1
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Su Kim H, Lee S, Moon M, Jong Jung H, Lee J, Chu YH, Rae Kim J, Kim D, Woo Park G, Hyun Ko C, Youn Lee S. Enhancing microbial CO 2 electrocatalysis for multicarbon reduction in a wet amine-based catholyte. CHEMSUSCHEM 2024; 17:e202301342. [PMID: 38287485 DOI: 10.1002/cssc.202301342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/17/2024] [Accepted: 01/29/2024] [Indexed: 01/31/2024]
Abstract
Microbial CO2 electroreduction (mCO2ER) offers a promising approach for producing high-value multicarbon reductants from CO2 by combining CO2 fixing microorganisms with conducting materials (i. e., cathodes). However, the solubility and availability of CO2 in an aqueous electrolyte pose significant limitations in this system. This study demonstrates the efficient production of long-chain multicarbon reductants, specifically carotenoids (~C40), within a wet amine-based catholyte medium during mCO2ER. Optimizing the concentration of the biocompatible CO2 absorbent, monoethanolamine (MEA), led to enhanced CO2 fixation in the electroautotroph bacteria. Molecular biological analyses revealed that MEA in the catholyte medium redirected the carbon flux towards carotenoid biosynthesis during mCO2ER. The faradaic efficiency of mCO2ER with MEA for carotenoid production was 4.5-fold higher than that of the control condition. These results suggest the mass transport bottleneck in bioelectrochemical systems could be effectively addressed by MEA-assissted mCO2ER, enabling highly efficient production of valuable products from CO2.
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Affiliation(s)
- Hui Su Kim
- Gwangju Clean Energy Research Center, Korea Institute of Energy Research, 61003, Gwangju, South Korea
- Department of Chemical Engineering, Chonnam National University, 61186, Gwangju, South Korea
| | - Sangmin Lee
- Gwangju Clean Energy Research Center, Korea Institute of Energy Research, 61003, Gwangju, South Korea
- Bio-Environmental Chemistry, Chungnam National University, 34134, Daejeon, South Korea
| | - Myounghoon Moon
- Gwangju Clean Energy Research Center, Korea Institute of Energy Research, 61003, Gwangju, South Korea
| | - Hwi Jong Jung
- Gwangju Clean Energy Research Center, Korea Institute of Energy Research, 61003, Gwangju, South Korea
- Department of Chemical Engineering, Chonnam National University, 61186, Gwangju, South Korea
| | - Jiye Lee
- Gwangju Clean Energy Research Center, Korea Institute of Energy Research, 61003, Gwangju, South Korea
| | - Young-Hwan Chu
- Energy AI ⋅ Computational Science Laboratory, Korea Institute of Energy Research, 34129, Daejeon, South Korea
| | - Jung Rae Kim
- School of Chemical and Biomolecular Engineering, Pusan National University, 46241, Pusan, South Korea
| | - Danbee Kim
- Gwangju Clean Energy Research Center, Korea Institute of Energy Research, 61003, Gwangju, South Korea
| | - Gwon Woo Park
- Gwangju Clean Energy Research Center, Korea Institute of Energy Research, 61003, Gwangju, South Korea
| | - Chang Hyun Ko
- Department of Chemical Engineering, Chonnam National University, 61186, Gwangju, South Korea
| | - Soo Youn Lee
- Gwangju Clean Energy Research Center, Korea Institute of Energy Research, 61003, Gwangju, South Korea
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2
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Kim W, Park Y, Jung J, Jeon CO, Toyofuku M, Lee J, Park W. Biological and Chemical Approaches for Controlling Harmful Microcystis Blooms. J Microbiol 2024; 62:249-260. [PMID: 38587591 DOI: 10.1007/s12275-024-00115-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 01/16/2024] [Accepted: 01/17/2024] [Indexed: 04/09/2024]
Abstract
The proliferation of harmful cyanobacterial blooms dominated by Microcystis aeruginosa has become an increasingly serious problem in freshwater ecosystems due to climate change and eutrophication. Microcystis-blooms in freshwater generate compounds with unpleasant odors, reduce the levels of dissolved O2, and excrete microcystins into aquatic ecosystems, potentially harming various organisms, including humans. Various chemical and biological approaches have thus been developed to mitigate the impact of the blooms, though issues such as secondary pollution and high economic costs have not been adequately addressed. Red clays and H2O2 are conventional treatment methods that have been employed worldwide for the mitigation of the blooms, while novel approaches, such as the use of plant or microbial metabolites and antagonistic bacteria, have also recently been proposed. Many of these methods rely on the generation of reactive oxygen species, the inhibition of photosynthesis, and/or the disruption of cellular membranes as their mechanisms of action, which may also negatively impact other freshwater microbiota. Nevertheless, the underlying molecular mechanisms of anticyanobacterial chemicals and antagonistic bacteria remain unclear. This review thus discusses both conventional and innovative approaches for the management of M. aeruginosa in freshwater bodies.
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Affiliation(s)
- Wonjae Kim
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Yerim Park
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Jaejoon Jung
- Department of Life Science, Chung-Ang University, Seoul, 02841, Republic of Korea
| | - Che Ok Jeon
- Department of Life Science, Chung-Ang University, Seoul, 02841, Republic of Korea
| | - Masanori Toyofuku
- Department of Life and Environmental Sciences, University of Tsukuba, Tsukuba, 305-0006, Japan
| | - Jiyoung Lee
- Division of Environmental Health Sciences, College of Public Health, The Ohio State University, Columbus, OH, 43210, USA
- Department of Food Science and Technology, The Ohio State University, Columbus, OH, 43210, USA
| | - Woojun Park
- Laboratory of Molecular Environmental Microbiology, Department of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea.
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3
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Huang X, Vasilev C, Swainsbury D, Hunter C. Excitation energy transfer in proteoliposomes reconstituted with LH2 and RC-LH1 complexes from Rhodobacter sphaeroides. Biosci Rep 2024; 44:BSR20231302. [PMID: 38227291 PMCID: PMC10876425 DOI: 10.1042/bsr20231302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 12/30/2023] [Accepted: 01/16/2024] [Indexed: 01/17/2024] Open
Abstract
Light-harvesting 2 (LH2) and reaction-centre light-harvesting 1 (RC-LH1) complexes purified from the photosynthetic bacterium Rhodobacter (Rba.) sphaeroides were reconstituted into proteoliposomes either separately, or together at three different LH2:RC-LH1 ratios, for excitation energy transfer studies. Atomic force microscopy (AFM) was used to investigate the distribution and association of the complexes within the proteoliposome membranes. Absorption and fluorescence emission spectra were similar for LH2 complexes in detergent and liposomes, indicating that reconstitution retains the structural and optical properties of the LH2 complexes. Analysis of fluorescence emission shows that when LH2 forms an extensive series of contacts with other such complexes, fluorescence is quenched by 52.6 ± 1.4%. In mixed proteoliposomes, specific excitation of carotenoids in LH2 donor complexes resulted in emission of fluorescence from acceptor RC-LH1 complexes engineered to assemble with no carotenoids. Extents of energy transfer were measured by fluorescence lifetime microscopy; the 0.72 ± 0.08 ns lifetime in LH2-only membranes decreases to 0.43 ± 0.04 ns with a ratio of 2:1 LH2 to RC-LH1, and to 0.35 ± 0.05 ns for a 1:1 ratio, corresponding to energy transfer efficiencies of 40 ± 14% and 51 ± 18%, respectively. No further improvement is seen with a 0.5:1 LH2 to RC-LH1 ratio. Thus, LH2 and RC-LH1 complexes perform their light harvesting and energy transfer roles when reconstituted into proteoliposomes, providing a way to integrate native, non-native, engineered and de novo designed light-harvesting complexes into functional photosynthetic systems.
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Affiliation(s)
- Xia Huang
- Department of Biological Sciences, Xi’an Jiaotong-Liverpool University, Suzhou, Jiangsu 215123, China
- Jinan Guoke Medical Technology Development Co., Ltd, Jinan, Shandong 250101, China
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K
| | - Cvetelin Vasilev
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K
| | - David J.K. Swainsbury
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, U.K
| | - C. Neil Hunter
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K
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Liu LN, Bracun L, Li M. Structural diversity and modularity of photosynthetic RC-LH1 complexes. Trends Microbiol 2024; 32:38-52. [PMID: 37380557 DOI: 10.1016/j.tim.2023.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 06/03/2023] [Accepted: 06/05/2023] [Indexed: 06/30/2023]
Abstract
Bacterial photosynthesis is essential for sustaining life on Earth as it aids in carbon assimilation, atmospheric composition, and ecosystem maintenance. Many bacteria utilize anoxygenic photosynthesis to convert sunlight into chemical energy while producing organic matter. The core machinery of anoxygenic photosynthesis performed by purple photosynthetic bacteria and Chloroflexales is the reaction center-light-harvesting 1 (RC-LH1) pigment-protein supercomplex. In this review, we discuss recent structural studies of RC-LH1 core complexes based on the advancement in structural biology techniques. These studies have provided fundamental insights into the assembly mechanisms, structural variations, and modularity of RC-LH1 complexes across different bacterial species, highlighting their functional adaptability. Understanding the natural architectures of RC-LH1 complexes will facilitate the design and engineering of artificial photosynthetic systems, which can enhance photosynthetic efficiency and potentially find applications in sustainable energy production and carbon capture.
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Affiliation(s)
- Lu-Ning Liu
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK; College of Marine Life Sciences and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao 266003, China.
| | - Laura Bracun
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Mei Li
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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Chen GE, Hunter CN. Engineering Chlorophyll, Bacteriochlorophyll, and Carotenoid Biosynthetic Pathways in Escherichia coli. ACS Synth Biol 2023; 12:2236-2244. [PMID: 37531642 PMCID: PMC10443036 DOI: 10.1021/acssynbio.3c00237] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Indexed: 08/04/2023]
Abstract
The biosynthesis of chlorophylls (Chls) and bacteriochlorophylls (BChls) represents a key aspect of photosynthesis research. Our previous work assembled the complete pathway for the synthesis of Chl a in Escherichia coli; here we engineer the more complex BChl a pathway in the same heterotrophic host. Coexpression of 18 genes enabled E. coli to produce BChl a, verifying that we have identified the minimum set of genes for the BChl a biosynthesis pathway. The protochlorophyllide reduction step was mediated by the bchNBL genes, and this same module was used to modify the Chl a pathway previously constructed in E. coli, eliminating the need for the light-dependent protochlorophyllide reductase. Furthermore, we demonstrate the feasibility of synthesizing more than one family of photosynthetic pigments in one host by engineering E. coli strains that accumulate the carotenoids neurosporene and β-carotene in addition to BChl a.
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Affiliation(s)
- Guangyu E. Chen
- State
Key Laboratory of Microbial Metabolism, School of Life Sciences and
Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - C. Neil Hunter
- School
of Biosciences, University of Sheffield, Sheffield S10 2TN, United Kingdom
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6
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Mrudulakumari Vasudevan U, Mai DHA, Krishna S, Lee EY. Methanotrophs as a reservoir for bioactive secondary metabolites: Pitfalls, insights and promises. Biotechnol Adv 2023; 63:108097. [PMID: 36634856 DOI: 10.1016/j.biotechadv.2023.108097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 12/10/2022] [Accepted: 01/06/2023] [Indexed: 01/11/2023]
Abstract
Methanotrophs are potent natural producers of several bioactive secondary metabolites (SMs) including isoprenoids, polymers, peptides, and vitamins. Cryptic biosynthetic gene clusters identified from these microbes via genome mining hinted at the vast and hidden SM biosynthetic potential of these microbes. Central carbon metabolism in methanotrophs offers rare pathway intermediate pools that could be further diversified using advanced synthetic biology tools to produce valuable SMs; for example, plant polyketides, rare carotenoids, and fatty acid-derived SMs. Recent advances in pathway reconstruction and production of isoprenoids, squalene, ectoine, polyhydroxyalkanoate copolymer, cadaverine, indigo, and shinorine serve as proof-of-concept. This review provides theoretical guidance for developing methanotrophs as microbial chassis for high-value SMs. We summarize the distinct secondary metabolic potentials of type I and type II methanotrophs, with specific attention to products relevant to biomedical applications. This review also includes native and non-native SMs from methanotrophs, their therapeutic potential, strategies to induce silent biosynthetic gene clusters, and challenges.
