DOCSLIB.ORG

On the Linear and Non-Linear Electronic Spectroscopy of Chlorophylls: a Computational Study

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
On the Linear and Non-Linear Electronic Spectroscopy of Chlorophylls: a Computational Study Heriot-Watt University Research Gateway On the linear and non-linear electronic spectroscopy of chlorophylls: a computational study Citation for published version: Graczyk, A, Zurek, JM & Paterson, MJ 2014, 'On the linear and non-linear electronic spectroscopy of chlorophylls: a computational study', Photochemical and Photobiological Sciences, vol. 13, no. 1, pp. 103- 111. https://doi.org/10.1039/c3pp50262g Digital Object Identifier (DOI): 10.1039/c3pp50262g Link: Link to publication record in Heriot-Watt Research Portal Document Version: Peer reviewed version Published In: Photochemical and Photobiological Sciences General rights Copyright for the publications made accessible via Heriot-Watt Research Portal is retained by the author(s) and / or other copyright owners and it is a condition of accessing these publications that users recognise and abide by the legal requirements associated with these rights. Take down policy Heriot-Watt University has made every reasonable effort to ensure that the content in Heriot-Watt Research Portal complies with UK legislation. If you believe that the public display of this file breaches copyright please contact [email protected] providing details, and we will remove access to the work immediately and investigate your claim. Download date: 27. Sep. 2021 Journal Name Dynamic Article Links ► Cite this: DOI: 10.1039/c0xx00000x www.rsc.org/xxxxxx ARTICLE TYPE On the Linear and Non-linear Electronic Spectroscopy of Chlorophylls: A Computational Study Alicja Graczyk, Justyna M. Żurek and Martin J. Paterson* 5 Institute of Chemical Sciences, Heriot Watt University, Edinburgh, EH14 4AS, United Kingdom Received (in XXX, XXX) Xth XXXXXXXXX 20XX, Accepted Xth XXXXXXXXX 20XX DOI: 10.1039/b000000x A theoretical analysis of linear and non-linear (two-photon absorption) electronic spectroscopy of all known porphyrinic pigments has been performed using linear and quadratic density functional response 10 theory, with long-range corrected CAM-B3LYP functional. We find that higher Soret transitions often contain non-Gouterman contributions and that each chlorophyll has the possibility for resonance enhanced TPA in the Soret region, although there are also significant TPA in the Q region. Introduction photons of light and transferring the excitation energy to nearby reaction centres in the process of Förster resonance energy Spectroscopic properties of porphyrins and their structural 13 50 transfer. 15 analogues have captured significant attention of both (a) experimental and theoretical chemists, and have been comprehensively studied since the middle of the twentieth R2 R3 century. The initial purpose of such research was to acquire knowledge of porphyrins’ roles in fundamental biochemical R1 1 N N CH 20 processes including photosynthesis and respiration. In more 3 recent times it has been discovered that porphyrins and their Mg Chl a:R1=CH3, R2=CHCH2, R3=CH3 Chl b: R1=CH3, R2=CHCH2, R3=CHO derivatives can be successfully used in many modern N N Chl d: R1=CH3, R2=CHO, R3=CH3 H C Chl f: R =CHO, R =CHCH R =CH technologies, for example, they can be employed as agents 3 1 2 2, 3 3 CH3 increasing the efficiency of solar cells,2 charge generation H 3 25 materials for laser printers, photosensitizers for use in H 4 H COOC O photodynamic therapy (PDT) and potential artificial blood 3 H components.5 The effectiveness of processes involving the family Phytyl tail O O of porphyrins is often related to both linear and non-linear optical properties of these molecules. This paper will focus on studies of 30 linear and non-linear optical properties of known types of (b) chlorophylls. Most chlorophylls are based on a reduced porphyrin macrocycle called chlorin.1, 6, 7 Currently five types of R1 