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Lambrecht N, Stevenson Z, Sheik CS, Pronschinske MA, Tong H, Swanner ED. " Candidatus Chlorobium masyuteum," a Novel Photoferrotrophic Green Sulfur Bacterium Enriched From a Ferruginous Meromictic Lake. Front Microbiol 2021; 12:695260. [PMID: 34305861 PMCID: PMC8302410 DOI: 10.3389/fmicb.2021.695260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/07/2021] [Indexed: 11/13/2022] Open
Abstract
Anoxygenic phototrophic bacteria can be important primary producers in some meromictic lakes. Green sulfur bacteria (GSB) have been detected in ferruginous lakes, with some evidence that they are photosynthesizing using Fe(II) as an electron donor (i.e., photoferrotrophy). However, some photoferrotrophic GSB can also utilize reduced sulfur compounds, complicating the interpretation of Fe-dependent photosynthetic primary productivity. An enrichment (BLA1) from meromictic ferruginous Brownie Lake, Minnesota, United States, contains an Fe(II)-oxidizing GSB and a metabolically flexible putative Fe(III)-reducing anaerobe. "Candidatus Chlorobium masyuteum" grows photoautotrophically with Fe(II) and possesses the putative Fe(II) oxidase-encoding cyc2 gene also known from oxygen-dependent Fe(II)-oxidizing bacteria. It lacks genes for oxidation of reduced sulfur compounds. Its genome encodes for hydrogenases and a reverse TCA cycle that may allow it to utilize H2 and acetate as electron donors, an inference supported by the abundance of this organism when the enrichment was supplied by these substrates and light. The anaerobe "Candidatus Pseudopelobacter ferreus" is in low abundance (∼1%) in BLA1 and is a putative Fe(III)-reducing bacterium from the Geobacterales ord. nov. While "Ca. C. masyuteum" is closely related to the photoferrotrophs C. ferroooxidans strain KoFox and C. phaeoferrooxidans strain KB01, it is unique at the genomic level. The main light-harvesting molecule was identified as bacteriochlorophyll c with accessory carotenoids of the chlorobactene series. BLA1 optimally oxidizes Fe(II) at a pH of 6.8, and the rate of Fe(II) oxidation was 0.63 ± 0.069 mmol day-1, comparable to other photoferrotrophic GSB cultures or enrichments. Investigation of BLA1 expands the genetic basis for phototrophic Fe(II) oxidation by GSB and highlights the role these organisms may play in Fe(II) oxidation and carbon cycling in ferruginous lakes.
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Affiliation(s)
- Nicholas Lambrecht
- Department of Geological and Atmospheric Sciences, Iowa State University, Ames, IA, United States
| | - Zackry Stevenson
- Department of Geological and Atmospheric Sciences, Iowa State University, Ames, IA, United States
| | - Cody S. Sheik
- Department of Biology, University of Minnesota Duluth, Duluth, MN, United States
- Large Lakes Observatory, University of Minnesota Duluth, Duluth, MN, United States
| | - Matthew A. Pronschinske
- Department of Geological and Atmospheric Sciences, Iowa State University, Ames, IA, United States
| | - Hui Tong
- Department of Geological and Atmospheric Sciences, Iowa State University, Ames, IA, United States
- Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Institute of Eco-environmental Science and Technology, Guangdong Academy of Sciences, Guangzhou, China
| | - Elizabeth D. Swanner
- Department of Geological and Atmospheric Sciences, Iowa State University, Ames, IA, United States
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Hamilton TL, Welander PV, Albrecht HL, Fulton JM, Schaperdoth I, Bird LR, Summons RE, Freeman KH, Macalady JL. Microbial communities and organic biomarkers in a Proterozoic-analog sinkhole. GEOBIOLOGY 2017; 15:784-797. [PMID: 29035021 DOI: 10.1111/gbi.12252] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 07/07/2017] [Indexed: 06/07/2023]
Abstract
Little Salt Spring (Sarasota County, FL, USA) is a sinkhole with groundwater vents at ~77 m depth. The entire water column experiences sulfidic (~50 μM) conditions seasonally, resulting in a system poised between oxic and sulfidic conditions. Red pinnacle mats occupy the sediment-water interface in the sunlit upper basin of the sinkhole, and yielded 16S rRNA gene clones affiliated with Cyanobacteria, Chlorobi, and sulfate-reducing clades of Deltaproteobacteria. Nine bacteriochlorophyll e homologues and isorenieratene indicate contributions from Chlorobi, and abundant chlorophyll a and pheophytin a are consistent with the presence of Cyanobacteria. The red pinnacle mat contains