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Affiliation(s)
- Ushasree Mrudulakumari Vasudevan
- Department of Chemical Engineering (BK21 FOUR Integrated Engineering Program), Kyung Hee University, Yongin-si, Gyeonggi-do 17104, Republic of Korea
| | - Dung Hoang Anh Mai
- Department of Chemical Engineering (BK21 FOUR Integrated Engineering Program), Kyung Hee University, Yongin-si, Gyeonggi-do 17104, Republic of Korea
| | - Shyam Krishna
- Department of Chemical Engineering (BK21 FOUR Integrated Engineering Program), Kyung Hee University, Yongin-si, Gyeonggi-do 17104, Republic of Korea
| | - Eun Yeol Lee
- Department of Chemical Engineering (BK21 FOUR Integrated Engineering Program), Kyung Hee University, Yongin-si, Gyeonggi-do 17104, Republic of Korea.
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7
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Serdyuk OP, Abdullatypov AV, Smolygina LD, Ashikhmin AA, Bolshakov MA. Simultaneous functioning of different light-harvesting complexes-a strategy of adaptation of purple bacterium Rhodopseudomonas palustris to low illumination conditions. PeerJ 2023; 11:e14769. [PMID: 36743963 PMCID: PMC9897067 DOI: 10.7717/peerj.14769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 12/29/2022] [Indexed: 02/03/2023] Open
Abstract
Novel peripheral light-harvesting (LH) complex designated as LL LH2 was isolated along with LH4 complex from Rhodopseudomonas palustris cells grown under low light intensity (LL). FPLC-MS/MS allowed to reveal PucABd and PucBabc apoproteins in LL LH2 complex, which is different from previously described LH4 complex containing PucABd, PucABa and PucBb. The main carotenoids in LL LH2 complex were rhodopin and 3,4-didehydrorhodopin. Three-dimensional modeling demonstrated which amino acid residues of all the β-subunits could interact with carotenoids (Car) and bacteriochlorophyll a (BChl a). Analysis of amino acid sequences of α-subunits of both LL complexes showed presence of different C-terminal motifs, IESSVNVG in αa subunit and IESSIKAV in αd subunit, in the same positions of C-termini, which could reflect different retention force of LL LH2 and LH4 on hydroxyl apatite, facilitating successful isolation of these complexes. Differences of these LL complexes in protein and carotenoid composition, in efficiency of energy transfer from Car to BChl a, which is two times lower in LL LH2 than in LH4, allow to assign it to a novel type of light-harvesting complex in Rhodopseudomonas palustris.
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Affiliation(s)
- Olga Petrovna Serdyuk
- Institute of Basic Biological Problems of the Russian Academy of Sciences—A Separate Subdivision of PSCBR RAS (IBBP RAS), Pushchino, Moscow Region, Russian Federation
| | - Azat Vadimovich Abdullatypov
- Institute of Basic Biological Problems of the Russian Academy of Sciences—A Separate Subdivision of PSCBR RAS (IBBP RAS), Pushchino, Moscow Region, Russian Federation
| | - Lidiya Dmitrievna Smolygina
- Institute of Basic Biological Problems of the Russian Academy of Sciences—A Separate Subdivision of PSCBR RAS (IBBP RAS), Pushchino, Moscow Region, Russian Federation
| | - Aleksandr Aleksandrovich Ashikhmin
- Institute of Basic Biological Problems of the Russian Academy of Sciences—A Separate Subdivision of PSCBR RAS (IBBP RAS), Pushchino, Moscow Region, Russian Federation
| | - Maxim Alexandrovich Bolshakov
- Institute of Basic Biological Problems of the Russian Academy of Sciences—A Separate Subdivision of PSCBR RAS (IBBP RAS), Pushchino, Moscow Region, Russian Federation
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8
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Hancock AM, Swainsbury DJK, Meredith SA, Morigaki K, Hunter CN, Adams PG. Enhancing the spectral range of plant and bacterial light-harvesting pigment-protein complexes with various synthetic chromophores incorporated into lipid vesicles. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2022; 237:112585. [PMID: 36334507 DOI: 10.1016/j.jphotobiol.2022.112585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 09/16/2022] [Accepted: 10/11/2022] [Indexed: 11/06/2022]
Abstract
The Light-Harvesting (LH) pigment-protein complexes found in photosynthetic organisms have the role of absorbing solar energy with high efficiency and transferring it to reaction centre complexes. LH complexes contain a suite of pigments that each absorb light at specific wavelengths, however, the natural combinations of pigments within any one protein complex do not cover the full range of solar radiation. Here, we provide an in-depth comparison of the relative effectiveness of five different organic "dye" molecules (Texas Red, ATTO, Cy7, DiI, DiR) for enhancing the absorption range of two different LH membrane protein complexes (the major LHCII from plants and LH2 from purple phototrophic bacteria). Proteoliposomes were self-assembled from defined mixtures of lipids, proteins and dye molecules and their optical properties were quantified by absorption and fluorescence spectroscopy. Both lipid-linked dyes and alternative lipophilic dyes were found to be effective excitation energy donors to LH protein complexes, without the need for direct chemical or generic modification of the proteins. The Förster theory parameters (e.g., spectral overlap) were compared between each donor-acceptor combination and found to be good predictors of an effective dye-protein combination. At the highest dye-to-protein ratios tested (over 20:1), the effective absorption strength integrated over the full spectral range was increased to ∼180% of its natural level for both LH complexes. Lipophilic dyes could be inserted into pre-formed membranes although their effectiveness was found to depend upon favourable physicochemical interactions. Finally, we demonstrated that these dyes can also be effective at increasing the spectral range of surface-supported models of photosynthetic membranes, using fluorescence microscopy. The results of this work provide insight into the utility of self-assembled lipid membranes and the great flexibility of LH complexes for interacting with different dyes.
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Affiliation(s)
- Ashley M Hancock
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK; Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - David J K Swainsbury
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK; School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK
| | - Sophie A Meredith
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK; Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Kenichi Morigaki
- Graduate School of Agricultural Science and Biosignal Research Center, Kobe University, Rokkodaicho 1-1, Nada, Kobe 657-8501, Japan
| | - C Neil Hunter
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Peter G Adams
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK; Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK.
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Microbial co-occurrence network in the rhizosphere microbiome: its association with physicochemical properties and soybean yield at a regional scale. J Microbiol 2022; 60:986-997. [DOI: 10.1007/s12275-022-2363-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 08/28/2022] [Accepted: 08/29/2022] [Indexed: 10/14/2022]
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Xing J, Li M, Li J, Shen W, Li P, Zhao J, Zhang Y. Stem canker pathogen Botryosphaeria dothidea inhibits poplar leaf photosynthesis in the early stage of inoculation. FRONTIERS IN PLANT SCIENCE 2022; 13:1008834. [PMID: 36204063 PMCID: PMC9530914 DOI: 10.3389/fpls.2022.1008834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 08/31/2022] [Indexed: 06/16/2023]
Abstract
Fungal pathogens can induce canker lesions, wilting, and even dieback in many species. Trees can suffer serious physiological effects from stem cankers. In this study, we investigated the effects of Botryosphaeria dothidea (B. dothidea) on Populus bolleana (P. bolleana) leaves photosynthesis and stomatal responses, when stems were inoculated with the pathogen. To provide experimental and theoretical basis for preventing poplar canker early. One-year-old poplar stems were inoculated with B. dothidea using an epidermal scraping method. In the early stage of B. dothidea inoculation (2-14 days post inoculation, dpi), the gas exchange, stomatal dynamics, hormone content, photosynthetic pigments content, chlorophyll fluorescence parameters, and non-structural carbohydrate (NSC) were evaluated to elucidate the pathophysiological mechanism of B. dothidea inhibiting photosynthesis. Compared with the control groups, B. dothidea noteworthily inhibited the net photosynthetic rate (P n), stomatal conductance (G s), intercellular CO2 concentration (C i), transpiration rate (T r), and other photosynthetic parameters of poplar leaves, but stomatal limit value (L s) increased. Consistent with the above results, B. dothidea also reduced stomatal aperture and stomatal opening rate. In addition, B. dothidea not only remarkably reduced the content of photosynthetic pigments, but also decreased the maximum photochemical efficiency (F v/F m), actual photochemical efficiency (Φ PSII), electron transfer efficiency (ETR), and photochemical quenching coefficient (q P). Furthermore, both chlorophyll and Φ PSII were positively correlated with P n. In summary, the main reason for the abated P n under stem canker pathogen was that B. dothidea not merely inhibited the stomatal opening, but hindered the conversion of light energy, electron transfer and light energy utilization of poplar leaves. In general, the lessened CO2 and P n would reduce the synthesis of photosynthetic products. Whereas, sucrose and starch accumulated in poplar leaves, which may be due to the local damage caused by B. dothidea inoculation in phloem, hindering downward transport of these products.
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11
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Capacity and kinetics of light-induced cytochrome oxidation in intact cells of photosynthetic bacteria. Sci Rep 2022; 12:14298. [PMID: 35995915 PMCID: PMC9395421 DOI: 10.1038/s41598-022-18399-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 08/10/2022] [Indexed: 11/08/2022] Open
Abstract
Light-induced oxidation of the reaction center dimer and periplasmic cytochromes was detected by fast kinetic difference absorption changes in intact cells of wild type and cytochrome mutants (cycA, cytC4 and pufC) of Rubrivivax gelatinosus and Rhodobacter sphaeroides. Constant illumination from a laser diode or trains of saturating flashes enabled the kinetic separation of acceptor and donor redox processes, and the electron contribution from the cyt bc1 complex via periplasmic cytochromes. Under continuous excitation, concentrations of oxidized cytochromes increased in three phases where light intensity, electron transfer rate and the number of reduced cytochromes were the rate liming steps, respectively. By choosing suitable flash timing, gradual steps of cytochrome oxidation in whole cells were observed; each successive flash resulted in a smaller, damped oxidation. We attribute this damping to lowered availability of reduced cytochromes resulting from both exchange (unbinding/binding) of the cytochromes and electron transfer at the reaction center interface since a similar effect is observed upon deletion of genes encoding periplasmic cytochromes. In addition, we present a simple model to calculate the damping effect; application of this method may contribute to understanding the function of the diverse range of c-type cytochromes in the electron transport chains of anaerobic phototrophic bacteria.