chlorophylls are known: chlorophyll a, b, c, d and f, which display small structural differences from each other. Chlorophyll R2 N N 35 c exists in three forms (c1, c2 and c3) and it is the only known Chl c1:R1=CH3, R2=CH2CH3 Chl c2:R =CH , R =CHCH chlorophyll, which is porphyrin rather than chlorin based (Fig. Mg 1 3 2 2 Chl c3:R =COOCH , R =CHCH 1).8-10 1 3 2 2 N N Chlorophylls participate in the most fundamental reaction for 1, 11 40 living organisms, photosynthesis. Through the production of carbohydrates and molecular oxygen, photosynthesis, directly or H COOC O indirectly, supports most life on our planet. Chlorophylls form 3 H part of the photosynthetic apparatus and contribute to its HO O stabilisation. They are collected in chloroplasts in plants, which 12 45 are one of the building blocks of the photosynthetic antenna. They participate in the first stage of photosynthesis, so-called Fig. 1 Structures of chlorophylls (a) a, b, d and f (b) c1, c2, c3 light reactions. Their role can be briefly described as capturing 55 The most abundant type of photosynthetic pigment is chlorophyll This journal is © The Royal Society of Chemistry [year] [journal], [year], [vol], 00–00 | 1 a, which was the first one isolated (in 1817) and has been the model, which describes positions and character of main electronic 1, 43 most frequently studied. Chlorophyll f, on the other hand, is a 60 transitions in such systems. Later this theory was extended to very recent discovery. It was first recognized and described in the porphyrins containing metal ions. According to this model, the second half of 2010.14 As a consequence, very little research has Soret and the Q bands are the result of the electronic transitions 5 been done on this molecule. between four orbitals, i.e., HOMO and HOMO-1 π orbitals to * LUMO and LUMO+1 π orbitals. These orbitals are centered on The family of chlorophyll molecules covers most of the 65 the porphyrin core. In a metal-containing D4h porphyrin, the photosynthethically useful spectrum with extremely intense LUMO and LUMO+1 π* orbitals are degenerate by symmetry, absorptions in the blue – the Soret band (330-480 nm), also called while the HOMO and HOMO-1 π orbitals are nearly degenerate. 10 the B band and less intense red regions – Q bands (620-1050 Gouterman labeled the HOMO orbitals as a1u and a2u, while 7 nm). Such a long absorption range makes chlorophylls good LUMO orbitals were designated egy and egx. Therefore the systems for OPA and TPA studies with potential applications in 70 possible transitions between these orbitals are a1u → egy and a2u ecophysiology, biochemistry, biophysics and also medicine. TPA → egx, having x polarization, and a1u → egx and a2u → egx, having studies have seen especially increasing importance in recent y polarization. X and y polarized excited states are further mixed 15 years. This is due to their wide applications in fluorescence and split in energy by configuration interaction and form two imaging, photonics, optical data storage, and most importantly transitions of low intensity and energy transitions (Qx and Qy, production of singlet oxygen with applications in photodynamic 75 with Qy being a lower energy transition than Qx and also higher anticancer therapy.15-20 Anticancer photodynamic therapy is a intensity), and two high intensity and higher energy transitions 1 relatively new branch of medical technology, which requires a (Bx and By). Some recent studies of OPA of chlorophylls and 20 photosensitizer, light of a wavelength suitable for the absorption similar systems will now be presented. Linnanto et al performed by the photosensitizer, and molecular oxygen.21 The absorption studies on spectroscopic properties of a, b, c1, c2, c3, d properties of a photosensitizer are clearly very important. A PDT 80 chlorophylls using semi-empirical ZINDO/S CIS (15,15) and drug must be able to absorb in the therapeutic window, which PM3 CISD (5,5) methods and also ab-initio CIS (5,5)/6-31G(d) ranges from 600 and 