hopanoids, including 2-methyl structures that have been interpreted as biomarkers for Cyanobacteria. A single sequence of hpnP, the gene required for methylation of hopanoids at the C-2 position, was recovered in both DNA and cDNA libraries from the red pinnacle mat. The hpnP sequence was most closely related to cyanobacterial hpnP sequences, implying that Cyanobacteria are a source of 2-methyl hopanoids present in the mat. The mats are capable of light-dependent primary productivity as evidenced by 13 C-bicarbonate photoassimilation. We also observed 13 C-bicarbonate photoassimilation in the presence of DCMU, an inhibitor of electron transfer to Photosystem II. Our results indicate that the mats carry out light-driven primary production in the absence of oxygen production-a mechanism that may have delayed the oxygenation of the Earth's oceans and atmosphere during the Proterozoic Eon. Furthermore, our observations of the production of 2-methyl hopanoids by Cyanobacteria under conditions of low oxygen and low light are consistent with the recovery of these structures from ancient black shales as well as their paucity in modern marine environments.
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Affiliation(s)
- T L Hamilton
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, USA
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN, USA
| | - P V Welander
- Department of Earth System Science, Stanford University, Stanford, CA, USA
| | - H L Albrecht
- Department of Geosciences and the Penn State Astrobiology Research Center (PSARC), The Pennsylvania State University, University Park, PA, USA
| | - J M Fulton
- Department of Geosciences, Baylor University, Waco, TX, USA
| | - I Schaperdoth
- Department of Geosciences and the Penn State Astrobiology Research Center (PSARC), The Pennsylvania State University, University Park, PA, USA
| | - L R Bird
- Department of Geosciences and the Penn State Astrobiology Research Center (PSARC), The Pennsylvania State University, University Park, PA, USA
| | - R E Summons
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - K H Freeman
- Department of Geosciences and the Penn State Astrobiology Research Center (PSARC), The Pennsylvania State University, University Park, PA, USA
| | - J L Macalady
- Department of Geosciences and the Penn State Astrobiology Research Center (PSARC), The Pennsylvania State University, University Park, PA, USA
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Naeher S, Lengger SK, Grice K. A new method for the rapid analysis of 1H-Pyrrole-2,5-diones (maleimides) in environmental samples by two-dimensional gas chromatography time-of-flight mass spectrometry. J Chromatogr A 2016; 1435:125-35. [PMID: 26850318 DOI: 10.1016/j.chroma.2016.01.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 01/11/2016] [Accepted: 01/11/2016] [Indexed: 11/17/2022]
Abstract
Maleimides (1H-Pyrrole-2,5-diones) are monopyrrolic pigment derivatives with specific alkyl side chains that can be directly linked to their tetrapyrrole precursors, most notably chlorophylls and bacteriochlorophylls. These compounds can be used as palaeoenvironmental indicators such as algal productivity and redox conditions in ancient and modern aquatic systems. Here, we present a new method using two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-ToF-MS), which enables the rapid analysis of maleimides in complex mixtures and different matrices (e.g. sediments and soils), therefore largely simplifying the previous intricate maleimide purification protocol. This method also reduces the potential for bias associated with partial losses due to low recovery and the high volatility of maleimides. The maleimide distributions and concentrations obtained by GC × GC-ToF-MS were reproducible and in agreement with the previously used purification procedure followed by analysis with traditional gas chromatography-mass spectrometry (GC-MS). The new method also resolved previously unrecognised, partial coelution of some maleimides with unknown compounds by quantification with the m/z 75 fragment ion. Furthermore, the higher sensitivity enabled the detection of previously unrecognised and preliminarily identified maleimides based on their relative retention times. The new, easier, rapid and more sensitive GC×GC-ToF-MS method greatly facilitates the analysis of maleimides in environmental samples to study tetrapyrrole degradation processes and will further the development of maleimides as biomarkers for palaeoenvironmental reconstructions.