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12
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Grassino M, Batstone DJ, Yong KW, Capson-Tojo G, Hülsen T. Method development for PPB culture screening, pigment analysis with UPLC-UV-HRMS vs. spectrophotometric methods, and spectral decomposition-based analysis. Talanta 2022; 246:123490. [DOI: 10.1016/j.talanta.2022.123490] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 04/12/2022] [Accepted: 04/15/2022] [Indexed: 11/30/2022]
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Li M, Ning P, Sun Y, Luo J, Yang J. Characteristics and Application of Rhodopseudomonas palustris as a Microbial Cell Factory. Front Bioeng Biotechnol 2022; 10:897003. [PMID: 35646843 PMCID: PMC9133744 DOI: 10.3389/fbioe.2022.897003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 04/27/2022] [Indexed: 01/20/2023] Open
Abstract
Rhodopseudomonas palustris, a purple nonsulfur bacterium, is a bacterium with the properties of extraordinary metabolic versatility, carbon source diversity and metabolite diversity. Due to its biodetoxification and biodegradation properties, R. palustris has been traditionally applied in wastewater treatment and bioremediation. R. palustris is rich in various metabolites, contributing to its application in agriculture, aquaculture and livestock breeding as additives. In recent years, R. palustris has been engineered as a microbial cell factory to produce valuable chemicals, especially photofermentation of hydrogen. The outstanding property of R. palustris as a microbial cell factory is its ability to use a diversity of carbon sources. R. palustris is capable of CO2 fixation, contributing to photoautotrophic conversion of CO2 into valuable chemicals. R. palustris can assimilate short-chain organic acids and crude glycerol from industrial and agricultural wastewater. Lignocellulosic biomass hydrolysates can also be degraded by R. palustris. Utilization of these feedstocks can reduce the industry cost and is beneficial for environment. Applications of R. palustris for biopolymers and their building blocks production, and biofuels production are discussed. Afterward, some novel applications in microbial fuel cells, microbial electrosynthesis and photocatalytic synthesis are summarized. The challenges of the application of R. palustris are analyzed, and possible solutions are suggested.
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Affiliation(s)
- Meijie Li
- Energy-Rich Compound Production by Photosynthetic Carbon Fixation Research Center, Shandong Key Lab of Applied Mycology, Qingdao Agricultural University, Qingdao, China
- College of Life Sciences, Qingdao Agricultural University, Qingdao, China
| | - Peng Ning
- Energy-Rich Compound Production by Photosynthetic Carbon Fixation Research Center, Shandong Key Lab of Applied Mycology, Qingdao Agricultural University, Qingdao, China
- College of Life Sciences, Qingdao Agricultural University, Qingdao, China
| | - Yi Sun
- Haiyang Comprehensive Administrative Law Enforcement Bureau (Agriculture), Haiyang, China
| | - Jie Luo
- Qingdao Garden Forestry Technology School, Qingdao, China
- *Correspondence: Jie Luo, ; Jianming Yang,
| | - Jianming Yang
- Energy-Rich Compound Production by Photosynthetic Carbon Fixation Research Center, Shandong Key Lab of Applied Mycology, Qingdao Agricultural University, Qingdao, China
- College of Life Sciences, Qingdao Agricultural University, Qingdao, China
- *Correspondence: Jie Luo, ; Jianming Yang,
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Lee YR, Lee WH, Lee SY, Lee J, Kim MS, Moon M, Park GW, Kim HS, Kim JI, Lee JS, Lee S. Regulation of Reactive Oxygen Species Promotes Growth and Carotenoid Production Under Autotrophic Conditions in Rhodobacter sphaeroides. Front Microbiol 2022; 13:847757. [PMID: 35295297 PMCID: PMC8920488 DOI: 10.3389/fmicb.2022.847757] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 02/07/2022] [Indexed: 11/26/2022] Open
Abstract
Industrial demand for capture and utilization using microorganisms to reduce CO2, a major cause of global warming, is significantly increasing. Rhodobacter sphaeroides is a suitable strain for the process of converting CO2 into high-value materials because it can accept CO2 and has various metabolic pathways. However, it has been mainly studied for heterotrophic growth that uses sugars and organic acids as carbon sources, not autotrophic growth. Here, we report that the regulation of reactive oxygen species is critical for growth when using CO2 as a sole carbon source in R. sphaeroides. In general, the growth rate is much slower under autotrophic conditions compared to heterotrophic conditions. To improve this, we performed random mutagenesis using N-methyl-N’-nitro-N-nitrosoguanidine (NTG). As a result, we selected the YR-1 strain with a maximum specific growth rate (μ) 1.44 day–1 in the early growth phase, which has a 110% faster growth rate compared to the wild-type. Based on the transcriptome analysis, it was confirmed that the growth was more sensitive to reactive oxygen species under autotrophic conditions. In the YR-1 mutant, the endogenous contents of H2O2 levels and oxidative damage were reduced by 33.3 and 42.7% in the cells, respectively. Furthermore, we measured that concentrations of carotenoids, which are important antioxidants. The total carotenoid is produced 9.63 g/L in the YR-1 mutant, suggesting that the production is 1.7-fold higher than wild-type. Taken together, our observations indicate that controlling ROS promotes cell growth and carotenoid production under autotrophic conditions.
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Affiliation(s)
- Yu Rim Lee
- Gwangju Bio/Energy R&D Center, Korea Institute of Energy Research, Gwangju, South Korea
- Interdisciplinary Program of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea
| | - Won-Heong Lee
- Interdisciplinary Program of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, South Korea
| | - Soo Youn Lee
- Gwangju Bio/Energy R&D Center, Korea Institute of Energy Research, Gwangju, South Korea
| | - Jiye Lee
- Gwangju Bio/Energy R&D Center, Korea Institute of Energy Research, Gwangju, South Korea
| | - Min-Sik Kim
- Energy Resources Upcycling Research Laboratory, Korea Institute of Energy Research, Daejeon, South Korea
| | - Myounghoon Moon
- Gwangju Bio/Energy R&D Center, Korea Institute of Energy Research, Gwangju, South Korea
| | - Gwon Woo Park
- Gwangju Bio/Energy R&D Center, Korea Institute of Energy Research, Gwangju, South Korea
| | - Hui Su Kim
- Gwangju Bio/Energy R&D Center, Korea Institute of Energy Research, Gwangju, South Korea
- Department of Advanced Chemicals and Engineering, Chonnam National University, Gwangju, South Korea
| | - Jeong-Il Kim
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, South Korea
| | - Jin-Suk Lee
- Gwangju Bio/Energy R&D Center, Korea Institute of Energy Research, Gwangju, South Korea
| | - Sangmin Lee
- Gwangju Bio/Energy R&D Center, Korea Institute of Energy Research, Gwangju, South Korea
- *Correspondence: Sangmin Lee,
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15
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Hitchcock A, Hunter CN, Sobotka R, Komenda J, Dann M, Leister D. Redesigning the photosynthetic light reactions to enhance photosynthesis - the PhotoRedesign consortium. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 109:23-34. [PMID: 34709696 DOI: 10.1111/tpj.15552] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/12/2021] [Accepted: 10/21/2021] [Indexed: 06/13/2023]
Abstract
In this Perspective article, we describe the visions of the PhotoRedesign consortium funded by the European Research Council of how to enhance photosynthesis. The light reactions of photosynthesis in individual phototrophic species use only a fraction of the solar spectrum, and high light intensities can impair and even damage the process. In consequence, expanding the solar spectrum and enhancing the overall energy capacity of the process, while developing resilience to stresses imposed by high light intensities, could have a strong positive impact on food and energy production. So far, the complexity of the photosynthetic machinery has largely prevented improvements by conventional approaches. Therefore, there is an urgent need to develop concepts to redesign the light-harvesting and photochemical capacity of photosynthesis, as well as to establish new model systems and toolkits for the next generation of photosynthesis researchers. The overall objective of PhotoRedesign is to reconfigure the photosynthetic light reactions so they can harvest and safely convert energy from an expanded solar spectrum. To this end, a variety of synthetic biology approaches, including de novo design, will combine the attributes of photosystems from different photoautotrophic model organisms, namely the purple bacterium Rhodobacter sphaeroides, the cyanobacterium Synechocystis sp. PCC 6803 and the plant Arabidopsis thaliana. In parallel, adaptive laboratory evolution will be applied to improve the capacity of reimagined organisms to cope with enhanced input of solar energy, particularly in high and fluctuating light.
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Affiliation(s)
- Andrew Hitchcock
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Christopher Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Roman Sobotka
- Laboratory of Photosynthesis, Institute of Microbiology of the Czech Academy of Sciences, Třeboň, 37901, Czech Republic
| | - Josef Komenda
- Laboratory of Photosynthesis, Institute of Microbiology of the Czech Academy of Sciences, Třeboň, 37901, Czech Republic
| | - Marcel Dann
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, 82152, Germany
| | - Dario Leister
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, 82152, Germany
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16
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Sutherland GA, Qian P, Hunter CN, Swainsbury DJ, Hitchcock A. Engineering purple bacterial carotenoid biosynthesis to study the roles of carotenoids in light-harvesting complexes. Methods Enzymol 2022; 674:137-184. [DOI: 10.1016/bs.mie.2022.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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17
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Bolshakov MA, Ashikhmin AA, Makhneva ZK, Moskalenko AA. Inhibition of Carotenoid Biosynthesis in LH2 and LH1-RC Pigment-Protein Complexes of a Purple Sulfur Bacterium Thermochromatium tepidum. Microbiology (Reading) 2021. [DOI: 10.1134/s0026261721060047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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18
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Carotenoid Cocktail Produced by An Antarctic Soil Flavobacterium with Biotechnological Potential. Microorganisms 2021; 9:microorganisms9122419. [PMID: 34946021 PMCID: PMC8704924 DOI: 10.3390/microorganisms9122419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 09/29/2021] [Accepted: 09/30/2021] [Indexed: 11/17/2022] Open
Abstract
Carotenoids are highly important in pigmentation, and its content in farmed crustaceans and fish correlates to their market value. These pigments also have a nutritional role in aquaculture where they are routinely added as a marine animal food supplement to ensure fish development and health. However, there is little information about carotenoids obtained from Antarctic bacteria and its use for pigmentation improvement and flesh quality in aquaculture. This study identified carotenoids produced by Antarctic soil bacteria. The pigmented strain (CN7) was isolated on modified Luria–Bertani (LB) media and incubated at 4 °C. This Gram-negative bacillus was identified by 16S rRNA analysis as Flavobacterium segetis. Pigment extract characterization was performed through high-performance liquid chromatography (HPLC) and identification with liquid chromatography–mass spectrometry (LC–MS). HPLC analyses revealed that this bacterium produces several pigments in the carotenoid absorption range (six peaks). LC–MS confirms the presence of one main peak corresponding to lutein or zeaxanthin (an isomer of lutein) and several other carotenoid pigments and intermediaries in a lower quantity. Therefore, we propose CN7 strain as an alternative model to produce beneficial carotenoid pigments with potential nutritional applications in aquaculture.
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19
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Cryo-EM structure of the dimeric Rhodobacter sphaeroides RC-LH1 core complex at 2.9 Å: the structural basis for dimerisation. Biochem J 2021; 478:3923-3937. [PMID: 34622934 PMCID: PMC8652583 DOI: 10.1042/bcj20210696] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 10/07/2021] [Accepted: 10/07/2021] [Indexed: 11/23/2022]
Abstract
The dimeric reaction centre light-harvesting 1 (RC-LH1) core complex of Rhodobacter sphaeroides converts absorbed light energy to a charge separation, and then it reduces a quinone electron and proton acceptor to a quinol. The angle between the two monomers imposes a bent configuration on the dimer complex, which exerts a major influence on the curvature of the membrane vesicles, known as chromatophores, where the light-driven photosynthetic reactions take place. To investigate the dimerisation interface between two RC-LH1 monomers, we determined the cryogenic electron microscopy structure of the dimeric complex at 2.9 Å resolution. The structure shows that each monomer consists of a central RC partly enclosed by a 14-subunit LH1 ring held in an open state by PufX and protein-Y polypeptides, thus enabling quinones to enter and leave the complex. Two monomers are brought together through N-terminal interactions between PufX polypeptides on the cytoplasmic side of the complex, augmented by two novel transmembrane polypeptides, designated protein-Z, that bind to the outer faces of the two central LH1 β polypeptides. The precise fit at the dimer interface, enabled by PufX and protein-Z, by C-terminal interactions between opposing LH1 αβ subunits, and by a series of interactions with a bound sulfoquinovosyl diacylglycerol lipid, bring together each monomer creating an S-shaped array of 28 bacteriochlorophylls. The seamless join between the two sets of LH1 bacteriochlorophylls provides a path for excitation energy absorbed by one half of the complex to migrate across the dimer interface to the other half.
