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Soleimani M, van Breemen LCA, Maddala SP, Joosten RRM, Wu H, Schreur-Piet I, van Benthem RATM, Friedrich H. In Situ Manipulation and Micromechanical Characterization of Diatom Frustule Constituents Using Focused Ion Beam Scanning Electron Microscopy. Small Methods 2021; 5:e2100638. [PMID: 34928031 DOI: 10.1002/smtd.202100638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 06/13/2021] [Revised: 09/17/2021] [Indexed: 06/14/2023]
Abstract
Biocomposite structures are difficult to characterize by bulk approaches due to their morphological complexity and compositional heterogeneity. Therefore, a versatile method is required to assess, for example, the mechanical properties of geometrically simple parts of biocomposites at the relevant length scales. Here, it is demonstrated how a combination of Focused Ion Beam Scanning Electron Microscopy (FIB-SEM) and micromanipulators can be used to isolate, transfer, and determine the mechanical properties of frustule constituents of diatom Thalassiosira pseudonana (T.p.). Specifically, two parts of the diatom frustule, girdle bands and valves, are separated by FIB milling and manipulated using a sharp tungsten tip without compromising their physical or chemical integrity. In situ mechanical studies on isolated girdle bands combined with Finite Element Method (FEM) simulations, enables the quantitative assessment of the Young's modulus of this biosilica; E = 40.0 GPa. In addition, the mechanical strength of isolated valves could be measured by transferring and mounting them on top of premilled holes in the sample support. This approach may be extended to any hierarchical biocomposite material, regardless of its chemical composition, to isolate, transfer, and investigate the mechanical properties of selected constituents or specific regions.
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Affiliation(s)
- Mohammad Soleimani
- Laboratory of Physical Chemistry, and Center for Multiscale Electron Microscopy, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Groene Loper 5, Eindhoven, 5612 AE, The Netherlands
| | - Lambèrt C A van Breemen
- Polymer Technology, Materials Technology Institute, Department of Mechanical Engineering, Eindhoven University of Technology, Groene Loper 15, Eindhoven, 5612 AE, The Netherlands
| | - Sai P Maddala
- Laboratory of Physical Chemistry, and Center for Multiscale Electron Microscopy, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Groene Loper 5, Eindhoven, 5612 AE, The Netherlands
| | - Rick R M Joosten
- Laboratory of Physical Chemistry, and Center for Multiscale Electron Microscopy, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Groene Loper 5, Eindhoven, 5612 AE, The Netherlands
| | - Hanglong Wu
- Laboratory of Physical Chemistry, and Center for Multiscale Electron Microscopy, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Groene Loper 5, Eindhoven, 5612 AE, The Netherlands
| | - Ingeborg Schreur-Piet
- Laboratory of Physical Chemistry, and Center for Multiscale Electron Microscopy, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Groene Loper 5, Eindhoven, 5612 AE, The Netherlands
| | - Rolf A T M van Benthem
- Laboratory of Physical Chemistry, and Center for Multiscale Electron Microscopy, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Groene Loper 5, Eindhoven, 5612 AE, The Netherlands
- DSM Materials Science Center, Netherlands, P.O. Box 18, Geleen, 6160 MD, The Netherlands
| | - Heiner Friedrich
- Laboratory of Physical Chemistry, and Center for Multiscale Electron Microscopy, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, Groene Loper 5, Eindhoven, 5612 AE, The Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology, Groene Loper 5, Eindhoven, 5612 AE, The Netherlands
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Arshad R, Calvaruso C, Boekema EJ, Büchel C, Kouřil R. Revealing the architecture of the photosynthetic apparatus in the diatom Thalassiosira pseudonana. Plant Physiol 2021; 186:2124-2136. [PMID: 33944951 PMCID: PMC8331139 DOI: 10.1093/plphys/kiab208] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 04/21/2021] [Indexed: 05/04/2023]
Abstract
Diatoms are a large group of marine algae that are responsible for about one-quarter of global carbon fixation. Light-harvesting complexes of diatoms are formed by the fucoxanthin chlorophyll a/c proteins and their overall organization around core complexes of photosystems (PSs) I and II is unique in the plant kingdom. Using cryo-electron tomography, we have elucidated the structural organization of PSII and PSI supercomplexes and their spatial segregation in the thylakoid membrane of the model diatom species Thalassiosira pseudonana. 3D sub-volume averaging revealed that the PSII supercomplex of T. pseudonana incorporates a trimeric form of light-harvesting antenna, which differs from the tetrameric antenna observed previously in another diatom, Chaetoceros gracilis. Surprisingly, the organization of the PSI supercomplex is conserved in both diatom species. These results strongly suggest that different diatom classes have various architectures of PSII as an adaptation strategy, whilst a convergent evolution occurred concerning PSI and the overall plastid structure.
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Affiliation(s)
- Rameez Arshad
- Department of Biophysics, Faculty of Science, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University, Olomouc 78371, Czech Republic
- Electron Microscopy Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen 9747AG, The Netherlands
| | - Claudio Calvaruso
- Institute for Molecular Biosciences, Goethe University of Frankfurt, Frankfurt 60438, Germany
| | - Egbert J Boekema
- Electron Microscopy Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen 9747AG, The Netherlands
| | - Claudia Büchel
- Institute for Molecular Biosciences, Goethe University of Frankfurt, Frankfurt 60438, Germany
| | - Roman Kouřil
- Department of Biophysics, Faculty of Science, Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University, Olomouc 78371, Czech Republic
- Author for communication:
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3
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Gastineau R, Davidovich NA, Davidovich OI, Lemieux C, Turmel M, Wróbel RJ, Witkowski A. Extreme Enlargement of the Inverted Repeat Region in the Plastid Genomes of Diatoms from the Genus Climaconeis. Int J Mol Sci 2021; 22:7155. [PMID: 34281209 PMCID: PMC8268801 DOI: 10.3390/ijms22137155] [Citation(s) in RCA: 6] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 06/29/2021] [Accepted: 06/30/2021] [Indexed: 11/17/2022] Open
Abstract
We sequenced the plastid genomes of three diatoms from the genus Climaconeis, including two strains formerly designated as Climaconeis scalaris. At 208,097 and 216,580 bp, the plastid genomes of the latter strains are the largest ever sequenced among diatoms and their increased size is explained by the massive expansion of the inverted repeat region. Important rearrangements of gene order were identified among the two populations of Climaconeis cf. scalaris. The other sequenced Climaconeis chloroplast genome is 1.5 times smaller compared with those of the Climaconeis cf. scalaris strains and it features an usual quadripartite structure. The extensive structural changes reported here for the genus Climaconeis are compared with those previously observed for other algae and plants displaying large plastid genomes.
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Affiliation(s)
- Romain Gastineau
- Institute of Marine and Environmental Sciences, University of Szczecin, Mickiewicza 16a, 70-383 Szczecin, Poland; (N.A.D.); (A.W.)
| | - Nikolaï A. Davidovich
- Institute of Marine and Environmental Sciences, University of Szczecin, Mickiewicza 16a, 70-383 Szczecin, Poland; (N.A.D.); (A.W.)
- Karadag Scientific Station–Natural Reserve of the Russian Academy of Sciences, p/o Kurortnoe, Feodosiya, 98188 Crimea, Russia;
| | - Olga I. Davidovich
- Karadag Scientific Station–Natural Reserve of the Russian Academy of Sciences, p/o Kurortnoe, Feodosiya, 98188 Crimea, Russia;
| | - Claude Lemieux
- Département de Biochimie, de Microbiologie et de Bio-Informatique, Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC G1V 0A6, Canada; (C.L.); (M.T.)
| | - Monique Turmel
- Département de Biochimie, de Microbiologie et de Bio-Informatique, Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, QC G1V 0A6, Canada; (C.L.); (M.T.)
| | - Rafał J. Wróbel
- Engineering of Catalytic and Sorbent Materials Department, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology Szczecin, Pułaskiego 10, 70-322 Szczecin, Poland;
| | - Andrzej Witkowski
- Institute of Marine and Environmental Sciences, University of Szczecin, Mickiewicza 16a, 70-383 Szczecin, Poland; (N.A.D.); (A.W.)
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Ishihara T, Ohkochi T, Yamaguchi A, Kotani Y, Oura M. Visualization of elemental distributions and local analysis of element-specific chemical states of an Arachnoidiscus sp. frustule using soft X-ray spectromicroscopy. PLoS One 2020; 15:e0243874. [PMID: 33326474 PMCID: PMC7743981 DOI: 10.1371/journal.pone.0243874] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 11/27/2020] [Indexed: 11/18/2022] Open
Abstract
Using soft X-ray (SX) spectromicroscopy, we show maps of the spatial distribution of constituent elements and local analysis of the density of states (DOS) related to the element-specific chemical states of diatom frustules, which are composed of naturally grown nanostructured hydrogenated amorphous silica. We applied X-ray photoemission electron microscopy (X-PEEM) as well as microprobe X-ray fluorescence (μXRF) analysis to characterize the surfaces of diatom frustules by means of X-ray absorption spectroscopy (XAS) and X-ray emission spectroscopy (XES). We successfully demonstrated that SX spectromicroscopy is able to participate in potential observation tools as a new method to spectroscopically investigate diatom frustules.
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Affiliation(s)
- Tomoko Ishihara
- Soft X-ray Spectroscopy Instrumentation Team, Physical and Chemical Research Infrastructure Group, Advanced Photon Technology Division, RIKEN SPring-8 Center, Sayo-gun, Hyogo, Japan
| | - Takuo Ohkochi
- Soft X-ray Spectroscopy Instrumentation Team, Physical and Chemical Research Infrastructure Group, Advanced Photon Technology Division, RIKEN SPring-8 Center, Sayo-gun, Hyogo, Japan
- Spectroscopic Analysis Group II, Spectroscopy and Imaging Division, Japan Synchrotron Radiation Research Institute (JASRI), Sayo-gun, Hyogo, Japan
| | - Akinobu Yamaguchi
- Soft X-ray Spectroscopy Instrumentation Team, Physical and Chemical Research Infrastructure Group, Advanced Photon Technology Division, RIKEN SPring-8 Center, Sayo-gun, Hyogo, Japan
- Laboratory of Advanced Science and Technology for Industry (LASTI), University of Hyogo, Ako-gun, Hyogo, Japan
| | - Yoshinori Kotani
- Spectroscopic Analysis Group II, Spectroscopy and Imaging Division, Japan Synchrotron Radiation Research Institute (JASRI), Sayo-gun, Hyogo, Japan
| | - Masaki Oura
- Soft X-ray Spectroscopy Instrumentation Team, Physical and Chemical Research Infrastructure Group, Advanced Photon Technology Division, RIKEN SPring-8 Center, Sayo-gun, Hyogo, Japan
- * E-mail:
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Khan MJ, Singh R, Shewani K, Shukla P, Bhaskar PV, Joshi KB, Vinayak V. Exopolysaccharides directed embellishment of diatoms triggered on plastics and other marine litter. Sci Rep 2020; 10:18448. [PMID: 33116244 PMCID: PMC7595185 DOI: 10.1038/s41598-020-74801-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 10/06/2020] [Indexed: 12/22/2022] Open
Abstract
In the present study, embellishment or beautification of diatoms on substrates like plastics, polydimethylsiloxane, graphite, glass plate, and titanium dioxide, triggered by exopolysaccharides was examined under laboratory conditions. Exopolysaccharides are secreted mainly by primary colonisers, bacteria, which is succeeded by secondary colonisers i.e. diatoms. Both diatom (Nitzschia sp.4) and bacteria (Bacillus subtilis) were exposed with substrates separately for 30 days. Diatoms adhere on substrates strongly, not only because of surface roughness of different substrates but also the nanoporous architecture of diatoms which enhanced their embellishment. This study attempted to identify the substrates that adhere to diatoms strongly and was mainly analyzed by scanning electron microscope and further the observations are well supported by math work software (MATLAB). The variation of diatom's binding on different substrates is due to the influence of marine litters on diatom population in ocean beds where they undergo slow degradation releasing macro, micro and nanoparticles besides radicals and ions causing cell death. Therefore a proof-of-concept model is developed to successfully deliver a message concerning benefit of using different diatom species.
