlorophyll d as major pigment. in the electron microscope the biliprotein aggregates appear as rod-shaped structures of 26.0 x 11.3 nm, composed of four ring-shaped subunits 5.8 nm thick and 11.7 nm in diameter. spectral data indicate that the aggregates contain two types of biliproteins: phycocyanin and an allophycocyanin-type pigment, with very efficient energy transfer from the phycocyanin- to allo ... | 1997 | 9237676 |
| light-harvesting in acaryochloris marina--spectroscopic characterization of a chlorophyll d-dominated photosynthetic antenna system. | oxygenic photosynthesis of the prokaryote acaryochloris marina involves chlorophyll d (chl d) as the major pigment [miyashita et al. (1996) nature 383, 402]. four spectral forms of chl d (peak wavelengths: 694, 714, 726 and 740 nm) are resolvable by low-temperature absorption spectroscopy on intact cells. based on fluorescence spectra (at 290 k and 77 k) and on analysis of fluorescence induction curves we conclude: (1) excitation energy is efficiently transferred between the various spectral for ... | 1997 | 9237677 |
| a photosystem i reaction center driven by chlorophyll d in oxygenic photosynthesis. | a far-red type of oxygenic photosynthesis was discovered in acaryochloris marina, a recently found marine prokaryote that produces an atypical pigment chlorophyll d (chl d). the purified photosystem i reaction center complex of a. marina contained 180 chl d per 1 chl a with psaa-f, -l, -k, and two extra polypeptides. laser excitation induced absorption changes of reaction center chl d that was named p740 after its peak wavelength. a midpoint oxidation reduction potential of p740 was determined t ... | 1998 | 9789086 |
| fluorescence properties of chlorophyll d-dominating prokaryotic alga, acaryochloris marina: studies using time-resolved fluorescence spectroscopy on intact cells | antenna components and the primary electron donor of the photosystem (ps) ii in the chlorophyll (chl) d-dominating prokaryote, acaryochloris marina, were studied using time-resolved fluorescence spectroscopy in the ps time range. by selective excitation of chl a or chl d, differences in fluorescence properties were clearly resolved. at physiological temperature, energy transfer was confirmed by a red shift of emission maximum among ps ii antenna components, and the equilibrium of energy distribu ... | 1999 | 10354492 |
| molecular structure, localization and function of biliproteins in the chlorophyll a/d containing oxygenic photosynthetic prokaryote acaryochloris marina. | we investigated the localization, structure and function of the biliproteins of the oxygenic photosynthetic prokaryote acaryochloris marina, the sole organism known to date that contains chlorophyll d as the predominant photosynthetic pigment. the biliproteins were isolated by means of sucrose gradient centrifugation, ion exchange and gel filtration chromatography. up to six biliprotein subunits in a molecular mass range of 15.5-18.4 kda were found that cross-reacted with antibodies raised again ... | 1999 | 10482787 |
| uphill energy transfer in a chlorophyll d-dominating oxygenic photosynthetic prokaryote, acaryochloris marina. | the steady-state fluorescence properties and uphill energy transfer were analyzed on intact cells of a chlorophyll (chl) d-dominating photosynthetic prokaryote, acaryochloris marina. observed spectra revealed clear differences, depending on the cell pigments that had been sensitized; using these properties, it was possible to assign fluorescence components to specific chl pigments. at 22 degrees c, the main emission at 724 nm came from photosystem (ps) ii chl d, which was also the source of one ... | 2000 | 10611453 |
| ultrastructure of acaryochloris marina, an oxyphotobacterium containing mainly chlorophyll d. | we present a detailed investigation of the ultrastructure of the chlorophyll a/d-containing unicellular oxyphotobacterium acaryochloris marina, combining light and transmission electron microscopy and showing freeze fractures of this organism for the first time. the cells were 1.8-2.1 microm x 1.5-1.7 microm in size. the cell envelope consisted of a peptidoglycan layer of approximately 10 nm thickness combined with an outer membrane. cell division was intermediate between the constrictive and th ... | 2000 | 11041349 |
| modification of photosystem i reaction center by the extraction and exchange of chlorophylls and quinones. | the photosystem (ps) i photosynthetic reaction center was modified thorough the selective extraction and exchange of chlorophylls and quinones. extraction of lyophilized photosystem i complex with diethyl ether depleted more than 90% chlorophyll (chl) molecules bound to the complex, preserving the photochemical electron transfer activity from the primary electron donor p700 to the acceptor chlorophyll a(0). the treatment extracted all the carotenoids and the secondary acceptor phylloquinone (a(1 ... | 2001 | 11687211 |
| the major light-harvesting pigment protein of acaryochloris marina. | the major light-harvesting protein complex containing chlorophyll (chl) d was isolated from acaryochloris marina thylakoid membranes. isolation was achieved by detergent solubilisation followed by separation on 6-40% sucrose gradients using ultracentrifugation. the best chl d yield (70%) used 0.3% dodecyl maltoside, 0.15% octyl glucoside, 0.05% zwittergent 3-14 with the detergent:total chl d ratio around 10:1 (w/w). characterisation of the light-harvesting pigment protein complex (lhc) involved ... | 2002 | 11943141 |
| detection of chlorophyll d' and pheophytin a in a chlorophyll d-dominating oxygenic photosynthetic prokaryote acaryochloris marina. | 2001 | 11993664 | |
| energy equilibration and primary charge separation in chlorophyll d-based photosystem i reaction center isolated from acaryochloris marina. | primary photochemistry in photosystem i (ps i) reaction center complex from acaryochloris marina that uses chlorophyll d instead of chlorophyll a has been studied with a femtosecond spectroscopy. upon excitation at 630 nm, almost full excitation equilibration among antenna chlorophylls and 40% of the excitation quenching by the reaction center are completed with time constants of 0.6(+/-0.1) and 4.9(+/-0.6) ps, respectively. the rise and decay of the primary charge-separated state proceed with a ... | 2002 | 12387884 |