800 nm. Light absorption and scattering in method.37 Ab-initio CIS(5,5) methods turned out to overestimate 25 tissue depend on the wavelength of the electromagnetic radiation. the transition energies of the lowest excited states of studied The optical window for tissue penetration lies in the range of chlorophylls while the obtained energies when using semi- 600-1300 nm. Its lower limit is set by principal tissue 85 empirical methods were very close to experiment. This is not a chromophores, such as melanin, haemoglobin and cytochromes, surprise as semi-empirical methods use experimental which have high absorption bands below 600 nm. The upper limit parametrisation. The semi-empirical PM3 CISD (5,5) method had 22 30 is set by the water absorption of near infrared light. The other problems with predicting oscillator strengths of studied important aspect is that light of a wavelength exceeding 800 nm transitions. Vokáčová and Burda used TD-DFT to study the is unable to activate the photosensitizer. Therefore the search for 90 spectroscopy of chlorophyll a, b, c1, c2, c3, d, different ideal photosensitizers concentrates on ones absorbing in the red, bacteriochlorophylls, phycobilins and carotenoids.35 In the case which posses a high tissue penetration power and are energetic of (bacterio)-chlorophylls the phytyl chain was removed from the 35 enough to produce singlet oxygen. In a TPA process the structure and replaced by a methyl group. TD-DFT with the electronic transition of a molecule can be thought of as the B3PW91 functional and 6-31+G(d) basis set were used. The simultaneous absorption two photons. The use of this non-linear 95 authors have obtained qualitatively good agreement with technique in PDT has been an attractive alternative to OPA since experimental spectra. The calculated values for the Qy band were the development of high-power femtosecond lasers.23 One of the blueshifted in comparison to experiment by about 60-80 nm and 40 advantages of TPA over OPA includes the fact that the about 20-30 nm for the Qx and Soret (B) bands.
Load more

Recommended publications
  • Femtosecond Visible Transient Absorption Spectroscopy of Chlorophyll-F-Containing Photosystem II
    Femtosecond visible transient absorption spectroscopy of chlorophyll-f-containing photosystem II Noura Zamzama, Rafal Rakowskia, Marius Kaucikasa, Gabriel Dorlhiaca,1, Sefania Violaa, Dennis J. Nürnberga,b, Andrea Fantuzzia, A. William Rutherforda, and Jasper J. van Thora,2 aDepartment of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom; and bInstitute of Experimental Physics, Freie Universität Berlin, 14195 Berlin, Germany Edited by Donald R. Ort, University of Illinois at Urbana–Champaign, Urbana, IL, and approved July 27, 2020 (received for review March 31, 2020) +• −• The recently discovered, chlorophyll-f-containing, far-red photo- some centers and PD1 ChlD1 in others (13, 14). However, the view +• −• system II (FR-PSII) supports far-red light photosynthesis. Participa- that RP1 in PSII is PD1 ChlD1 in all of the centers is still advo- tion and kinetics of spectrally shifted far-red pigments are directly cated (15). This model was originally based on the photochemistry in observable and separated from that of bulk chlorophyll-a.Wepre- the well-characterized purple bacterial reaction center, where RP1 is − sent an ultrafast transient absorption study of FR-PSII, investigating P+B , P is a special pair of (bacterio)chlorophylls over which the energy transfer and charge separation processes. Results show a cation is shared and B is a monomeric (bacterio)chlorophyll (16). rapid subpicosecond energy transfer from chlorophyll-a to the Irrespective of the identity of RP1, the secondary radical pair (RP2) f/d +• −• long-wavelength chlorophylls- . The data demonstrate the decay in PSII is thought to be PD1 PheoD1 . The electron transfer from of an ∼720-nm negative feature on the picosecond-to-nanosecond −• +• −• PheoD1 to QA, leads to formation of PD1 QA , RP3 (2–4, 9, 15).