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Affiliation(s)
- Mohd Jahir Khan
- Diatom Nanoengineering and Metabolism Laboratory (DNM), School of Applied Sciences, Dr. Harisingh Gour Central University, Sagar, Madhya Pradesh, 470003, India
| | - Ramesh Singh
- Department of Chemistry, School of Chemical Science and Technology, Dr. Harisingh Gour Central University, Sagar, Madhya Pradesh, 470003, India
| | - Kunal Shewani
- Department of Physics, School of Physical and Mathematical Sciences, Dr. Harisingh Gour Central University, Sagar, Madhya Pradesh, 470003, India
| | - Prashant Shukla
- Department of Physics, School of Physical and Mathematical Sciences, Dr. Harisingh Gour Central University, Sagar, Madhya Pradesh, 470003, India
| | - P V Bhaskar
- National Centre for Polar and Oceanic Research, Vasco Da Gama, Goa, 403804, India
| | - Khashti Ballabh Joshi
- Department of Chemistry, School of Chemical Science and Technology, Dr. Harisingh Gour Central University, Sagar, Madhya Pradesh, 470003, India
| | - Vandana Vinayak
- Diatom Nanoengineering and Metabolism Laboratory (DNM), School of Applied Sciences, Dr. Harisingh Gour Central University, Sagar, Madhya Pradesh, 470003, India.
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Liu Q, Tang X, Zhang X, Yang Y, Sun Z, Jian X, Zhao Y, Zhang X. Evaluation of the toxic response induced by BDE-47 in a marine alga, Phaeodactylum tricornutum, based on photosynthesis-related parameters. Aquat Toxicol 2020; 227:105588. [PMID: 32861020 DOI: 10.1016/j.aquatox.2020.105588] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [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: 02/05/2020] [Revised: 07/20/2020] [Accepted: 07/29/2020] [Indexed: 06/11/2023]
Abstract
The pollution of polybrominated diphenyl ethers (PBDEs) is becoming a pressing environmental problem in aquatic environments, and its threat to aquatic organism has received much attention. In this study, Phaeodactylum tricornutum was treated with 0.8 and 4 mg L-1 2,2',4,4'-tetrabrominated biphenyl ether (BDE-47), the most toxic PBDEs, for 96 h. BDE-47 inhibited cell growth in a time- and concentration-dependent manner. Observation of cell ultrastructure suggested the damage of the chloroplasts morphology. BDE-47 also decreased the chlorophyll content and the oxygen evolution rate, and altered the performance of photosystems. Transcriptomic analysis revealed differential expression of 62 genes related to photosynthesis in BDE-47 treatments (4 mg L-1) and transcription suppression of 58 genes involved in chlorophyll synthesis, antenna proteins, oxygen evolution, electron transport and downstream carbon fixation, implying potential toxicity targets in cells. Additionally, the levels of reactive oxygen species (ROS) and lipid peroxidation increased under BDE-47 stress and were positively correlated with photosynthesis inhibition. Pretreatment with the ROS scavenger N-acetyl-l-cysteine reduced the extent of inhibition, suggesting that ROS was responsible for these effects. Another experiment with the electron transport chain inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea showed that the generation of ROS was partially blocked, primarily indicating that photosynthetic inhibition induced by BDE-47 contributed to ROS overproduction. Thus, BDE-47 inhibited the photosynthesis by down-regulating the gene expression. This change stimulated ROS production, further leading to chloroplast membrane damage to aggravate this inhibition via a feedback loop. These effects of BDE-47 had adverse outcomes on the entire physiological state and the population growth of the microalgae.
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Affiliation(s)
- Qian Liu
- Department of Marine Ecology, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Xuexi Tang
- Department of Marine Ecology, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China; Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266237, China
| | - Xin Zhang
- Department of Marine Ecology, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Yingying Yang
- Department of Marine Ecology, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Zijie Sun
- Department of Marine Ecology, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China
| | - Xiaoyang Jian
- North China Sea Environmental Monitoring Center, State Oceanic Administration, Fushun Road 22, Qingdao, Shandong Province 266033, China
| | - Yan Zhao
- Department of Marine Ecology, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China; Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266237, China
| | - Xinxin Zhang
- Department of Marine Ecology, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China; Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266237, China.
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Liu Q, Tang X, Wang Y, Yang Y, Zhang W, Zhao Y, Zhang X. ROS changes are responsible for tributyl phosphate (TBP)-induced toxicity in the alga Phaeodactylum tricornutum. Aquat Toxicol 2019; 208:168-178. [PMID: 30677712 DOI: 10.1016/j.aquatox.2019.01.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [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: 12/06/2018] [Revised: 01/14/2019] [Accepted: 01/14/2019] [Indexed: 06/09/2023]
Abstract
As a newly emerging environmental contaminant, tributyl phosphate (TBP) is an additive flame retardant of high production volume that is frequently detected in biota and the environment. Despite evidence that TBP is a potential threat to marine organisms, ecotoxicology data for TBP in marine organisms at low trophic levels are scarce. In this study, the acute toxicological effect of TBP on the marine phytoplankton Phaeodactylum tricornutum was thoroughly investigated, and the possible mechanism was explored. The results showed that TBP at concentrations ≥0.2 mg L-1 significantly inhibited P. tricornutum growth in a clear dose-response manner, with 72-h EC10, EC20, EC50 and EC90 values of 0.067, 0.101, 0.219 and 0.716 mg L-1, respectively. Algal cells treated with TBP exhibited distorted shapes, ruptured cell membranes and damaged organelles, especially mitochondria. Additionally, apoptosis was triggered, followed by a decrease in mitochondrial membrane potential, indicating that cellular damage occurred during exposure. Although the activities of two antioxidant enzymes, superoxide peroxidase and catalase, were upregulated by TBP at 1.2 mg L-1, excess reactive oxygen species (ROS) and malondialdehyde still accumulated in algal cells after exposure, suggesting that the cells experienced oxidative stress. Moreover, both growth inhibition and apoptosis were positively correlated with ROS levels and were ameliorated by pretreatment with the ROS scavenger N-acetyl-l-cysteine. Taken together, the results indicate that TBP exposure leads to growth inhibition and cellular damage in P. tricornutum, and a ROS-mediated pathway might contribute to these observed toxicological effects.
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Affiliation(s)
- Qian Liu
- Department of Marine Ecology, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China.
| | - Xuexi Tang
- Department of Marine Ecology, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China; Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266237, China.
| | - You Wang
- Department of Marine Ecology, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China; Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266237, China.
| | - Yingying Yang
- Department of Marine Ecology, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China.
| | - Wei Zhang
- Department of Marine Ecology, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China.
| | - Yunchen Zhao
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, Fujian, China.
| | - Xinxin Zhang
- Department of Marine Ecology, College of Marine Life Science, Ocean University of China, Qingdao, 266003, China; Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266237, China.
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Li Y, Dong HC, Teng ST, Bates SS, Lim PT. Pseudo-nitzschia nanaoensis sp. nov. (Bacillariophyceae) from the Chinese coast of the South China Sea. J Phycol 2018; 54:918-922. [PMID: 30270437 DOI: 10.1111/jpy.12791] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 07/07/2018] [Indexed: 06/08/2023]
Abstract
Pseudo-nitzschia nanaoensis sp. nov. is described from waters around Nan'ao Island (South China Sea), using morphological data and molecular evidence. This species is morphologically most similar to P. brasiliana, but differs by a denser arrangement of fibulae, interstriae, and poroids, as well as by the structure of the valvocopula and the narrow second band. Pseudo-nitzschia nanaoensis constitutes a monophyletic lineage and is well differentiated from other species on the LSU and ITS2 sequence-structure trees. Pseudo-nitzschia nanaoensis makes up the basal node on the LSU tree, and forms a sister clade with a group of P. pungens and P. multiseries on the ITS2 tree. The ability of cultured strains to produce domoic acid was assessed, including its possible induction by the presence of a copepod and brine shrimp, by liquid chromatography-tandem mass spectrometry. However, no strains showed detectable domoic acid.
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Affiliation(s)
- Yang Li
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Healthy and Safe Aquaculture, College of Life Science, South China Normal University, West 55 of Zhongshan Avenue, Guangzhou, 510631, China
| | - Huan Chang Dong
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Healthy and Safe Aquaculture, College of Life Science, South China Normal University, West 55 of Zhongshan Avenue, Guangzhou, 510631, China
| | - Sing Tung Teng
- Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, Kota Samarahan, 94300, Sarawak, Malaysia
| | - Stephen S Bates
- Fisheries and Oceans Canada, Gulf Fisheries Centre, P.O. Box 5030, Moncton, New Brunswick, Canada, E1C 9B6
| | - Po Teen Lim
- Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaya, Bachok, Kelantan, 16310, Malaysia
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Gómez F, Wang L, Lin S. Morphology and molecular phylogeny of epizoic araphid diatoms on marine zooplankton, including Pseudofalcula hyalina gen. & comb. nov. (Fragilariophyceae, Bacillariophyta). J Phycol 2018; 54:557-570. [PMID: 29908074 DOI: 10.1111/jpy.12760] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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: 12/17/2017] [Accepted: 05/24/2018] [Indexed: 06/08/2023]
Abstract
Some diatoms are able to colonize as epibionts on their potential zooplankton predators. Here, we report Pseudohimantidium pacificum living on the copepod Corycaeus giesbrechti and as a new finding on Oithona nana, Protoraphis atlantica living on the copepod Pontellopsis brevis, Protoraphis hustedtiana on the cypris larvae of barnacles, and Falcula hyalina on the copepod Acartia lilljeborgii. The epizoic diatoms were able to grow as free-living forms under culture conditions. Pseudohimantidium pacificum and P. atlantica appeared as the most derived species from their benthic diatom ancestors. The mucilage pad or stalk of the strains of these species showed important morphological distinction when compared with their epizoic forms. Barnacle larvae explore benthic habitats before settlement, and epibiosis on them is an example where P. hustedtiana profits from the host behavior for dispersal of its benthic populations. Molecular phylogenies based on the SSU rRNA and RuBisCO large subunit (rbcL) gene sequences revealed F. hyalina as an independent lineage within the Fragilariales (Tabularia, Catacombas, and others), consistent with its morphological distinction in the low number of rows (≤6) in the ocellulimbus, among other features. We propose the transfer of F. hyalina to the genus Pseudofalcula gen. nov. Molecular phylogeny suggests a single order for the members of the Cyclophorales and the Protoraphidales, and that the epibioses of araphid diatoms on marine zooplankton have been independently acquired several times. These clades are constituted of both epizoic and epiphytic/epilithic forms that evidence a recent acquisition of the epizoic modus vivendi.
