july 26 2018
New preprint now available on biorxiv.org “Microscale light management and inherent optical properties of intact corals studied with optical coherence tomography” Coral reefs are highly productive photosynthetic systems and coral optics studies suggest that such high efficiency is due to optimised light scattering by coral tissue and skeleton. Here, we characterise the inherent optical properties, i.e., the scattering coefficient, μs, and the anisotropy of scattering, g, of 8 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 vs skeleton, while in other corals (e.g., Hydnophora pilosa) no difference was found between tissue and skeletal scattering. Tissue scattering was 3-fold enhanced in coenosarc tissues (μs = 24.6 mm-1) vs 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 characterising optical properties of photosynthetic soft tissues via OCT in vivo.
Authors: Daniel Wangpraseurt, Steven L Jacques, Niclas Lyndby, Jacob B Holm, Christine Ferrier Pages, Michael Kuhl
August 28: New manuscript submitted:
Title: “Elevated CO2 leads to enhanced photosynthesis but decreased growth in early life stages of reef building coralline algae”
Alexandra Ordoñez,Daniel Wangpraseurt, Niclas Lyndby, Michael Kühl, and Guillermo Diaz-Pulido.
July 28: New manuscript submitted:
Title: “Correlation of bio-optical properties with photosynthetic pigment and microorganism distribution in stromatolites from Hamelin Pool, Australia”
Authors: Fisher, Amy; Wangpraseurt, Daniel; Larkum, Anthony; Johnson, Michael; Kühl, Michael; Wong, Hon; Chen, Min; Burns, Brendan
July, 2018: New preprint on Bio-optical properties and radiative energy budgets in fed and starved scleractinian corals (Pocillopora damicornis) during thermal bleaching in collaboration with researchers from the micro-ecology group at the University of Copenhagen and the coral group at the Centre of Scientifique de Monaco. The study uses optical coherence tomography to characterize the optical properties of intact corals.
Public news coverage: The preprint is featured in OCT news.
Daniel Wangpraseurt, Steven L Jacques, Niclas Lyndby, Jacob B Holm, Christine Ferrier Pages, Michael Kuhl
MAY 14, 2018: Frommlett, Wangpraseurt and co-authors publish in Frontiers in Microbiology on mechanisms underlying ‘Symbiolite’ formation. Symbiolites are aragonitic microbialites that incorporate Symbiodinium as endolithic cells. The first report of Symbiodinium (i.e. symbiotic microalgae) calcification outside of the coral host was an unexpected discovery (see PNAS paper). The new study now suggests that this calcification process is tightly controlled by the physico-chemical microenviroment and the structure of the developing biofilm. The research uses Ca2+ microsensors to study single cell calcification. The study sheds new fundamental research in microalgal calcification which has also applications for the construction of hybrid living calcifying photosynthetic structures.
Details: Frommlet JC*, Wangpraseurt D*, Sousa ML, Guimarães B, da Silva MM, Kühl M, Serôdio J. Symbiodinium-induced formation of microbialites: Mechanistic insights from in vitro experiments and the prospect of its occurrence in nature. Frontiers in Microbiology. 2018;9. *shared first author
April 19, 2018: New paper published in New Phytologist on “Structure-based optics of centric diatom frustules: modulation of the in vivo light field for efficient diatom photosynthesis” by Goessling J, Su Y, Cartaxana PI, Maibohm C, Rickelt LF< Trampe ECL, Walby SL, Wangpraseurt D, Wu X, Ellegaard M, Kuhl M. The paper demonstrates 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. The publication highlights the importance of diatom frustule morphology for diatom photosynthesis.
APRIL 1 2018
Noah Martin (UC Berkeley) and Tatum Bernat (UCLA) join the biomicfuel team. Noah and Tatum will be working on the development of Bio-inspired algal-bacterial hydrogels for space efficeint microalgal growth.
aPRIL 11-14, 2018 living light conference, cambridge, uk
APRIL 13, 2018: Daniel Wangpraseurt gives a talk on ‘3D bioprinted photosynthetic matter inspired by corals’. The talk is co-authored by an international research group from the University of Cambridge, the University of California San Diego and the University of Copenagen. The abstract booklet can be found here.
Living light 2018 is organised by the Vignolini lab. Living light is a biennial interdisciplinary conference focusing on light-matter interaction in living organisms. Following the 2016's success at the Scripps Research Institute, the next conference will take place in Cambridge, United Kingdom from the 11th to 14th of April 2018. We invite everyone with an interest in light in living organisms to participate. The conference topics covers (without being limited to):
Biological photonic structures
Optics of natural materials
Development and evolution of structural colouration in nature
Ecology and biochemistry of structural colour in nature
FEBRUARY 19: Researcheres from the University of Copenhagen, Ringhospitalet Copnhagen and Cambridge University develop an alginate bead model that mimics chronic bacterial infections. The study is published NPJ Biofilms and Microbiomes. The developed model system is suitable for testing antiomicrobial susceptibility and tolerance of bacterial strains causing chronic infections. The study also developed new approaches that combine Optical coherence tomography imaging, confocal imaging and microsensor technology to characterise the non-invasive rapid development of bacterial aggregates and biofilms. Such model systems are now optimized for efficient algal-bacterial co-culture.
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 and microbiomes. 2018 Feb 19;4(1):3.
Public news coverage:
Video by Prof Thomas Bjarsnholt (University of Copenhhagen):
January 18, 2018 gordon research conference, ventura, usa
JANUARY 18, 2018: Daniel Wangpraseurt presenting his work on coral-inspired photosynthetic matter at the Gordon Research Conference for Multifunctional Materials and Structures in Venutra, California. The conference focusses on addressing the scientific issues underpinning advancements in: the translation of model biological functions to synthetic systems, signaling (e.g. chemical, electrical, mechanical), self-learning, chemical transport and transformation for control of mechanical properties, the role of interfaces and design/fabrication approaches for creating multi-scale hierarchical material systems with multifunctional performance. The conference program and furher can be found here.