| raman spectroscopy of chlorophyll d from acaryochloris marina. | the raman spectroscopy of chlorophyll (chl) d isolated from acaryochloris marina has been measured in the range of 250-3200 cm(-1) at 77 k following excitation of its b(x) band at 488 nm. a peak at 1659 cm(-1) of medium intensity arising from cz=o stretching vibration in the formyl group 3(1) specific to chl d was observed clearly. peaks due to other cz=o stretching vibrations of the 13(1) keto-, 13(3) ester- and 17(3) groups have also been observed with much weaker intensities. intense raman pe ... | 2002 | 12460664 |
| examination of the photophysical processes of chlorophyll d leading to a clarification of proposed uphill energy transfer processes in cells of acaryochloris marinas. | a comprehensive study of the photophysical properties of chlorophyll (chl) d in 1:40 acetonitrile-methanol solution is performed over the temperature range 170-295 k. from comparison of absorption and emission spectra, time-dependent density-functional calculations and homologies with those of chl a, we assign the key features of the absorption and fluorescence spectra. possible photophysical energy relaxation mechanisms are summarized, and thermal equilibration processes are studied in detail b ... | 2003 | 12870849 |
| photo-oxidation of p740, the primary electron donor in photosystem i from acaryochloris marina. | fourier transform infrared spectroscopy (ftir) difference spectroscopy in combination with deuterium exchange experiments has been used to study the photo-oxidation of p740, the primary electron donor in photosystem i from acaryochloris marina. comparison of (p740(+)-p740) and (p700(+)-p700) ftir difference spectra show that p700 and p740 share many structural similarities. however, there are several distinct differences also: 1), the (p740(+)-p740) ftir difference spectrum is significantly alte ... | 2003 | 14581216 |
| identification of the primary electron donor in ps ii of the chl d-dominated cyanobacterium acaryochloris marina. | the primary electron donor of photosystem (ps) ii in the chlorophyll (chl) d-dominated cyanobacterium acaryochloris marina was confirmed by delayed fluorescence (df) and further proved by pigment contents of cells grown under several light intensities. the df was found only in the chl a region, identical to synechocystis sp. pcc 6803, and disappeared following heat treatment. pigment analyses indicated that at least two chl a molecules were present per each two pheophytin a molecules, and these ... | 2004 | 14706833 |
| raman properties of chlorophyll d, the major pigment of acaryochloris marina: studies using both raman spectroscopy and density functional theory. | the raman spectroscopy of purified chlorophyll (chl) d extracted from acaryochloris marina has been measured over the wide region of 250-3200 cm(-1) at 77 k following excitation of its soret band at 488 nm and analyzed with the aid of hybrid density-functional vibrational analyses. a raman peak specific to chl d, which arises from the formyl group 3(1) c=o stretching, was clearly observed at 1659 cm(-1) with medium intensity. peaks due to other c=o stretching vibrations of the 13(1) keto-, 13(3) ... | 2004 | 14747075 |
| unique origin and lateral transfer of prokaryotic chlorophyll-b and chlorophyll-d light-harvesting systems. | pcb genes, encoding proteins binding light-harvesting chlorophylls, were cloned and sequenced from the chl d-containing cyanobacterium, acaryochloris marina, and the chl b-containing cyanobacterium, prochloron didemni. both organisms contained two tandem pcb genes. peptide fingerprinting confirmed the expression of one of the a. marina pcb genes. phylogenetic tree reconstruction using distance-matrix and maximum-likelihood methods indicated a single origin of the pcb gene family, whether occurri ... | 2005 | 15356274 |
| structure of a large photosystem ii supercomplex from acaryochloris marina. | acaryochloris marina is a prochlorophyte-like cyanobacterium containing both phycobilins and chlorophyll d as light harvesting pigments. we show that the chlorophyll d light harvesting system, composed of pcb proteins, functionally associates with the photosystem ii (psii) reaction center (rc) core to form a giant supercomplex. this supercomplex has a molecular mass of about 2300 kda and dimensions of 385 a x 240 a. it is composed of two psii-rc core dimers arranged end-to-end, flanked by eight ... | 2005 | 15710430 |
| ecology: a niche for cyanobacteria containing chlorophyll d. | the cyanobacterium known as acaryochloris marina is a unique phototroph that uses chlorophyll d as its principal light-harvesting pigment instead of chlorophyll a, the form commonly found in plants, algae and other cyanobacteria; this means that it depends on far-red light for photosynthesis. here we demonstrate photosynthetic activity in acaryochloris-like phototrophs that live underneath minute coral-reef invertebrates (didemnid ascidians) in a shaded niche enriched in near-infrared light. thi ... | 2005 | 15729331 |
| iron deficiency induces a chlorophyll d-binding pcb antenna system around photosystem i in acaryochloris marina. | the prochlorophyte-like cyanobacterium acaryochloris marina contains two pcb genes, pcba and pcbc, which encode chlorophyll (chl) d-binding antenna proteins pcba and pcbc, respectively. using real-time reverse transcriptase polymerase chain reaction (rt-pcr), it is shown that when acaryochloris cells are grown in an iron-deficient medium, the transcription of the pcbc gene is up-regulated compared to that of pcba. biochemical and immunological analyses indicated that under the same iron-deficien ... | 2005 | 15975547 |
| pigment exchange of photosystem ii reaction center by chlorophyll d. | pigment exchanges among photosystem reaction centers (rcs) are useful for the identification and functional analysis of chromophores in photosynthetic organisms. pigment replacement within the spinach photosystem ii rc was performed with chl d derived from the oxygenic alga acaryochloris marina, using a protocol similar to that reported previously [gall et al. (1998) febs lett 434: 88-92] based on the incubation of reaction centers with an excess of other pigments. in this study, we analyzed chl ... | 2005 | 16049758 |
| minor but key chlorophylls in photosystem ii. | a 'metal-free' chlorophyll (chl) a, pheophytin (phe) a, functions as the primary electron acceptor in ps ii. on the basis of phe a/ps ii = 2, phe a content is postulated as an index for estimation of the stoichiometry of pigments and photosystems. we found phe a in a chl d-dominant cyanobacterium acaryochloris marina, whereas phe d was absent. the minimum chl a:phe a ratio was 2:2, indicating that the primary electron donor is chl a, accessory is chl d, and the primary electron acceptor is phe a ... | 2005 | 16049775 |