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Affiliation(s)
| | - Lu Wang
- Marine Biodiversity and Global Change Research Center and State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361005, China
- Department of Marine Sciences, University of Connecticut, Groton, Connecticut, 06340, USA
- Institute of Oceanography, Minjiang University, Fuzhou, 350108, China
| | - Senjie Lin
- Marine Biodiversity and Global Change Research Center and State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361005, China
- Department of Marine Sciences, University of Connecticut, Groton, Connecticut, 06340, USA
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10
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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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11
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Sabir JSM, Theriot EC, Manning SR, Al-Malki AL, Khiyami MA, Al-Ghamdi AK, Sabir MJ, Romanovicz DK, Hajrah NH, El Omri A, Jansen RK, Ashworth MP. Phylogenetic analysis and a review of the history of the accidental phytoplankter, Phaeodactylum tricornutum Bohlin (Bacillariophyta). PLoS One 2018; 13:e0196744. [PMID: 29883488 PMCID: PMC5993285 DOI: 10.1371/journal.pone.0196744] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Accepted: 04/18/2018] [Indexed: 11/18/2022] Open
Abstract
The diatom Phaeodactylum tricornutum has been used as a model for cell biologists and ecologists for over a century. We have incorporated several new raphid pennates into a three gene phylogenetic dataset (SSU, rbcL, psbC), and recover Gomphonemopsis sp. as sister to P. tricornutum with 100% BS support. This is the first time a close relative has been identified for P. tricornutum with robust statistical support. We test and reject a succession of hypotheses for other relatives. Our molecular data are statistically significantly incongruent with placement of either or both species among the Cymbellales, an order of diatoms with which both have been associated. We believe that further resolution of the phylogenetic position of P. tricornutum will rely more on increased taxon sampling than increased genetic sampling. Gomphonemopsis is a benthic diatom, and its phylogenetic relationship with P. tricornutum is congruent with the hypothesis that P. tricornutum is a benthic diatom with specific adaptations that lead to active recruitment into the plankton. We hypothesize that other benthic diatoms are likely to have similar adaptations and are not merely passively recruited into the plankton.
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Affiliation(s)
- Jamal S. M. Sabir
- Genomic and Biotechnology Research Group, Department of Biological Sciences, Faculty of Science, King Abdulaziz University (KAU), Jeddah, Saudi Arabia
| | - Edward C. Theriot
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas, United States of America
- * E-mail:
| | - Schonna R. Manning
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, United States of America
| | - Abdulrahman L. Al-Malki
- Department of Biochemistry, Faculty of Science, King Abdulaziz University (KAU), Jeddah, Saudi Arabia
| | | | - Areej K. Al-Ghamdi
- Genomic and Biotechnology Research Group, Department of Biological Sciences, Faculty of Science, King Abdulaziz University (KAU), Jeddah, Saudi Arabia
| | - Mumdooh J. Sabir
- Department of Information Technology, Faculty of Computing and Information Technology, King Abdulaziz University (KAU), Jeddah, Saudi Arabia
| | - Dwight K. Romanovicz
- Center for Biomedical Research Support, University of Texas at Austin, Austin, Texas, United States of America
| | - Nahid H. Hajrah
- Genomic and Biotechnology Research Group, Department of Biological Sciences, Faculty of Science, King Abdulaziz University (KAU), Jeddah, Saudi Arabia
| | - Abdelfatteh El Omri
- Genomic and Biotechnology Research Group, Department of Biological Sciences, Faculty of Science, King Abdulaziz University (KAU), Jeddah, Saudi Arabia
| | - Robert K. Jansen
- Genomic and Biotechnology Research Group, Department of Biological Sciences, Faculty of Science, King Abdulaziz University (KAU), Jeddah, Saudi Arabia
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas, United States of America
| | - Matt P. Ashworth
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas, United States of America
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12
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Gai FF, Hedemand CK, Louw DC, Grobler K, Krock B, Moestrup Ø, Lundholm N. Morphological, molecular and toxigenic characteristics of Namibian Pseudo-nitzschia species - including Pseudo-nitzschia bucculenta sp. nov. Harmful Algae 2018; 76:80-95. [PMID: 29887207 DOI: 10.1016/j.hal.2018.05.003] [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: 02/04/2018] [Revised: 05/14/2018] [Accepted: 05/14/2018] [Indexed: 06/08/2023]
Abstract
A field study was undertaken to investigate the occurrence and toxin production of species in the diatom genus Pseudo-nitzschia in Namibian waters, in the extremely productive Benguela upwelling system. From surveys conducted on the R/V Mirabilis and the R/V !Anichab, 52 strains were morphologically determined to species level, supported by nuclear ITS rDNA data. Seven species were identified; P. australis, P. decipiens, P. dolorosa, P. fraudulenta, P. plurisecta, P. pungens var. cingulata, and the new species P. bucculenta F. Gai, C. K. Hedemand, N. Lundholm & Ø. Moestrup sp. nov. Molecular and morphological diversity of the Namibian Pseudo-nitzschia species is discussed. Most importantly, P. bucculenta is both morphologically and phylogenetically most similar to P. dolorosa differing mainly in valve width and densities of striae, poroids and band striae as well as by four hemi-compensatory base changes in the ITS2. Morphological and molecular differences among the strains of P. decipiens suggest a temperate and a warm water subdivision. The geographical and toxigenic characteristics of the identified Pseudo-nitzschia species are described and compared to previous studies. Initial tests of toxin production in all seven species revealed production of domoic acid (DA) in two species: one strain of P. australis (0.074 pg DA cell-1) and two strains of P. plurisecta (0.338 pg DA cell-1 and 0.385 pg DA cell-1).
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Affiliation(s)
- Frederik Frøsig Gai
- Natural History Museum of Denmark, University of Copenhagen, Sølvgade 83S, 1307, Copenhagen K, Denmark
| | | | - Deon C Louw
- Ministry of Fisheries and Marine Resources, National Marine Information and Research Centre (NatMIRC), Swakopmund, P.O. Box 912, Namibia
| | - Kolette Grobler
- Ministry of Fisheries and Marine Resources, National Marine Information and Research Centre (NatMIRC), Lüderitz, PO Box 394, Shark Island, Namibia
| | - Bernd Krock
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
| | - Øjvind Moestrup
- Marine Biological Section, University of Copenhagen, Universitetsparken 4, 2100, Copenhagen Ø, Denmark
| | - Nina Lundholm
- Natural History Museum of Denmark, University of Copenhagen, Sølvgade 83S, 1307, Copenhagen K, Denmark.
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13
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Salta M, Dennington SP, Wharton JA. Biofilm Inhibition by Novel Natural Product- and Biocide-Containing Coatings Using High-Throughput Screening. Int J Mol Sci 2018; 19:ijms19051434. [PMID: 29748514 PMCID: PMC5983801 DOI: 10.3390/ijms19051434] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/02/2018] [Accepted: 05/03/2018] [Indexed: 01/31/2023] Open
Abstract
The use of natural products (NPs) as possible alternative biocidal compounds for use in antifouling coatings has been the focus of research over the past decades. Despite the importance of this field, the efficacy of a given NP against biofilm (mainly bacteria and diatoms) formation is tested with the NP being in solution, while almost no studies test the effect of an NP once incorporated into a coating system. The development of a novel bioassay to assess the activity of NP-containing and biocide-containing coatings against marine biofilm formation has been achieved using a high-throughput microplate reader and highly sensitive confocal laser scanning microscopy (CLSM), as well as nucleic acid staining. Juglone, an isolated NP that has previously shown efficacy against bacterial attachment, was incorporated into a simple coating matrix. Biofilm formation over 48 h was assessed and compared against coatings containing the NP and the commonly used booster biocide, cuprous oxide. Leaching of the NP from the coating was quantified at two time points, 24 h and 48 h, showing evidence of both juglone and cuprous oxide being released. Results from the microplate reader showed that the NP coatings exhibited antifouling efficacy, significantly inhibiting biofilm formation when compared to the control coatings, while NP coatings and the cuprous oxide coatings performed equally well. CLSM results and COMSTAT analysis on biofilm 3D morphology showed comparable results when the NP coatings were tested against the controls, with higher biofilm biovolume and maximum thickness being found on the controls. This new method proved to be repeatable and insightful and we believe it is applicable in antifouling and other numerous applications where interactions between biofilm formation and surfaces is of interest.
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Affiliation(s)
- Maria Salta
- Faculty of Sciences, School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, UK.
| | - Simon P Dennington
- Faculty of Engineering and the Environment, National Centre for Advanced Tribology at Southampton (nCATS), University of Southampton, Highfield, Southampton SO17 1BJ, UK.
| | - Julian A Wharton
- Faculty of Engineering and the Environment, National Centre for Advanced Tribology at Southampton (nCATS), University of Southampton, Highfield, Southampton SO17 1BJ, UK.
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14
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Bedoshvili YD, Gneusheva KV, Popova MS, Avezova TN, Arsentyev KY, Likhoshway YV. Frustule morphogenesis of raphid pennate diatom Encyonema ventricosum (Agardh) Grunow. Protoplasma 2018; 255:911-921. [PMID: 29270874 DOI: 10.1007/s00709-017-1199-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [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: 07/25/2017] [Accepted: 12/15/2017] [Indexed: 06/07/2023]
Abstract
Diatoms stand out among other microalgae due to the high diversity of species-specific silica frustules whose components (valves and girdle bands) are formed within the cell in special organelles called silica deposition vesicles (SDVs). Research on cell structure and morphogenesis of frustule elements in diatoms of different taxonomic groups has been carried out since the 1950s but is still relevant today. Here, cytological features and valve morphogenesis in the freshwater raphid pennate diatom Encyonema ventricosum (Agardh) Grunow have been studied using light and transmission electron microscopy of cleaned frustules and ultrathin sections of cells, and scanning electron and atomic force microscopy of the frustule surface. Data have been obtained on chloroplast structure: the pyrenoid is spherical, penetrated by a lamella (a stack of two thylakoids); the girdle lamella consists of several short lamellae. The basic stages of frustule morphogenesis characteristic of raphid pennate diatoms have been traced, with the presence of cytoskeletal elements near SDVs being observed throughout this process. Degradation of the plasmalemma and silicalemma is shown to take place when the newly formed valve is released into the space between sister cells. The role of vesicular transport and exocytosis in the gliding of pennate diatoms is discussed.
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Affiliation(s)
- Yekaterina D Bedoshvili
- Limnological Institute, Siberian Branch, Russian Academy of Sciences, 3 Ulan-Batorskaya St., Irkutsk, Russia, 664033.
| | - Ksenia V Gneusheva
- Limnological Institute, Siberian Branch, Russian Academy of Sciences, 3 Ulan-Batorskaya St., Irkutsk, Russia, 664033
| | - Maria S Popova
- Limnological Institute, Siberian Branch, Russian Academy of Sciences, 3 Ulan-Batorskaya St., Irkutsk, Russia, 664033
| | - Tatyana N Avezova
- Limnological Institute, Siberian Branch, Russian Academy of Sciences, 3 Ulan-Batorskaya St., Irkutsk, Russia, 664033
| | - Kirill Yu Arsentyev
- Limnological Institute, Siberian Branch, Russian Academy of Sciences, 3 Ulan-Batorskaya St., Irkutsk, Russia, 664033
| | - Yelena V Likhoshway
- Limnological Institute, Siberian Branch, Russian Academy of Sciences, 3 Ulan-Batorskaya St., Irkutsk, Russia, 664033
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15
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Louw DC, Doucette GJ, Lundholm N. Morphology and toxicity of Pseudo-nitzschia species in the northern Benguela Upwelling System. Harmful Algae 2018; 75:118-128. [PMID: 29778221 DOI: 10.1016/j.hal.2018.04.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [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: 11/22/2017] [Revised: 04/22/2018] [Accepted: 04/23/2018] [Indexed: 06/08/2023]
Abstract
The Benguela upwelling system, considered the world's most productive marine ecosystem, has a long record of potentially toxic diatoms belonging to the genus Pseudo-nitzschia. Species of Pseudo-nitzschia were reported as early as 1936 from the northern Benguela upwelling system (nBUS). For the current study, long-term phytoplankton monitoring data (2004-2011) for the Namibian coast were analysed to examine inshore and offshore temporal distribution of Pseudo-nitzschia species, their diversity and ultrastructure. The potentially toxigenic P. pungens and P. australis were the dominant inshore species, whereas offshore Pseudo-nitzschia showed a higher diversity that also included potentially toxic species. During a warming event, a community shift from P. pungens and P. australis dominance to P. fraudulenta and P. multiseries was documented in the central nBUS. A case study of a toxic event (August 2004) revealed that P. australis and P. pungens were present at multiple inshore and offshore stations, coincident with fish (pilchard) and bird mortalities reported from the central part of Namibia. Toxin analyses (LC-MS/MS) of samples collected from June to August 2004 revealed the presence of particulate domoic acid (DA) in seawater at multiple stations (maximum ∼180 ng DA/L) in the >0.45 μm size-fraction, as well as detectable DA (0.12 μg DA/g) in the gut of one of two pilchard samples tested. These findings indicate that DA may have been associated with the fish and bird mortalities reported from this event in the nBUS. However, the co-occurrence of very high biomass phytoplankton blooms suggests that other explanations may be possible.
