1
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Linsmayer LB, Noel SK, Leray M, Wangpraseurt D, Hassibi C, Kline DI, Tresguerres M. Effects of bleaching on oxygen dynamics and energy metabolism of two Caribbean coral species. Sci Total Environ 2024; 919:170753. [PMID: 38360316 DOI: 10.1016/j.scitotenv.2024.170753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 02/02/2024] [Accepted: 02/04/2024] [Indexed: 02/17/2024]
Abstract
As mass coral bleaching events become more frequent, it is increasingly important to elucidate the factors underlying coral susceptibility and survival. We measured photosynthesis, respiration, and O2 concentration at the coral tissue surface, Symbiodiniaceae genotypes, and energy metabolic enzyme activities in Agaricia agaricites and Orbicella franksi throughout experimentally-induced thermal bleaching (+3 °C). A. agaricites colonies started to bleach two days into the thermal treatment and were fully bleached between Days 19-31. In contrast, O. franksi colonies only started to bleach on Day 12 and five colonies fully bleached between Days 24-38 while the remining three colonies took up 55 days. Both species experienced decreased photosynthesis and respiration rates as bleaching progressed. As a result, daytime O2 concentration at the coral surface shifted from hyperoxia in unbleached corals to normoxia in partially bleached corals, and to near hypoxia in fully bleached corals. Additionally, nighttime tissue surface O2 concentration shifted from hypoxia to normoxia, likely resulting from decreased symbiotic algae density, respiration, and photosynthates that fuel coral aerobic respiration. Genetic profiling of internal transcribed spacer 2 (ITS2) revealed differences in Symbiodiniaceae clade proportions between control and bleached colonies. Activity levels of energy metabolic enzymes did not significantly vary between control and bleached A. agaricites, but malate dehydrogenase and strombine dehydrogenase activities were significantly higher in bleached O. franksi colonies compared to controls. These differences were driven by the three O. franksi colonies that took the longest to bleach and contained >98 % Durusdinium sp. D1. The shifts in O2 dynamics within the microhabitat of bleached corals may have important implications for the metabolism of the coral holobiont while the changes in Symbiodiniaceae ITS2 profile and the upregulation of energy metabolic enzymes identify a potential factor contributing to bleaching dynamics.
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Affiliation(s)
- L B Linsmayer
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093, USA
| | - S K Noel
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093, USA
| | - M Leray
- Smithsonian Tropical Research Institute, Apartado Postal 0843-03092, Panamá, Panama
| | - D Wangpraseurt
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093, USA; Department of Nanoengineering, University of California San Diego, La Jolla, CA 92093, USA
| | - C Hassibi
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093, USA
| | - D I Kline
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093, USA; Smithsonian Tropical Research Institute, Apartado Postal 0843-03092, Panamá, Panama
| | - M Tresguerres
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093, USA.
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2
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Datta D, Weiss EL, Wangpraseurt D, Hild E, Chen S, Golden JW, Golden SS, Pokorski JK. Phenotypically complex living materials containing engineered cyanobacteria. Nat Commun 2023; 14:4742. [PMID: 37550278 PMCID: PMC10406891 DOI: 10.1038/s41467-023-40265-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 07/20/2023] [Indexed: 08/09/2023] Open
Abstract
The field of engineered living materials lies at the intersection of materials science and synthetic biology with the aim of developing materials that can sense and respond to the environment. In this study, we use 3D printing to fabricate a cyanobacterial biocomposite material capable of producing multiple functional outputs in response to an external chemical stimulus and demonstrate the advantages of utilizing additive manufacturing techniques in controlling the shape of the fabricated photosynthetic material. As an initial proof-of-concept, a synthetic riboswitch is used to regulate the expression of a yellow fluorescent protein reporter in Synechococcus elongatus PCC 7942 within a hydrogel matrix. Subsequently, a strain of S. elongatus is engineered to produce an oxidative laccase enzyme; when printed within a hydrogel matrix the responsive biomaterial can decolorize a common textile dye pollutant, indigo carmine, potentially serving as a tool in environmental bioremediation. Finally, cells are engineered for inducible cell death to eliminate their presence once their activity is no longer required, which is an important function for biocontainment and minimizing environmental impact. By integrating genetically engineered stimuli-responsive cyanobacteria in volumetric 3D-printed designs, we demonstrate programmable photosynthetic biocomposite materials capable of producing functional outputs including, but not limited to, bioremediation.
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Affiliation(s)
- Debika Datta
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA
| | - Elliot L Weiss
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
- Department of Molecular Biology, University of California San Diego, La Jolla, CA, USA
| | - Daniel Wangpraseurt
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Erica Hild
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA
| | - Shaochen Chen
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA
| | - James W Golden
- Department of Molecular Biology, University of California San Diego, La Jolla, CA, USA
| | - Susan S Golden
- Department of Molecular Biology, University of California San Diego, La Jolla, CA, USA.
| | - Jonathan K Pokorski
- Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA.
- Center for Nano-ImmunoEngineering and Institute for Materials Discovery and Design, University of California San Diego, La Jolla, CA, USA.
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3
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Roger L, Lewinski N, Putnam H, Chen S, Roxbury D, Tresguerres M, Wangpraseurt D. Nanotechnology for coral reef conservation, restoration and rehabilitation. Nat Nanotechnol 2023; 18:831-833. [PMID: 37231144 DOI: 10.1038/s41565-023-01402-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Affiliation(s)
- Liza Roger
- Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA, USA.
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA.
- School of Ocean Futures, Arizona State University, Tempe, AZ, USA.
| | - Nastassja Lewinski
- Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - Hollie Putnam
- College of Environment and Life Sciences, University of Rhode Island, Kingston, RI, USA
| | - Shaochen Chen
- Department of NanoEngineering, University of California San Diego, La Jolla, CA, USA
| | - Daniel Roxbury
- Department of Chemical Engineering, University of Rhode Island, Kingston, RI, USA
| | - Martin Tresguerres
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Daniel Wangpraseurt
- Department of NanoEngineering, University of California San Diego, La Jolla, CA, USA.
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA.
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4
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Kramer N, Tamir R, Galindo-Martínez CT, Wangpraseurt D, Loya Y. Light pollution alters the skeletal morphology of coral juveniles and impairs their light capture capacity. Mar Pollut Bull 2023; 193:115212. [PMID: 37385181 DOI: 10.1016/j.marpolbul.2023.115212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 06/13/2023] [Accepted: 06/21/2023] [Indexed: 07/01/2023]
Abstract
Urbanization and infrastructure development have changed the night-time light regime of many coastal marine habitats. Consequently, Artificial Light at Night (ALAN) is becoming a global ecological concern, particularly in nearshore coral reef ecosystems. However, the effects of ALAN on coral architecture and their optical properties are unexplored. Here, we conducted a long-term ex situ experiment (30 months from settlement) on juvenile Stylophora pistillata corals grown under ALAN conditions using light-emitting diodes (LEDs) and fluorescent lamps, mimicking light-polluted habitats. We found that corals exposed to ALAN exhibited altered skeletal morphology that subsequently resulted in reduced light capture capacity, while also gaining better structural and optical modifications to increased light levels than their ambient-light counterparts. Additionally, light-polluted corals developed a more porous skeleton compared to the control corals. We suggest that ALAN induces light stress in corals, leading to a decrease in the solar energy available for photosynthesis during daytime illumination.