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20
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Qian P, Swainsbury DJK, Croll TI, Castro-Hartmann P, Divitini G, Sader K, Hunter CN. Cryo-EM Structure of the Rhodobacter sphaeroides Light-Harvesting 2 Complex at 2.1 Å. Biochemistry 2021; 60:3302-3314. [PMID: 34699186 PMCID: PMC8775250 DOI: 10.1021/acs.biochem.1c00576] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Light-harvesting 2 (LH2) antenna
complexes augment the collection
of solar energy in many phototrophic bacteria. Despite its frequent
role as a model for such complexes, there has been no three-dimensional
(3D) structure available for the LH2 from the purple phototroph Rhodobacter sphaeroides. We used cryo-electron microscopy
(cryo-EM) to determine the 2.1 Å resolution structure of this
LH2 antenna, which is a cylindrical assembly of nine αβ
heterodimer subunits, each of which binds three bacteriochlorophyll a (BChl) molecules and one carotenoid. The high resolution
of this structure reveals all of the interpigment and pigment–protein
interactions that promote the assembly and energy-transfer properties
of this complex. Near the cytoplasmic face of the complex there is
a ring of nine BChls, which absorb maximally at 800 nm and are designated
as B800; each B800 is coordinated by the N-terminal carboxymethionine
of LH2-α, part of a network of interactions with nearby residues
on both LH2-α and LH2-β and with the carotenoid. Nine
carotenoids, which are spheroidene in the strain we analyzed, snake
through the complex, traversing the membrane and interacting with
a ring of 18 BChls situated toward the periplasmic side of the complex.
Hydrogen bonds with C-terminal aromatic residues modify the absorption
of these pigments, which are red-shifted to 850 nm. Overlaps between
the macrocycles of the B850 BChls ensure rapid transfer of excitation
energy around this ring of pigments, which act as the donors of energy
to neighboring LH2 and reaction center light-harvesting 1 (RC–LH1)
complexes.
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Affiliation(s)
- Pu Qian
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG Eindhoven, Netherlands.,Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, U.K
| | - David J K Swainsbury
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, U.K
| | - Tristan I Croll
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, U.K
| | - Pablo Castro-Hartmann
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG Eindhoven, Netherlands
| | - Giorgio Divitini
- Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB3 0FS, U.K
| | - Kasim Sader
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG Eindhoven, Netherlands
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, U.K
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21
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Cryo-EM structure of the monomeric Rhodobacter sphaeroides RC-LH1 core complex at 2.5 Å. Biochem J 2021; 478:3775-3790. [PMID: 34590677 PMCID: PMC8589327 DOI: 10.1042/bcj20210631] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/22/2021] [Accepted: 09/30/2021] [Indexed: 12/02/2022]
Abstract
Reaction centre light-harvesting 1 (RC–LH1) complexes are the essential components of bacterial photosynthesis. The membrane-intrinsic LH1 complex absorbs light and the energy migrates to an enclosed RC where a succession of electron and proton transfers conserves the energy as a quinol, which is exported to the cytochrome bc1 complex. In some RC–LH1 variants quinols can diffuse through small pores in a fully circular, 16-subunit LH1 ring, while in others missing LH1 subunits create a gap for quinol export. We used cryogenic electron microscopy to obtain a 2.5 Å resolution structure of one such RC–LH1, a monomeric complex from Rhodobacter sphaeroides. The structure shows that the RC is partly enclosed by a 14-subunit LH1 ring in which each αβ heterodimer binds two bacteriochlorophylls and, unusually for currently reported complexes, two carotenoids rather than one. Although the extra carotenoids confer an advantage in terms of photoprotection and light harvesting, they could impede passage of quinones through small, transient pores in the LH1 ring, necessitating a mechanism to create a dedicated quinone channel. The structure shows that two transmembrane proteins play a part in stabilising an open ring structure; one of these components, the PufX polypeptide, is augmented by a hitherto undescribed protein subunit we designate as protein-Y, which lies against the transmembrane regions of the thirteenth and fourteenth LH1α polypeptides. Protein-Y prevents LH1 subunits 11–14 adjacent to the RC QB site from bending inwards towards the RC and, with PufX preventing complete encirclement of the RC, this pair of polypeptides ensures unhindered quinone diffusion.
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22
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Cryo-EM structure of the Rhodospirillum rubrum RC-LH1 complex at 2.5 Å. Biochem J 2021; 478:3253-3263. [PMID: 34402504 PMCID: PMC8454704 DOI: 10.1042/bcj20210511] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/12/2021] [Accepted: 08/17/2021] [Indexed: 12/03/2022]
Abstract
The reaction centre light-harvesting 1 (RC–LH1) complex is the core functional component of bacterial photosynthesis. We determined the cryo-electron microscopy (cryo-EM) structure of the RC–LH1 complex from Rhodospirillum rubrum at 2.5 Å resolution, which reveals a unique monomeric bacteriochlorophyll with a phospholipid ligand in the gap between the RC and LH1 complexes. The LH1 complex comprises a circular array of 16 αβ-polypeptide subunits that completely surrounds the RC, with a preferential binding site for a quinone, designated QP, on the inner face of the encircling LH1 complex. Quinols, initially generated at the RC QB site, are proposed to transiently occupy the QP site prior to traversing the LH1 barrier and diffusing to the cytochrome bc1 complex. Thus, the QP site, which is analogous to other such sites in recent cryo-EM structures of RC–LH1 complexes, likely reflects a general mechanism for exporting quinols from the RC–LH1 complex.
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23
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Razjivin A, Götze J, Lukashev E, Kozlovsky V, Ashikhmin A, Makhneva Z, Moskalenko A, Lokstein H, Paschenko V. Lack of Excitation Energy Transfer from the Bacteriochlorophyll Soret Band to Carotenoids in Photosynthetic Complexes of Purple Bacteria. J Phys Chem B 2021; 125:3538-3545. [PMID: 33818091 DOI: 10.1021/acs.jpcb.1c00719] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The excitation energy transfer (EET) from the bacteriochlorophyll (BChl) Soret band to the second excited state(s) (S2) of carotenoids in pigment-protein complexes of purple bacteria was investigated. The efficiency of EET was determined, based on fluorescence excitation and absorption spectra of chromatophores, peripheral light-harvesting complexes (LH2), core complexes (LH1-RC), and pigments in solution. Carotenoid-containing and carotenoid-less samples were compared: LH1-RC and LH2 from Allochromatium minutissimum, Ectothiorhodospira haloalkaliphila, and chromatophores from Rhodobacter sphaeroides and Rhodospirillum rubrum wild type and carotenoid-free strains R-26 and G9. BChl-to-carotenoid EET was absent, or its efficiency was less than the accuracy of the measurements of ∼5%. Quantum chemical calculations support the experimental results: The transition dipole moments of spatially close carotenoid/BChl pairs were found to be nearly orthogonal. The structural arrangements suggest that Soret EET may be lacking for the studied systems, however, EET from carotenoids to Qx appears to be possible.
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Affiliation(s)
- Andrei Razjivin
- Belozersky Research Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Jan Götze
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Evgeny Lukashev
- Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Vladimir Kozlovsky
- Belozersky Research Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Aleksandr Ashikhmin
- Institute of Basic Biological Problems of Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of Russian Academy of Sciences", 142290, Pushchino, Russia
| | - Zoya Makhneva
- Institute of Basic Biological Problems of Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of Russian Academy of Sciences", 142290, Pushchino, Russia
| | - Andrey Moskalenko
- Institute of Basic Biological Problems of Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of Russian Academy of Sciences", 142290, Pushchino, Russia
| | - Heiko Lokstein
- Department of Chemical Physics and Optics, Charles University, Ke Karlovu 3, 121 16 Prague, Czech Republic
| | - Vladimir Paschenko
- Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
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24
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Qu Y, Su A, Li Y, Meng Y, Chen Z. Manipulation of the Regulatory Genes ppsR and prrA in Rhodobacter sphaeroides Enhances Lycopene Production. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:4134-4143. [PMID: 33813825 DOI: 10.1021/acs.jafc.0c08158] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Rhodobacter sphaeroides is a non-sulfur purple bacterium with great metabolic versatility, capable of producing a variety of valuable compounds that include carotenoids and CoQ10. In order to enhance lycopene production, we deleted the photosynthetic gene cluster repressor ppsR from a lycopene-producing Rb. sphaeroides strain (RL1) constructed in a previous study to break the control of carotenoid synthesis by the oxygen level. Also, lycopene production was further increased by overexpression of the activator prrA. The superior lycopene producer DppsR/OprrA thus obtained had a high growth rate and a lycopene production of 150.15 mg/L with a yield of 21.45 mg/g dry cell weight (DCW) under high oxygen conditions; these values were ≥6.85-fold higher than those of RL1 (19.13 mg/L; 3.32 mg/g DCW). Our findings indicate that elimination of oxygen repression led to more efficient lycopene production by DppsR/OprrA and that its increased productivity under high oxygen conditions makes it a potentially useful strain for industrial-scale lycopene production.
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Affiliation(s)
- Yuling Qu
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Anping Su
- Shaanxi Engineering Laboratory for Food Green Processing and Security Control, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an, Shaanxi 710119, China
| | - Ying Li
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yonghong Meng
- Shaanxi Engineering Laboratory for Food Green Processing and Security Control, College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an, Shaanxi 710119, China
| | - Zhi Chen
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
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25
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Maróti P, Kovács IA, Kis M, Smart JL, Iglói F. Correlated clusters of closed reaction centers during induction of intact cells of photosynthetic bacteria. Sci Rep 2020; 10:14012. [PMID: 32814810 PMCID: PMC7438532 DOI: 10.1038/s41598-020-70966-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 07/29/2020] [Indexed: 01/18/2023] Open
Abstract
Antenna systems serve to absorb light and to transmit excitation energy to the reaction center (RC) in photosynthetic organisms. As the emitted (bacterio)chlorophyll fluorescence competes with the photochemical utilization of the excitation, the measured fluorescence yield is informed by the migration of the excitation in the antenna. In this work, the fluorescence yield concomitant with the oxidized dimer (P+) of the RC were measured during light excitation (induction) and relaxation (in the dark) for whole cells of photosynthetic bacterium Rhodobacter sphaeroides lacking cytochrome c2 as natural electron donor to P+ (mutant cycA). The relationship between the fluorescence yield and P+ (fraction of closed RC) showed deviations from the standard Joliot-Lavergne-Trissl model: (1) the hyperbola is not symmetric and (2) exhibits hysteresis. These phenomena originate from the difference between the delays of fluorescence relative to P+ kinetics during induction and relaxation, and in structural terms from the non-random distribution of the closed RCs during induction. The experimental findings are supported by Monte Carlo simulations and by results from statistical physics based on random walk approximations of the excitation in the antenna. The applied mathematical treatment demonstrates the generalization of the standard theory and sets the stage for a more adequate description of the long-debated kinetics of fluorescence and of the delicate control and balance between efficient light harvest and photoprotection in photosynthetic organisms.