| spectroscopic studies of photosystem ii in chlorophyll d-containing acaryochloris marina. | photosystem ii (psii) electron transfer (et) in the chlorophyll d-containing cyanobacterium acaryochloris marina (a. marina) was studied by time-resolved electron paramagnetic resonance (epr) spectroscopy at room temperature, chlorophyll fluorescence, and low-temperature optical spectroscopy. to maximize the ability to measure psii et in the intact cells of this organism, growth conditions were optimized to provide the highest specific o(2) activity and the instrumental parameters for the epr me ... | 2005 | 16101302 |
| functional characteristics of chlorophyll d-predominating photosynthetic apparatus in intact cells of acaryochloris marina. | functional organization of the photosynthetic apparatus in the unique chlorophyll d-predominating prokaryote, acaryochloris marina, was studied using polarographic measurements of single-turnover flash yields, action spectra and optical cross sections for ps-specific reactions. o(2) evolution was indicative of ps ii activity, while reversible photoinhibition of respiratory o(2) uptake under aerobic conditions in the presence of dcmu and h(2) photoevolution by anaerobically adapted cells were the ... | 2000 | 16228493 |
| quest for minor but key chlorophyll molecules in photosynthetic reaction centers - unusual pigment composition in the reaction centers of the chlorophyll d-dominated cyanobacterium acaryochloris marina. | a short overview, based on our own findings, is given of the minor pigments that function as key components in photosynthesis. recently, we found the presence of chlorophyll a, chlorophyll d' and pheophytin a as minor pigments in the chlorophyll d-dominated cyanobacterium acaryochloris marina. | 2002 | 16228548 |
| excitation energy transfer from phycobiliprotein to chlorophyll d in intact cells of acaryochloris marina studied by time- and wavelength-resolved fluorescence spectroscopy. | the fluorescence decay spectra and the excitation energy transfer from the phycobiliproteins (pbp) to the chlorophyll-antennae of intact cells of the chlorophyll (chl) d-dominated cyanobacterium acaryochloris marina were investigated at 298 and 77 k by time- and wavelength-correlated single photon counting fluorescence spectroscopy. at 298 k it was found that (i) the fluorescence dynamics in a. marina is characterized by two emission peaks located at about 650 and 725 nm, (ii) the intensity of t ... | 2005 | 16307116 |
| the nature of the photosystem ii reaction centre in the chlorophyll d-containing prokaryote, acaryochloris marina. | pigment-protein complexes enriched in photosystem ii (ps ii) have been isolated from the chlorophyll (chl) d containing cyanobacterium, acaryochloris marina. a small ps ii-enriched particle, we call 'crude reaction centre', contained 20 chl d, 0.5 chl a and 1 redox active cytochrome b-559 per 2 pheophytin a, plus the d1 and d2 proteins. a larger ps ii-enriched particle, we call 'core', additionally bound the antenna complexes, cp47 and cp43, and had a higher chlorophyll per pheophytin ratio. phe ... | 2005 | 16307123 |
| effect of iron on growth and ultrastructure of acaryochloris marina. | the cyanobacterial genus acaryochloris is the only known group of oxygenic phototrophs that contain chlorophyll d rather than chlorophyll a as the major photosynthetic pigment. studies on this organism are still in their earliest stages, and biochemical analysis has rapidly outpaced growth optimization. we have investigated culture growth of the major strains of acaryochloris marina (mbic11017 and mbic10697) by using several published and some newly developed growth media. it was determined that ... | 2005 | 16332853 |
| stereochemical determination of chlorophyll-d molecule from acaryochloris marina and its modification to a self-aggregative chlorophyll as a model of green photosynthetic bacterial antennae. | acaryochloris marina is a unique photosynthetic prokaryote containing chlorophyll(chl)-d as a major photoactive pigment (over 95%). the molecular structure of chl-d is proposed as the 3-formyl analog of chl-a. however, the stereochemistry of chl-d at the 13(2)-, 17- and 18-positions has not yet been established unambiguously. in the first part of this paper, we describe the determination of their stereochemistries to be 13(2)-(r)-, 17-(s)- and 18-(s)-configurations by using 1h-1h noe correlation ... | 2006 | 16520864 |
| consistent sets of spectrophotometric chlorophyll equations for acetone, methanol and ethanol solvents. | a set of equations for determining chlorophyll a (chl a) and accessory chlorophylls b, c2, c1 + c2 and the special case of acaryochloris marina, which uses chl d as its primary photosynthetic pigment and also has chl a, have been developed for 90% acetone, methanol and ethanol solvents. these equations for different solvents give chlorophyll assays that are consistent with each other. no algorithms for chl c compounds (c2, c1 + c2) in the presence of chl a have previously been published for meth ... | 2006 | 16763878 |
| characterization of the water oxidizing complex of photosystem ii of the chl d-containing cyanobacterium acaryochloris marina via its reactivity towards endogenous electron donors and acceptors. | acaroychloris (a.) marina is a unique oxygen evolving organism that contains a large amount of chlorophyll d (chl d) and only very few chl a molecules. this feature raises questions on the nature of the photoactive pigment, which supports light-induced oxidative water splitting in photosystem ii (ps ii). in this study, flash-induced oxygen evolution patterns (fiops) were measured to address the question whether the s(i) state transition probabilities and/or the redox-potentials of the water oxid ... | 2006 | 16855726 |
| molecular detection of epiphytic acaryochloris spp. on marine macroalgae. | a molecular method for detecting the epiphyte community on marine macroalgae was developed by using pcr-denaturing gradient gel electrophoresis. selective amplification of 16s rrna gene fragments from either cyanobacteria or algal plastids improved the detection of minor epiphytes. two phylotypes of acaryochloris, a chlorophyll d-containing cyanobacterium, were found not only on red macroalgae but also on green and brown macroalgae. | 2006 | 17028237 |