    [Show full text]
  • Non-Destructive in Situ Measurement of Aquaponic Lettuce Leaf Photosynthetic Pigments and Nutrient Concentration Using Hybrid Genetic Programming Ronnie S
    589 AGRIVITA Journal of Agricultural Science. 2021. 43(3): 589-610 AGRIVITA Journal of Agricultural Science www.agrivita.ub.ac.id Non-destructive in Situ Measurement of Aquaponic Lettuce Leaf Photosynthetic Pigments and Nutrient Concentration Using Hybrid Genetic Programming Ronnie S. Concepcion II1*), Elmer P. Dadios1) and Joel Cuello2) 1) De La Salle University, Manila, Philippines 2) University of Arizona, Tucson, USA ARTICLE INFO ABSTRACT Keywords: Phytopigment and nutrient concentration determination normally rely Computer vision on laboratory chemical analysis. However, non-destructive and onsite Leaf nutrient level prediction measurements are necessary for intelligent closed environment Leaf pigment prediction agricultural systems. In this study, the impact of photosynthetic light Lettuce treatments on aquaponic lettuce leaf canopy (Lactuca sativa var. Machine learning Altima) was evaluated using UV-Vis spectrophotometry (300-800 nm), fourier transform infrared spectroscopy (4000-500 per cm), and Article History: the integrated computer vision and computational intelligence. Hybrid Received: March 6, 2021 decision tree and multigene symbolic regression genetic programming Accepted: August 16, 2021 (DT-MSRGP) exhibited the highest predictive accuracies of 80.9%, 89.9%, 83.5%, 85.5%, 81.3%, and 83.4% for chlorophylls a and b, *) Corresponding author: β-carotene, anthocyanin, lutein, and vitamin C concentrations present E-mail: [email protected]. in lettuce leaf canopy based on spectro-textural-morphological ph signatures. An increase in β-carotene and anthocyanin concentrations verified that these molecular pigments act as a natural sunscreen to protect lettuce from light stress and an increase in chlorophylls a and b ratio in the white light treatment corresponds to reduced emphasis on photon energy absorbance in chloroplast photosystem II.
    [Show full text]
  • The Impact of Light Irradiance, Chlorophyll Concentration And
    THE IMPACT OF LIGHT IRRADIANCE, CHLOROPHYLL CONCENTRATION AND SOLVENT ON CHLOROPHYLL ABSORBANCE SPECTRUM Vidya Sagar Kuncham Department of Bioresource Engineering McGill University Montreal, Quebec, Canada A thesis submitted to McGill University in partial fulfillment of the requirements of the degree of Master of Science April 2021 © Vidya Sagar Kuncham, 2021 1 ABSTRACT The plant pigment chlorophyll (Chl) is considered as obligatory pigment in photosynthesis as it is used in the light harvesting process. Chl absorbs light energy predominately in the blue and red region of the visible spectrum with defined peaks at 433 nm and 665 nm for Chl a and at 458 nm and 646 nm for Chl b. Our first study was used to determine the impact that light irradiance had on Chl. Chl a and Chl b absorbance was measured under dark and after treating with different light intensities. It was identified that both Chl a and Chl b were sensitive to the light and the absorbance capacity (absorbance spectrum) of the chlorophyll changed based on the light intensity by which the chlorophyll pigments were treated. Chl a and Chl b absorbance level was inversely proportional to the light intensity supplied to the pigments. The Chl a absorbed significantly more light in the green region (between 500 nm and 530 nm) after treatment with higher light irradiance. Chl b absorbed more light in green region with distinct peaks at 518 nm and 570 nm after light treatments. The ability of Chl to return to a baseline absorbance based on a no light (dark) treatment was tested by storing Chl a and Chl b under dark conditions, however no significant recovery in absorbance was measured.