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Affiliation(s)
- Deon C Louw
- National Marine Information and Research Centre, PO Box 912, Swakopmund, Namibia.
| | - Gregory J Doucette
- National Centers for Coastal Ocean Science, NOAA/National Ocean Service, Charleston, SC, 29412, USA.
| | - Nina Lundholm
- Natural History Museum of Denmark, University of Copenhagen, Sølvgade 83S, DK-1307 Copenhagen K, Denmark.
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16
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Mu W, Chen Y, Liu Y, Pan X, Fan Y. Toxicological effects of cadmium and lead on two freshwater diatoms. Environ Toxicol Pharmacol 2018; 59:152-162. [PMID: 29597078 DOI: 10.1016/j.etap.2018.03.013] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Revised: 03/18/2018] [Accepted: 03/19/2018] [Indexed: 06/08/2023]
Abstract
In recent years, there have been significant advances in the knowledge and understanding of the pollution attributed to effects of aquatic toxic metals on fresh water benthic diatoms. In this study, the cell growth, chlorophyll a content and superoxide dismutase activity in Halamphora veneta (Kützing) Levkov and Surirella crumena Brébisson exposed to cadmium and lead, were investigated. Furthermore, in order to explore the potential function of H. veneta on environmental monitoring and environmental remediation, expression of two genes (psbA, psaB) and morphological analysis of H. veneta were carried out. The cells growth of H. veneta and S. crumena were generally inhibited with cadmium and lead exposure during 96 h, while cells density of H. veneta was significantly increased under the low concentration at 24 h cadmium exposure. Our results indicated that H. veneta had a certain tolerance to toxic metals at initial treated time. In addition, the significantly changes of chlorophyll a content and SOD activities in H. veneta and S. crumena indicated that both photosynthetic system and the antioxidant system in benthic diatom might play important roles on the toxic metals tolerant mechanism. Meanwhile, it can be confirmed that the diatom photosynthetic systems play roles on toxic metals resistance inferred from the gene expression of psbA and psaB in H. veneta. Finally, the results of scanning electron microscopy showed that there was a slightly deformation on cells following the cadmium exposure in H. veneta, while obvious deformation with cell greatly widened after lead exposure. The present work will be helpful to understand the effect mechanisms of toxic metal by comparing two kinds of diatom on cell inhibition, biological response and morphological changes, which will provide more information for possible use of benthic diatoms in bioremediation.
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Affiliation(s)
- Weijie Mu
- College of Life Science and Technology, Harbin Normal University, Harbin 150025, China
| | - Ying Chen
- College of Life Science and Technology, Harbin Normal University, Harbin 150025, China
| | - Yan Liu
- College of Life Science and Technology, Harbin Normal University, Harbin 150025, China
| | - Xuming Pan
- College of Life Science and Technology, Harbin Normal University, Harbin 150025, China
| | - Yawen Fan
- College of Life Science and Technology, Harbin Normal University, Harbin 150025, China.
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17
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Mejdandžić M, Bosak S, Nakov T, Ruck E, Orlić S, Gligora Udovič M, Peharec Štefanić P, Špoljarić I, Mršić G, Ljubešić Z. Morphological diversity and phylogeny of the diatom genus Entomoneis (Bacillariophyta) in marine plankton: six new species from the Adriatic Sea. J Phycol 2018; 54:275-298. [PMID: 29419886 DOI: 10.1111/jpy.12622] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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: 06/09/2017] [Accepted: 01/17/2018] [Indexed: 06/08/2023]
Abstract
The diatom genus Entomoneis is known from the benthos and plankton of marine, brackish, and freshwaters. Entomoneis includes diatoms with a bilobate keel elevated above the valve surface, a sigmoid canal raphe, and numerous girdle bands. Owing mostly to the scarcity of molecular data for a diverse set of species, the phylogeny of Entomoneis has not been investigated in depth. The few previous studies that included Entomoneis were focused on broader questions and the available data were from a small number of either unidentified Entomoneis or well-known species (e.g., E. paludosa). Since the first description of new species combining both molecular and morphological characters (E. tenera), we have continued to cultivate and investigate Entomoneis in the plankton of the Adriatic Sea. Combined multigene phylogeny (SSU rDNA sequences, rbcL, and psbC genes) and morphological observations (LM, SEM and TEM) revealed six new Entomoneis species supported by phylogenetic and morphological data: E. pusilla, E. gracilis, E. vilicicii, E. infula, E. adriatica, and E. umbratica. The most important morphological features for species delineation were cell shape, the degree and mode of torsion, valve apices, the appearance and structure of the transition between keel and valve body, the ultrastructure and the shape of the girdle bands, and the arrangement and density of perforations along the valve and valvocopulae. Our results highlight the underappreciated diversity of Entomoneis and call for a more in-depth morphological and molecular investigation of this genus especially in planktonic habitats.
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Affiliation(s)
- Maja Mejdandžić
- Department of Biology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000, Zagreb, Croatia
| | - Sunčica Bosak
- Department of Biology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000, Zagreb, Croatia
| | - Teofil Nakov
- Department of Biological Sciences, University of Arkansas, 1 University of Arkansas, SCEN 601, Fayetteville, Arkansas, 72701, USA
| | - Elizabeth Ruck
- Department of Biological Sciences, University of Arkansas, 1 University of Arkansas, SCEN 601, Fayetteville, Arkansas, 72701, USA
| | - Sandi Orlić
- Ruđer Bošković Institute, Bijenička 54, 10000, Zagreb, Croatia
- Microbial Ecology, Center of Excellence for Science and Technology Integrating Mediterranean Region, Bijenička 54, 10000, Zagreb, Croatia
| | - Marija Gligora Udovič
- Department of Biology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000, Zagreb, Croatia
| | - Petra Peharec Štefanić
- Department of Biology, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000, Zagreb, Croatia
| | - Igor Špoljarić
- Forensic Science Office, University of Zagreb, Ilica 335, 10000, Zagreb, Croatia
- Forensic Science Center "Ivan Vučetić" Zagreb, Ilica 335, 10000, Zagreb, Croatia
| | - Gordan Mršić
- Forensic Science Office, University of Zagreb, Ilica 335, 10000, Zagreb, Croatia
- Forensic Science Center "Ivan Vučetić" Zagreb, Ilica 335, 10000, Zagreb, Croatia
| | - Zrinka Ljubešić
- Department of Biology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000, Zagreb, Croatia
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18
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Prasad AKSKKSK, Nienow JA, Lochner E. Thalassiosira mala (Bacillariophyta), a potentially harmful, marine diatom from Chilka Lake and other coastal localities of Odisha, India: Nomenclature, frustule morphology and global biogeography. J Biosci 2018; 43:59-74. [PMID: 29485115] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
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19
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Köhler L, Machill S, Werner A, Selzer C, Kaskel S, Brunner E. Are Diatoms "Green" Aluminosilicate Synthesis Microreactors for Future Catalyst Production? Molecules 2017; 22:E2232. [PMID: 29258162 PMCID: PMC6149991 DOI: 10.3390/molecules22122232] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 12/06/2017] [Accepted: 12/12/2017] [Indexed: 11/21/2022] Open
Abstract
Diatom biosilica may offer an interesting perspective in the search for sustainable solutions meeting the high demand for heterogeneous catalysts. Diatomaceous earth (diatomite), i.e., fossilized diatoms, is already used as adsorbent and carrier material. While diatomite is abundant and inexpensive, freshly harvested and cleaned diatom cell walls have other advantages, with respect to purity and uniformity. The present paper demonstrates an approach to modify diatoms both in vivo and in vitro to produce a porous aluminosilicate that is serving as a potential source for sustainable catalyst production. The obtained material was characterized at various processing stages with respect to morphology, elemental composition, surface area, and acidity. The cell walls appeared normal without morphological changes, while their aluminum content was raised from the molar ratio n(Al):n(Si) 1:600 up to 1:50. A specific surface area of 55 m²/g was measured. The acidity of the material increased from 149 to 320 µmol NH₃/g by ion exchange, as determined by NH₃ TPD. Finally, the biosilica was examined by an acid catalyzed test reaction, the alkylation of benzene. While the cleaned cell walls did not catalyze the reaction at all, and the ion exchanged material was catalytically active. This demonstrates that modified biosilica does indeed has potential as a basis for future catalytically active materials.
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Affiliation(s)
- Lydia Köhler
- Chair of Bioanalytical Chemistry, Faculty of Chemistry and Food Chemistry, TU Dresden, 01062 Dresden, Germany.
| | - Susanne Machill
- Chair of Bioanalytical Chemistry, Faculty of Chemistry and Food Chemistry, TU Dresden, 01062 Dresden, Germany.
| | - Anja Werner
- Institute of Inorganic Chemistry, Faculty of Chemistry and Food Chemistry, TU Dresden, 01062 Dresden, Germany.
| | - Carolin Selzer
- Institute of Inorganic Chemistry, Faculty of Chemistry and Food Chemistry, TU Dresden, 01062 Dresden, Germany.
| | - Stefan Kaskel
- Institute of Inorganic Chemistry, Faculty of Chemistry and Food Chemistry, TU Dresden, 01062 Dresden, Germany.
| | - Eike Brunner
- Chair of Bioanalytical Chemistry, Faculty of Chemistry and Food Chemistry, TU Dresden, 01062 Dresden, Germany.
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20
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Pennesi C, Danovaro R. Assessing marine environmental status through microphytobenthos assemblages colonizing the Autonomous Reef Monitoring Structures (ARMS) and their potential in coastal marine restoration. Mar Pollut Bull 2017; 125:56-65. [PMID: 28784269 DOI: 10.1016/j.marpolbul.2017.08.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [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: 03/13/2017] [Revised: 07/17/2017] [Accepted: 08/01/2017] [Indexed: 06/07/2023]
Abstract
Microphytobenthos is potentially highly sensitive to environmental alterations, but has been rarely utilized in monitoring studies. Here we investigated the use of microphytobenthos colonizing Autonomous Reef Monitoring Structures (ARMS) to assess the marine environmental quality. We analysed microphytobenthic assemblages in terms of abundance, biomass and species composition on ARMS deployed in northern Adriatic Sea along a gradient of increasing impacts. We show that microphytobenthic variables changed significantly across sites, with lowest abundance and biodiversity in the highly impacted site. Moreover, the specific analysis of Diatoms revealed that genera like Entomoneis and Cylindrotheca could be used as indicators of nutrient enriched and stressed conditions. We provide evidence that the analysis of microphytobenthos colonizing artificial substrates could be used as a tool for detecting altered environmental characteristics. We also show that the ARMS, recreating hot spots of microphytobenthic biodiversity, and protect them from grazing, could be potentially utilized to restore degraded hard substrates. Our result indicates that microphytobenthos can be easily incorporated in future monitoring and restoration programmes to assess and improve marine environmental health.