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Affiliation(s)
- Netanel Kramer
- School of Zoology, Tel-Aviv University, Tel Aviv, Israel; The Steinhardt Museum of Natural History, Israel National Center for Biodiversity Studies, Tel Aviv, Israel.
| | - Raz Tamir
- Israel Oceanography & Limnological Research, National Institute of Oceanography, Haifa, Israel
| | | | - Daniel Wangpraseurt
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego,San Diego, USA; Department of Nanoengineering, University of California San Diego, San Diego, USA
| | - Yossi Loya
- School of Zoology, Tel-Aviv University, Tel Aviv, Israel
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5
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You S, Xiang Y, Hwang HH, Berry DB, Kiratitanaporn W, Guan J, Yao E, Tang M, Zhong Z, Ma X, Wangpraseurt D, Sun Y, Lu TY, Chen S. High cell density and high-resolution 3D bioprinting for fabricating vascularized tissues. Sci Adv 2023; 9:eade7923. [PMID: 36812321 PMCID: PMC9946358 DOI: 10.1126/sciadv.ade7923] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 01/24/2023] [Indexed: 06/18/2023]
Abstract
Three-dimensional (3D) bioprinting techniques have emerged as the most popular methods to fabricate 3D-engineered tissues; however, there are challenges in simultaneously satisfying the requirements of high cell density (HCD), high cell viability, and fine fabrication resolution. In particular, bioprinting resolution of digital light processing-based 3D bioprinting suffers with increasing bioink cell density due to light scattering. We developed a novel approach to mitigate this scattering-induced deterioration of bioprinting resolution. The inclusion of iodixanol in the bioink enables a 10-fold reduction in light scattering and a substantial improvement in fabrication resolution for bioinks with an HCD. Fifty-micrometer fabrication resolution was achieved for a bioink with 0.1 billion per milliliter cell density. To showcase the potential application in tissue/organ 3D bioprinting, HCD thick tissues with fine vascular networks were fabricated. The tissues were viable in a perfusion culture system, with endothelialization and angiogenesis observed after 14 days of culture.
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Affiliation(s)
- Shangting You
- Department of NanoEngineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yi Xiang
- Department of NanoEngineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Henry H. Hwang
- Department of NanoEngineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - David B. Berry
- Department of NanoEngineering, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Orthopedic Surgery, University of California, San Diego, La Jolla, CA 92093, USA
| | - Wisarut Kiratitanaporn
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jiaao Guan
- Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Emmie Yao
- Department of NanoEngineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Min Tang
- Department of NanoEngineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Zheng Zhong
- Department of NanoEngineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Xinyue Ma
- School of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Daniel Wangpraseurt
- Department of NanoEngineering, University of California, San Diego, La Jolla, CA 92093, USA
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yazhi Sun
- Department of NanoEngineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ting-yu Lu
- Materials Science and Engineering Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Shaochen Chen
- Department of NanoEngineering, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, CA 92093, USA
- Materials Science and Engineering Program, University of California, San Diego, La Jolla, CA 92093, USA
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6
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Kramer N, Guan J, Chen S, Wangpraseurt D, Loya Y. Morpho-functional traits of the coral Stylophora pistillata enhance light capture for photosynthesis at mesophotic depths. Commun Biol 2022; 5:861. [PMID: 36002592 PMCID: PMC9402581 DOI: 10.1038/s42003-022-03829-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 08/10/2022] [Indexed: 12/03/2022] Open
Abstract
The morphological architecture of photosynthetic corals modulates the light capture and functioning of the coral-algal symbiosis on shallow-water corals. Since corals can thrive on mesophotic reefs under extreme light-limited conditions, we hypothesized that microskeletal coral features enhance light capture under low-light environments. Utilizing micro-computed tomography scanning, we conducted a novel comprehensive three-dimensional (3D) assessment of the small-scale skeleton morphology of the depth-generalist coral Stylophora pistillata collected from shallow (4–5 m) and mesophotic (45–50 m) depths. We detected a high phenotypic diversity between depths, resulting in two distinct morphotypes, with calyx diameter, theca height, and corallite marginal spacing contributing to most of the variation between depths. To determine whether such depth-specific morphotypes affect coral light capture and photosynthesis on the corallite scale, we developed 3D simulations of light propagation and photosynthesis. We found that microstructural features of corallites from mesophotic corals provide a greater ability to use solar energy under light-limited conditions; while corals associated with shallow morphotypes avoided excess light through self-shading skeletal architectures. The results from our study suggest that skeleton morphology plays a key role in coral photoadaptation to light-limited environments. Micro-computed tomography scanning and 3D light simulation models reveals distinct morphotypes of the coral species Stylophora pistillata depending on depth, and suggest that coral skeletal micromorphology plays a key role in coral photoadaptation.
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Affiliation(s)
- Netanel Kramer
- School of Zoology, Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, Israel.
| | - Jiaao Guan
- Department of Electrical and Computer Engineering, University of California San Diego, San Diego, USA
| | - Shaochen Chen
- Department of Nanoengineering, University of California San Diego, San Diego, USA
| | - Daniel Wangpraseurt
- Department of Nanoengineering, University of California San Diego, San Diego, USA.,Scripps Institution of Oceanography, University of California San Diego, San Diego, USA
| | - Yossi Loya
- School of Zoology, Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, Israel
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7
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Bollati E, Lyndby NH, D'Angelo C, Kühl M, Wiedenmann J, Wangpraseurt D. Green fluorescent protein-like pigments optimize the internal light environment in symbiotic reef building corals. eLife 2022; 11:73521. [PMID: 35801683 PMCID: PMC9342951 DOI: 10.7554/elife.73521] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 07/07/2022] [Indexed: 11/25/2022] Open
Abstract
Pigments homologous to the green fluorescent protein (GFP) have been proposed to fine-tune the internal light microclimate of corals, facilitating photoacclimation of photosynthetic coral symbionts (Symbiodiniaceae) to life in different reef habitats and environmental conditions. However, direct measurements of the in vivo light conditions inside the coral tissue supporting this conclusion are lacking. Here, we quantified the intra-tissue spectral light environment of corals expressing GFP-like proteins from widely different light regimes. We focus on: (1) photoconvertible red fluorescent proteins (pcRFPs), thought to enhance photosynthesis in mesophotic habitats via wavelength conversion, and (2) chromoproteins (CPs), which provide photoprotection to the symbionts in shallow water via light absorption. Optical microsensor measurements indicated that both pigment groups strongly alter the coral intra-tissue light environment. Estimates derived from light spectra measured in pcRFP-containing corals showed that fluorescence emission can contribute to >50% of orange-red light available to the photosynthetic symbionts at mesophotic depths. We further show that upregulation of pink CPs in shallow-water corals during bleaching leads to a reduction of orange light by 10–20% compared to low-CP tissue. Thus, screening by CPs has an important role in mitigating the light-enhancing effect of coral tissue scattering and skeletal reflection during bleaching. Our results provide the first experimental quantification of the importance of GFP-like proteins in fine-tuning the light microclimate of corals during photoacclimation.
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Affiliation(s)
- Elena Bollati
- Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Niclas H Lyndby
- Laboratory for Biological Geochemistry, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Cecilia D'Angelo
- Coral Reef Laboratory, University of Southampton, Southampton, United Kingdom
| | - Michael Kühl
- Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Jörg Wiedenmann
- Coral Reef Laboratory, University of Southampton, Southampton, United Kingdom
| | - Daniel Wangpraseurt
- Department of NanoEngineering, University of California, San Diego, San Diego, United States
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8
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Wangpraseurt D, You S, Sun Y, Chen S. Biomimetic 3D living materials powered by microorganisms. Trends Biotechnol 2022; 40:843-857. [DOI: 10.1016/j.tibtech.2022.01.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 01/03/2022] [Accepted: 01/04/2022] [Indexed: 12/14/2022]
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9
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Kramer N, Tamir R, Ben‐Zvi O, Jacques SL, Loya Y, Wangpraseurt D. Efficient light‐harvesting of mesophotic corals is facilitated by coral optical traits. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13948] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Raz Tamir
- School of Zoology Tel‐Aviv University Tel Aviv Israel
- The Interuniversity Institute for Marine Sciences of Eilat Eilat Israel
| | - Or Ben‐Zvi
- School of Zoology Tel‐Aviv University Tel Aviv Israel
- The Interuniversity Institute for Marine Sciences of Eilat Eilat Israel
| | - Steven L. Jacques
- Department of Bioengineering University of Washington Seattle WA USA
| | - Yossi Loya
- School of Zoology Tel‐Aviv University Tel Aviv Israel
| | - Daniel Wangpraseurt
- Department of Nanoengineering University of California San Diego San Diego CA USA
- Department of Chemistry University of Cambridge Cambridge UK
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10
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Wangpraseurt D, You S, Azam F, Jacucci G, Gaidarenko O, Hildebrand M, Kühl M, Smith AG, Davey MP, Smith A, Deheyn DD, Chen S, Vignolini S. Bionic 3D printed corals. Nat Commun 2020; 11:1748. [PMID: 32273516 PMCID: PMC7145811 DOI: 10.1038/s41467-020-15486-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 03/10/2020] [Indexed: 01/03/2023] Open
Abstract
Corals have evolved as optimized photon augmentation systems, leading to space-efficient microalgal growth and outstanding photosynthetic quantum efficiencies. Light attenuation due to algal self-shading is a key limiting factor for the upscaling of microalgal cultivation. Coral-inspired light management systems could overcome this limitation and facilitate scalable bioenergy and bioproduct generation. Here, we develop 3D printed bionic corals capable of growing microalgae with high spatial cell densities of up to 109 cells mL−1. The hybrid photosynthetic biomaterials are produced with a 3D bioprinting platform which mimics morphological features of living coral tissue and the underlying skeleton with micron resolution, including their optical and mechanical properties. The programmable synthetic microenvironment thus allows for replicating both structural and functional traits of the coral-algal symbiosis. Our work defines a class of bionic materials that is capable of interacting with living organisms and can be exploited for applied coral reef research and photobioreactor design. Corals have evolved as finely tuned light collectors. Here, the authors report on the 3D printing of coral-inspired biomaterials, that mimic the coral-algal symbiosis; these bionic corals lead to dense microalgal growth and can find applications in algal biotechnology and applied coral science.