| chromatic photoacclimation, photosynthetic electron transport and oxygen evolution in the chlorophyll d-containing oxyphotobacterium acaryochloris marina. | changes in photosynthetic pigment ratios showed that the chlorophyll d-dominated oxyphotobacterium acaryochloris marina was able to photoacclimate to different light regimes. chl d per cell were higher in cultures grown under low irradiance and red or green light compared to those found when grown under high white light, but phycocyanin/chl d and carotenoid/chl d indices under the corresponding conditions were lower. chl a, considered an accessory pigment in this organism, decreased respective t ... | 2007 | 17223068 |
| theoretical study on the thermodynamic properties of chlorophyll d-peptides coordinating ligand. | the chlorophyll d containing cyanobacterium, acaryochloris marina has provided a model system for the study of chlorophyll replacement in the function of oxygenic photosynthesis. chlorophyll d replaces most functions of chlorophyll a in acaryochloris marina. it not only functions as the major light-harvesting pigment, but also acts as an electron transfer cofactor in the primary charge separation reaction in the two photosystems. the mg-chlorophyll d-peptide coordinating interaction between the ... | 2007 | 17306215 |
| ultrastructural and genetic characteristics of endolithic cyanobacterial biofilms colonizing antarctic granite rocks. | the precise identification of the cyanobacteria that comprise an endolithic biofilm is hindered by difficulties in culturing the organisms found in these biofilms and a lack of previous molecular and ultrastructural data. this study characterizes, both at the ultrastructural and molecular level, two different cyanobacterial biofilms found in fissures of granite from continental antarctica. electron microscopy revealed structural differences between the two biofilms. one was only loosely adhered ... | 2007 | 17328119 |
| an electron paramagnetic resonance investigation of the electron transfer reactions in the chlorophyll d containing photosystem i of acaryochloris marina. | electron paramagnetic resonance (epr) spectroscopy reveals functional and structural similarities between the reaction centres of the chlorophyll d-binding photosystem i (ps i) and chlorophyll a-binding ps i. continuous wave epr spectrometry at 12k identifies iron-sulphur centres as terminal electron acceptors of chlorophyll d-binding ps i. a transient light-induced electron spin echo (ese) signal indicates the presence of a quinone as the secondary electron acceptor (q) between p(740)(+) and th ... | 2007 | 17382323 |
| redox potential of chlorophyll d in vitro. | chlorophyll (chl) d is a major chlorophyll in a novel oxygenic prokaryote acaryochloris marina. here we first report the redox potential of chl d in vitro. the oxidation potential of chl d was +0.88 v vs. she in acetonitrile; the value was higher than that of chl a (+0.81 v) and lower than that of chl b (+0.94 v). the oxidation potential order, chl b>chl d>chl a, can be explained by inductive effect of substituent groups on the conjugated pi-electron system on the macrocycle. corresponding pheop ... | 2007 | 17418087 |
| both chlorophylls a and d are essential for the photochemistry in photosystem ii of the cyanobacteria, acaryochloris marina. | we have measured the flash-induced absorbance difference spectrum attributed to the formation of the secondary radical pair, p(+)q(-), between 270 nm and 1000 nm at 77 k in photosystem ii of the chlorophyll d containing cyanobacterium, acaryochloris marina. despite the high level of chlorophyll d present, the flash-induced absorption difference spectrum of an approximately 2 ms decay component shows a number of features which are typical of the difference spectrum seen in oxygenic photosynthetic ... | 2007 | 17428440 |
| identification of the special pair of photosystem ii in a chlorophyll d-dominated cyanobacterium. | the composition of photosystem ii (psii) in the chlorophyll (chl) d-dominated cyanobacterium acaryochloris marina mbic 11017 was investigated to enhance the general understanding of the energetics of the psii reaction center. we first purified photochemically active complexes consisting of a 47-kda chl protein (cp47), cp43' (pcbc), d1, d2, cytochrome b(559), psbi, and a small polypeptide. the pigment composition per two pheophytin (phe) a molecules was 55 +/- 7 chl d, 3.0 +/- 0.4 chl a, 17 +/- 3 ... | 2007 | 17431035 |
| pigment composition and adaptation in free-living and symbiotic strains of acaryochloris marina. | acaryochloris marina strains have been isolated from several varied locations and habitats worldwide demonstrating a diverse and dynamic ecology. in this study, the whole cell photophysiologies of strain mbic11017, originally isolated from a colonial ascidian, and the free-living epilithic strain ccmee5410 are analyzed by absorbance and fluorescence spectroscopy, laser scanning confocal microscopy, sodium dodecyl sulfate polyacrylamide gel electrophoresis and subsequent protein analysis. we demo ... | 2007 | 17466026 |
| the fast and slow kinetics of chlorophyll a fluorescence induction in plants, algae and cyanobacteria: a viewpoint. | the light-induced/dark-reversible changes in the chlorophyll (chl) a fluorescence of photosynthetic cells and membranes in the mus-to-several min time window (fluorescence induction, fi; or kautsky transient) reflect quantum yield changes (quenching/de-quenching) as well as changes in the number of chls a in photosystem ii (ps ii; state transitions). both relate to excitation trapping in ps ii and the ensuing photosynthetic electron transport (pset), and to secondary pset effects, such as ion tr ... | 2007 | 17665151 |
| vibrational mode frequency calculations of chlorophyll-d for assessing (p740(+)-p740) ftir difference spectra obtained using photosystem i particles from acaryochloris marina. | acaryochloris marina is an oxygen-evolving organism that utilizes chlorophyll-d for light induced photochemistry. in photosystem i particles from acaryochloris marina, the primary electron donor is called p740, and it is thought that p740 consist of two chlorophyll-d molecules. (p740(+)-p740) ftir difference spectra have been produced, and vibrational features that are specific to chlorophyll-d (and not chlorophyll-a) were observed, supporting the idea that p740 consists chlorophyll-d molecules. ... | 2008 | 17710563 |