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Affiliation(s)
- Chiara Pennesi
- Department of Life and Environmental Sciences, Polytechnic University of Marche, via Brecce Bianche, 60131 Ancona, Italy.
| | - Roberto Danovaro
- Department of Life and Environmental Sciences, Polytechnic University of Marche, via Brecce Bianche, 60131 Ancona, Italy; Stazione Zoologica Anton Dohrn, Naples, Italy
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21
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Wang R, Xue Q, Wang J, Tan L, Zhang Q, Zhao Y, Anderson DM. Effects of an allelochemical in Phaeodactylum tricornutum filtrate on Heterosigma akashiwo: Morphological, physiological and growth effects. Chemosphere 2017; 186:527-534. [PMID: 28810223 PMCID: PMC6507415 DOI: 10.1016/j.chemosphere.2017.08.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 07/16/2017] [Accepted: 08/07/2017] [Indexed: 05/11/2023]
Abstract
The effects of an allelochemical extracted from the culture filtrate of diatom Phaeodactylum tricornutum on the raphidophyte Heterosigma akashiwo were investigated using a series of morphological, physiological and biochemical characters. Growth experiments showed that H. akashiwo was significantly inhibited immediately after exposure to the allelochemical, with many cells rapidly dying and lysing based on microscopic observation. The effects of the allelochemical on the surviving cells were explored using Scanning Electron Microscopy (SEM) and Flow cytometry (FCM), the latter by examination of a suite of physiological parameters (membrane integrity, esterase activity, chlorophyll-a content, membrane potential). The results demonstrate that the membrane of H. akashiwo was attacked by the allelochemical directly, causing cell membrane breakage and loss of integrity. Esterase activity was the most sensitive indicator of the impacts of the allelochemical. Membrane potential and chlorophyll-a content both showed significant decreases following exposure of the Heterosigma cells to high concentrations of the allelochemical for 5 and 6 days. Both were affected, but the membrane potential response was more gradual compared to other effects. The cell size of H. akashiwo did not change compared with the control group. The surviving cells were able to continue to grow and in a few days, re-establish a successful culture, even in the presence of residual allelochemical, suggesting either development of cellular resistance, or the degradation of the chemical.
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Affiliation(s)
- Rui Wang
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China; Shenzhen Key Laboratory for the Sustainable Use of Marine Biodiversity, Research Centre for the Oceans and Human Health, City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, China
| | - Qiaona Xue
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China
| | - Jiangtao Wang
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
| | - Liju Tan
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China
| | - Qingchun Zhang
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Yue Zhao
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Donald M Anderson
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States
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22
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Kwon JE, Jeong HJ, Kim SJ, Jang SH, Lee KH, Seong KA. Newly discovered role of the heterotrophic nanoflagellate Katablepharis japonica, a predator of toxic or harmful dinoflagellates and raphidophytes. Harmful Algae 2017; 68:224-239. [PMID: 28962983 DOI: 10.1016/j.hal.2017.08.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [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: 04/10/2017] [Revised: 08/30/2017] [Accepted: 08/30/2017] [Indexed: 06/07/2023]
Abstract
Heterotrophic nanoflagellates are ubiquitous and known to be major predators of bacteria. The feeding of free-living heterotrophic nanoflagellates on phytoplankton is poorly understood, although these two components usually co-exist. To investigate the feeding and ecological roles of major heterotrophic nanoflagellates Katablepharis spp., the feeding ability of Katablepharis japonica on bacteria and phytoplankton species and the type of the prey that K. japonica can feed on were explored. Furthermore, the growth and ingestion rates of K. japonica on the dinoflagellate Akashiwo sanguinea-a suitable algal prey item-heterotrophic bacteria, and the cyanobacteria Synechococcus sp., as a function of prey concentration were determined. Among the prey tested, K. japonica ingested heterotrophic bacteria, Synechococcus sp., the prasinophyte Pyramimonas sp., the cryptophytes Rhodomonas salina and Teleaulax sp., the raphidophytes Heterosigma akashiwo and Chattonella ovata, the dinoflagellates Heterocapsa rotundata, Amphidinium carterae, Prorocentrum donghaiense, Alexandrium minutum, Cochlodinium polykrikoides, Gymnodinium catenatum, A. sanguinea, Coolia malayensis, and the ciliate Mesodinium rubrum, however, it did not feed on the dinoflagellates Alexandrium catenella, Gambierdiscus caribaeus, Heterocapsa triquetra, Lingulodinium polyedra, Prorocentrum cordatum, P. micans, and Scrippsiella acuminata and the diatom Skeletonema costatum. Many K. japonica cells attacked and ingested a prey cell together after pecking and rupturing the surface of the prey cell and then uptaking the materials that emerged from the ruptured cell surface. Cells of A. sanguinea supported positive growth of K. japonica, but neither heterotrophic bacteria nor Synechococcus sp. supported growth. The maximum specific growth rate of K. japonica on A. sanguinea was 1.01 d-1. In addition, the maximum ingestion rate of K. japonica for A. sanguinea was 0.13ngC predator-1d-1 (0.06 cells predator-1d-1). The maximum ingestion rate of K. japonica for heterotrophic bacteria was 0.019ngC predator-1d-1 (266 bacteria predator-1d-1), and the highest ingestion rate of K. japonica for Synechococcus sp. at the given prey concentrations of up to ca. 107 cells ml-1 was 0.01ngC predator-1d-1 (48 Synechococcus predator-1d-1). The maximum daily carbon acquisition from A. sanguinea, heterotrophic bacteria, and Synechococcus sp. were 307, 43, and 22%, respectively, of the body carbon of the predator. Thus, low ingestion rates of K. japonica on heterotrophic bacteria and Synechococcus sp. may be responsible for the lack of growth. The results of the present study clearly show that K. japonica is a predator of diverse phytoplankton, including toxic or harmful algae, and may also affect the dynamics of red tides caused by these prey species.
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Affiliation(s)
- Ji Eun Kwon
- School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Hae Jin Jeong
- School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea; Advanced Institutes of Convergence Technology, Suwon, Gyeonggi-do, 16229, Republic of Korea.
| | - So Jin Kim
- School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Se Hyeon Jang
- School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Kyung Ha Lee
- School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Kyeong Ah Seong
- Department of Marine Biotechnology, College of Ocean Science and Technology, Kunsan National University, Kunsan 54150, Republic of Korea
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23
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Kaczmarska I, Gray BS, Ehrman JM, Thaler M. Sexual reproduction in plagiogrammacean diatoms: First insights into the early pennates. PLoS One 2017; 12:e0181413. [PMID: 28813426 PMCID: PMC5558960 DOI: 10.1371/journal.pone.0181413] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 06/16/2017] [Indexed: 11/18/2022] Open
Abstract
The genera Plagiogramma and Dimeregramma are members of a small, but evolutionarily important group of diatoms, the "basal" araphids. They are sister to all other pennates, both araphid and raphid taxa. Thus, their phylogenetic position carries the potential for providing insights into the earliest pennates. We documented sexual reproduction, mating system and sex cell development in the first members of the "basal" araphid clade ever investigated. The mating system in all these species involved heterothally. It was, however, more complex in P. tsawwassen, where in addition to heterothallic clones, intraclonal and polysexual clones also exist. Auxospore development and wall structure was similar in all three species and demonstrated several characters also reported from "core" araphids. Of these, vigorous, pseudopodial motility of male secondary spermatocytes and gametes was most notable because it indicates that this character was likely present in the last common ancestor of all the pennates. Pseudopodial motility of the male sex cells might have afforded sufficient compensation and/or benefits to the emerging pennates for replacing flagellated sperm, present in centrics. The characters thus far uniquely present among our plagiogrammaceans but not reported from other pennates were: the "gametic" fusion between sex-compatible secondary spermatocytes, in some cases before completion of Meiosis II in males, transverse perizonial bands produced all together or in quick succession rather than being added to the auxospore apex one at a time, and expanding auxospores with 3-4 nuclei. An initial epivalve, similar in morphology to what in some diatoms had been interpreted as a "longitudinal" perizonium, may be more widespread among pennates than thus far appreciated. In addition, we discovered two species new to science (D. acutumontgo, P. tsawwassen), and refined delineation of P. staurophorum by including metric data from the original material.
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Affiliation(s)
- Irena Kaczmarska
- Department of Biology, Mount Allison University, Sackville, New Brunswick, Canada
| | - Benjamin S. Gray
- Department of Biology, Mount Allison University, Sackville, New Brunswick, Canada
| | - James M. Ehrman
- Digital Microscopy Facility, Mount Allison University, Sackville, New Brunswick, Canada
| | - Mary Thaler
- Institut de biologie intégrative et des systèmes, Université Laval, Québec, Québec, Canada
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24
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Gaonkar CC, Kooistra WHCF, Lange CB, Montresor M, Sarno D. Two new species in the Chaetoceros socialis complex (Bacillariophyta): C. sporotruncatus and C. dichatoensis, and characterization of its relatives, C. radicans and C. cinctus. J Phycol 2017; 53:889-907. [PMID: 28593733 DOI: 10.1111/jpy.12554] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [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: 12/21/2016] [Accepted: 05/28/2017] [Indexed: 06/07/2023]
Abstract
The diatom genus Chaetoceros is one of the most abundant and diverse phytoplankton in marine and brackish waters worldwide. Within this genus, Chaetoceros socialis has been cited as one of the most common species. However, recent studies from different geographic areas have shown the presence of pseudo-cryptic diversity within the C. socialis complex. Members of this complex are characterized by curved chains (primary colonies) aggregating into globular clusters, where one of the four setae of each cell curves toward the center of the cluster and the other three orient outwards. New light and electron microscopy observations as well as molecular data on marine planktonic diatoms from the coastal waters off Chile revealed the presence of two new species, Chaetoceros sporotruncatus sp. nov. and C. dichatoensis. sp. nov. belonging to the C. socialis complex. The two new species are similar to other members of the complex (i.e., C. socialis and C. gelidus) in the primary and secondary structure of the colony, the orientation pattern of the setae, and the valve ultrastructure. The only morphological characters that can be used to differentiate the species of this complex are aspects related to resting spore morphology. The two newly described species are closely related to each other and form a sister clade to C. gelidus in molecular phylogenies. We also provide a phylogenetic status along with the morphological characterization of C. radicans and C. cintus, which are genetically related to the C. socialis complex.