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Affiliation(s)
- Daniel Wangpraseurt
- Bioinspired Photonics Group, Department of Chemistry, University of Cambridge, Cambridge, UK. .,Scripps Institution of Oceanography, University of California San Diego, San Diego, USA. .,Marine Biological Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
| | - Shangting You
- Department of Nanoengineering, University of California San Diego, San Diego, CA, USA
| | - Farooq Azam
- Scripps Institution of Oceanography, University of California San Diego, San Diego, USA
| | - Gianni Jacucci
- Bioinspired Photonics Group, Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Olga Gaidarenko
- Scripps Institution of Oceanography, University of California San Diego, San Diego, USA
| | - Mark Hildebrand
- Scripps Institution of Oceanography, University of California San Diego, San Diego, USA
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark.,Climate Change Cluster, University of Technology Sydney, Ultimo, Australia
| | - Alison G Smith
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Matthew P Davey
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Alyssa Smith
- Bioinspired Photonics Group, Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Dimitri D Deheyn
- Scripps Institution of Oceanography, University of California San Diego, San Diego, USA
| | - Shaochen Chen
- Department of Nanoengineering, University of California San Diego, San Diego, CA, USA.
| | - Silvia Vignolini
- Bioinspired Photonics Group, Department of Chemistry, University of Cambridge, Cambridge, UK.
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11
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Wangpraseurt D, Jacques S, Lyndby N, Holm JB, Pages CF, Kühl M. Microscale light management and inherent optical properties of intact corals studied with optical coherence tomography. J R Soc Interface 2020; 16:20180567. [PMID: 30958182 DOI: 10.1098/rsif.2018.0567] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Coral reefs are highly productive photosynthetic systems and coral optics studies suggest that such high efficiency is due to optimized light scattering by coral tissue and skeleton. Here, we characterize the inherent optical properties, i.e. the scattering coefficient, μs, and the anisotropy of scattering, g, of eight intact coral species using optical coherence tomography (OCT). Specifically, we describe light scattering by coral skeletons, coenoarc tissues, polyp tentacles and areas covered by fluorescent pigments (FP). Our results reveal that light scattering between coral species ranges from μs = 3 mm-1 ( Stylophora pistillata) to μs = 25 mm-1 ( Echinopora lamelosa) . For Platygyra pini, μs was 10-fold higher for tissue versus skeleton, while in other corals (e.g. Hydnophora pilosa) no difference was found between tissue and skeletal scattering. Tissue scattering was threefold enhanced in coenosarc tissues ( μs = 24.6 mm-1) versus polyp tentacles ( μs = 8.3 mm-1) in Turbinaria reniformis. FP scattering was almost isotropic when FP were organized in granule chromatophores ( g = 0.34) but was forward directed when FP were distributed diffusely in the tissue ( g = 0.96). Our study provides detailed measurements of coral scattering and establishes a rapid approach for characterizing optical properties of photosynthetic soft tissues via OCT in vivo.
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Affiliation(s)
- Daniel Wangpraseurt
- 1 Marine Biological Section, Department of Biology, University of Copenhagen , Strandpromenaden 5, 3000 Helsingør , Denmark.,2 Department of Chemistry, University of Cambridge , Lensfield Road, Cambridge , UK.,3 Scripps Institution of Oceanography, University of California , San Diego, CA , USA
| | - Steven Jacques
- 4 Department of Biomedical Engineering, Tufts University , Medford, MA , USA
| | - Niclas Lyndby
- 1 Marine Biological Section, Department of Biology, University of Copenhagen , Strandpromenaden 5, 3000 Helsingør , Denmark
| | - Jacob Boiesen Holm
- 1 Marine Biological Section, Department of Biology, University of Copenhagen , Strandpromenaden 5, 3000 Helsingør , Denmark
| | | | - Michael Kühl
- 1 Marine Biological Section, Department of Biology, University of Copenhagen , Strandpromenaden 5, 3000 Helsingør , Denmark.,6 Climate Change Cluster, University of Technology Sydney , Ultimo, New South Wales 2007 , Australia
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12
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Spicer GLC, Eid A, Wangpraseurt D, Swain TD, Winkelmann JA, Yi J, Kühl M, Marcelino LA, Backman V. Author Correction: Measuring light scattering and absorption in corals with Inverse Spectroscopic Optical Coherence Tomography (ISOCT): a new tool for non-invasive monitoring. Sci Rep 2019; 9:18056. [PMID: 31772266 PMCID: PMC6879626 DOI: 10.1038/s41598-019-54379-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- G L C Spicer
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA.,Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, Boston, MA, USA
| | - A Eid
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | - D Wangpraseurt
- Department of Chemistry, University of Cambridge, Lensfield Road, UK.,Scripps Institution of Oceanography, University of California, San Diego, USA
| | - T D Swain
- Department of Civil and Environmental Engineering, Northwestern University, Evanston, IL, USA.,Integrative Research Center, Field Museum of Natural History, Chicago, IL, USA.,Department of Marine and Environmental Sciences, Nova Southeastern University, Dania Beach, FL, USA
| | - J A Winkelmann
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | - J Yi
- Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - M Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark.,Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, Australia
| | - L A Marcelino
- Department of Civil and Environmental Engineering, Northwestern University, Evanston, IL, USA. .,Integrative Research Center, Field Museum of Natural History, Chicago, IL, USA.
| | - V Backman
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA.
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13
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Fisher A, Wangpraseurt D, Larkum AWD, Johnson M, Kühl M, Chen M, Wong HL, Burns BP. Correlation of bio-optical properties with photosynthetic pigment and microorganism distribution in microbial mats from Hamelin Pool, Australia. FEMS Microbiol Ecol 2019; 95:5151331. [PMID: 30380056 DOI: 10.1093/femsec/fiy219] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 10/30/2018] [Indexed: 11/14/2022] Open
Abstract
Microbial mats and stromatolites are widespread in Hamelin Pool, Shark Bay, however the phototrophic capacity of these systems is unknown. This study has determined the optical properties and light-harvesting potential of these mats with light microsensors. These characteristics were linked via a combination of 16S rDNA sequencing, pigment analyses and hyperspectral imaging. Local scalar irradiance was elevated over the incident downwelling irradiance by 1.5-fold, suggesting light trapping and strong scattering by the mats. Visible light (400-700 nm) penetrated to a depth of 2 mm, whereas near-infrared light (700-800 nm) penetrated to at least 6 mm. Chlorophyll a and bacteriochlorophyll a (Bchl a) were found to be the dominant photosynthetic pigments present, with BChl a peaking at the subsurface (2-4 mm). Detailed 16S rDNA analyses revealed the presence of putative Chl f-containing Halomicronema sp. and photosynthetic members primarily decreased from the mat surface down to a depth of 6 mm. Data indicated high abundances of some pigments and phototrophic organisms in deeper layers of the mats (6-16 mm). It is proposed that the photosynthetic bacteria present in this system undergo unique adaptations to lower light conditions below the mat surface, and that phototrophic metabolisms are major contributors to ecosystem function.