| function of chlorophyll d in reaction centers of photosystems i and ii of the oxygenic photosynthesis of acaryochloris marina. | reaction center chlorophylls (chls) in photosystems ii and i were studied in the isolated thylakoid membranes of a cyanobacterium, acaryochloris marina, which contains chls d and a as the major and minor pigments, respectively. the membranes contained ps i and ii complexes at a 1.8:1 molar ratio on the basis of the spin densities on the tyrosine d radical and the photo-oxidized ps i primary donor (p740+). in the presence of ferricyanide, laser excitation induced bleach at 725 nm that recovered w ... | 2007 | 17918957 |
| niche adaptation and genome expansion in the chlorophyll d-producing cyanobacterium acaryochloris marina. | acaryochloris marina is a unique cyanobacterium that is able to produce chlorophyll d as its primary photosynthetic pigment and thus efficiently use far-red light for photosynthesis. acaryochloris species have been isolated from marine environments in association with other oxygenic phototrophs, which may have driven the niche-filling introduction of chlorophyll d. to investigate these unique adaptations, we have sequenced the complete genome of a. marina. the dna content of a. marina is compose ... | 2008 | 18252824 |
| fitting light saturation curves measured using modulated fluorometry. | a blue diode pam (pulse amplitude modulation) fluorometer was used to measure rapid photosynthesis (p) versus irradiance (e) curves (p vs. e curves) in synechococcus (classical cyanobacteria), prochlorothrix (prochlorophyta), chlorella (chlorophyta), rhodomonas (cryptophyta), phaeodactylum (bacillariophyta) acaryochloris (chl d/a cyanobacteria) and subterranean clover (trifolium subterraneum, papilionaceae, angiospermae). effective quantum yield (phi(psii)) versus irradiance curves could be desc ... | 2008 | 18415696 |
| characterization of highly purified photosystem i complexes from the chlorophyll d-dominated cyanobacterium acaryochloris marina mbic 11017. | photochemically active photosystem (ps) i complexes were purified from the chlorophyll (chl) d-dominated cyanobacterium acaryochloris marina mbic 11017, and several of their properties were characterized. ps i complexes consist of 11 subunits, including psak1 and psak2; a new small subunit was identified and named psa27. the new subunit might replace the function of psai that is absent in a. marina. the amounts of pigments per one molecule of chl d' were 97.0 +/- 11.0 chl d, 1.9 +/- 0.5 chl a, 2 ... | 2008 | 18458090 |
| the primary electron donor of photosystem ii of the cyanobacterium acaryochloris marina is a chlorophyll d and the water oxidation is driven by a chlorophyll a/chlorophyll d heterodimer. | we present a theoretical analysis of the flash-induced absorbance difference spectrum assigned to the formation of the secondary radical pair p(+)qa(-) in photosystem ii of the chlorophyll d-containing cyanobacterium acaryochloris marina. an exciton hamiltonian determined previously for chlorophyll a-containing photosystem ii complexes is modified to take into account the occupancy of certain binding sites by chlorophyll d instead of chlorophyll a. different assignments of the reaction center pi ... | 2008 | 18512893 |
| two unique cyanobacteria lead to a traceable approach of the first appearance of oxygenic photosynthesis. | the evolutionary route from anoxygenic photosynthetic bacteria to oxygenic cyanobacteria is discontinuous in terms of photochemical/photophysical reaction systems. it is difficult to describe this transition process simply because there are no recognized intermediary organisms between the two bacterial groups. gloeobacter violaceus pcc 7421 might be a model organism that is suitable for analysis because it still possesses primordial characteristics such as the absence of thylakoid membranes. who ... | 2008 | 18568415 |
| the thermodynamics and kinetics of electron transfer between cytochrome b6f and photosystem i in the chlorophyll d-dominated cyanobacterium, acaryochloris marina. | we have investigated the photosynthetic properties of acaryochloris marina, a cyanobacterium distinguished by having a high level of chlorophyll d, which has its absorption bands shifted to the red when compared with chlorophyll a. despite this unusual pigment content, the overall rate and thermodynamics of the photosynthetic electron flow are similar to those of chlorophyll a-containing species. the midpoint potential of both cytochrome f and the primary electron donor of photosystem i (p(740)) ... | 2008 | 18635535 |
| spectroscopic studies of the chlorophyll d containing photosystem i from the cyanobacterium, acaryochloris marina. | absorbance difference spectroscopy and redox titrations have been applied to investigate the properties of photosystem i from the chlorophyll d containing cyanobacterium acaryochloris marina. at room temperature, the (p740(+)-p740) and (f(a/b)(-)-f(a/b)) absorbance difference spectra were recorded in the range between 300 and 1000 nm while at cryogenic temperatures, (p740(+)a(1)(-)-p740a(1)) and ((3)p740-p740) absorbance difference spectra have been measured. spectroscopic and kinetic evidence i ... | 2008 | 18817746 |
| energetics of photosystem ii charge recombination in acaryochloris marina studied by thermoluminescence and flash-induced chlorophyll fluorescence measurements. | we studied the charge recombination characteristics of photosystem ii (psii) redox components in whole cells of the chlorophyll (chl) d-dominated cyanobacterium, acaryochloris marina, by flash-induced chlorophyll fluorescence and thermoluminescence measurements. flash-induced chlorophyll fluorescence decay was retarded in the mus and ms time ranges and accelerated in the s time range in acaryochloris marina relative to that in the chl a-containing cyanobacterium, synechocystis pcc 6803. in the p ... | 2008 | 18839331 |
| unique photosystems in acaryochloris marina. | a short overview is given on the discovery of the chlorophyll d-dominated cyanobacterium acaryochloris marina and the minor pigments that function as key components therein. in photosystem i, chlorophyll d', chlorophyll a, and phylloquinone function as the primary electron donor, the primary electron acceptor and the secondary electron acceptor, respectively. in photosystem ii, pheophytin a serves as the primary electron acceptor. the oxidation potential of chlorophyll d was higher than that of ... | 2008 | 18985431 |