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MESH Headings
- Chile
- DNA, Algal/genetics
- Diatoms/classification
- Diatoms/cytology
- Diatoms/genetics
- Diatoms/ultrastructure
- France
- Italy
- Microscopy, Electron, Scanning
- Microscopy, Electron, Transmission
- Phylogeny
- Phytoplankton/classification
- Phytoplankton/cytology
- Phytoplankton/genetics
- Phytoplankton/ultrastructure
- RNA, Ribosomal, 18S/genetics
- RNA, Ribosomal, 28S/genetics
- Sequence Analysis, DNA
- Species Specificity
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Affiliation(s)
- Chetan C Gaonkar
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Naples, Italy
| | | | - Carina B Lange
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Naples, Italy
- Department of Oceanography, Centers COPAS Sur-Austral and FONDAP-IDEAL, University of Concepción, Concepción, Chile
| | - Marina Montresor
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Naples, Italy
| | - Diana Sarno
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Naples, Italy
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25
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McCarthy JK, Smith SR, McCrow JP, Tan M, Zheng H, Beeri K, Roth R, Lichtle C, Goodenough U, Bowler CP, Dupont CL, Allen AE. Nitrate Reductase Knockout Uncouples Nitrate Transport from Nitrate Assimilation and Drives Repartitioning of Carbon Flux in a Model Pennate Diatom. Plant Cell 2017; 29:2047-2070. [PMID: 28765511 PMCID: PMC5590495 DOI: 10.1105/tpc.16.00910] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 06/06/2017] [Accepted: 07/29/2017] [Indexed: 05/03/2023]
Abstract
The ecological prominence of diatoms in the ocean environment largely results from their superior competitive ability for dissolved nitrate (NO3-). To investigate the cellular and genetic basis of diatom NO3- assimilation, we generated a knockout in the nitrate reductase gene (NR-KO) of the model pennate diatom Phaeodactylum tricornutum In NR-KO cells, N-assimilation was abolished although NO3- transport remained intact. Unassimilated NO3- accumulated in NR-KO cells, resulting in swelling and associated changes in biochemical composition and physiology. Elevated expression of genes encoding putative vacuolar NO3- chloride channel transporters plus electron micrographs indicating enlarged vacuoles suggested vacuolar storage of NO3- Triacylglycerol concentrations in the NR-KO cells increased immediately following the addition of NO3-, and these increases coincided with elevated gene expression of key triacylglycerol biosynthesis components. Simultaneously, induction of transcripts encoding proteins involved in thylakoid membrane lipid recycling suggested more abrupt repartitioning of carbon resources in NR-KO cells compared with the wild type. Conversely, ribosomal structure and photosystem genes were immediately deactivated in NR-KO cells following NO3- addition, followed within hours by deactivation of genes encoding enzymes for chlorophyll biosynthesis and carbon fixation and metabolism. N-assimilation pathway genes respond uniquely, apparently induced simultaneously by both NO3- replete and deplete conditions.
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Affiliation(s)
- James K McCarthy
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, California 92037
| | - Sarah R Smith
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, California 92037
- Integrative Oceanography Division, Scripps Institution of Oceanography, UC San Diego, La Jolla, California 92037
| | - John P McCrow
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, California 92037
| | - Maxine Tan
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, California 92037
| | - Hong Zheng
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, California 92037
| | - Karen Beeri
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, California 92037
| | - Robyn Roth
- Department of Biology, Washington University, St. Louis, Missouri 63130
| | - Christian Lichtle
- Institut de Biologie de l'École Normale Supérieure, École Normale Supérieure, Paris Sciences et Lettres Research University, CNRS UMR8197 INSERM U1024, 75005 Paris, France
| | - Ursula Goodenough
- Department of Biology, Washington University, St. Louis, Missouri 63130
| | - Chris P Bowler
- Institut de Biologie de l'École Normale Supérieure, École Normale Supérieure, Paris Sciences et Lettres Research University, CNRS UMR8197 INSERM U1024, 75005 Paris, France
| | - Christopher L Dupont
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, California 92037
| | - Andrew E Allen
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, California 92037
- Integrative Oceanography Division, Scripps Institution of Oceanography, UC San Diego, La Jolla, California 92037
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26
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Zgłobicka I, Chlanda A, Woźniak M, Łojkowski M, Szoszkiewicz R, Mazurkiewicz-Pawlicka M, Święszkowski W, Wyroba E, Kurzydłowski KJ. Microstructure and nanomechanical properties of single stalks from diatom Didymosphenia geminata and their change due to adsorption of selected metal ions. J Phycol 2017; 53:880-888. [PMID: 28523651 DOI: 10.1111/jpy.12548] [Citation(s) in RCA: 9] [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: 08/16/2016] [Accepted: 05/11/2017] [Indexed: 05/21/2023]
Abstract
We present topographical and nanomechanical characterization of single Didymosphenia geminata stalk. We compared the samples before and after adsorption of metal ions from freshwater samples. Transmission electron microscopy studies of single stalk cross-sections have shown three distinct layers and an additional thin extra coat on the external layer (called "EL"). Using scanning electron microscopy and atomic force microscopy (AFM), we found that topography of single stalks after ionic adsorption differed significantly from topography of pristine stalks. AFM nanoindentation studies in ambient conditions yielded elastic moduli of 214 ± 170 MPa for pristine stalks and 294 ± 108 MPa for stalks after ionic adsorption. Statistical tests showed that those results were significantly different. We conducted only preliminary comparisons between ionic adsorption of several stalks in air and in water. While the stalks with ions were on average stiffer than the pristine stalks in air, they became more compliant than the pristine stalks in water. We also heated the stalks and detected EL softening at 50°C ± 15°C. AFM nanoindentation in air on the softened samples yielded elastic moduli of 26 ± 9 MPa for pristine samples and 43 ± 22 MPa for stalks with absorbed metal ions. Substantial decrease of the EL elastic moduli after heating was expected. Significantly different elastic moduli for the samples after ionic adsorption in both cases (i.e., for heated and nonheated samples), as well as behavior of the stalks immersed in water, point to permanent structural EL changes due to ions.
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Affiliation(s)
- Izabela Zgłobicka
- Materials Design Division, Faculty of Materials Science and Engineering, Warsaw University of Technology, Wołoska 141, 02-507, Warsaw, Poland
| | - Adrian Chlanda
- Materials Design Division, Faculty of Materials Science and Engineering, Warsaw University of Technology, Wołoska 141, 02-507, Warsaw, Poland
| | - Michał Woźniak
- Materials Design Division, Faculty of Materials Science and Engineering, Warsaw University of Technology, Wołoska 141, 02-507, Warsaw, Poland
| | - Maciej Łojkowski
- Materials Design Division, Faculty of Materials Science and Engineering, Warsaw University of Technology, Wołoska 141, 02-507, Warsaw, Poland
| | - Robert Szoszkiewicz
- Materials Design Division, Faculty of Materials Science and Engineering, Warsaw University of Technology, Wołoska 141, 02-507, Warsaw, Poland
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093, Warsaw, Poland
| | - Marta Mazurkiewicz-Pawlicka
- Faculty of Chemical and Process Engineering, Warsaw University of Technology, Waryńskiego 1, 00-645, Warsaw, Poland
| | - Wojciech Święszkowski
- Materials Design Division, Faculty of Materials Science and Engineering, Warsaw University of Technology, Wołoska 141, 02-507, Warsaw, Poland
| | - Elżbieta Wyroba
- Nencki Institute of Experimental Biology of the Polish Academy of Sciences, Pasteura 3, 02-093, Warsaw, Poland
| | - Krzysztof J Kurzydłowski
- Materials Design Division, Faculty of Materials Science and Engineering, Warsaw University of Technology, Wołoska 141, 02-507, Warsaw, Poland
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27
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Lefebvre KE, Hamilton PB, Pick FR. A comparison of molecular markers and morphology for Neidium taxa (Bacillariophyta) from eastern North America. J Phycol 2017; 53:680-702. [PMID: 28369873 DOI: 10.1111/jpy.12537] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [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: 06/13/2016] [Accepted: 03/06/2017] [Indexed: 06/07/2023]
Abstract
Historically, a morphological species concept has applied shape subjectively in the delimitation of diatom species. This has led to confusion between taxa within the benthic diatom genus Neidium. Samples from Ontario, Quebec, Nova Scotia, Newfoundland (Canada) and New York (USA) were examined for Neidium taxa under LM and SEM. Fourier shape analysis showed that shape as a taxonomic character was not able to discern all species. Isolated individuals from the samples were amplified and sequenced for three chloroplast molecular markers (rbcL, psbC, and psbA) and one nuclear ribosomal molecular marker (18S). Phylogenetic reconstructions were completed with the concatenated chloroplast and 18S dataset using Maximum Likelihood and Bayesian analyses. The concatenated chloroplast dataset exhibited a species-level resolution phylogeny of Neidium taxa. The 18S dataset had a lower level of sequence divergence and was unable to differentiate between Neidium taxa. We present emended species descriptions and sequence data for four previously described species: Neidium sacoense, N. longiceps, N. fossum, and N. affine. We describe three novel species (Neidium lowei, N. promontorium, and N. potapovae) and identify two forms with unique molecular signatures. The distinguishing features of N. lowei are its size, valve shape, and longitudinal canal structure. Distinguishing features of N. promontorium are its valve shape, longitudinal canal and apex formation, and surface depression along the axial area. Neidium potapovae is distinguished by its size, formation of valve and apices and single longitudinal canal. This paper demonstrates how future phylogenetic treatments using single cell multigene sequencing can help resolve taxonomic confusion within diatoms.
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Affiliation(s)
- Keely E Lefebvre
- Biology & Environmental Science, Centre for Advanced Research in Environmental Genomics, University of Ottawa, Ottawa, Ontario, Canada, K1N 6N5
| | - Paul B Hamilton
- Research and Collections Division, Canadian Museum of Nature, P.O. Box 3443, Station D., Ottawa, Ontario, Canada, K1P 6P4
| | - Frances R Pick
- Department of Biology, Centre for Advanced Research in Environmental Genomics, University of Ottawa, Ottawa, Ontario, Canada, K1N 6N5
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28
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Duan W, Meng F, Lin Y, Wang G. Toxicological effects of phenol on four marine microalgae. Environ Toxicol Pharmacol 2017; 52:170-176. [PMID: 28432996 DOI: 10.1016/j.etap.2017.04.006] [Citation(s) in RCA: 19] [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: 10/29/2016] [Revised: 04/03/2017] [Accepted: 04/06/2017] [Indexed: 06/07/2023]
Abstract
The toxic effects of phenol on four marine microalgae (Dunaliella salina, Platymonas subcordiformis, Phaeodactylum tricornutum Bohlin, and Skeletonema costatum) were evaluated. The 96h EC50 values were 72.29, 92.97, 27.32, and 27.32mgL-1, respectively, which were lower than those values of freshwater microalgae reported in the literature. During a 96-h exposure to a sub-lethal concentration of phenol (1/2 96h EC50) with green alga (D. salina) and diatom (S. costatum), reactive oxygen species (ROS) accumulation, and chlorophyll a (Chl a) content decrease were simultaneously observed in diatom cells after 48h treatment. On the contrary, other chlorophylls in both algae were unaffected. Under transmission electron microscopy (TEM), the phenol-induced ultrastructure alterations included disappearance, or shrinkage, of nucleolus and enlargement of vacuoles, which may result in programmed cell death (PCD). The increase in number of lipid droplets may be related to phenol detoxification. These results indicate that the sensitivity of marine microalgae to phenol was dependent on some biotic factors such as cell size, ROS production, and phenol degradation ability in algal cells.