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Affiliation(s)
- Amy Fisher
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052, Australia.,Australian Centre for Astrobiology, University of New South Wales, Sydney 2052, Australia
| | - Daniel Wangpraseurt
- Marine Biological Section, University of Copenhagen, Copenhagen 1017, Denmark.,Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK.,Scripps Institution of Oceanography, University of California, San Diego 92037, CA, USA
| | - Anthony W D Larkum
- Climate Change Cluster, University of Technology, Sydney 2007, Australia
| | - Michael Johnson
- Climate Change Cluster, University of Technology, Sydney 2007, Australia
| | - Michael Kühl
- Marine Biological Section, University of Copenhagen, Copenhagen 1017, Denmark.,Climate Change Cluster, University of Technology, Sydney 2007, Australia
| | - Min Chen
- School of Life and Environmental Sciences, University of Sydney, Sydney 2006, Australia
| | - Hon Lun Wong
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052, Australia.,Australian Centre for Astrobiology, University of New South Wales, Sydney 2052, Australia
| | - Brendan P Burns
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052, Australia.,Australian Centre for Astrobiology, University of New South Wales, Sydney 2052, Australia
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14
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Wangpraseurt D, Lichtenberg M, Jacques SL, Larkum AWD, Kühl M. Optical Properties of Corals Distort Variable Chlorophyll Fluorescence Measurements. Plant Physiol 2019; 179:1608-1619. [PMID: 30692219 PMCID: PMC6446749 DOI: 10.1104/pp.18.01275] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 01/16/2019] [Indexed: 06/09/2023]
Abstract
Pulse-amplitude-modulated (PAM) fluorimetry is widely used in photobiological studies of corals, as it rapidly provides numerous photosynthetic parameters to assess coral ecophysiology. Coral optics studies have revealed the presence of light gradients in corals, which are strongly affected by light scattering in coral tissue and skeleton. We investigated whether coral optics affects variable chlorophyll (Chl) fluorescence measurements and derived photosynthetic parameters by developing planar hydrogel slabs with immobilized microalgae and with bulk optical properties similar to those of different types of corals. Our results show that PAM-based measurements of photosynthetic parameters differed substantially between hydrogels with different degrees of light scattering but identical microalgal density, yielding deviations in apparent maximal electron transport rates by a factor of 2. Furthermore, system settings such as the measuring light intensity affected F 0, Fm , and Fv /Fm in hydrogels with identical light absorption but different degrees of light scattering. Likewise, differences in microalgal density affected variable Chl fluorescence parameters, where higher algal densities led to greater Fv /Fm values and relative electron transport rates. These results have important implications for the use of variable Chl fluorimetry in ecophysiological studies of coral stress and photosynthesis, as well as other optically dense systems such as plant tissue and biofilms.
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Affiliation(s)
- Daniel Wangpraseurt
- Marine Biological Section, Department of Biology, University of Copenhagen, DK-3000 Helsingør, Denmark
- Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, California 92037
| | - Mads Lichtenberg
- Marine Biological Section, Department of Biology, University of Copenhagen, DK-3000 Helsingør, Denmark
| | | | - Anthony W D Larkum
- Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, DK-3000 Helsingør, Denmark
- Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales 2007, Australia
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15
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Quinn RA, Comstock W, Zhang T, Morton JT, da Silva R, Tran A, Aksenov A, Nothias LF, Wangpraseurt D, Melnik AV, Ackermann G, Conrad D, Klapper I, Knight R, Dorrestein PC. Niche partitioning of a pathogenic microbiome driven by chemical gradients. Sci Adv 2018; 4:eaau1908. [PMID: 30263961 PMCID: PMC6157970 DOI: 10.1126/sciadv.aau1908] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 08/10/2018] [Indexed: 05/25/2023]
Abstract
Environmental microbial communities are stratified by chemical gradients that shape the structure and function of these systems. Similar chemical gradients exist in the human body, but how they influence these microbial systems is more poorly understood. Understanding these effects can be particularly important for dysbiotic shifts in microbiome structure that are often associated with disease. We show that pH and oxygen strongly partition the microbial community from a diseased human lung into two mutually exclusive communities of pathogens and anaerobes. Antimicrobial treatment disrupted this chemical partitioning, causing complex death, survival, and resistance outcomes that were highly dependent on the individual microorganism and on community stratification. These effects were mathematically modeled, enabling a predictive understanding of this complex polymicrobial system. Harnessing the power of these chemical gradients could be a drug-free method of shaping microbial communities in the human body from undesirable dysbiotic states.
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Affiliation(s)
- Robert A. Quinn
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, CA 92093, USA
- Center for Microbiome Innovation, University of California at San Diego, La Jolla, CA 92093, USA
| | - William Comstock
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, CA 92093, USA
| | - Tianyu Zhang
- Department of Mathematical Sciences, Montana State University, Bozeman, MT 59717, USA
| | - James T. Morton
- Department of Computer Science and Engineering, University of California at San Diego, La Jolla, CA 92093, USA
| | - Ricardo da Silva
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, CA 92093, USA
| | - Alda Tran
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, CA 92093, USA
| | - Alexander Aksenov
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, CA 92093, USA
- Center for Microbiome Innovation, University of California at San Diego, La Jolla, CA 92093, USA
| | - Louis-Felix Nothias
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, CA 92093, USA
| | - Daniel Wangpraseurt
- Department of Chemistry, University of Cambridge, Cambridge, UK
- Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA 92093, USA
| | - Alexey V. Melnik
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, CA 92093, USA
| | - Gail Ackermann
- Department of Pediatrics, University of California at San Diego, La Jolla, CA 92093, USA
| | - Douglas Conrad
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093, USA
| | - Isaac Klapper
- Department of Mathematics, Temple University, Philadelphia, PA 19122, USA
| | - Rob Knight
- Center for Microbiome Innovation, University of California at San Diego, La Jolla, CA 92093, USA
- Department of Computer Science and Engineering, University of California at San Diego, La Jolla, CA 92093, USA
- Department of Pediatrics, University of California at San Diego, La Jolla, CA 92093, USA
| | - Pieter C. Dorrestein
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California at San Diego, La Jolla, CA 92093, USA
- Center for Microbiome Innovation, University of California at San Diego, La Jolla, CA 92093, USA
- Department of Pediatrics, University of California at San Diego, La Jolla, CA 92093, USA
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16
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Goessling JW, Su Y, Cartaxana P, Maibohm C, Rickelt LF, Trampe ECL, Walby SL, Wangpraseurt D, Wu X, Ellegaard M, Kühl M. Structure-based optics of centric diatom frustules: modulation of the in vivo light field for efficient diatom photosynthesis. New Phytol 2018; 219:122-134. [PMID: 29672846 DOI: 10.1111/nph.15149] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Accepted: 03/06/2018] [Indexed: 05/08/2023]
Abstract
The optical properties of diatom silicate frustules inspire photonics and nanotechnology research. Whether light interaction with the nano-structure of the frustule also affects diatom photosynthesis has remained unclear due to lack of information on frustule optical properties under more natural conditions. Here we demonstrate that the optical properties of the frustule valves in water affect light harvesting and photosynthesis in live cells of centric diatoms (Coscinodiscus granii). Microscale cellular mapping of photosynthesis around localized spot illumination demonstrated optical coupling of chloroplasts to the valve wall. Photonic structures of the three-layered C. granii valve facilitated light redistribution and efficient photosynthesis in cell regions distant from the directly illuminated area. The different porous structure of the two sides of the valve exhibited photon trapping and forward scattering of blue light enhancing photosynthetic active radiation inside the cell. Photonic structures of diatom frustules thus alter the cellular light field with implications on diatom photobiology.