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Affiliation(s)
- Péter Maróti
- Department of Medical Physics and Informatics, Szeged University, Rerrich Béla tér 1., 6720, Szeged, Hungary.
| | - István A Kovács
- Department of Physics and Astronomy, Northwestern University, Evanston, IL, 60208-3112, USA
- Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, P.O. Box 49, 1525, Budapest, Hungary
- Department of Network and Data Science, Central European University, Budapest, 1051, Hungary
| | - Mariann Kis
- Department of Medical Physics and Informatics, Szeged University, Rerrich Béla tér 1., 6720, Szeged, Hungary
| | - James L Smart
- Department of Biological Sciences, University of Tennessee at Martin, Martin, TN, 38238, USA
| | - Ferenc Iglói
- Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, P.O. Box 49, 1525, Budapest, Hungary
- Institute of Theoretical Physics, Szeged University, 6720, Szeged, Hungary
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26
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Hollensteiner J, Schneider D, Poehlein A, Daniel R. Complete Genome of Roseobacter ponti DSM 106830T. Genome Biol Evol 2020; 12:1013-1018. [PMID: 32658259 DOI: 10.1093/gbe/evaa114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2020] [Indexed: 12/28/2022] Open
Abstract
Members of the Roseobacter group are known for their different ecologically relevant metabolic traits and high abundance in many marine environments. This includes traits like carbon monoxide oxidation, sulfur oxidation, nitrogen oxidation, DMSP demethylation, denitrification, and production of bioactive compounds. Nevertheless, their role in the marine biogeochemical cycles remains to be elucidated. Roseobacter ponti DSM 106830T, also designated strain MM-7T (=KCTC 52469T =NBRC 112431T), is a novel type strain of the Roseobacter group, which was proposed as new Roseobacter species. It was isolated from seawater of the Yellow Sea in South Korea. We report the complete genome sequence of R. ponti DSM 106830T, which belongs to the family Rhodobacteraceae. The genome of R. ponti DSM 106830T comprises a single circular chromosome (3,861,689 bp) with a GC content of 60.52% and an additional circular plasmid (p1) of 100,942 bp with a GC content of 61.51%. The genome encodes 3,812 putative genes, including 3 rRNA, 42 tRNA, 1 tmRNA, and 3 ncRNA. The genome information was used to perform a phylogenetic analysis, which confirmed that the strain represents a new species. Moreover, the genome sequence enabled the investigation of the metabolic capabilities and versatility of R. ponti DSM 106830T. Finally, it provided insight into the high niche adaptation potential of Roseobacter group members.
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Affiliation(s)
- Jacqueline Hollensteiner
- Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August University of Göttingen, Germany
| | - Dominik Schneider
- Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August University of Göttingen, Germany
| | - Anja Poehlein
- Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August University of Göttingen, Germany
| | - Rolf Daniel
- Genomic and Applied Microbiology and Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August University of Göttingen, Germany
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27
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Niedzwiedzki DM, Swainsbury DJK, Hunter CN. Carotenoid-to-(bacterio)chlorophyll energy transfer in LH2 antenna complexes from Rba. sphaeroides reconstituted with non-native (bacterio)chlorophylls. PHOTOSYNTHESIS RESEARCH 2020; 144:155-169. [PMID: 31350671 PMCID: PMC7203092 DOI: 10.1007/s11120-019-00661-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 07/16/2019] [Indexed: 05/04/2023]
Abstract
Six variants of the LH2 antenna complex from Rba. sphaeroides, comprising the native B800-B850, B800-free LH2 (B850) and four LH2s with various (bacterio)chlorophylls reconstituted into the B800 site, have been investigated with static and time-resolved optical spectroscopies at room temperature and at 77 K. The study particularly focused on how reconstitution of a non-native (bacterio)chlorophylls affects excitation energy transfer between the naturally bound carotenoid spheroidene and artificially substituted pigments in the B800 site. Results demonstrate there is no apparent trend in the overall energy transfer rate from spheroidene to B850 bacteriochlorophyll a; however, a trend in energy transfer rate from the spheroidene S1 state to Qy of the B800 (bacterio)chlorophylls is noticeable. These outcomes were applied to test the validity of previously proposed energy values of the spheroidene S1 state, supporting a value in the vicinity of 13,400 cm-1 (746 nm).
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Affiliation(s)
- Dariusz M Niedzwiedzki
- Center for Solar Energy and Energy Storage, Washington University, St. Louis, MO, 63130, USA.
- Department of Energy, Environmental & Chemical Engineering, Washington University, St. Louis, MO, 63130, USA.
| | - David J K Swainsbury
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
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Bolshakov MA, Ashikhmin AA, Makhneva ZK, Moskalenko AA. Assembly of the LH2 Light-Harvesting Complexes of Thiorhodospira sibirica with Different Carotenoid Levels. Microbiology (Reading) 2020. [DOI: 10.1134/s0026261720030042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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29
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Makhneva ZK, Ashikhmin AA, Bolshakov MA, Moskalenko AA. Carotenoids are Probably Involved in Singlet Oxygen Generation in the Membranes of Purple Photosynthetic Bacteria under Light Irradiation. Microbiology (Reading) 2020. [DOI: 10.1134/s0026261720010099] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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A photosynthetic antenna complex foregoes unity carotenoid-to-bacteriochlorophyll energy transfer efficiency to ensure photoprotection. Proc Natl Acad Sci U S A 2020; 117:6502-6508. [PMID: 32139606 DOI: 10.1073/pnas.1920923117] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Carotenoids play a number of important roles in photosynthesis, primarily providing light-harvesting and photoprotective energy dissipation functions within pigment-protein complexes. The carbon-carbon double bond (C=C) conjugation length of carotenoids (N), generally between 9 and 15, determines the carotenoid-to-(bacterio)chlorophyll [(B)Chl] energy transfer efficiency. Here we purified and spectroscopically characterized light-harvesting complex 2 (LH2) from Rhodobacter sphaeroides containing the N = 7 carotenoid zeta (ζ)-carotene, not previously incorporated within a natural antenna complex. Transient absorption and time-resolved fluorescence show that, relative to the lifetime of the S1 state of ζ-carotene in solvent, the lifetime decreases ∼250-fold when ζ-carotene is incorporated within LH2, due to transfer of excitation energy to the B800 and B850 BChls a These measurements show that energy transfer proceeds with an efficiency of ∼100%, primarily via the S1 → Qx route because the S1 → S0 fluorescence emission of ζ-carotene overlaps almost perfectly with the Qx absorption band of the BChls. However, transient absorption measurements performed on microsecond timescales reveal that, unlike the native N ≥ 9 carotenoids normally utilized in light-harvesting complexes, ζ-carotene does not quench excited triplet states of BChl a, likely due to elevation of the ζ-carotene triplet energy state above that of BChl a These findings provide insights into the coevolution of photosynthetic pigments and pigment-protein complexes. We propose that the N ≥ 9 carotenoids found in light-harvesting antenna complexes represent a vital compromise that retains an acceptable level of energy transfer from carotenoids to (B)Chls while allowing acquisition of a new, essential function, namely, photoprotective quenching of harmful (B)Chl triplets.
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31
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Usmani Z, Sharma M, Sudheer S, Gupta VK, Bhat R. Engineered Microbes for Pigment Production Using Waste Biomass. Curr Genomics 2020; 21:80-95. [PMID: 32655303 PMCID: PMC7324876 DOI: 10.2174/1389202921999200330152007] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/08/2020] [Accepted: 03/16/2020] [Indexed: 12/17/2022] Open
Abstract
Agri-food waste biomass is the most abundant organic waste and has high valorisation potential for sustainable bioproducts development. These wastes are not only recyclable in nature but are also rich sources of bioactive carbohydrates, peptides, pigments, polyphenols, vitamins, natural antioxidants, etc. Bioconversion of agri-food waste to value-added products is very important towards zero waste and circular economy concepts. To reduce the environmental burden, food researchers are seeking strategies to utilize this waste for microbial pigments production and further biotechnological exploitation in functional foods or value-added products. Microbes are valuable sources for a range of bioactive molecules, including microbial pigments production through fermentation and/or utilisation of waste. Here, we have reviewed some of the recent advancements made in important bioengineering technologies to develop engineered microbial systems for enhanced pigments production using agri-food wastes biomass/by-products as substrates in a sustainable way.
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Affiliation(s)
| | - Minaxi Sharma
- Address correspondence to these authors at the ERA Chair for Food (By-) Products Valorization Technologies- VALORTECH, Estonian University of Life Sciences, Kreutzwaldi 56/5, 51006, Tartu, Estonia; Tel/Fax: +372 7313927; E-mails: ;, ;
| | | | | | - Rajeev Bhat
- Address correspondence to these authors at the ERA Chair for Food (By-) Products Valorization Technologies- VALORTECH, Estonian University of Life Sciences, Kreutzwaldi 56/5, 51006, Tartu, Estonia; Tel/Fax: +372 7313927; E-mails: ;, ;
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32
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Qiang S, Su AP, Li Y, Chen Z, Hu CY, Meng YH. Elevated β-Carotene Synthesis by the Engineered Rhodobacter sphaeroides with Enhanced CrtY Expression. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:9560-9568. [PMID: 31368704 DOI: 10.1021/acs.jafc.9b02597] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
β-Carotene is a precursor of vitamin A and a dietary supplement for its antioxidant property. Producing β-carotene by microbial fermentation has attracted much attention owing to consumers' preference for the natural product. In this study, an engineered photosynthetic Rhodobacter sphaeroides producing β-carotene was constructed by the following strategies: (1) five promoters of different strengths were used to investigate the effect of the expression level of crtY on β-carotene content. It was found that PrrnB increased the β-carotene content by 109%. (2) blocking of the branched pentose phosphate pathway by zwf deletion, and (3) overexpressing dxs could restore the transcriptional levels of crtE and crtB. Finally, the engineered RS-C3 has the highest β-carotene content of 14.93 mg/g dry cell weight (DCW) among all of the reported photosynthetic bacteria and the β-carotene content reached 3.34 mg/g DCW under light conditions. Our results will be available for industrial use to supply a large quantity of natural β-carotene.
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Affiliation(s)
- Shan Qiang
- Shaanxi Engineering Lab for Food Green Processing and Security Control, College of Food Engineering and Nutritional Science , Shaanxi Normal University , 620 West Chang'an Avenue , Chang'an, Xi'an 710119 , P. R. China
- Xi'an Healthful Biotechnology Co., Ltd. , HangTuo Road , Chang'an, Xi'an 710100 , P. R. China
| | - An Ping Su
- Shaanxi Engineering Lab for Food Green Processing and Security Control, College of Food Engineering and Nutritional Science , Shaanxi Normal University , 620 West Chang'an Avenue , Chang'an, Xi'an 710119 , P. R. China
| | - Ying Li
- State Key Laboratory of Agrobiotechnology , China Agricultural University , No. 2 Yuanmingyuan West Road , Haidian District, Beijing 100193 , P. R. China
| | - Zhi Chen
- State Key Laboratory of Agrobiotechnology , China Agricultural University , No. 2 Yuanmingyuan West Road , Haidian District, Beijing 100193 , P. R. China
| | - Ching Yuan Hu
- Human Nutrition, Food, and Animal Science , University of Hawai'i at Manoa , 1955 East-West Road, AgSci. 415J , Honolulu , Hawaii 96822-2217 , United States
| | - Yong Hong Meng
- Shaanxi Engineering Lab for Food Green Processing and Security Control, College of Food Engineering and Nutritional Science , Shaanxi Normal University , 620 West Chang'an Avenue , Chang'an, Xi'an 710119 , P. R. China
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33
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Wang C, Zhao S, Shao X, Park JB, Jeong SH, Park HJ, Kwak WJ, Wei G, Kim SW. Challenges and tackles in metabolic engineering for microbial production of carotenoids. Microb Cell Fact 2019; 18:55. [PMID: 30885243 PMCID: PMC6421696 DOI: 10.1186/s12934-019-1105-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 03/08/2019] [Indexed: 02/07/2023] Open
Abstract
Naturally occurring carotenoids have been isolated and used as colorants, antioxidants, nutrients, etc. in many fields. There is an ever-growing demand for carotenoids production. To comfort this, microbial production of carotenoids is an attractive alternative to current extraction from natural sources. This review summarizes the biosynthetic pathway of carotenoids and progresses in metabolic engineering of various microorganisms for carotenoid production. The advances in synthetic pathway and systems biology lead to many versatile engineering tools available to manipulate microorganisms. In this context, challenges and possible directions are also discussed to provide an insight of microbial engineering for improved production of carotenoids in the future.