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Affiliation(s)
- Weiyan Duan
- Key Laboratory for Marine Environment and Ecology of Ministry of Education, Ocean University of China, Qingdao, Shandong Province, PR China
| | - Fanping Meng
- Key Laboratory for Marine Environment and Ecology of Ministry of Education, Ocean University of China, Qingdao, Shandong Province, PR China.
| | - Yufei Lin
- National Marine Hazard Mitigation Service, State Oceanic Administration of China, Beijing, PR China
| | - Guoshan Wang
- National Marine Hazard Mitigation Service, State Oceanic Administration of China, Beijing, PR China
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29
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Abstract
The earliest known diatom fossils with well-preserved siliceous frustules are from Lower Cretaceous neritic marine deposits in Antarctica. In this study, we analyzed the cell wall structure to establish whether their cell and life cycles were similar to modern forms. At least two filamentous species (Basilicostephanus ornatus and Archepyrgus melosiroides) had girdle band structures that functioned during cell division in a similar way to present day Aulacoseira species. Also, size analyses of cell diameter indicated that the cyclic process of size decline and size restoration used to time modern diatom life cycles was present in five species from the Lower Cretaceous (B. ornatus, A. melosiroides, Gladius antiquus, Ancylopyrgus reticulatus, Kreagra forfex) as well as two species from Upper Cretaceous deposits (Trinacria anissimowii and Eunotogramma fueloepi) from the Southwest Pacific. The results indicate that the "Diatom Sex Clock" was present from an early evolutionary stage. Other ecological adaptations included changes in mantle height and coiling. Overall, the results suggest that at least some of the species in these early assemblages are on a direct ancestral line to modern forms.
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Affiliation(s)
- David H Jewson
- Freshwater Laboratory, University of Ulster, Cromore Road, Co. Derry, BT52 1SA, UK
| | - David M Harwood
- Department of Earth and Atmospheric Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588-0340, USA
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30
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Balzano S, Percopo I, Siano R, Gourvil P, Chanoine M, Marie D, Vaulot D, Sarno D. Morphological and genetic diversity of Beaufort Sea diatoms with high contributions from the Chaetoceros neogracilis species complex. J Phycol 2017; 53:161-187. [PMID: 27809344 DOI: 10.1111/jpy.12489] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [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: 12/23/2015] [Accepted: 07/19/2016] [Indexed: 06/06/2023]
Abstract
Seventy-five diatom strains isolated from the Beaufort Sea (Canadian Arctic) in the summer of 2009 were characterized by light and electron microscopy (SEM and TEM), as well as 18S and 28S rRNA gene sequencing. These strains group into 20 genotypes and 17 morphotypes and are affiliated with the genera Arcocellulus, Attheya, Chaetoceros, Cylindrotheca, Eucampia, Nitzschia, Porosira, Pseudo-nitzschia, Shionodiscus, Thalassiosira, and Synedropsis. Most of the species have a distribution confined to the northern/polar area. Chaetoceros neogracilis and Chaetoceros gelidus were the most represented taxa. Strains of C. neogracilis were morphologically similar and shared identical 18S rRNA gene sequences, but belonged to four distinct genetic clades based on 28S rRNA, ITS-1 and ITS-2 phylogenies. Secondary structure prediction revealed that these four clades differ in hemi-compensatory base changes (HCBCs) in paired positions of the ITS-2, suggesting their inability to interbreed. Reproductively isolated C. neogracilis genotypes can thus co-occur in summer phytoplankton communities in the Beaufort Sea. C. neogracilis generally occurred as single cells but also formed short colonies. It is phylogenetically distinct from an Antarctic species, erroneously identified in some previous studies as C. neogracilis, but named here as Chaetoceros sp. This work provides taxonomically validated sequences for 20 Arctic diatom taxa, which will facilitate future metabarcoding studies on phytoplankton in this region.
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Affiliation(s)
- Sergio Balzano
- CNRS, UMR7144, Station Biologique De Roscoff, Sorbonne Universités, UPMC Univ Paris 06, 29680, Roscoff, France
| | - Isabella Percopo
- Integrative Marine Ecology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Naples, Italy
| | | | - Priscillia Gourvil
- CNRS, UMR7144, Station Biologique De Roscoff, Sorbonne Universités, UPMC Univ Paris 06, 29680, Roscoff, France
| | - Mélanie Chanoine
- CNRS, UMR7144, Station Biologique De Roscoff, Sorbonne Universités, UPMC Univ Paris 06, 29680, Roscoff, France
| | - Dominique Marie
- CNRS, UMR7144, Station Biologique De Roscoff, Sorbonne Universités, UPMC Univ Paris 06, 29680, Roscoff, France
| | - Daniel Vaulot
- CNRS, UMR7144, Station Biologique De Roscoff, Sorbonne Universités, UPMC Univ Paris 06, 29680, Roscoff, France
| | - Diana Sarno
- Integrative Marine Ecology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Naples, Italy
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Bedoshvili YD, Gneusheva KV, Likhoshway YV. CHANGING OF SILICA VALVES OF DIATOM SYNEDRA ACUS subsp. RADIANS INFLUENCED BY PACLITAXEL. Tsitologiia 2017; 59:53-61. [PMID: 30188103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Diatoms are unicellular microscopic eukaryotes able to form species-specific frustules with micro- and nanostructures of biogenic silica. The morphogenesis of frustules components occurs intracellularly within special organelles under control of cytoskeleton. The mechanisms of morphogenesis control are not clear. The influence of paclitaxel, the microtubule inhibitor, onto morphogenesis of valve of pennate diatom Synedra acus subsp. radians was investigated. It has been shown that microtubule disturbance on the early morphogenesis stages provoke symmetry axis displacement of immature valve followed by curvature of the valve. At subsequent stages of morphogenesis stages, disturbance of the fine silica micro- and submicroscale structures (areolae and velums) occurs. It is supposed that a necessary condition for successful diatom valve morphogenesis is a balance between stable and dynamic microtubules.
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Teng ST, Tan SN, Lim HC, Dao VH, Bates SS, Leaw CP. High diversity of Pseudo-nitzschia along the northern coast of Sarawak (Malaysian Borneo), with descriptions of P. bipertita sp. nov. and P. limii sp. nov. (Bacillariophyceae). J Phycol 2016; 52:973-989. [PMID: 27403749 DOI: 10.1111/jpy.12448] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [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: 06/05/2015] [Accepted: 06/06/2016] [Indexed: 06/06/2023]
Abstract
Forty-eight isolates of Pseudo-nitzschia species were established from the Miri coast of Sarawak (Malaysian Borneo) and underwent TEM observation and molecular characterization. Ten species were found: P. abrensis, P. batesiana, P. fukuyoi, P. kodamae, P. lundholmiae, P. multistriata, P. pungens, P. subfraudulenta, as well as two additional new morphotypes, herein designated as P. bipertita sp. nov. and P. limii sp. nov. This is the first report of P. abrensis, P. batesiana, P. kodamae, P. fukuyoi, and P. lundholmiae in coastal waters of Malaysian Borneo. Pseudo-nitzschia bipertita differs from its congeners by the number of sectors that divide the poroids, densities of band striae, and its cingular band structure. Pseudo-nitzschia limii, a pseudo-cryptic species in the P. pseudodelicatissima complex sensu lato, is distinct by having wider proximal and distal mantles, a higher number of striae, and greater poroid height in the striae of the valvocopula. The species were further supported by the phylogenetic reconstructions of the nuclear-encoded large subunit ribosomal gene and the second internal transcribed spacer. Phylogenetically, P. bipertita clustered with its sister taxa (P. subpacifica + P. heimii); P. limii appears as a sister taxon to P. kodamae and P. hasleana in the ITS2 tree. Pairwise comparison of ITS2 transcripts with its closest relatives revealed the presence of both hemi- and compensatory base changes. Toxicity analysis showed detectable levels of domoic acid in P. abrensis, P. batesiana, P. lundholmiae, and P. subfraudulenta, but both new species tested below the detection limit.
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Affiliation(s)
- Sing Tung Teng
- Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, 94300 Kota Samarahan, Sarawak, Malaysia
| | - Suh Nih Tan
- Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaya, 16310 Bachok, Kelantan, Malaysia
| | - Hong Chang Lim
- Tunku Abdul Rahman University College, Johor Branch Campus, 85000 Segamat, Johor, Malaysia
| | - Viet Ha Dao
- Institute of Oceanography, VAST, 01 Cau Da, Nha Trang, Vietnam
| | - Stephen S Bates
- Fisheries and Oceans Canada, Gulf Fisheries Centre, P.O. Box 5030, Moncton, New Brunswick, Canada, E1C 9B6
| | - Chui Pin Leaw
- Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaya, 16310 Bachok, Kelantan, Malaysia
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Li CL, Ashworth MP, Witkowski A, Lobban CS, Zgłobicka I, Kurzydłowski KJ, Qin S. Ultrastructural and molecular characterization of diversity among small araphid diatoms all lacking rimoportulae. I. Five new genera, eight new species. J Phycol 2016; 52:1018-1036. [PMID: 27549783 DOI: 10.1111/jpy.12460] [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] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 07/23/2016] [Indexed: 06/06/2023]
Abstract
Pennate diatoms are important contributors to primary production in freshwater and marine habitats. But the extent of their diversity, ecology, and evolution is still largely unknown. This is particularly evident among the clades of pennate diatoms without raphe slits, whose diversity is likely underestimated due to their small size and features that can be difficult to discern under light microscopy. In this study, we described five new araphid genera with eight new species based on morphological observations (light and electron microscopy) and molecular data (nuclear-encoded small subunit ribosomal RNA and chloroplast-encoded rbcL and psbC): Serratifera varisterna, Hendeyella rhombica, H. dimeregrammopsis, H. lineata, Psammotaenia lanceolata, Castoridens striata, C. hyalina, and Cratericulifera shandongensis. We also transferred Dimeregramma dubium to Hendeyella dubia. Phylogenetic analysis of the molecular data revealed that all the newly established taxa fell into a monophyletic group, with Fragilariforma virescens located at the base. The group was composed by two subclades: one comprising Castoridens, Cratericulifera, and Plagiostriata, and the larger including also the rest of the new genera plus some of the smallest known diatoms, such as Nanofrustulum, Opephora, Pseudostaurosira, Staurosirella, and Staurosira with a high level of support. This study enhances the general knowledge on the phylogeny and biodiversity of a group of small araphid diatoms that have been generally poorly described both by electron microscopy and DNA sequence data.
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Affiliation(s)
- Chun L Li
- Palaeoceanology Unit, Faculty of Geosciences, Natural Sciences Research and Educational Center, University of Szczecin, Mickiewicza 16a, PL-70-383, Szczecin, Poland
| | - Matt P Ashworth
- Department of Integrative Biology, University of Texas at Austin, 205 W. 24th St. MS C0930, Austin, Texas, 78712, USA
| | - Andrzej Witkowski
- Palaeoceanology Unit, Faculty of Geosciences, Natural Sciences Research and Educational Center, University of Szczecin, Mickiewicza 16a, PL-70-383, Szczecin, Poland
| | | | - Izabela Zgłobicka
- Faculty of Materials Science and Engineering, Warsaw University of Technology, Wołoska 141, 02-507, Warsaw, Poland
| | - Krzysztof J Kurzydłowski
- Faculty of Materials Science and Engineering, Warsaw University of Technology, Wołoska 141, 02-507, Warsaw, Poland
| | - Song Qin
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, 17 Chunhui Rd, 264003, Yantai, China
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Kulikovskiy MS, Andreevab SA, Guseva ES, Kuznetsova IV, Annenkova NV. Molecular Phylogeny of Monoraphid Diatoms and Raphe Significance in Evolution and Taxonomy. Izv Akad Nauk Ser Biol 2016:468-478. [PMID: 30226934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The phylogenetic position of the genera Rossithidium and Psammothidium was studied using the plastid gene rbcL. The genus Rossithidium is not an independent taxon and should be transferred to Psammothidium. Taxa from Psammothidium genus formed a sister, but independent clade to taxa with Achnanthidium. Our data has shown that the order Achnathales was not the natural taxon and should be reduced, but the three families included in it were natural. Genera like Psammothidium (including Rossithidium) and Lemnicola should be included into the family Achnanthidiaceae. Therefore, raphe does not play an important role in diatom taxonomy and its loss occurred many times during the evolution of diatoms.