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Affiliation(s)
- Sebastian Naeher
- Curtin University, Western Australia Organic and Isotope Geochemistry Centre (WA-OIGC), Department of Chemistry, The Institute for Geoscience Research, GPO Box U1987, Perth, WA 6845, Australia.
| | - Sabine K Lengger
- Curtin University, Western Australia Organic and Isotope Geochemistry Centre (WA-OIGC), Department of Chemistry, The Institute for Geoscience Research, GPO Box U1987, Perth, WA 6845, Australia
| | - Kliti Grice
- Curtin University, Western Australia Organic and Isotope Geochemistry Centre (WA-OIGC), Department of Chemistry, The Institute for Geoscience Research, GPO Box U1987, Perth, WA 6845, Australia.
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Wei J, O'Connor PB. Extensive fragmentation of pheophytin-a by infrared multiphoton dissociation tandem mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2015; 29:2411-2418. [PMID: 26563711 DOI: 10.1002/rcm.7391] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 09/04/2015] [Accepted: 09/07/2015] [Indexed: 06/05/2023]
Abstract
RATIONALE In a previous tandem mass spectrometry (MS/MS) study on chlorophyll-a, infrared multiphoton dissociation (IRMPD) was demonstrated as a more effective fragmentation method than collision-induced dissociation (CID) and electron-induced dissociation (EID), where odd-electron product ions were observed ubiquitously in CID and IRMPD. To further understand the role of the macrocycle and the central Mg atom in the MS/MS process, the fragmentation behaviour of pheophytin-a, the Mg-free chlorophyll-a, was investigated. METHODS CID, IRMPD, and EID were applied to the singly protonated pheophytin-a using an ultra-high-resolution Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. The result is compared with the MS/MS study of chlorophyll-a. RESULTS For pheophytin-a, some different fragmentation patterns from chlorophyll-a were obtained by all three MS/MS methods, but IRMPD still appears the most efficient method of generating product ions. The detection of odd-electron fragments in the CID and IRMPD spectra of protonated pheophytin-a suggests that the macrocyclic structure effectively stabilizes radicals, and these radical ions seem to have a relatively higher abundance in the presence of the central Mg atom. CONCLUSIONS The strong absorption in the infrared region of pheophytin-a and secondary free radical rearrangement are proposed to explain the extensive frgmentation in IRMPD spectra. In addition, a comparison of the IRMPD spectra of chlorophyll-a and pheophytin-a shows that the macrocycle in the absence of the Mg atom is much more fragile.
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Affiliation(s)
- Juan Wei
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
| | - Peter B O'Connor
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK
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Airs R, Temperton B, Sambles C, Farnham G, Skill S, Llewellyn C. Chlorophyllfand chlorophylldare produced in the cyanobacteriumChlorogloeopsis fritschiiwhen cultured under natural light and near-infrared radiation. FEBS Lett 2014; 588:3770-7. [DOI: 10.1016/j.febslet.2014.08.026] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 08/20/2014] [Accepted: 08/20/2014] [Indexed: 11/26/2022]
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Zhang H, Cui W, Gross ML, Blankenship RE. Native mass spectrometry of photosynthetic pigment-protein complexes. FEBS Lett 2013; 587:1012-20. [PMID: 23337874 PMCID: PMC3856239 DOI: 10.1016/j.febslet.2013.01.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 12/25/2012] [Accepted: 01/06/2013] [Indexed: 12/16/2022]
Abstract
Native mass spectrometry (MS), or as is sometimes called "native electrospray ionization" allows proteins in their native or near-native states in solution to be introduced into the gas phase and interrogated by mass spectrometry. This approach is now a powerful tool to investigate protein complexes. This article reviews the background of native MS of protein complexes and describes its strengths, taking photosynthetic pigment-protein complexes as examples. Native MS can be utilized in combination with other MS-based approaches to obtain complementary information to that provided by tools such as X-ray crystallography and NMR spectroscopy to understand the structure-function relationships of protein complexes. When additional information beyond that provided by native MS is required, other MS-based strategies can be successfully applied to augment the results of native MS.