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Affiliation(s)
- Johannes W Goessling
- Marine Biology Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, 3000, Helsingør, Denmark
| | - Yanyan Su
- Section for Plant Glycobiology, Department for Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg, Denmark
| | - Paulo Cartaxana
- Marine Biology Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, 3000, Helsingør, Denmark
- Departamento de Biologia & CESAM, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal
| | - Christian Maibohm
- International Iberian Nanotechnology Laboratory, 4715-330, Braga, Portugal
| | - Lars F Rickelt
- Marine Biology Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, 3000, Helsingør, Denmark
- Oxyguard International A/S, Farum Gydevej 64, 3520, Farum, Denmark
- Zenzor, Krondrevet 31, 3140, Ålsgårde, Denmark
| | - Erik C L Trampe
- Marine Biology Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, 3000, Helsingør, Denmark
| | - Sandra L Walby
- Section for Plant Glycobiology, Department for Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg, Denmark
| | - Daniel Wangpraseurt
- Marine Biology Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, 3000, Helsingør, Denmark
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Xia Wu
- Department of Chemistry, Paderborn University, Warburger Str. 100, 33098, Paderborn, Germany
| | - Marianne Ellegaard
- Section for Plant Glycobiology, Department for Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg, Denmark
| | - Michael Kühl
- Marine Biology Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, 3000, Helsingør, Denmark
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, 2007, Australia
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17
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Frommlet JC, Wangpraseurt D, Sousa ML, Guimarães B, Medeiros da Silva M, Kühl M, Serôdio J. Symbiodinium-Induced Formation of Microbialites: Mechanistic Insights From in Vitro Experiments and the Prospect of Its Occurrence in Nature. Front Microbiol 2018; 9:998. [PMID: 29892272 PMCID: PMC5966549 DOI: 10.3389/fmicb.2018.00998] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 04/27/2018] [Indexed: 12/21/2022] Open
Abstract
Dinoflagellates in the genus Symbiodinium exhibit a variety of life styles, ranging from mutualistic endosymbioses with animal and protist hosts to free-living life styles. In culture, Symbiodinium spp. and naturally associated bacteria are known to form calcifying biofilms that produce so-called symbiolites, i.e., aragonitic microbialites that incorporate Symbiodinium as endolithic cells. In this study, we investigated (i) how algal growth and the combined physiological activity of these bacterial-algal associations affect the physicochemical macroenvironment in culture and the microenvironment within bacterial-algal biofilms, and (ii) how these interactions induce the formation of symbiolites. In batch culture, calcification typically commenced when Symbiodinium spp. growth approached stationary phase and when photosynthetic activity and its influence on pH and the carbonate system of the culture medium had already subsided, indicating that symbiolite formation is not simply a function of photosynthetic activity in the bulk medium. Physical disturbance of bacteria-algal biofilms, via repeated detaching and dispersing of the developing biofilm, generally impeded symbiolite formation, suggesting that the structural integrity of biofilms plays an important role in generating conditions conducive to calcification. Microsensor measurements of pH and O2 revealed a biofilm microenvironment characterized by high photosynthetic rates and by dynamic changes in photosynthesis and respiration with light intensity and culture age. Ca2+ microsensor measurements confirmed the significance of the biofilm microenvironment in inducing calcification, as photosynthesis within the biofilm induced calcification without the influence of batch culture medium and under environmentally relevant flow conditions. Furthermore, first quantitative data on calcification from 26 calcifying cultures enabled a first broad comparison of Symbiodinium-induced bacterial-algal calcification with other calcification processes. Our findings support the idea that symbiolite formation is a typical, photosynthesis-induced, bacterial-algal calcification process that is likely to occur under natural conditions.
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Affiliation(s)
- Jörg C Frommlet
- Department of Biology and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Aveiro, Portugal
| | - Daniel Wangpraseurt
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark.,Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Maria L Sousa
- Department of Biology and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Aveiro, Portugal
| | - Bárbara Guimarães
- Department of Biology and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Aveiro, Portugal
| | - Mariana Medeiros da Silva
- Coral Reef and Global Changes Research Group (RECOR), Department of Oceanography, Institute of Geosciences, Federal University of Bahia (UFBA), Salvador, Brazil
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark.,Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - João Serôdio
- Department of Biology and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Aveiro, Portugal
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18
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Sønderholm M, Koren K, Wangpraseurt D, Jensen PØ, Kolpen M, Kragh KN, Bjarnsholt T, Kühl M. Tools for studying growth patterns and chemical dynamics of aggregated Pseudomonas aeruginosa exposed to different electron acceptors in an alginate bead model. NPJ Biofilms Microbiomes 2018; 4:3. [PMID: 29479470 PMCID: PMC5818519 DOI: 10.1038/s41522-018-0047-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 01/07/2018] [Accepted: 01/24/2018] [Indexed: 12/31/2022] Open
Abstract
In chronic infections, bacterial pathogens typically grow as small dense cell aggregates embedded in a matrix consisting of, e.g., wound bed sludge or lung mucus. Such biofilm growth mode exhibits extreme tolerance towards antibiotics and the immune defence system. The bacterial aggregates are exposed to physiological heterogeneity and O2 limitation due to steep chemical gradients through the matrix, which is are hypothesised to contribute to antibiotic tolerance. Using a novel combination of microsensor and bioimaging analysis, we investigated growth patterns and chemical dynamics of the pathogen Pseudomonas aeruginosa in an alginate bead model, which mimics growth in chronic infections better than traditional biofilm experiments in flow chambers. Growth patterns were strongly affected by electron acceptor availability and the presence of chemical gradients, where the combined presence of O2 and nitrate yielded highest bacterial growth by combined aerobic respiration and denitrification.
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Affiliation(s)
- Majken Sønderholm
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen N, Denmark
| | - Klaus Koren
- Marine Biology Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, DK-3000 Helsingør, Denmark
| | - Daniel Wangpraseurt
- Marine Biology Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, DK-3000 Helsingør, Denmark
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Peter Østrup Jensen
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen N, Denmark
- Department of Clinical Microbiology 9301, Copenhagen University Hospital, Rigshospitalet, Juliane Maries Vej 22, Copenhagen, Denmark
| | - Mette Kolpen
- Department of Clinical Microbiology 9301, Copenhagen University Hospital, Rigshospitalet, Juliane Maries Vej 22, Copenhagen, Denmark
| | - Kasper Nørskov Kragh
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen N, Denmark
| | - Thomas Bjarnsholt
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen N, Denmark
- Department of Clinical Microbiology 9301, Copenhagen University Hospital, Rigshospitalet, Juliane Maries Vej 22, Copenhagen, Denmark
| | - Michael Kühl
- Marine Biology Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, DK-3000 Helsingør, Denmark
- Climate Change Cluster, University of Technology Sydney, Broadway, NSW 2007 Australia
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19
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Wangpraseurt D, Wentzel C, Jacques SL, Wagner M, Kühl M. In vivo imaging of coral tissue and skeleton with optical coherence tomography. J R Soc Interface 2017; 14:20161003. [PMID: 28250104 PMCID: PMC5378135 DOI: 10.1098/rsif.2016.1003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 02/01/2017] [Indexed: 11/12/2022] Open
Abstract
Application of optical coherence tomography (OCT) for in vivo imaging of tissue and skeleton structure of intact living corals enabled the non-invasive visualization of coral tissue layers (endoderm versus ectoderm), skeletal cavities and special structures such as mesenterial filaments and mucus release from intact living corals. Coral host chromatophores containing green fluorescent protein-like pigment granules appeared hyper-reflective to near-infrared radiation allowing for excellent optical contrast in OCT and a rapid characterization of chromatophore size, distribution and abundance. In vivo tissue plasticity could be quantified by the linear contraction velocity of coral tissues upon illumination resulting in dynamic changes in the live coral tissue surface area, which varied by a factor of 2 between the contracted and expanded state of a coral. Our study provides a novel view on the in vivo organization of coral tissue and skeleton and highlights the importance of microstructural dynamics for coral ecophysiology.