    [Show full text]
  • Discovery of Chlorophyll D in Acaryochloris Marina And
    Chem cal ist si ry y & h P B f i o o p l Miyashita et al., J Phys Chem Biophys 2014, 4:4 h a Journal of Physical Chemistry & y n s r i u c DOI: 10.4172/2161-0398.1000149 o s J ISSN: 2161-0398 Biophysics ResearchReview Article Article OpenOpen Access Access Discovery of Chlorophyll d in Acaryochloris marina and Chlorophyll f in a Unicellular Cyanobacterium, Strain KC1, Isolated from Lake Biwa Hideaki Miyashita1,2, Satoshi Ohkubo2, Hirohisa Komatsu3, Yuhta Sorimachi3, Daisuke Fukayama3, Daiki Fujinuma3, Shinya Akutsu3 and Masami Kobayashi3* 1Graduate School of Global and Environmental Studies, Kyoto University, Kyoto 606-8501, Japan 2Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501, Japan 3Division of Materials Science, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan Abstract In this review, we described the biological characteristics of a cyanobacterium Acaryochloris marina and a unicellular cyanobacterium strain KC1 and the possible photosynthetic systems of the cells based on the physicochemical properties of chlorophylls. Strain KC1 as well as Acaryochloris spp. in addition to Halomiclonema hongdechloris should contribute the understanding of photosynthesis utilizing far red light. Keywords: Acaryochloris marina; Chlorophyll a; Chlorophyll cyanobacteria distributed in marine or salty lakes, since it had only been a’; Chlorophyll d; Chlorophyll d’; Chlorophyll f; Cyanobacteria; found in the cyanobacteria in the genus Acaryochloris, and the strains Pheophytin a; Strain KC1 in Acaryochloris had only been isolated from saline environments but not from freshwater environments at all [4-7]. Actually, the strain A. Abbreviations: A.
    [Show full text]
  • 2016 National Algal Biofuels Technology Review
    National Algal Biofuels Technology Review Bioenergy Technologies Office June 2016 National Algal Biofuels Technology Review U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Bioenergy Technologies Office June 2016 Review Editors: Amanda Barry,1,5 Alexis Wolfe,2 Christine English,3,5 Colleen Ruddick,4 and Devinn Lambert5 2010 National Algal Biofuels Technology Roadmap: eere.energy.gov/bioenergy/pdfs/algal_biofuels_roadmap.pdf A complete list of roadmap and review contributors is available in the appendix. Suggested Citation for this Review: DOE (U.S. Department of Energy). 2016. National Algal Biofuels Technology Review. U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Bioenergy Technologies Office. Visit bioenergy.energy.gov for more information. 1 Los Alamos National Laboratory 2 Oak Ridge Institute for Science and Education 3 National Renewable Energy Laboratory 4 BCS, Incorporated 5 Bioenergy Technologies Office This report is being disseminated by the U.S. Department of Energy. As such, the document was prepared in compliance with Section 515 of the Treasury and General Government Appropriations Act for Fiscal Year 2001 (Public Law No. 106-554) and information quality guidelines issued by the Department of Energy. Further, this report could be “influential scientific information” as that term is defined in the Office of Management and Budget’s Information Quality Bulletin for Peer Review (Bulletin). This report has been peer reviewed pursuant to section II.2 of the Bulletin. Cover photo courtesy of Qualitas Health, Inc. BIOENERGY TECHNOLOGIES OFFICE Preface Thank you for your interest in the U.S. Department of Energy (DOE) Bioenergy Technologies Office’s (BETO’s) National Algal Biofuels Technology Review.
    [Show full text]
  • Photosynthetic Light-Harvesting (Antenna) Complexes—Structures and Functions
    molecules Review Photosynthetic Light-Harvesting (Antenna) Complexes—Structures and Functions Heiko Lokstein 1,* , Gernot Renger 2,† and Jan P. Götze 3 1 Department of Chemical Physics and Optics, Charles University, Ke Karlovu 3, 12116 Prague, Czech Republic 2 Max-Volmer-Laboratorium, Technische Universität Berlin, Straße des 17. Juni 135, D-10623 Berlin, Germany 3 Institut für Chemie und Biochemie, Freie Universität Berlin, Arnimallee 22, D-14195 Berlin, Germany; [email protected] * Correspondence: [email protected] † Sadly, Professor Dr. Gernot Renger passed away on 12 January 2013. This article is dedicated to commemorate the outstanding contributions of Gernot Renger to oxygenic photosynthesis research. Abstract: Chlorophylls and bacteriochlorophylls, together with carotenoids, serve, noncovalently bound to specific apoproteins, as principal light-harvesting and energy-transforming pigments in photosynthetic organisms. In recent years, enormous progress has been achieved in the elucidation of structures and functions of light-harvesting (antenna) complexes, photosynthetic reaction centers and even entire photosystems. It is becoming increasingly clear that light-harvesting complexes not only serve to enlarge the absorption cross sections of the respective reaction centers but are vitally important in short- and long-term adaptation of the photosynthetic apparatus and regulation of the energy-transforming processes in response to external and internal conditions. Thus, the wide variety of structural diversity in photosynthetic antenna “designs” becomes conceivable. It is, however, common for LHCs to form trimeric (or multiples thereof) structures. We propose a simple, tentative explanation of the trimer issue, based on the 2D world created by photosynthetic membrane systems. Citation: Lokstein, H.; Renger, G.; Götze, J.P.