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Affiliation(s)
- Hao Zhang
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
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Garcia Costas AM, Tsukatani Y, Rijpstra WIC, Schouten S, Welander PV, Summons RE, Bryant DA. Identification of the bacteriochlorophylls, carotenoids, quinones, lipids, and hopanoids of "Candidatus Chloracidobacterium thermophilum". J Bacteriol 2012; 194:1158-68. [PMID: 22210764 PMCID: PMC3294765 DOI: 10.1128/jb.06421-11] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 12/19/2011] [Indexed: 11/20/2022] Open
Abstract
"Candidatus Chloracidobacterium thermophilum" is a recently discovered chlorophototroph from the bacterial phylum Acidobacteria, which synthesizes bacteriochlorophyll (BChl) c and chlorosomes like members of the green sulfur bacteria (GSB) and the green filamentous anoxygenic phototrophs (FAPs). The pigments (BChl c homologs and carotenoids), quinones, lipids, and hopanoids of cells and chlorosomes of this new chlorophototroph were characterized in this study. "Ca. Chloracidobacterium thermophilum" methylates its antenna BChls at the C-8(2) and C-12(1) positions like GSB, but these BChls were esterified with a variety of isoprenoid and straight-chain alkyl alcohols as in FAPs. Unlike the chlorosomes of other green bacteria, "Ca. Chloracidobacterium thermophilum" chlorosomes contained two major xanthophyll carotenoids, echinenone and canthaxanthin. These carotenoids may confer enhanced protection against reactive oxygen species and could represent a specific adaptation to the highly oxic natural environment in which "Ca. Chloracidobacterium thermophilum" occurs. Dihydrogenated menaquinone-8 [menaquinone-8(H(2))], which probably acts as a quencher of energy transfer under oxic conditions, was an abundant component of both cells and chlorosomes of "Ca. Chloracidobacterium thermophilum." The betaine lipid diacylglycerylhydroxymethyl-N,N,N-trimethyl-β-alanine, esterified with 13-methyl-tetradecanoic (isopentadecanoic) acid, was a prominent polar lipid in the membranes of both "Ca. Chloracidobacterium thermophilum" cells and chlorosomes. This lipid may represent a specific adaptive response to chronic phosphorus limitation in the mats. Finally, three hopanoids, diploptene, bacteriohopanetetrol, and bacteriohopanetetrol cyclitol ether, which may help to stabilize membranes during diel shifts in pH and other physicochemical conditions in the mats, were detected in the membranes of "Ca. Chloracidobacterium thermophilum."