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Affiliation(s)
- Daniel Wangpraseurt
- Marine Biological Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, Helsingør 3000, Denmark
| | - Camilla Wentzel
- Marine Biological Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, Helsingør 3000, Denmark
| | - Steven L Jacques
- Department of Biomedical Engineering, Oregon Health and Science University, 3303 SW Bond Avenue, Portland, OR 97239, USA
| | - Michael Wagner
- Engler-Bunte Institute, Chair of Water Chemistry and Water Technology, Karlsruhe Institute of Technology, Engler-Bunte-Ring 1, 76131 Karlsruhe, Germany
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, Helsingør 3000, Denmark
- Climate Change Cluster, University of Technology Sydney, PO Box 123, Broadway, Sydney, New South Wales 2007, Australia
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20
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Wangpraseurt D, Holm JB, Larkum AWD, Pernice M, Ralph PJ, Suggett DJ, Kühl M. In vivo Microscale Measurements of Light and Photosynthesis during Coral Bleaching: Evidence for the Optical Feedback Loop? Front Microbiol 2017; 8:59. [PMID: 28174567 PMCID: PMC5258690 DOI: 10.3389/fmicb.2017.00059] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 01/09/2017] [Indexed: 12/21/2022] Open
Abstract
Climate change-related coral bleaching, i.e., the visible loss of zooxanthellae from the coral host, is increasing in frequency and extent and presents a major threat to coral reefs globally. Coral bleaching has been proposed to involve accelerating light stress of their microalgal endosymbionts via a positive feedback loop of photodamage, symbiont expulsion and excess in vivo light exposure. To test this hypothesis, we used light and O2 microsensors to characterize in vivo light exposure and photosynthesis of Symbiodinium during a thermal stress experiment. We created tissue areas with different densities of Symbiodinium cells in order to understand the optical properties and light microenvironment of corals during bleaching. Our results showed that in bleached Pocillopora damicornis corals, Symbiodinium light exposure was up to fivefold enhanced relative to healthy corals, and the relationship between symbiont loss and light enhancement was well-described by a power-law function. Cell-specific rates of Symbiodinium gross photosynthesis and light respiration were enhanced in bleached P. damicornis compared to healthy corals, while areal rates of net photosynthesis decreased. Symbiodinium light exposure in Favites sp. revealed the presence of low light microniches in bleached coral tissues, suggesting that light scattering in thick coral tissues can enable photoprotection of cryptic symbionts. Our study provides evidence for the acceleration of in vivo light exposure during coral bleaching but this optical feedback mechanism differs between coral hosts. Enhanced photosynthesis in relation to accelerating light exposure shows that coral microscale optics exerts a key role on coral photophysiology and the subsequent degree of radiative stress during coral bleaching.
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Affiliation(s)
- Daniel Wangpraseurt
- Marine Biological Section, Department of Biology, University of CopenhagenHelsingør, Denmark; Climate Change Cluster, Department of Environmental Sciences, University of Sydney, SydneyNSW, Australia
| | - Jacob B Holm
- Marine Biological Section, Department of Biology, University of Copenhagen Helsingør, Denmark
| | - Anthony W D Larkum
- Climate Change Cluster, Department of Environmental Sciences, University of Sydney, Sydney NSW, Australia
| | - Mathieu Pernice
- Climate Change Cluster, Department of Environmental Sciences, University of Sydney, Sydney NSW, Australia
| | - Peter J Ralph
- Climate Change Cluster, Department of Environmental Sciences, University of Sydney, Sydney NSW, Australia
| | - David J Suggett
- Climate Change Cluster, Department of Environmental Sciences, University of Sydney, Sydney NSW, Australia
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of CopenhagenHelsingør, Denmark; Climate Change Cluster, Department of Environmental Sciences, University of Sydney, SydneyNSW, Australia
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21
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Lyndby NH, Kühl M, Wangpraseurt D. Heat generation and light scattering of green fluorescent protein-like pigments in coral tissue. Sci Rep 2016; 6:26599. [PMID: 27225857 PMCID: PMC4880895 DOI: 10.1038/srep26599] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 05/05/2016] [Indexed: 11/29/2022] Open
Abstract
Green fluorescent protein (GFP)-like pigments have been proposed to have beneficial effects on coral photobiology. Here, we investigated the relationships between green fluorescence, coral heating and tissue optics for the massive coral Dipsastraea sp. (previously Favia sp.). We used microsensors to measure tissue scalar irradiance and temperature along with hyperspectral imaging and combined imaging of variable chlorophyll fluorescence and green fluorescence. Green fluorescence correlated positively with coral heating and scalar irradiance enhancement at the tissue surface. Coral tissue heating saturated for maximal levels of green fluorescence. The action spectrum of coral surface heating revealed that heating was highest under red (peaking at 680 nm) irradiance. Scalar irradiance enhancement in coral tissue was highest when illuminated with blue light, but up to 62% (for the case of highest green fluorescence) of this photon enhancement was due to green fluorescence emission. We suggest that GFP-like pigments scatter the incident radiation, which enhances light absorption and heating of the coral. However, heating saturates, because intense light scattering reduces the vertical penetration depth through the tissue eventually leading to reduced light absorption at high fluorescent pigment density. We conclude that fluorescent pigments can have a central role in modulating coral light absorption and heating.
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Affiliation(s)
- Niclas H Lyndby
- Marine Biological Section, Department of Biology, University of Copenhagen, DK-3000 Helsingør, Denmark
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, DK-3000 Helsingør, Denmark.,Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia
| | - Daniel Wangpraseurt
- Marine Biological Section, Department of Biology, University of Copenhagen, DK-3000 Helsingør, Denmark.,Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, New South Wales 2007, Australia
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22
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Wangpraseurt D, Jacques SL, Petrie T, Kühl M. Monte Carlo Modeling of Photon Propagation Reveals Highly Scattering Coral Tissue. Front Plant Sci 2016; 7:1404. [PMID: 27708657 PMCID: PMC5030289 DOI: 10.3389/fpls.2016.01404] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 09/02/2016] [Indexed: 05/21/2023]
Abstract
Corals are very efficient at using solar radiation, with photosynthetic quantum efficiencies approaching theoretical limits. Here, we investigated potential mechanisms underlying such outstanding photosynthetic performance through extracting inherent optical properties of the living coral tissue and skeleton in a massive faviid coral. Using Monte Carlo simulations developed for medical tissue optics it is shown that for the investigated faviid coral, the coral tissue was a strongly light scattering matrix with a reduced scattering coefficient of μs' = 10 cm-1 (at 636 nm). In contrast, the scattering coefficient of the coral skeleton was μs' = 3.4 cm-1, which facilitated the efficient propagation of light to otherwise shaded coral tissue layers, thus supporting photosynthesis in lower tissues. Our study provides a quantification of coral tissue optical properties in a massive faviid coral and suggests a novel light harvesting strategy, where tissue and skeletal optics act in concert to optimize the illumination of the photosynthesizing algal symbionts embedded within the living coral tissue.