    [Show full text]
  • A Niche for Cyanobacteria Producing Chlorophyll F Within a Microbial Mat
    The ISME Journal (2017) 11, 2368–2378 © 2017 International Society for Microbial Ecology All rights reserved 1751-7362/17 www.nature.com/ismej ORIGINAL ARTICLE A niche for cyanobacteria producing chlorophyll f within a microbial mat Satoshi Ohkubo1,3 and Hideaki Miyashita1,2 1Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan and 2Graduate School of Global and Environmental Studies, Kyoto University, Kyoto, Japan Acquisition of additional photosynthetic pigments enables photosynthetic organisms to survive in particular niches. To reveal the ecological significance of chlorophyll (Chl) f, we investigated the distribution of Chl and cyanobacteria within two microbial mats. In a 7-mm-thick microbial mat beneath the running water of the Nakabusa hot spring, Japan, Chl f was only distributed 4.0–6.5 mm below the surface, where the intensity of far-red light (FR) was higher than that of photosynthetically active radiation (PAR). In the same mat, two ecotypes of Synechococcus and two ecotypes of Chl f- producing Leptolyngbya were detected in the upper and deeper layers, respectively. Only the Leptolyngbya strains could grow when FR was the sole light source. These results suggest that the deeper layer of the microbial mat was a habitat for Chl f-producing cyanobacteria, and Chl f enabled them to survive in a habitat with little PAR. The ISME Journal (2017) 11, 2368–2378; doi:10.1038/ismej.2017.98; published online 16 June 2017 Introduction from stromatolites in Australia (Chen et al., 2012). To date, this strain has been used to study the Light quality is one of the most important drivers in extinction coefficient (Li et al., 2012), biochemical niche differentiation of phototrophs, and the spec- structure (Willows et al., 2013) and biophysical trum of available light determines the distribution characteristics (Li et al., 2013; Tomo et al., 2014; and community composition of photosynthetic Akimoto et al., 2015) of Chl f.
    [Show full text]
  • Optimization and Effects of Different Culture Conditions on Growth of Halomicronema Hongdechloris – a filamentous Cyanobacterium Containing Chlorophyll F
    ORIGINAL RESEARCH ARTICLE published: 25 February 2014 doi: 10.3389/fpls.2014.00067 Optimization and effects of different culture conditions on growth of Halomicronema hongdechloris – a filamentous cyanobacterium containing chlorophyll f Yaqiong Li,Yuankui Lin, Patrick C. Loughlin and Min Chen* School of Biological Sciences, University of Sydney, Sydney, NSW, Australia Edited by: A chlorophyll f containing cyanobacterium, Halomicronema hongdechloris (H. hongdechlo- Suleyman I. Allakhverdiev, Russian ris) was isolated from a stromatolite cyanobacterial community.The extremely slow growth Academy of Sciences, Russia rate of H. hongdechloris has hindered research on this newly isolated cyanobacterium and Reviewed by: the investigation of chlorophyll f -photosynthesis. Therefore, optimizing H. hongdechlo- Suleyman I. Allakhverdiev, Russian Academy of Sciences, Russia ris culture conditions has become an essential requirement for future research. This Nabil I. Elsheery, Tanta University, work investigated the effects of various culture conditions, essential nutrients and light Egypt environments to determine the optimal growth conditions for H. hongdechloris and the *Correspondence: biosynthetic rate of chlorophyll f. Based on the total chlorophyll concentration, an optimal Min Chen, School of Biological growth rate of 0.22 ± 0.02 day−1(doubling time: 3.1 ± 0.3 days) was observed when cells Sciences (A08), University of Sydney, Sydney, NSW 2006, Australia were grown under continuous illumination with far-red light with an intensity of 20 μE ◦ e-mail: [email protected] at 32 C in modified K + ES seawater (pH 8.0) with additional nitrogen and phosphor supplements. High performance liquid chromatography on H. hongdechloris pigments confirmed that chlorophyll a is the major chlorophyll and chlorophyll f constitutes ∼10% of the total chlorophyll from cells grown under far-red light.