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Affiliation(s)
- Chonglong Wang
- School of Biology and Basic Medical Sciences, Soochow University, 199 Renai Road, Suzhou, 215123, People's Republic of China.
| | - Shuli Zhao
- School of Biology and Basic Medical Sciences, Soochow University, 199 Renai Road, Suzhou, 215123, People's Republic of China
| | - Xixi Shao
- School of Biology and Basic Medical Sciences, Soochow University, 199 Renai Road, Suzhou, 215123, People's Republic of China
| | - Ji-Bin Park
- Division of Applied Life Science (BK21 Plus), PMBBRC, Gyeongsang National University, 501 Jinju-daero, Jinju, 52828, Republic of Korea
| | - Seong-Hee Jeong
- Division of Applied Life Science (BK21 Plus), PMBBRC, Gyeongsang National University, 501 Jinju-daero, Jinju, 52828, Republic of Korea
| | - Hyo-Jin Park
- Division of Applied Life Science (BK21 Plus), PMBBRC, Gyeongsang National University, 501 Jinju-daero, Jinju, 52828, Republic of Korea
| | - Won-Ju Kwak
- Division of Applied Life Science (BK21 Plus), PMBBRC, Gyeongsang National University, 501 Jinju-daero, Jinju, 52828, Republic of Korea
| | - Gongyuan Wei
- School of Biology and Basic Medical Sciences, Soochow University, 199 Renai Road, Suzhou, 215123, People's Republic of China
| | - Seon-Won Kim
- Division of Applied Life Science (BK21 Plus), PMBBRC, Gyeongsang National University, 501 Jinju-daero, Jinju, 52828, Republic of Korea.
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34
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Rhodobacter thermarum sp. nov., a novel phototrophic bacterium isolated from sediment of a hot spring. Antonie van Leeuwenhoek 2019; 112:867-875. [DOI: 10.1007/s10482-018-01219-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 12/13/2018] [Indexed: 10/27/2022]
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35
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Golub M, Pieper J, Peters J, Kangur L, Martin EC, Hunter CN, Freiberg A. Picosecond Dynamical Response to a Pressure-Induced Break of the Tertiary Structure Hydrogen Bonds in a Membrane Chromoprotein. J Phys Chem B 2019; 123:2087-2093. [PMID: 30739452 DOI: 10.1021/acs.jpcb.8b11196] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We used elastic incoherent neutron scattering (EINS) to find out if structural changes accompanying local hydrogen bond rupture are also reflected in global dynamical response of the protein complex. Chromatophore membranes from LH2-only strains of the photosynthetic bacterium Rhodobacter sphaeroides, with spheroidenone or neurosporene as the major carotenoids, were subjected to high hydrostatic pressure at ambient temperature. Optical spectroscopy conducted at high pressure confirmed rupture of tertiary structure hydrogen bonds. In parallel, we used EINS to follow average motions of the hydrogen atoms in LH2, which reflect the flexibility of this complex. A decrease of the average atomic mean square displacements of hydrogen atoms was observed up to a pressure of 5 kbar in both carotenoid samples due to general stiffening of protein structures, while at higher pressures a slight increase of the displacements was detected in the neurosporene mutant LH2 sample only. These data show a correlation between the local pressure-induced breakage of H-bonds, observed in optical spectra, with the altered protein dynamics monitored by EINS. The slightly higher compressibility of the neurosporene mutant sample shows that even subtle alterations of carotenoids are manifested on a larger scale and emphasize a close connection between the local structure and global dynamics of this membrane protein complex.
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Affiliation(s)
- Maksym Golub
- Institute of Physics , University of Tartu , W. Ostwald Str. 1 , 50411 Tartu , Estonia
| | - Jörg Pieper
- Institute of Physics , University of Tartu , W. Ostwald Str. 1 , 50411 Tartu , Estonia
| | - Judith Peters
- Institut Laue Langevin , F-38042 Grenoble Cedex 9 , France.,University Grenoble Alpes, CNRS, LIPhy , 38000 Grenoble , France
| | - Liina Kangur
- Institute of Physics , University of Tartu , W. Ostwald Str. 1 , 50411 Tartu , Estonia
| | - Elizabeth C Martin
- Department of Molecular Biology and Biotechnology , University of Sheffield , S10 2TN Sheffield , U.K
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology , University of Sheffield , S10 2TN Sheffield , U.K
| | - Arvi Freiberg
- Institute of Physics , University of Tartu , W. Ostwald Str. 1 , 50411 Tartu , Estonia.,Institute of Molecular and Cell Biology , University of Tartu , Riia 23 , 51010 Tartu , Estonia
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36
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Autenrieth C, Ghosh R. The Methoxylated, Highly Conjugated C 40 Carotenoids, Spirilloxanthin and Anhydrorhodovibrin, Can Be Separated Using High Performance Liquid Chromatography with Safe and Environmentally Friendly Solvents. Metabolites 2019; 9:metabo9020020. [PMID: 30682824 PMCID: PMC6410002 DOI: 10.3390/metabo9020020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/11/2019] [Accepted: 01/19/2019] [Indexed: 11/21/2022] Open
Abstract
High performance liquid chromatography (HPLC) is a frequently used technique in carotenoid research. So far, however, little attention has been paid to the fact that many of the organic solvents used in HPLC separation of highly apolar C40 carotenoids impose a significant threat to both health (especially for women) and the general laboratory environment. Here, we developed a solvent combination capable of allowing high-resolution HPLC separation of the C40 carotenoid, spirilloxanthin, and all of its biosynthetic precursors beginning with phytoene, using relatively safe, environmentally friendly solvents. We show that separation of spirilloxanthin and its precursors anhydrorhodovibrin and lycopene using modern ultra-high performance chromatography (UHPLC) poses particular problems for apolar carotenoid separation, due to the long residence times in the sample delivery system, which facilitates carotenoid aggregation. We resolved these problems by developing the solvent delivery combination acetone/acetonitrile/isopropanol/methanol (65/30/5/2 (v/v/v/v)), which allows excellent column separation using the safe isocratic solvent system methanol/tetrahydrofuran (98/2 (v/v)). We also demonstrate that the development strategy for optimizing a solvent system for carotenoid separation can be well-described by the use of the average dielectric constant of the total sample delivery solvent, and present a formal method for analysis of the efficiency of separation.
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Affiliation(s)
- Caroline Autenrieth
- Department of Bioenergetics, Institute of Biomaterials and Biomolecular Systems, University of Stuttgart, Pfaffenwaldring 57, D-70569 Stuttgart, Germany.
| | - Robin Ghosh
- Department of Bioenergetics, Institute of Biomaterials and Biomolecular Systems, University of Stuttgart, Pfaffenwaldring 57, D-70569 Stuttgart, Germany.
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37
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Introduction of Glyoxylate Bypass Increases Hydrogen Gas Yield from Acetate and l-Glutamate in Rhodobacter sphaeroides. Appl Environ Microbiol 2019; 85:AEM.01873-18. [PMID: 30413472 DOI: 10.1128/aem.01873-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 11/05/2018] [Indexed: 11/20/2022] Open
Abstract
Rhodobacter sphaeroides produces hydrogen gas (H2) from organic compounds via nitrogenase under anaerobic-light conditions in the presence of poor nitrogen sources, such as l-glutamate. R. sphaeroides utilizes the ethylmalonyl-coenzyme A (EMC) pathway for acetate assimilation, but its H2 yield from acetate in the presence of l-glutamate has been reported to be low. In this study, the deletion of ccr encoding crotonyl-coenzyme A (crotonyl-CoA) carboxylase/reductase, a key enzyme for the EMC pathway in R. sphaeroides, revealed that the EMC pathway is essential for H2 production from acetate and l-glutamate but not for growth and acetate consumption in the presence of l-glutamate. We introduced a plasmid expressing aceBA from Rhodobacter capsulatus encoding two key enzymes for the glyoxylate bypass into R. sphaeroides, which resulted in a 64% increase in H2 production. However, compared with the wild-type strain expressing heterologous aceBA genes, the strain with aceBA introduced in the genetic background of an EMC pathway-disrupted mutant showed a lower H2 yield. These results indicate that a combination of the endogenous EMC pathway and a heterologously expressed glyoxylate bypass is beneficial for H2 production. In addition, introduction of the glyoxylate bypass into a polyhydroxybutyrate (PHB) biosynthesis-disrupted mutant resulted in a delay in growth along with H2 production, although its H2 yield was comparable to that of the wild-type strain expressing heterologous aceBA genes. These results suggest that PHB production is important for fitness to the culture during H2 production from acetate and l-glutamate when both acetate-assimilating pathways are present.IMPORTANCE As an alternative to fossil fuel, H2 is a promising renewable energy source. Although photofermentative H2 production from acetate is key to developing an efficient process of biohydrogen production from biomass-derived sugars, H2 yields from acetate and l-glutamate by R. sphaeroides have been reported to be low. In this study, we observed that in addition to the endogenous EMC pathway, heterologous expression of the glyoxylate bypass in R. sphaeroides markedly increased H2 yields from acetate and l-glutamate. Therefore, this study provides a novel strategy for improving H2 yields from acetate in the presence of l-glutamate and contributes to a clear understanding of acetate metabolism in R. sphaeroides during photofermentative H2 production.
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Ashikhmin AA, Makhneva ZK, Bolshakov MA, Moskalenko AA. The Influence of the Number of Conjugated Double Bonds in Carotenoid Molecules on the Energy Transfer Efficiency to Bacteriochlorophyll in Light-Harvesting Complexes LH2 from Allochromatium vinosum Strain MSU. DOKL BIOCHEM BIOPHYS 2019; 483:321-325. [PMID: 30607730 DOI: 10.1134/s160767291806008x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Indexed: 11/23/2022]
Abstract
Seven different carotenoids with the number of conjugated double bonds (N) from 5 to 11 were incorporated in vitro into carotenoidless complexes LH2 of the sulfur bacterium Allochromatium vinosum strain MSU. The efficiency of their incorporation varied from 4 to 99%. The influence of N in the carotenoid molecules on the energy transfer efficiency from these pigments to bacteriochlorophyll (BChl) in the modified LH2 complexes was studied for the first time. The highest level of energy transfer was recorded for rhodopin (N = 11) and neurosporene (N = 7) (37 and 51%, respectively). In the other carotenoids, this parameter ranged from 11 to 33%. In the LH2 complexes studied, we found no direct correlation between the decrease in N in carotenoids and increase in the energy transfer efficiency from these pigments to BChl.
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Affiliation(s)
- A A Ashikhmin
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow oblast, 142290, Russia.
| | - Z K Makhneva
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow oblast, 142290, Russia
| | - M A Bolshakov
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow oblast, 142290, Russia
| | - A A Moskalenko
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow oblast, 142290, Russia
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39
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Engineering of B800 bacteriochlorophyll binding site specificity in the Rhodobacter sphaeroides LH2 antenna. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1860:209-223. [PMID: 30414933 PMCID: PMC6358721 DOI: 10.1016/j.bbabio.2018.11.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 10/19/2018] [Accepted: 11/07/2018] [Indexed: 11/22/2022]
Abstract
The light-harvesting 2 complex (LH2) of the purple phototrophic bacterium Rhodobacter sphaeroides is a highly efficient, light-harvesting antenna that allows growth under a wide-range of light intensities. In order to expand the spectral range of this antenna complex, we first used a series of competition assays to measure the capacity of the non-native pigments 3-acetyl chlorophyll (Chl) a, Chl d, Chl f or bacteriochlorophyll (BChl) b to replace native BChl a in the B800 binding site of LH2. We then adjusted the B800 site and systematically assessed the binding of non-native pigments. We find that Arg-10 of the LH2 β polypeptide plays a crucial role in binding specificity, by providing a hydrogen-bond to the 3-acetyl group of native and non-native pigments. Reconstituted LH2 complexes harbouring the series of (B)Chls were examined by transient absorption and steady-state fluorescence spectroscopies. Although slowed 10-fold to ~6 ps, energy transfer from Chl a to B850 BChl a remained highly efficient. We measured faster energy-transfer time constants for Chl d (3.5 ps) and Chl f (2.7 ps), which have red-shifted absorption maxima compared to Chl a. BChl b, red-shifted from the native BChl a, gave extremely rapid (≤0.1 ps) transfer. These results show that modified LH2 complexes, combined with engineered (B)Chl biosynthesis pathways in vivo, have potential for retaining high efficiency whilst acquiring increased spectral range.