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Affiliation(s)
- Daniel Wangpraseurt
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, SydneyNSW, Australia
- Marine Biological Section, Department of Biology, University of CopenhagenHelsingør, Denmark
- *Correspondence: Daniel Wangpraseurt,
| | - Steven L. Jacques
- Department of Biomedical Engineering, Oregon Health & Science University, PortlandOR, USA
| | - Tracy Petrie
- Department of Biomedical Engineering, Oregon Health & Science University, PortlandOR, USA
| | - Michael Kühl
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, SydneyNSW, Australia
- Marine Biological Section, Department of Biology, University of CopenhagenHelsingør, Denmark
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Sandel V, Martínez-Fernández D, Wangpraseurt D, Sierra L. Ecology and management of the invasive lionfish Pterois volitans/miles complex (Perciformes: Scorpaenidae) in Southern Costa Rica. REV BIOL TROP 2015; 63:213-21. [PMID: 26299126 DOI: 10.15517/rbt.v63i1.14749] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Invasive species alter ecosystem integrity and functioning and are considered one of the major threats to biodiversity on a global scale. The indopacific lionfish (Plerois volitans [Linnaeus, 1758] / miles [Bennet, 1882] complex) is the first non-native marine fish that has established itself in the Western Atlantic. It was first reported in Florida in the 1980s and then spread across the entire Caribbean in subsequent years. In Costa Rica, lionfish were first sighted by the end of 2008 and are now present in all South Caribbean reefs. Lionfish are a major problem for local fisherman by displacing native fish species. The aim of this study was to determine population density, size and diet of lionfish populations at four study sites along the Southern Caribbean coast of Costa Rica. Two of the sites were located inside the National Park Cahuita where regular lionfish removal occurs, whereas the other two study sides do not experiment this kind of management. Total length and wet weight of >450 lionfish individuals were determined between March and June 2011. Three relative metrics of prey quantity (percent number, percent frequency, and percent weight) were compared from approximately 300 lionfish caught with the polespear in shallow waters (<7 m depth). Population density was assessed weekly through visual transect surveys. Our results showed that lionfish preyed mostly upon teleosts and crustaceans. Teleosts dominated lionfish diet in percent frequency (71%) and percent weight (85%), whereas crustaceans had the highest percent number (58%). The top five teleost families of dietary importance were Pomacentridae, Acanthuridae, Blennidae, Labridae and Serranidae. The average total length (+/- SD) of lionfish was 18.7 (+/- 5.7)cm and varied significantly between sites (p<0.001). Mean density of lionfish was 92fish/ha with no significant differences between sites. Smallest fish and lowest densities were found at the two sites inside the National Park Cahuita. Despite management efforts on a regional scale, nationwide efforts are ineffective and lionfish control activities are poorly implemented. We conclude that there is an urgent need to develop an improved institutional framework for local lionfish control that promotes effective coordination among the relevant stakeholders in order to deal with invasive lionfish in Costa Rica.
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Nielsen DA, Pernice M, Schliep M, Sablok G, Jeffries TC, Kühl M, Wangpraseurt D, Ralph PJ, Larkum AWD. Microenvironment and phylogenetic diversity of Prochloron inhabiting the surface of crustose didemnid ascidians. Environ Microbiol 2015; 17:4121-32. [PMID: 26176189 DOI: 10.1111/1462-2920.12983] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2014] [Accepted: 07/09/2015] [Indexed: 11/28/2022]
Abstract
The cyanobacterium Prochloron didemni is primarily found in symbiotic relationships with various marine hosts such as ascidians and sponges. Prochloron remains to be successfully cultivated outside of its host, which reflects a lack of knowledge of its unique ecophysiological requirements. We investigated the microenvironment and diversity of Prochloron inhabiting the upper, exposed surface of didemnid ascidians, providing the first insights into this microhabitat. The pH and O2 concentration in this Prochloron biofilm changes dynamically with irradiance, where photosynthetic activity measurements showed low light adaptation (Ek ∼ 80 ± 7 μmol photons m(-2) s(-1)) but high light tolerance. Surface Prochloron cells exhibited a different fine structure to Prochloron cells from cloacal cavities in other ascidians, the principle difference being a central area of many vacuoles dissected by single thylakoids in the surface Prochloron. Cyanobacterial 16S rDNA pyro-sequencing of the biofilm community on four ascidians resulted in 433 operational taxonomic units (OTUs) where on average -85% (65-99%) of all sequence reads, represented by 136 OTUs, were identified as Prochloron via blast search. All of the major Prochloron-OTUs clustered into independent, highly supported phylotypes separate from sequences reported for internal Prochloron, suggesting a hitherto unexplored genetic variability among Prochloron colonizing the outer surface of didemnids.
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Affiliation(s)
- Daniel A Nielsen
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales, 2007, Australia
| | - Mathieu Pernice
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales, 2007, Australia
| | - Martin Schliep
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales, 2007, Australia
| | - Gaurav Sablok
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales, 2007, Australia
| | - Thomas C Jeffries
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales, 2007, Australia.,Hawkesbury Institute for the Environment, University of Western Sydney, Penrith, New South Wales, 2751, Australia
| | - Michael Kühl
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales, 2007, Australia.,Marine Biology Section, Department of Biology, University of Copenhagen, Helsingør, DK-3000, Denmark
| | - Daniel Wangpraseurt
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales, 2007, Australia
| | - Peter J Ralph
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales, 2007, Australia
| | - Anthony W D Larkum
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales, 2007, Australia
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25
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Wangpraseurt D, Tamburic B, Szabó M, Suggett D, Ralph PJ, Kühl M. Spectral effects on Symbiodinium photobiology studied with a programmable light engine. PLoS One 2014; 9:e112809. [PMID: 25389753 PMCID: PMC4229233 DOI: 10.1371/journal.pone.0112809] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 10/16/2014] [Indexed: 11/19/2022] Open
Abstract
The spectral light field of Symbiodinium within the tissue of the coral animal host can deviate strongly from the ambient light field on a coral reef and that of artificial light sources used in lab studies on coral photobiology. Here, we used a novel approach involving light microsensor measurements and a programmable light engine to reconstruct the spectral light field that Symbiodinium is exposed to inside the coral host and the light field of a conventional halogen lamp in a comparative study of Symbiodinium photobiology. We found that extracellular gross photosynthetic O2 evolution was unchanged under different spectral illumination, while the more red-weighted halogen lamp spectrum decreased PSII electron transport rates and there was a trend towards increased light-enhanced dark respiration rates under excess irradiance. The approach provided here allows for reconstructing and comparing intra-tissue coral light fields and other complex spectral compositions of incident irradiance. This novel combination of sensor technologies provides a framework to studying the influence of macro- and microscale optics on Symbiodinium photobiology with unprecedented spectral resolution.
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Affiliation(s)
- Daniel Wangpraseurt
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Sydney, Australia
| | - Bojan Tamburic
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Sydney, Australia
| | - Milán Szabó
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Sydney, Australia
| | - David Suggett
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Sydney, Australia
| | - Peter J. Ralph
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Sydney, Australia
| | - Michael Kühl
- Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Sydney, Australia
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
- Singapore Centre on Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- * E-mail:
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Schrameyer V, Wangpraseurt D, Hill R, Kühl M, Larkum AWD, Ralph PJ. Light respiratory processes and gross photosynthesis in two scleractinian corals. PLoS One 2014; 9:e110814. [PMID: 25360746 PMCID: PMC4216011 DOI: 10.1371/journal.pone.0110814] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 09/25/2014] [Indexed: 11/18/2022] Open
Abstract
The light dependency of respiratory activity of two scleractinian corals was examined using O2 microsensors and CO2 exchange measurements. Light respiration increased strongly but asymptotically with elevated irradiance in both species. Light respiration in Pocillopora damicornis was higher than in Pavona decussata under low irradiance, indicating species-specific differences in light-dependent metabolic processes. Overall, the coral P. decussata exhibited higher CO2 uptake rates than P. damicornis over the experimental irradiance range. P. decussata also harboured twice as many algal symbionts and higher total protein biomass compared to P. damicornis, possibly resulting in self-shading of the symbionts and/or changes in host tissue specific light distribution. Differences in light respiration and CO2 availability could be due to host-specific characteristics that modulate the symbiont microenvironment, its photosynthesis, and hence the overall performance of the coral holobiont.