| determining the specific microbial populations and their spatial distribution within the stromatolite ecosystem of shark bay. | the stromatolites at shark bay, western australia, are analogues of some of the oldest evidence of life on earth. the aim of this study was to identify and spatially characterize the specific microbial communities associated with shark bay intertidal columnar stromatolites. conventional culturing methods and construction of 16s rdna clone libraries from community genomic dna with both universal and specific pcr primers were employed. the estimated coverage, richness and diversity of stromatolite ... | 2009 | 19092864 |
| evidence for an ionic intermediate in the transformation of fatty acid hydroperoxide by a catalase-related allene oxide synthase from the cyanobacterium acaryochloris marina. | allene oxides are reactive epoxides biosynthesized from fatty acid hydroperoxides by specialized cytochrome p450s or by catalase-related hemoproteins. here we cloned, expressed, and characterized a gene encoding a lipoxygenase-catalase/peroxidase fusion protein from acaryochloris marina. we identified novel allene oxide synthase (aos) activity and a by-product that provides evidence of the reaction mechanism. the fatty acids 18.4omega3 and 18.3omega3 are oxygenated to the 12r-hydroperoxide by th ... | 2009 | 19531485 |
| wide-field photon counting fluorescence lifetime imaging microscopy: application to photosynthesizing systems. | fluorescence lifetime imaging microscopy (flim) is a technique that visualizes the excited state kinetics of fluorescence molecules with the spatial resolution of a fluorescence microscope. we present a scanningless implementation of flim based on a time- and spacecorrelated single photon counting (tscspc) method employing a position-sensitive quadrant anode detector and wide-field illumination. the standard time-correlated photon counting approach leads to picosecond temporal resolution, making ... | 2009 | 19533411 |
| chromatic photoacclimation extends utilisable photosynthetically active radiation in the chlorophyll d-containing cyanobacterium, acaryochloris marina. | chromatic photoacclimation and photosynthesis were examined in two strains of acaryochloris marina (mbic11017 and ccmee5410) and in synechococcus pcc7942. acaryochloris contains chl d, which has an absorption peak at ca 710 nm in vivo. cultures were grown in one of the three wavelengths (525 nm, 625 nm and 720 nm) of light from narrow-band photodiodes to determine the effects on pigment composition, growth rate and photosynthesis: no growth occurred in 525 nm light. synechococcus did not grow in ... | 2009 | 19582591 |
| supramolecular organization of phycobiliproteins in the chlorophyll d-containing cyanobacterium acaryochloris marina. | here we report the high-resolution detail of the organization of phycobiliprotein structures associated with photosynthetic membranes of the chlorophyll d-containing cyanobacterium acaryochloris marina. cryo-electron transmission-microscopy on native cell sections show extensive patches of near-crystalline phycobiliprotein rods that are associated with the stromal side of photosynthetic membranes. this supramolecular photosynthetic structure represents a novel mechanism of organizing the photosy ... | 2009 | 19596002 |
| purification and characterization of cytochrome c(6) from acaryochloris marina. | cytochrome c(6), (cyt c(6)) a soluble monoheme electron transport protein, was isolated and characterized from the chlorophyll d-containing cyanobacterium acaryochoris marina, the type strain mbic11017. the protein was purified using ammonium sulfate precipitation, ion exchange and gel filtration column chromatography, and fast performance liquid chromatography. its molecular mass and pi have been determined to be 8.87 kda and less than 4.2, respectively, by mass spectrometry and isoelectrofocus ... | 2009 | 19680778 |
| omega-3 fatty acids are oxygenated at the n-7 carbon by the lipoxygenase domain of a fusion protein in the cyanobacterium acaryochloris marina. | lipoxygenases (lox) are found in most organisms that contain polyunsaturated fatty acids, usually existing as individual genes although occasionally encoded as a fusion protein with a catalase-related hemoprotein. such a fusion protein occurs in the cyanobacterium acaryochloris marina and herein we report the novel catalytic activity of its lox domain. the full-length protein and the c-terminal lox domain were expressed in escherichia coli, and the catalytic activities characterized by uv, hplc, ... | 2010 | 19786119 |
| incorporation of the chlorophyll d-binding light-harvesting protein from acaryochloris marina and its localization within the photosynthetic apparatus of synechocystis sp. pcc6803. | the gene encoding a chlorophyll d-binding light-harvesting protein, pcba from acaryochloris marina (now called as accessory chlorophyll binding protein cbpii) marked with a his-tag was transformed into the genome of synechocystis pcc6803. protein gel electrophoresis and western blotting confirmed that this foreign chlorophyll d-binding protein cbpii was expressed and integrated into the thylakoid membrane and bound with chlorophyll a, the only type of chlorophyll present in synechocystis pcc 680 ... | 2010 | 19854153 |
| timing of morphological and ecological innovations in the cyanobacteria--a key to understanding the rise in atmospheric oxygen. | when cyanobacteria originated and diversified, and what their ancient traits were, remain critical unresolved problems. here, we used a phylogenomic approach to construct a well-resolved 'core' cyanobacterial tree. the branching positions of four lineages (thermosynechococcus elongatus, synechococcus elongatus, synechococcus pcc 7335 and acaryochloris marina) were problematic, probably due to long branch attraction artifacts. a consensus genomic tree was used to study trait evolution using ances ... | 2010 | 19863595 |
| demetalation kinetics of natural chlorophylls purified from oxygenic photosynthetic organisms: effect of the formyl groups conjugated directly to the chlorin pi-macrocycle. | demetalation kinetics of natural chlorophyll (chl) d purified from acaryochloris marina was first studied and compared with those of chls a and b. the demetalation rate constant of chl d, which possessed a formyl group at the 3-position, was five-fold smaller than that of chl a possessing a vinyl group at the same position in aqueous acetone at the proton concentration of 1.2 x 10(-3) m at 25 degrees c. in contrast, the demetalation rate constant of chl b possessing a formyl group at the 7-posit ... | 2009 | 20024167 |