    [Show full text]
  • Expanding the Solar Spectrum Used by Photosynthesis
    Review Expanding the solar spectrum used by photosynthesis Min Chen1 and Robert E. Blankenship2 1 School of Biological Sciences, University of Sydney, Sydney, NSW 2006, Australia 2 Departments of Biology and Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA A limiting factor for photosynthetic organisms is their imately 700 nm, whereas the peak of the energy curve is at light-harvesting efficiency, that is the efficiency of their approximately 500 nm. The importance of the spectral conversion of light energy to chemical energy. Small region at longer wavelengths than 700 nm is made more modifications or variations of chlorophylls allow photo- apparent when the solar spectrum is represented as pho- synthetic organisms to harvest sunlight at different ton flux. Even small increases in the ability to utilize these wavelengths. Oxygenic photosynthetic organisms usu- photons can be significant because they occur at the place ally utilize only the visible portion of the solar spectrum. where the solar spectrum is at its maximum. The cyanobacterium Acaryochloris marina carries out Most oxygenic photosynthetic organisms are able to oxygenic photosynthesis but contains mostly chloro- utilize essentially the same region of the solar spectrum phyll d and only traces of chlorophyll a. Chlorophyll d that our eyes are sensitive to, namely the visible range provides a potential selective advantage because it extending from 400 nm to 700 nm [2]. This region is called enables Acaryochloris to use infrared light (700– photosynthetically active radiation (PAR). Using the 750 nm) that is not absorbed by chlorophyll a. Recently, ASTM 1.5 reference solar spectrum [1], the integrated an even more red-shifted chlorophyll termed chlorophyll 400–700 nm PAR photon flux is 1.05 Â 1021 photons mÀ2 f has been reported.
    [Show full text]
  • Far-Red Light Acclimation for Improved Mass Cultivation of Cyanobacteria
    H OH metabolites OH Article Far-Red Light Acclimation for Improved Mass Cultivation of Cyanobacteria Alla Silkina 1 , Bethan Kultschar 2 and Carole A. Llewellyn 2,* 1 Centre for Sustainable Aquatic Research (CSAR), Bioscience department, College of Science, Swansea University, Singleton Park, Swansea SA2 8PP, UK 2 Department of Biosciences, College of Science, Swansea University, Singleton Park, Swansea SA2 8PP, UK * Correspondence: [email protected] Received: 1 August 2019; Accepted: 15 August 2019; Published: 19 August 2019 Abstract: Improving mass cultivation of cyanobacteria is a goal for industrial biotechnology. In this study, the mass cultivation of the thermophilic cyanobacterium Chlorogloeopsis fritschii was assessed for biomass production under light-emitting diode white light (LEDWL), far-red light (FRL), and combined white light and far-red light (WLFRL) adaptation. The induction of chl f was confirmed at 24 h after the transfer of culture from LEDWL to FRL. Using combined light (WLFRL), chl f, a, and d, maintained the same level of concentration in comparison to FRL conditions. However, phycocyanin and xanthophylls (echinone, caloxanthin, myxoxanthin, nostoxanthin) concentration increased 2.7–4.7 times compared to LEDWL conditions. The productivity of culture was double under WLFRL compared with LEDWL conditions. No significant changes in lipid, protein, and carbohydrate concentrations were found in the two different light conditions. The results are important for informing on optimum biomass cultivation of this species for biomass production and bioactive product development. Keywords: cyanobacteria; chromatic adaptation; LED; far-red light; growth; photosynthesis; mass cultivation; pigments; Chlorogloeopsis 1. Introduction Cyanobacteria are photosynthetic prokaryotes that are increasingly explored for use in industrial biotechnology.