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Affiliation(s)
- Verena Schrameyer
- Plant Functional Biology and Climate Change Cluster, School of the Environment, University of Technology, Sydney, Ultimo, New South Wales, Australia
| | - Daniel Wangpraseurt
- Plant Functional Biology and Climate Change Cluster, School of the Environment, University of Technology, Sydney, Ultimo, New South Wales, Australia
| | - Ross Hill
- Plant Functional Biology and Climate Change Cluster, School of the Environment, University of Technology, Sydney, Ultimo, New South Wales, Australia
- Centre for Marine Bio-Innovation and Sydney Institute of Marine Science, School of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, New South Wales, Australia
| | - Michael Kühl
- Plant Functional Biology and Climate Change Cluster, School of the Environment, University of Technology, Sydney, Ultimo, New South Wales, Australia
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
- Singapore Centre on Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Anthony W. D. Larkum
- Plant Functional Biology and Climate Change Cluster, School of the Environment, University of Technology, Sydney, Ultimo, New South Wales, Australia
| | - Peter J. Ralph
- Plant Functional Biology and Climate Change Cluster, School of the Environment, University of Technology, Sydney, Ultimo, New South Wales, Australia
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Szabó M, Wangpraseurt D, Tamburic B, Larkum AWD, Schreiber U, Suggett DJ, Kühl M, Ralph PJ. Effective light absorption and absolute electron transport rates in the coral Pocillopora damicornis. Plant Physiol Biochem 2014; 83:159-167. [PMID: 25146689 DOI: 10.1016/j.plaphy.2014.07.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2014] [Accepted: 07/20/2014] [Indexed: 06/03/2023]
Abstract
Pulse Amplitude Modulation (PAM) fluorometry has been widely used to estimate the relative photosynthetic efficiency of corals. However, both the optical properties of intact corals as well as past technical constrains to PAM fluorometers have prevented calculations of the electron turnover rate of PSII. We used a new Multi-colour PAM (MC-PAM) in parallel with light microsensors to determine for the first time the wavelength-specific effective absorption cross-section of PSII photochemistry, σII(λ), and thus PAM-based absolute electron transport rates of the coral photosymbiont Symbiodinium both in culture and in hospite in the coral Pocillopora damicornis. In both cases, σII of Symbiodinium was highest in the blue spectral region and showed a progressive decrease towards red wavelengths. Absolute values for σII at 440 nm were up to 1.5-times higher in culture than in hospite. Scalar irradiance within the living coral tissue was reduced by 20% in the blue when compared to the incident downwelling irradiance. Absolute electron transport rates of P. damicornis at 440 nm revealed a maximum PSII turnover rate of ca. 250 electrons PSII(-1) s(-1), consistent with one PSII turnover for every 4 photons absorbed by PSII; this likely reflects the limiting steps in electron transfer between PSII and PSI. Our results show that optical properties of the coral host strongly affect light use efficiency of Symbiodinium. Therefore, relative electron transport rates do not reflect the productivity rates (or indeed how the photosynthesis-light response is parameterised). Here we provide a non-invasive approach to estimate absolute electron transport rates in corals.
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Affiliation(s)
- Milán Szabó
- Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, Broadway 2007, NSW, Australia.
| | - Daniel Wangpraseurt
- Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, Broadway 2007, NSW, Australia
| | - Bojan Tamburic
- Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, Broadway 2007, NSW, Australia
| | - Anthony W D Larkum
- Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, Broadway 2007, NSW, Australia
| | - Ulrich Schreiber
- Julius-von-Sachs Institut für Biowissenschaften, Lehrstuhl Botanik I, Universität Würzburg, Germany
| | - David J Suggett
- Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, Broadway 2007, NSW, Australia
| | - Michael Kühl
- Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, Broadway 2007, NSW, Australia; Marine Biological Section, Department of Biology, University of Copenhagen, DK-3000 Helsingør, Denmark
| | - Peter J Ralph
- Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, Broadway 2007, NSW, Australia
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Wangpraseurt D, Larkum AWD, Franklin J, Szabó M, Ralph PJ, Kühl M. Lateral light transfer ensures efficient resource distribution in symbiont-bearing corals. J Exp Biol 2014; 217:489-98. [DOI: 10.1242/jeb.091116] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Coral tissue optics has received very little attention in the past, although the interaction between tissue and light is central to our basic understanding of coral physiology. Here we used fibre-optic and electrochemical microsensors along with variable chlorophyll fluorescence imaging to directly measure lateral light propagation within living coral tissues. Our results show that corals can transfer light laterally within their tissues to a distance of ~2 cm. Such light transport stimulates O2 evolution and photosystem II operating efficiency in areas >0.5–1 cm away from direct illumination. Light is scattered strongly in both coral tissue and skeleton, leading to photon trapping and lateral redistribution within the tissue. Lateral light transfer in coral tissue is a new mechanism by which light is redistributed over the coral colony and we argue that tissue optical properties are one of the key factors in explaining the high photosynthetic efficiency of corals.
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Affiliation(s)
- Daniel Wangpraseurt
- Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, Syndey, NSW 2007, Australia
| | - Anthony W. D. Larkum
- Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, Syndey, NSW 2007, Australia
| | - Jim Franklin
- Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, Syndey, NSW 2007, Australia
| | - Milán Szabó
- Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, Syndey, NSW 2007, Australia
| | - Peter J. Ralph
- Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, Syndey, NSW 2007, Australia
| | - Michael Kühl
- Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, Syndey, NSW 2007, Australia
- Marine Biological Section, Department of Biology, University of Copenhagen, DK-3000 Helsingør, Denmark
- Singapore Centre on Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, 639798 Singapore
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Brodersen KE, Lichtenberg M, Ralph PJ, Kühl M, Wangpraseurt D. Radiative energy budget reveals high photosynthetic efficiency in symbiont-bearing corals. J R Soc Interface 2014; 11:20130997. [PMID: 24478282 DOI: 10.1098/rsif.2013.0997] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The light field on coral reefs varies in intensity and spectral composition, and is the key regulating factor for phototrophic reef organisms, for example scleractinian corals harbouring microalgal symbionts. However, the actual efficiency of light utilization in corals and the mechanisms affecting the radiative energy budget of corals are underexplored. We present the first balanced light energy budget for a symbiont-bearing coral based on a fine-scale study of the microenvironmental photobiology of the massive coral Montastrea curta. The majority (more than 96%) of the absorbed light energy was dissipated as heat, whereas the proportion of the absorbed light energy used in photosynthesis was approximately 4.0% under an irradiance of 640 µmol photons m(-2) s(-1). With increasing irradiance, the proportion of heat dissipation increased at the expense of photosynthesis. Despite such low energy efficiency, we found a high photosynthetic efficiency of the microalgal symbionts showing high gross photosynthesis rates and quantum efficiencies (QEs) of approximately 0.1 O2 photon(-1) approaching theoretical limits under moderate irradiance levels. Corals thus appear as highly efficient light collectors with optical properties enabling light distribution over the corallite/tissue microstructural canopy that enables a high photosynthetic QE of their photosynthetic microalgae in hospite.
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Affiliation(s)
- Kasper Elgetti Brodersen
- Marine Biological Section, Department of Biology, University of Copenhagen, , Strandpromenaden 5, Helsingør 3000, Denmark
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Abstract
Light quantity and quality are among the most important factors determining the physiology and stress response of zooxanthellate corals. Yet, almost nothing is known about the light field that Symbiodinium experiences within their coral host, and the basic optical properties of coral tissue are unknown. We used scalar irradiance microprobes to characterize vertical and lateral light gradients within and across tissues of several coral species. Our results revealed the presence of steep light gradients with photosynthetically available radiation decreasing by about one order of magnitude from the tissue surface to the coral skeleton. Surface scalar irradiance was consistently higher over polyp tissue than over coenosarc tissue in faviid corals. Coral bleaching increased surface scalar irradiance by ~150% (between 500 and 700 nm) relative to a healthy coral. Photosynthesis peaked around 300 μm within the tissue, which corresponded to a zone exhibiting strongest depletion of scalar irradiance. Deeper coral tissue layers, e.g., ~1000 μm into aboral polyp tissues, harbor optical microniches, where only ~10% of the incident irradiance remains. We conclude that the optical microenvironment of corals exhibits strong lateral and vertical gradients of scalar irradiance, which are affected by both tissue and skeleton optical properties. Our results imply that zooxanthellae populations inhabit a strongly heterogeneous light environment and highlight the presence of different optical microniches in corals; an important finding for understanding the photobiology, stress response, as well as the phenotypic and genotypic plasticity of coral symbionts.
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Affiliation(s)
- Daniel Wangpraseurt
- Plant Functional Biology and Climate Change Cluster, Department of Environmental Sciences, University of Technology Sydney Sydney, NSW, Australia
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