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40
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Canniffe DP, Thweatt JL, Gomez Maqueo Chew A, Hunter CN, Bryant DA. A paralog of a bacteriochlorophyll biosynthesis enzyme catalyzes the formation of 1,2-dihydrocarotenoids in green sulfur bacteria. J Biol Chem 2018; 293:15233-15242. [PMID: 30126840 PMCID: PMC6166724 DOI: 10.1074/jbc.ra118.004672] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 08/17/2018] [Indexed: 12/03/2022] Open
Abstract
Chlorobaculum tepidum, a green sulfur bacterium, utilizes chlorobactene as its major carotenoid, and this organism also accumulates a reduced form of this monocyclic pigment, 1′,2′-dihydrochlorobactene. The protein catalyzing this reduction is the last unidentified enzyme in the biosynthetic pathways for all of the green sulfur bacterial pigments used for photosynthesis. The genome of C. tepidum contains two paralogous genes encoding members of the FixC family of flavoproteins: bchP, which has been shown to encode an enzyme of bacteriochlorophyll biosynthesis; and bchO, for which a function has not been assigned. Here we demonstrate that a bchO mutant is unable to synthesize 1′,2′-dihydrochlorobactene, and when bchO is heterologously expressed in a neurosporene-producing mutant of the purple bacterium, Rhodobacter sphaeroides, the encoded protein is able to catalyze the formation of 1,2-dihydroneurosporene, the major carotenoid of the only other organism reported to synthesize 1,2-dihydrocarotenoids, Blastochloris viridis. Identification of this enzyme completes the pathways for the synthesis of photosynthetic pigments in Chlorobiaceae, and accordingly and consistent with its role in carotenoid biosynthesis, we propose to rename the gene cruI. Notably, the absence of cruI in B. viridis indicates that a second 1,2-carotenoid reductase, which is structurally unrelated to CruI (BchO), must exist in nature. The evolution of this carotenoid reductase in green sulfur bacteria is discussed herein.
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Affiliation(s)
- Daniel P Canniffe
- From the Department of Molecular Biology & Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom, .,the Department of Biochemistry & Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, and
| | - Jennifer L Thweatt
- the Department of Biochemistry & Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, and
| | - Aline Gomez Maqueo Chew
- the Department of Biochemistry & Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, and
| | - C Neil Hunter
- From the Department of Molecular Biology & Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Donald A Bryant
- the Department of Biochemistry & Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, and .,the Department of Chemistry & Biochemistry, Montana State University, Bozeman, Montana 59717
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41
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Lishchuk A, Kodali G, Mancini JA, Broadbent M, Darroch B, Mass OA, Nabok A, Dutton PL, Hunter CN, Törmä P, Leggett GJ. A synthetic biological quantum optical system. NANOSCALE 2018; 10:13064-13073. [PMID: 29956712 PMCID: PMC6044288 DOI: 10.1039/c8nr02144a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 06/06/2018] [Indexed: 06/08/2023]
Abstract
In strong plasmon-exciton coupling, a surface plasmon mode is coupled to an array of localized emitters to yield new hybrid light-matter states (plexcitons), whose properties may in principle be controlled via modification of the arrangement of emitters. We show that plasmon modes are strongly coupled to synthetic light-harvesting maquette proteins, and that the coupling can be controlled via alteration of the protein structure. For maquettes with a single chlorin binding site, the exciton energy (2.06 ± 0.07 eV) is close to the expected energy of the Qy transition. However, for maquettes containing two chlorin binding sites that are collinear in the field direction, an exciton energy of 2.20 ± 0.01 eV is obtained, intermediate between the energies of the Qx and Qy transitions of the chlorin. This observation is attributed to strong coupling of the LSPR to an H-dimer state not observed under weak coupling.
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Affiliation(s)
- Anna Lishchuk
- Department of Chemistry
, University of Sheffield
,
Brook Hill
, Sheffield S3 7HF
, UK
.
| | - Goutham Kodali
- The Johnson Research Foundation and Department of Biochemistry and Biophysics
, University of Pennsylvania
,
Philadelphia
, PA 10104
, USA
| | - Joshua A. Mancini
- The Johnson Research Foundation and Department of Biochemistry and Biophysics
, University of Pennsylvania
,
Philadelphia
, PA 10104
, USA
| | - Matthew Broadbent
- Department of Chemistry
, University of Sheffield
,
Brook Hill
, Sheffield S3 7HF
, UK
.
| | - Brice Darroch
- Department of Chemistry
, University of Sheffield
,
Brook Hill
, Sheffield S3 7HF
, UK
.
| | - Olga A. Mass
- N. Carolina State University
, Department of Chemistry
,
Raleigh
, NC 27695
, USA
| | - Alexei Nabok
- Materials and Engineering Research Institute
, Sheffield Hallam University
,
Howard St
, Sheffield S1 1WB
, UK
| | - P. Leslie Dutton
- The Johnson Research Foundation and Department of Biochemistry and Biophysics
, University of Pennsylvania
,
Philadelphia
, PA 10104
, USA
| | - C. Neil Hunter
- Department of Molecular Biology and Biotechnology
, University of Sheffield
,
Western Bank
, Sheffield S10 2TN
, UK
| | - Päivi Törmä
- COMP Centre of Excellence
, Department of Applied Physics
, Aalto University
, School of Science
,
P.O. Box 15100
, 00076 Aalto
, Finland
| | - Graham J. Leggett
- Department of Chemistry
, University of Sheffield
,
Brook Hill
, Sheffield S3 7HF
, UK
.
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42
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Su A, Chi S, Li Y, Tan S, Qiang S, Chen Z, Meng Y. Metabolic Redesign of Rhodobacter sphaeroides for Lycopene Production. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:5879-5885. [PMID: 29806774 DOI: 10.1021/acs.jafc.8b00855] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Lycopene plays an important role as an antioxidative and anticancer agent, and is an increasingly valuable commodity in the global market. Rhodobacter sphaeroides, a carotenogenic and phototrophic bacterium, is an efficient and practical host for carotenoid production. Herein, we explored the potential of metabolically engineered Rb. sphaeroides as a novel platform to produce lycopene. The basal lycopene-producing strain was generated by introducing an exogenous crtI4 from Rhodospirillum rubrum to replace the native crtI3 and deleting crtC in Rb. sphaeroides. Furthermore, knocking out zwf blocked the competitive pentose phosphate pathway and improved the lycopene content by 88%. Finally, the methylerythritol phosphate pathway was reinforced by integration of dxs combined with zwf deletion, which further increased the lycopene content. The final engineered strain produced lycopene to 10.32 mg/g dry cell weight. This study describes a new lycopene producer and provides insight into a photosynthetic bacterium as a host for lycopene biosynthesis.
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Affiliation(s)
- Anping Su
- Shaanxi Engineering Lab for Food Green Processing and Security Control, College of Food Engineering and Nutritional Science , Shaanxi Normal University , 620 West Chang'an Avenue , Chang'an, Xi'an 710119 , P.R. China
| | - Shuang Chi
- State Key Laboratory of Agrobiotechnology , China Agricultural University , No. 2 Yuanmingyuan West Road, Haidian District , Beijing 100193 , P.R. China
| | - Ying Li
- State Key Laboratory of Agrobiotechnology , China Agricultural University , No. 2 Yuanmingyuan West Road, Haidian District , Beijing 100193 , P.R. China
| | - Siyuan Tan
- Shaanxi Engineering Lab for Food Green Processing and Security Control, College of Food Engineering and Nutritional Science , Shaanxi Normal University , 620 West Chang'an Avenue , Chang'an, Xi'an 710119 , P.R. China
| | - Shan Qiang
- Xi'an Healthful Biotechnology Co., Ltd., HangTuo Road , Chang'an, Xi'an 710100 , P.R. China
| | - Zhi Chen
- State Key Laboratory of Agrobiotechnology , China Agricultural University , No. 2 Yuanmingyuan West Road, Haidian District , Beijing 100193 , P.R. China
| | - Yonghong Meng
- Shaanxi Engineering Lab for Food Green Processing and Security Control, College of Food Engineering and Nutritional Science , Shaanxi Normal University , 620 West Chang'an Avenue , Chang'an, Xi'an 710119 , P.R. China
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43
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Liu J, Friebe V, Swainsbury DJK, Crouch LI, Szabo DA, Frese RN, Jones MR. Engineered photoproteins that give rise to photosynthetically-incompetent bacteria are effective as photovoltaic materials for biohybrid photoelectrochemical cells. Faraday Discuss 2018; 207:307-327. [PMID: 29364305 PMCID: PMC5903125 DOI: 10.1039/c7fd00190h] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 09/04/2017] [Indexed: 01/27/2023]
Abstract
Reaction centre/light harvesting proteins such as the RCLH1X complex from Rhodobacter sphaeroides carry out highly quantum-efficient conversion of solar energy through ultrafast energy transfer and charge separation, and these pigment-proteins have been incorporated into biohybrid photoelectrochemical cells for a variety of applications. In this work we demonstrate that, despite not being able to support normal photosynthetic growth of Rhodobacter sphaeroides, an engineered variant of this RCLH1X complex lacking the PufX protein and with an enlarged light harvesting antenna is unimpaired in its capacity for photocurrent generation in two types of bio-photoelectrochemical cells. Removal of PufX also did not impair the ability of the RCLH1 complex to act as an acceptor of energy from synthetic light harvesting quantum dots. Unexpectedly, the removal of PufX led to a marked improvement in the overall stability of the RCLH1 complex under heat stress. We conclude that PufX-deficient RCLH1 complexes are fully functional in solar energy conversion in a device setting and that their enhanced structural stability could make them a preferred choice over their native PufX-containing counterpart. Our findings on the competence of RCLH1 complexes for light energy conversion in vitro are discussed with reference to the reason why these PufX-deficient proteins are not capable of light energy conversion in vivo.
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Affiliation(s)
- Juntai Liu
- School of Biochemistry , University of Bristol , Medical Sciences Building, University Walk , Bristol BS8 1TD , UK .
| | - Vincent M. Friebe
- Department of Physics and Astronomy , LaserLaB Amsterdam , VU University Amsterdam , De Boelelaan 1081, 1081 HV , Amsterdam , The Netherlands
| | - David J. K. Swainsbury
- School of Biochemistry , University of Bristol , Medical Sciences Building, University Walk , Bristol BS8 1TD , UK .
| | - Lucy I. Crouch
- School of Biochemistry , University of Bristol , Medical Sciences Building, University Walk , Bristol BS8 1TD , UK .
| | - David A. Szabo
- School of Biochemistry , University of Bristol , Medical Sciences Building, University Walk , Bristol BS8 1TD , UK .
| | - Raoul N. Frese
- Department of Physics and Astronomy , LaserLaB Amsterdam , VU University Amsterdam , De Boelelaan 1081, 1081 HV , Amsterdam , The Netherlands
| | - Michael R. Jones
- School of Biochemistry , University of Bristol , Medical Sciences Building, University Walk , Bristol BS8 1TD , UK .