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Affiliation(s)
- Amaya M. Garcia Costas
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Yusuke Tsukatani
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - W. Irene C. Rijpstra
- NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, Den Burg, The Netherlands
| | - Stefan Schouten
- NIOZ Royal Netherlands Institute for Sea Research, Department of Marine Organic Biogeochemistry, Den Burg, The Netherlands
| | - Paula V. Welander
- Department of Earth, Atmospheric and Planetary Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Roger E. Summons
- Department of Earth, Atmospheric and Planetary Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Donald A. Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA
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Meyer KM, Macalady JL, Fulton JM, Kump LR, Schaperdoth I, Freeman KH. Carotenoid biomarkers as an imperfect reflection of the anoxygenic phototrophic community in meromictic Fayetteville Green Lake. GEOBIOLOGY 2011; 9:321-329. [PMID: 21682840 DOI: 10.1111/j.1472-4669.2011.00285.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Organic biomarkers in marine sedimentary rocks hold important clues about the early history of Earth's surface environment. The chemical relicts of carotenoids from anoxygenic sulfur bacteria are of particular interest to geoscientists because of their potential to signal episodes of marine photic-zone euxinia such as those proposed for extended periods in the Proterozoic as well as brief intervals during the Phanerozoic. It is therefore critical to constrain the environmental and physiological factors that influence carotenoid production and preservation in modern environments. Here, we present the results of coupled pigment and nucleic acid clone library analyses from planktonic and benthic samples collected from a microbially dominated meromictic lake, Fayetteville Green Lake (New York). Purple sulfur bacteria (PSB) are abundant and diverse both in the water column at the chemocline and in benthic mats below oxygenated shallow waters, with different PSB species inhabiting the two environments. Okenone (from PSB) is an abundant carotenoid in both the chemocline waters and in benthic mats. Green sulfur bacteria and their primary pigment Bchl e are also represented in and below the chemocline. However, the water column and sediments are devoid of the green sulfur bacteria carotenoid isorenieratene. The unexpected absence of isorenieratene and apparent benthic production of okenone provide strong rationale for continued exploration of the microbial ecology of biomarker production in modern euxinic environments.
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Affiliation(s)
- K M Meyer
- Department of Geological and Environmental Sciences, Stanford University, CA, USA.
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Mizoguchi T, Tamiaki H. The Effect of Esterifying Chains at the 17-Propionate of Bacteriochlorophylls-con Their Self-Assembly. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2007. [DOI: 10.1246/bcsj.80.2196] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Frigaard NU, Bryant DA. Chlorosomes: Antenna Organelles in Photosynthetic Green Bacteria. MICROBIOLOGY MONOGRAPHS 2006. [DOI: 10.1007/7171_021] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Self-aggregates of bacteriochlorophylls-c, d and e in a light-harvesting antenna system of green photosynthetic bacteria: Effect of stereochemistry at the chiral 3-(1-hydroxyethyl) group on the supramolecular arrangement of chlorophyllous pigments. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2005. [DOI: 10.1016/j.jphotochemrev.2005.06.001] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Wilson MA, Hodgson DA, Keely BJ. Atmospheric pressure chemical ionisation liquid chromatography/multistage mass spectrometry for assignment of sedimentary bacteriochlorophyll derivatives. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2005; 19:38-46. [PMID: 15570571 DOI: 10.1002/rcm.1749] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Atmospheric pressure chemical ionisation liquid chromatography/multistage mass spectrometry (APCI-LC/MSn) provides a rapid, on-line method for the assignment of individual bacteriophaeophorbide c and d methyl esters (BPMEs) in complex mixtures. The MS2 spectrum for each component is diagnostic of the type of BPME (c or d), and characteristic losses in MS5 and MS6 permit assignment of the alkyl substituents at positions C-8 and C-12 of the macrocycle. MS5 mass chromatograms permit the deconvolution of coeluting isobaric BPMEs, revealing the true profiles of the individual components. The distributions are different in lake sediments from la Salada de Chiprana (Spain) and Kirisjes Pond (Antarctica), and a novel BPME c with a neo-pentyl substituent has been observed in the Kirisjes Pond sediment.