| redox potential of pheophytin a in photosystem ii of two cyanobacteria having the different special pair chlorophylls. | water oxidation by photosystem (ps) ii in oxygenic photosynthetic organisms is a major source of energy on the earth, leading to the production of a stable reductant. mechanisms generating a high oxidation potential for water oxidation have been a major focus of photosynthesis research. this potential has not been estimated directly but has been measured by the redox potential of the primary electron acceptor, pheophytin (phe) a. however, the reported values for phe a are still controversial. he ... | 2010 | 20142495 |
| genome-wide comparative analysis of metacaspases in unicellular and filamentous cyanobacteria. | cyanobacteria are an ancient group of photoautotrophic prokaryotes with wide variations in genome size and ecological habitat. metacaspases (mcas) are cysteine proteinases that have sequence homology to caspases and play essential roles in programmed cell death (pcd). mcas have been identified in several prokaryotes, fungi and plants; however, knowledge about cyanobacterial metacaspases still remains obscure. with the availability of sequenced genomes of 33 cyanobacteria, we perform a comparativ ... | 2010 | 20334693 |
| primary photophysical processes in photosystem ii: bridging the gap between crystal structure and optical spectra. | this minireview summarizes our current knowledge of the optical properties of photosystem ii (ps-ii) and how these properties are related to the photosynthetic function, that is, excitation energy transfer from the antenna complexes to the reaction center (rc) and the subsequent transmembrane charge separation in the latter. interpretation of the optical spectra of ps-ii is much more difficult than for the rc of purple bacteria, due to the "spectral congestion" problem, namely, the strong spectr ... | 2010 | 20394099 |
| a new chlorophyll d-containing cyanobacterium: evidence for niche adaptation in the genus acaryochloris. | chlorophyll d is a photosynthetic pigment that, based on chemical analyses, has only recently been recognized to be widespread in oceanic and lacustrine environments. however, the diversity of organisms harbouring this pigment is not known. until now, the unicellular cyanobacterium acaryochloris marina is the only characterized organism that uses chlorophyll d as a major photopigment. in this study we describe a new cyanobacterium possessing a high amount of chlorophyll d, which was isolated fro ... | 2010 | 20505751 |
| epibiosis of oxygenic phototrophs containing chlorophylls a, b, c, and d on the colonial ascidian cystodytes dellechiajei. | the external surfaces of marine animals are colonized by a wide variety of epibionts. here, we study the phototrophic epibiotic community attached to the colonial ascidian cystodytes dellechiajei collected in the mediterranean sea. epifluorescence microscopy analysis showed abundant filamentous cyanobacteria on the upper and basal parts of the ascidian that displayed autofluorescence, as well as some unicellular cyanobacteria, diatoms, and structures, which could belong to microscopic rhodophyte ... | 2011 | 20532497 |
| 18o labeling of chlorophyll d in acaryochloris marina reveals that chlorophyll a and molecular oxygen are precursors. | the cyanobacterium acaryochloris marina was cultured in the presence of either h(2)(18)o or (18)o(2), and the newly synthesized chlorophylls (chl a and chl d) were isolated using high performance liquid chromatography and analyzed by mass spectroscopy. in the presence of h(2)(18)o, newly synthesized chl a and d, both incorporated up to four isotopic (18)o atoms. time course h(2)(18)o labeling experiments showed incorporation of isotopic (18)o atoms originating from h(2)(18)o into chl a, with ove ... | 2010 | 20610399 |
| endolithic chlorophyll d-containing phototrophs. | cyanobacteria in the genus acaryochloris are the only known oxyphototrophs that have exchanged chlorophyll a (chl a) with chl d as their primary photopigment, facilitating oxygenic photosynthesis with near infrared (nir) light. yet their ecology and natural habitats are largely unknown. we used hyperspectral and variable chlorophyll fluorescence imaging, scanning electron microscopy, photopigment analysis and dna sequencing to show that acaryochloris-like cyanobacteria thrive underneath crustose ... | 2010 | 21160540 |
| halotolerant cyanobacterium aphanothece halophytica contains an na+-dependent f1f0-atp synthase with a potential role in salt-stress tolerance. | aphanothece halophytica is a halotolerant alkaliphilic cyanobacterium that can grow in media of up to 3.0 m nacl and ph 11. here, we show that in addition to a typical h(+)-atp synthase, aphanothece halophytica contains a putative f(1)f(0)-type na(+)-atp synthase (apna(+)-atpase) operon (apna(+)-atp). the operon consists of nine genes organized in the order of putative subunits ß, e, i, hypothetical protein, a, c, b, a, and ?. homologous operons could also be found in some cyanobacteria such as ... | 2011 | 21262962 |
| discovery of cyanophage genomes which contain mitochondrial dna polymerase. | dna polymerase ? is a family a dna polymerase responsible for the replication of mitochondrial dna in eukaryotes. the origins of dna polymerase ? have remained elusive because it is not present in any known bacterium, though it has been hypothesized that mitochondria may have inherited the enzyme by phage-mediated nonorthologous displacement. here, we present an analysis of two full-length homologues of this gene, which were found in the genomes of two bacteriophages, which infect the chlorophyl ... | 2011 | 21335340 |
| excitation energy transfer in intact cells and in the phycobiliprotein antennae of the chlorophyll d containing cyanobacterium acaryochloris marina. | the cyanobacterium acaryochloris marina is unique because it mainly contains chlorophyll d (chl d) in the core complexes of ps i and ps ii instead of the usually dominant chl a. furthermore, its light harvesting system has a structure also different from other cyanobacteria. it has both, a membrane-internal chlorophyll containing antenna and a membrane-external phycobiliprotein (pbp) complex. the first one binds chl d and is structurally analogous to cp43. the latter one has a rod-like structure ... | 2011 | 21396735 |