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44
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Sipka G, Maróti P. Photoprotection in intact cells of photosynthetic bacteria: quenching of bacteriochlorophyll fluorescence by carotenoid triplets. PHOTOSYNTHESIS RESEARCH 2018; 136:17-30. [PMID: 29064080 DOI: 10.1007/s11120-017-0434-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 08/16/2017] [Indexed: 06/07/2023]
Abstract
Upon high light excitation in photosynthetic bacteria, various triplet states of pigments can accumulate leading to harmful effects. Here, the generation and lifetime of flash-induced carotenoid triplets (3Car) have been studied by observation of the quenching of bacteriochlorophyll (BChl) fluorescence in different strains of photosynthetic bacteria including Rvx. gelatinosus (anaerobic and semianaerobic), Rsp. rubrum, Thio. roseopersicina, Rba. sphaeroides 2.4.1 and carotenoid- and cytochrome-deficient mutants Rba. sphaeroides Ga, R-26, and cycA, respectively. The following results were obtained: (1) 3Car quenching is observed during and not exclusively after the photochemical rise of the fluorescence yield of BChl indicating that the charge separation in the reaction center (RC) and the carotenoid triplet formation are not consecutive but parallel processes. (2) The photoprotective function of 3Car is not limited to the RC only and can be described by a model in which the carotenoids are distributed in the lake of the BChl pigments. (3) The observed lifetime of 3Car in intact cells is the weighted average of the lifetimes of the carotenoids with various numbers of conjugated double bonds in the bacterial strain. (4) The lifetime of 3Car measured in the light is significantly shorter (1-2 μs) than that measured in the dark (2-10 μs). The difference reveals the importance of the dynamics of 3Car before relaxation. The results will be discussed not only in terms of energy levels of the 3Car but also in terms of the kinetics of transitions among different sublevels in the excited triplet state of the carotenoid.
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Affiliation(s)
- Gábor Sipka
- Department of Medical Physics, University of Szeged, Rerrich Béla tér 1, Szeged, 6720, Hungary
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Szeged, 6726, Hungary
| | - Péter Maróti
- Department of Medical Physics, University of Szeged, Rerrich Béla tér 1, Szeged, 6720, Hungary.
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45
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Šlouf V, Keşan G, Litvín R, Swainsbury DJK, Martin EC, Hunter CN, Polívka T. Carotenoid to bacteriochlorophyll energy transfer in the RC-LH1-PufX complex from Rhodobacter sphaeroides containing the extended conjugation keto-carotenoid diketospirilloxanthin. PHOTOSYNTHESIS RESEARCH 2018; 135:33-43. [PMID: 28528494 DOI: 10.1007/s11120-017-0397-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 05/09/2017] [Indexed: 06/07/2023]
Abstract
RC-LH1-PufX complexes from a genetically modified strain of Rhodobacter sphaeroides that accumulates carotenoids with very long conjugation were studied by ultrafast transient absorption spectroscopy. The complexes predominantly bind the carotenoid diketospirilloxanthin, constituting about 75% of the total carotenoids, which has 13 conjugated C=C bonds, and the conjugation is further extended to two terminal keto groups. Excitation of diketospirilloxanthin in the RC-LH1-PufX complex demonstrates fully functional energy transfer from diketospirilloxanthin to BChl a in the LH1 antenna. As for other purple bacterial LH complexes having carotenoids with long conjugation, the main energy transfer route is via the S2-Qx pathway. However, in contrast to LH2 complexes binding diketospirilloxanthin, in RC-LH1-PufX we observe an additional, minor energy transfer pathway associated with the S1 state of diketospirilloxanthin. By comparing the spectral properties of the S1 state of diketospirilloxanthin in solution, in LH2, and in RC-LH1-PufX, we propose that the carotenoid-binding site in RC-LH1-PufX activates the ICT state of diketospirilloxanthin, resulting in the opening of a minor S1/ICT-mediated energy transfer channel.
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Affiliation(s)
- Václav Šlouf
- Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Gürkan Keşan
- Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - Radek Litvín
- Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic
- Biological Centre, Czech Academy of Sciences, Branišovská 31, 370 05, České Budějovice, Czech Republic
| | - David J K Swainsbury
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Elizabeth C Martin
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, UK
| | - Tomáš Polívka
- Faculty of Science, University of South Bohemia, Branišovská 31, 370 05, České Budějovice, Czech Republic.
- Biological Centre, Czech Academy of Sciences, Branišovská 31, 370 05, České Budějovice, Czech Republic.
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46
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Bol’shakov MA, Ashikhmin AA, Makhneva ZK, Moskalenko AA. Spirilloxanthin incorporation into the LH2 and LH1-RC pigment-protein complexes from a purple sulfur bacterium Allochromatium minutissimum. Microbiology (Reading) 2017. [DOI: 10.1134/s0026261717050058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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47
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Swainsbury DJK, Martin EC, Vasilev C, Parkes-Loach PS, Loach PA, Neil Hunter C. Engineering of a calcium-ion binding site into the RC-LH1-PufX complex of Rhodobacter sphaeroides to enable ion-dependent spectral red-shifting. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:927-938. [PMID: 28826909 PMCID: PMC5604489 DOI: 10.1016/j.bbabio.2017.08.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 08/02/2017] [Accepted: 08/17/2017] [Indexed: 01/01/2023]
Abstract
The reaction centre-light harvesting 1 (RC-LH1) complex of Thermochromatium (Tch.) tepidum has a unique calcium-ion binding site that enhances thermal stability and red-shifts the absorption of LH1 from 880nm to 915nm in the presence of calcium-ions. The LH1 antenna of mesophilic species of phototrophic bacteria such as Rhodobacter (Rba.) sphaeroides does not possess such properties. We have engineered calcium-ion binding into the LH1 antenna of Rba. sphaeroides by progressively modifying the native LH1 polypeptides with sequences from Tch. tepidum. We show that acquisition of the C-terminal domains from LH1 α and β of Tch. tepidum is sufficient to activate calcium-ion binding and the extent of red-shifting increases with the proportion of Tch. tepidum sequence incorporated. However, full exchange of the LH1 polypeptides with those of Tch. tepidum results in misassembled core complexes. Isolated α and β polypeptides from our most successful mutant were reconstituted in vitro with BChl a to form an LH1-type complex, which was stabilised 3-fold by calcium-ions. Additionally, carotenoid specificity was changed from spheroidene found in Rba. sphaeroides to spirilloxanthin found in Tch. tepidum, with the latter enhancing in vitro formation of LH1. These data show that the C-terminal LH1 α/β domains of Tch. tepidum behave autonomously, and are able to transmit calcium-ion induced conformational changes to BChls bound to the rest of a foreign antenna complex. Thus, elements of foreign antenna complexes, such as calcium-ion binding and blue/red switching of absorption, can be ported into Rhodobacter sphaeroides using careful design processes.
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Affiliation(s)
- David J K Swainsbury
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, United Kingdom.
| | - Elizabeth C Martin
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, United Kingdom
| | - Cvetelin Vasilev
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, United Kingdom
| | - Pamela S Parkes-Loach
- Department of Molecular Biosciences, Northwestern University, Hogan 2100, 2205 Tech Drive, Evanston, IL 60208, United States
| | - Paul A Loach
- Department of Molecular Biosciences, Northwestern University, Hogan 2100, 2205 Tech Drive, Evanston, IL 60208, United States
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, United Kingdom
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48
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Niedzwiedzki DM, Swainsbury DJK, Martin EC, Hunter CN, Blankenship RE. Origin of the S* Excited State Feature of Carotenoids in Light-Harvesting Complex 1 from Purple Photosynthetic Bacteria. J Phys Chem B 2017; 121:7571-7585. [PMID: 28719215 DOI: 10.1021/acs.jpcb.7b04251] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
This spectroscopic study investigates the origin of the transient feature of the S* excited state of carotenoids bound in LH1 complexes from purple bacteria. The studies were performed on two RC-LH1 complexes from Rba. sphaeroides strains that bound carotenoids with different carbon-carbon double bond conjugation N, neurosporene (N = 9) and spirilloxanthin (N = 13). The S* transient spectral feature, originally associated with an elusive and optically silent excited state of spirilloxanthin in the LH1 complex, may be successfully explained and mimicked without involving any unknown electronic state. The spectral and temporal characteristics of the S* feature suggest that it is associated with triplet-triplet annihilation of carotenoid triplets formed after direct excitation of the molecule via a singlet fission mechanism. Depending on pigment homogeneity and carotenoid assembly in the LH1 complex, the spectro-temporal component associated with triplet-triplet annihilation may simply resolve a pure T-S spectrum of a carotenoid. In some cases (like spirilloxanthin), the T-S feature will also be accompanied by a carotenoid Stark spectrum and/or residual transient absorption of minor carotenoid species bound into LH1 antenna complex.
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Affiliation(s)
| | - David J K Swainsbury
- Department of Molecular Biology and Biotechnology, University of Sheffield , Sheffield S10 2TN, United Kingdom
| | - Elizabeth C Martin
- Department of Molecular Biology and Biotechnology, University of Sheffield , Sheffield S10 2TN, United Kingdom
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield , Sheffield S10 2TN, United Kingdom
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49
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Disruption of a horizontally transferred phytoene desaturase abolishes carotenoid accumulation and diapause in Tetranychus urticae. Proc Natl Acad Sci U S A 2017; 114:E5871-E5880. [PMID: 28674017 DOI: 10.1073/pnas.1706865114] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Carotenoids underlie many of the vibrant yellow, orange, and red colors in animals, and are involved in processes ranging from vision to protection from stresses. Most animals acquire carotenoids from their diets because de novo synthesis of carotenoids is primarily limited to plants and some bacteria and fungi. Recently, sequencing projects in aphids and adelgids, spider mites, and gall midges identified genes with homology to fungal sequences encoding de novo carotenoid biosynthetic proteins like phytoene desaturase. The finding of horizontal gene transfers of carotenoid biosynthetic genes to three arthropod lineages was unprecedented; however, the relevance of the transfers for the arthropods that acquired them has remained largely speculative, which is especially true for spider mites that feed on plant cell contents, a known source of carotenoids. Pigmentation in spider mites results solely from carotenoids. Using a combination of genetic approaches, we show that mutations in a single horizontally transferred phytoene desaturase result in complete albinism in the two-spotted spider mite, Tetranychus urticae, as well as in the citrus red mite, Panonychus citri Further, we show that phytoene desaturase activity is essential for photoperiodic induction of diapause in an overwintering strain of T. urticae, consistent with a role for this enzyme in provisioning provitamin A carotenoids required for light perception. Carotenoid biosynthetic genes of fungal origin have therefore enabled some mites to forgo dietary carotenoids, with endogenous synthesis underlying their intense pigmentation and ability to enter diapause, a key to the global distribution of major spider mite pests of agriculture.
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50
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Light harvesting in phototrophic bacteria: structure and function. Biochem J 2017; 474:2107-2131. [DOI: 10.1042/bcj20160753] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 04/03/2017] [Accepted: 04/06/2017] [Indexed: 12/23/2022]
Abstract
This review serves as an introduction to the variety of light-harvesting (LH) structures present in phototrophic prokaryotes. It provides an overview of the LH complexes of purple bacteria, green sulfur bacteria (GSB), acidobacteria, filamentous anoxygenic phototrophs (FAP), and cyanobacteria. Bacteria have adapted their LH systems for efficient operation under a multitude of different habitats and light qualities, performing both oxygenic (oxygen-evolving) and anoxygenic (non-oxygen-evolving) photosynthesis. For each LH system, emphasis is placed on the overall architecture of the pigment–protein complex, as well as any relevant information on energy transfer rates and pathways. This review addresses also some of the more recent findings in the field, such as the structure of the CsmA chlorosome baseplate and the whole-cell kinetics of energy transfer in GSB, while also pointing out some areas in need of further investigation.
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