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Affiliation(s)
- Michael A Wilson
- Chemistry Department, University of York, Heslington, York YO10 5DD, UK
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Massé A, Airs RL, Keely BJ, de Wit R. The impact of different intensities of green light on the bacteriochlorophyll homologue composition of the chlorobiaceae Prosthecochloris aestuarii and Chlorobium phaeobacteroides. Microbiology (Reading) 2004; 150:2555-2564. [PMID: 15289552 DOI: 10.1099/mic.0.27048-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Members of theChlorobiaceaeandChloroflexaceaeare unique among the phototrophic micro-organisms in having a remarkably rich chlorophyll pigment diversity. The physiological regulation of this diversity and its ecological implications are still enigmatic. The bacteriochlorophyll composition of the chlorobiaceaeProsthecochloris aestuariistrain CE 2404 andChlorobium phaeobacteroidesstrain UdG 6030 was therefore studied by both HPLC with photodiode array (PDA) detection and liquid chromatography-mass spectrometry (LC-MS). These strains were grown in liquid cultures under green light (480–615 nm) at different light intensities (0·2–55·7 μmol photons m−2 s−1), simulating the irradiance regime at different depths of the water column of deep lakes. The specific growth rates ofPtc. aestuariiunder green light achieved a maximum of 0·06 h−1at light intensities exceeding 6 μmol photons m−2 s−1, lower than the maximum observed under white light (approx. 0·1 h−1). The maximal growth rates ofChl. phaeobacteroidesunder green light were slightly higher (0·07 h−1) than observed forPtc. aestuariiand were achieved at 3·5 and 4·3 μmol photons m−2 s−1. LC-MS/MS analysis of pigment extracts revealed most (>90 %) BChlchomologues ofPtc. aestuariito be esterified with farnesol. The homologues differed in mass by multiples of 14 Da, reflecting different alkyl subsituents at positions C-8 and C-12 on the tetrapyrrole macrocycle. The relative proportions of the individual homologues varied only slightly among different light intensities. The specific content of BChlcwas maximal at 3–5 μmol photons m−2 s−1[400±150 nmol BChlc(mg protein)−1]. In the case ofChl. phaeobacteroides, the specific content of BChlewas maximal at 4·3 μmol photons m−2 s−1[115 nmol BChle(mg protein)−1], and this species was characterized by high carotenoid (isorenieratene) contents. The major BChleforms were esterified with a range of isoprenoid and straight-chain alcohols. The major isoprenoid alcohols comprised mainly farnesol and to a lesser extent geranylgeraniol. The straight-chain alcohols included C15, C15 : 1, C16, C16 : 1and C17. Interestingly, the proportion of straight alkyl chains over isoprenoid esterified side chains shifted markedly with increasing light intensity: the isoprenoid side chains dominated at low light intensities, while the straight-chain alkyl substituents dominated at higher light intensities. The authors propose that this phenomenon may be explained as a result of changing availability of reducing power, i.e. the highly reduced straight-chain alcohols have a higher biosynthetic demand for NADPH2than the polyunsaturated isoprenoid with the same number of carbon atoms.
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Affiliation(s)
- Astrid Massé
- Laboratoire d'Océanographie Biologique, CNRS-UMR 5805 Université Bordeaux 1, 2 rue du Professeur Jolyet, F-33120 Arcachon, France
| | - Ruth L Airs
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
| | - Brendan J Keely
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
| | - Rutger de Wit
- Laboratoire d'Océanographie Biologique, CNRS-UMR 5805 Université Bordeaux 1, 2 rue du Professeur Jolyet, F-33120 Arcachon, France
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Squier AH, Airs RL, Hodgson DA, Keely BJ. Atmospheric pressure chemical ionisation liquid chromatography/mass spectrometry of the ultraviolet screening pigment scytonemin: characteristic fragmentations. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2004; 18:2934-2938. [PMID: 15529415 DOI: 10.1002/rcm.1714] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Atmospheric pressure chemical ionisation reversed-phase high-performance liquid chromatography/multistage mass spectrometry has been used to study the mass spectral fragmentation of the cyanobacterial sheath pigment scytonemin and its reduced counterpart. The two pigments exhibit characteristic fragment ions in their MS2 and MS3 spectra that are of value in confirming the identification of the structures in extracts from natural environments.
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Affiliation(s)
- Angela H Squier
- Department of Chemistry, University of York, Heslington, York YO10 5DD, UK
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Wilson MA, Md Saleh SR, Hodgson DA, Keely BJ. Atmospheric pressure chemical ionisation liquid chromatography/multi-stage mass spectrometry of isobaric bacteriophaeophorbide d methyl esters. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2003; 17:2455-2458. [PMID: 14587093 DOI: 10.1002/rcm.1205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
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Current literature in mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2002; 37:545-556. [PMID: 12112761 DOI: 10.1002/jms.252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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