| expanding the solar spectrum used by photosynthesis. | a limiting factor for photosynthetic organisms is their light-harvesting efficiency, that is the efficiency of their conversion of light energy to chemical energy. small modifications or variations of chlorophylls allow photosynthetic organisms to harvest sunlight at different wavelengths. oxygenic photosynthetic organisms usually utilize only the visible portion of the solar spectrum. the cyanobacterium acaryochloris marina carries out oxygenic photosynthesis but contains mostly chlorophyll d a ... | 2011 | 21493120 |
| redox potentials of primary electron acceptor quinone molecule (qa)- and conserved energetics of photosystem ii in cyanobacteria with chlorophyll a and chlorophyll d. | in a previous study, we measured the redox potential of the primary electron acceptor pheophytin (phe) a of photosystem (ps) ii in the chlorophyll d-dominated cyanobacterium acaryochloris marina and a chlorophyll a-containing cyanobacterium, synechocystis. we obtained the midpoint redox potential (e(m)) values of -478 mv for a. marina and -536 mv for synechocystis. in this study, we measured the redox potentials of the primary electron acceptor quinone molecule (q(a)), i.e., e(m)(q(a)/q(a)(-)), ... | 2011 | 21521792 |
| constitution and energetics of photosystem i and photosystem ii in the chlorophyll d-dominated cyanobacterium acaryochloris marina. | this mini review presents current topics of discussion about photosystem (ps) i and ps ii of photosynthesis in the acaryochloris marina. a. marina is a photosynthetic cyanobacterium in which chlorophyll (chl) d is the major antenna pigment (>95%). however, chl a is always present in a few percent. chl d absorbs light with a wavelength up to 30nm red-shifted from chl a. therefore, the chlorophyll species of the special pair in ps ii has been a matter of debate because if chl d was the special pai ... | 2011 | 21530298 |
| phosphorescence study of chlorophyll d photophysics. determination of the energy and lifetime of the photo-excited triplet state. evidence of singlet oxygen photosensitization. | chlorophyll d (chl d) is the major pigment in both photosystems (psi and ii) of the cyanobacterium acaryochloris marina, whose pigment composition represents an interesting alternative in oxygenic photosynthesis. while abundant information is available relative to photophysical properties of chl a , the understanding of chl d photophysics is still incomplete. in this paper, we present for the first time a characterization of chl d phosphorescence, which accompanies radiative deactivation of the ... | 2011 | 21573948 |
| dynamics of gene duplication in the genomes of chlorophyll d-producing cyanobacteria: implications for the ecological niche. | gene duplication may be an important mechanism for the evolution of new functions and for the adaptive modulation of gene expression via dosage effects. here, we analyzed the fate of gene duplicates for two strains of a novel group of cyanobacteria (genus acaryochloris) that produces the far-red light absorbing chlorophyll d as its main photosynthetic pigment. the genomes of both strains contain an unusually high number of gene duplicates for bacteria. as has been observed for eukaryotic genomes ... | 2011 | 21697100 |
| efficiency of photosynthesis in a chl d-utilizing cyanobacterium is comparable to or higher than that in chl a-utilizing oxygenic species. | the cyanobacterium acaryochloris marina uses chlorophyll d to carry out oxygenic photosynthesis in environments depleted in visible and enhanced in lower-energy, far-red light. however, the extent to which low photon energies limit the efficiency of oxygenic photochemistry in a. marina is not known. here, we report the first direct measurements of the energy-storage efficiency of the photosynthetic light reactions in a. marina whole cells, and find it is comparable to or higher than that in typi ... | 2011 | 21708123 |
| Cyanobacterial diversity and a new acaryochloris-like symbiont from Bahamian sea-squirts. | Symbiotic interactions between ascidians (sea-squirts) and microbes are poorly understood. Here we characterized the cyanobacteria in the tissues of 8 distinct didemnid taxa from shallow-water marine habitats in the Bahamas Islands by sequencing a fragment of the cyanobacterial 16S rRNA gene and the entire 16S-23S rRNA internal transcribed spacer region (ITS) and by examining symbiont morphology with transmission electron (TEM) and confocal microscopy (CM). As described previously for other spec ... | 2011 | 21915246 |
| Kinetics of phyllosemiquinone oxidation in the Photosystem I reaction centre of Acaryochloris marina. | Light-induced electron transfer reactions in the chlorophyll a/d-binding Photosystem I reaction centre of Acaryochloris marina were investigated in whole cells by pump-probe optical spectroscopy with a temporal resolution of ~5ns at room temperature. It is shown that phyllosemiquinone, the secondary electron transfer acceptor anion, is oxidised with bi-phasic kinetics characterised by lifetimes of 88±6ns and 345±10ns. These lifetimes, particularly the former, are significantly slower than those ... | 2012 | 22037394 |
| Microbial diversity of biofilm communities in microniches associated with the didemnid ascidian Lissoclinum patella. | We assessed the microbial diversity and microenvironmental niche characteristics in the didemnid ascidian Lissoclinum patella using 16S rRNA gene sequencing, microsensor and imaging techniques. L. patella harbors three distinct microbial communities spatially separated by few millimeters of tunic tissue: (i) a biofilm on its upper surface exposed to high irradiance and O(2) levels, (ii) a cloacal cavity dominated by the prochlorophyte Prochloron spp. characterized by strong depletion of visible ... | 2011 | 22134643 |
| Cationic state distribution over the chlorophyll d-containing P(D1)/P(D2) pair in photosystem II. | Most of the chlorophyll (Chl) cofactors in photosystem II (PSII) from Acaryochloris marina are Chld, although a few Chla molecules are also present. To evaluate the possibility that Chla may participate in the P(D1)/P(D2) Chl pair in PSII from A. marina, the P(D1)(•+)/P(D2)(•+) charge ratio was investigated using the PSII crystal structure analyzed at 1.9-Å resolution, while considering all possibilities for the Chld-containing P(D1)/P(D2) pair, i.e., Chld/Chld, Chla/Chld, and Chld/Chla pairs. C ... | 2011 | 22192718 |