    [Show full text]
  • Cold-Induced Photoinhibition, Pigment Chemistry, Growth and Nutrition of Eucalyptus Nitens and E
    Cold-induced photoinhibition, pigment chemistry, growth and nutrition of Eucalyptus nitens and E. globulus seedlings during establishment Dugald C. Close Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy Schools of Agricultural and Plant Science .and CRC for Sustainable Production Forestry University of Tasmania Declarations This thesis contains no material which has been accepted for a degree or diploma by the University of Tasmania or any other institution. To the best of my knowledge and belief this thesis contains no material previously published or written by another person except where due acknowledgement is made in the text of the thesis. Dugald C. Close This thesis may be made available for loan and limited copying in accordance with the Copyright Act 1968. Dugald C. Close Abstract Australia is aiming to treble plantation wood production by 2020. Eucalyptus globulus Labill. and E. nitens (Deane and Maidem) Maiden are the predominant plantation species in southern Australia. This thesis describes physiological strategies employed by these species in response to cold-induced photoinhibition during seedling establishment. A series of experiments was conducted on seedlings pre- hardened in the nursery. Their physiological and growth responses after planting in the field was investigated. A field trial was established at 350 m asl in early spring 1997. Severe cold-induced photoinhibition caused photodamage which restricted growth of non-hardened E. globulus. Artificial shading alleviated cold-induced photoinhibition and photodamage in both E. globulus and E. nitens, and increased growth in E. globulus. Before planting, nutrient-starved E. nitens were photoinhibited and had high anthocyanin levels.
    [Show full text]
  • Excited State Frequencies of Chlorophyll F and Chlorophyll a and Evaluation of Displacement Through Franck-Condon Progression Calculations
    molecules Article Excited State Frequencies of Chlorophyll f and Chlorophyll a and Evaluation of Displacement through Franck-Condon Progression Calculations Noura Zamzam and Jasper J. van Thor * Department of Life Sciences, Molecular Biophysics, Imperial College London, London SW7 2AZ, UK; [email protected] * Correspondence: [email protected]; Tel.: +44-(0)20-7594-5071 Academic Editor: Chong Fang Received: 16 February 2019; Accepted: 2 April 2019; Published: 4 April 2019 Abstract: We present ground and excited state frequency calculations of the recently discovered extremely red-shifted chlorophyll f. We discuss the experimentally available vibrational mode assignments of chlorophyll f and chlorophyll a which are characterised by particularly large downshifts of 131-keto mode in the excited state. The accuracy of excited state frequencies and their displacements are evaluated by the construction of Franck–Condon (FC) and Herzberg–Teller (HT) progressions at the CAM-B3LYP/6-31G(d) level. Results show that while CAM-B3LYP results are improved relative to B3LYP calculations, the displacements and downshifts of high-frequency modes are underestimated still, and that the progressions calculated for low temperature are dominated by low-frequency modes rather than fingerprint modes that are Resonant Raman active. Keywords: vibrational frequencies; chlorophyll a; chlorophyll f; excited state; density functional theory; B3LYP; CAM-B3LYP; Franck–Condon 1. Introduction Chlorophylls found in photosynthetic organisms are responsible for light harvesting in the antenna complexes, and the subsequent transfer of excitation energy to photosynthetic reaction centres with almost 100% quantum efficiency. In the reaction centres, specific chlorophylls act as electron transfer cofactors and are involved in the initial charge separation processes [1].
    [Show full text]