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Kikutani S, Nakajima K, Nagasato C, Tsuji Y, Miyatake A, Matsuda Y. Thylakoid luminal θ-carbonic anhydrase critical for growth and photosynthesis in the marine diatom Phaeodactylum tricornutum. Proc Natl Acad Sci U S A 2016; 113:9828-33. [PMID: 27531955 PMCID: PMC5024579 DOI: 10.1073/pnas.1603112113] [Citation(s) in RCA: 168] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The algal pyrenoid is a large plastid body, where the majority of the CO2-fixing enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) resides, and it is proposed to be the hub of the algal CO2-concentrating mechanism (CCM) and CO2 fixation. The thylakoid membrane is often in close proximity to or penetrates the pyrenoid itself, implying there is a functional cooperation between the pyrenoid and thylakoid. Here, GFP tagging and immunolocalization analyses revealed that a previously unidentified protein, Pt43233, is targeted to the lumen of the pyrenoid-penetrating thylakoid in the marine diatom Phaeodactylum tricornutum The recombinant Pt43233 produced in Escherichia coli cells had both carbonic anhydrase (CA) and esterase activities. Furthermore, a Pt43233:GFP-fusion protein immunoprecipitated from P. tricornutum cells displayed a greater specific CA activity than detected for the purified recombinant protein. In an RNAi-generated Pt43233 knockdown mutant grown in atmospheric CO2 levels, photosynthetic dissolved inorganic carbon (DIC) affinity was decreased and growth was constantly retarded; in contrast, overexpression of Pt43233:GFP yielded a slightly greater photosynthetic DIC affinity. The discovery of a θ-type CA localized to the thylakoid lumen, with an essential role in photosynthetic efficiency and growth, strongly suggests the existence of a common role for the thylakoid-luminal CA with respect to the function of diverse algal pyrenoids.
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Affiliation(s)
- Sae Kikutani
- Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo 669-1337, Japan
| | - Kensuke Nakajima
- Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo 669-1337, Japan
| | - Chikako Nagasato
- Muroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Muroran, Hokkaido 051-0013, Japan
| | - Yoshinori Tsuji
- Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo 669-1337, Japan
| | - Ai Miyatake
- Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo 669-1337, Japan
| | - Yusuke Matsuda
- Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo 669-1337, Japan;
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Fimbres-Olivarría D, López-Elías JA, Carvajal-Millán E, Márquez-Escalante JA, Martínez-Córdova LR, Miranda-Baeza A, Enríquez-Ocaña F, Valdéz-Holguín JE, Brown-Bojórquez F. Navicula sp. Sulfated Polysaccharide Gels Induced by Fe(III): Rheology and Microstructure. Int J Mol Sci 2016; 17:E1238. [PMID: 27483255 PMCID: PMC5000636 DOI: 10.3390/ijms17081238] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 07/14/2016] [Accepted: 07/19/2016] [Indexed: 11/22/2022] Open
Abstract
A sulfated polysaccharide extracted from Navicula sp. presented a yield of 4.4 (% w/w dry biomass basis). Analysis of the polysaccharide using gas chromatography showed that this polysaccharide contained glucose (29%), galactose (21%), rhamnose (10%), xylose (5%) and mannose (4%). This polysaccharide presented an average molecular weight of 107 kDa. Scanning electron microscopy (SEM) micrographs showed that the lyophilized Navicula sp. polysaccharide is an amorphous solid with particles of irregular shapes and sharp angles. The polysaccharide at 1% (w/v) solution in water formed gels in the presence of 0.4% (w/v) FeCl₃, showing elastic and viscous moduli of 1 and 0.7 Pa, respectively. SEM analysis performed on the lyophilized gel showed a compact pore structure, with a pore size of approximately 150 nm. Very few studies on the gelation of sulfated polysaccharides using trivalent ions exist in the literature, and, to the best of our knowledge, this study is the first to describe the gelation of sulfated polysaccharides extracted from Navicula sp.
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Affiliation(s)
- Diana Fimbres-Olivarría
- DICTUS, Department of Scientific and Technological Investigations, University of Sonora, Hermosillo, Sonora 83000, Mexico.
| | - José Antonio López-Elías
- DICTUS, Department of Scientific and Technological Investigations, University of Sonora, Hermosillo, Sonora 83000, Mexico.
| | | | | | - Luis Rafael Martínez-Córdova
- DICTUS, Department of Scientific and Technological Investigations, University of Sonora, Hermosillo, Sonora 83000, Mexico.
| | | | - Fernando Enríquez-Ocaña
- DICTUS, Department of Scientific and Technological Investigations, University of Sonora, Hermosillo, Sonora 83000, Mexico.
| | - José Eduardo Valdéz-Holguín
- DICTUS, Department of Scientific and Technological Investigations, University of Sonora, Hermosillo, Sonora 83000, Mexico.
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Robinson NJ, Majewska R, Lazo-Wasem EA, Nel R, Paladino FV, Rojas L, Zardus JD, Pinou T. Epibiotic Diatoms Are Universally Present on All Sea Turtle Species. PLoS One 2016; 11:e0157011. [PMID: 27257972 PMCID: PMC4892466 DOI: 10.1371/journal.pone.0157011] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 05/22/2016] [Indexed: 11/19/2022] Open
Abstract
The macro-epibiotic communities of sea turtles have been subject to growing interest in recent years, yet their micro-epibiotic counterparts are almost entirely unknown. Here, we provide the first evidence that diatoms are epibionts for all seven extant species of sea turtle. Using Scanning Electron Microscopy, we inspected superficial carapace or skin samples from a single representative of each turtle species. We distinguished 18 diatom taxa from these seven individuals, with each sea turtle species hosting at least two diatom taxa. We recommend that future research is undertaken to confirm whether diatom communities vary between sea turtle species and whether these diatom taxa are facultative or obligate commensals.
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Affiliation(s)
- Nathan J. Robinson
- The Leatherback Trust, Goldring-Gund Marine Biology Station, Playa Grande, Guanacaste, Costa Rica
- Department of Biology, Indiana University-Purdue University Fort Wayne, Fort Wayne, Indiana, United States of America
- * E-mail:
| | - Roksana Majewska
- BioNEM Laboratory, Department of Experimental and Clinical Medicine, University “Magna Graecia” of Catanzaro, Catanzaro, Italy
| | - Eric A. Lazo-Wasem
- Division of Invertebrate Zoology, Peabody Museum of Natural History, Yale University, New Haven, Connecticut, United States of America
| | - Ronel Nel
- Institute For Coastal and Marine Research, Nelson Mandela Metropolitan University, Port Elizabeth, South Africa
| | - Frank V. Paladino
- The Leatherback Trust, Goldring-Gund Marine Biology Station, Playa Grande, Guanacaste, Costa Rica
- Department of Biology, Indiana University-Purdue University Fort Wayne, Fort Wayne, Indiana, United States of America
| | - Lourdes Rojas
- Division of Invertebrate Zoology, Peabody Museum of Natural History, Yale University, New Haven, Connecticut, United States of America
| | - John D. Zardus
- Department of Biology, The Citadel, 171 Moultrie Street, Charleston, South Carolina, 29407, United States of America
| | - Theodora Pinou
- Department of Biological and Environmental Sciences, Western Connecticut State University, Danbury, Connecticut, United States of America
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Percopo I, Ruggiero MV, Balzano S, Gourvil P, Lundholm N, Siano R, Tammilehto A, Vaulot D, Sarno D. Pseudo-nitzschia arctica sp. nov., a new cold-water cryptic Pseudo-nitzschia species within the P. pseudodelicatissima complex. J Phycol 2016; 52:184-199. [PMID: 27037584 DOI: 10.1111/jpy.12395] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [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: 07/29/2015] [Accepted: 12/17/2015] [Indexed: 06/05/2023]
Abstract
A new nontoxic Pseudo-nitzschia species belonging to the P. pseudodelicatissima complex, P. arctica, was isolated from different areas of the Arctic. The erection of P. arctica is mainly supported by molecular data, since the species shares identical ultrastructure with another species in the complex, P. fryxelliana, and represents a new case of crypticity within the genus. Despite their morphological similarity, the two species are not closely related in phylogenies based on LSU, ITS and rbcL. Interestingly, P. arctica is phylogenetically most closely related to P. granii and P. subcurvata, from which the species is, however, morphologically different. P. granii and P. subcurvata lack the central larger interspace which is one of the defining features of the P. pseudodelicatissima complex. The close genetic relationship between P. arctica and the two species P. granii and P. subcurvata is demonstrated by analysis of the secondary structure of ITS2 which revealed no compensatory base changes, two hemi-compensatory base changes, and two deletions in P. arctica with respect to the other two species. These findings emphasize that rates of morphological differentiation, molecular evolution and speciation are often incongruent for Pseudo-nitzschia species, resulting in a restricted phylogenetic value for taxonomic characters used to discriminate species. The description of a new cryptic species, widely distributed in the Arctic and potentially representing an endemic component of the Arctic diatom flora, reinforces the idea of the existence of noncosmopolitan Pseudo-nitzschia species and highlights the need for combined morphological and molecular analyses to assess the distributional patterns of phytoplankton species.
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Affiliation(s)
- Isabella Percopo
- Integrative Marine Ecology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, Naples, 80121, Italy
| | - Maria Valeria Ruggiero
- Integrative Marine Ecology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, Naples, 80121, Italy
| | - Sergio Balzano
- Station Biologique, Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 7144, Place Georges Teissier, Roscoff, 29680, France
| | - Priscillia Gourvil
- Station Biologique, Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 7144, Place Georges Teissier, Roscoff, 29680, France
| | - Nina Lundholm
- The Natural History Museum of Denmark, University of Copenhagen, Sølvgade 83S, Copenhagen K, 1307, Denmark
| | - Raffaele Siano
- DYNECO/Pelagos, IFREMER, Centre de Brest, BP 70, Plouzané, 29280, France
| | - Anna Tammilehto
- The Natural History Museum of Denmark, University of Copenhagen, Sølvgade 83S, Copenhagen K, 1307, Denmark
| | - Daniel Vaulot
- Station Biologique, Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 7144, Place Georges Teissier, Roscoff, 29680, France
| | - Diana Sarno
- Integrative Marine Ecology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, Naples, 80121, Italy
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Alipour L, Hamamoto M, Nakashima S, Harui R, Furiki M, Oku O. Infrared Microspectroscopy of Bionanomaterials (Diatoms) with Careful Evaluation of Void Effects. Appl Spectrosc 2016; 70:427-442. [PMID: 26823543 DOI: 10.1177/0003702815626665] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [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: 09/17/2014] [Accepted: 07/13/2015] [Indexed: 06/05/2023]
Abstract
In order to characterize a representative natural bionanomaterial, present day centric diatom samples (diameter, 175-310 µm) have been analyzed and imaged by infrared (IR) micro-spectroscopy and scanning electron microscopy (SEM). Because diatom silica frustules have complex microscopic morphology, including many void areas such as micro- or nano-pores, the effects of voids on the spectral band shapes were first evaluated. With increasing void area percentage, 1220 cm(-1)/1070 cm(-1) peak height ratio (Si-O polymerization index) increases and 950 cm(-1)/800 cm(-1) peak height ratio (Si-OH/Si-O-Si) decreases, both approaching 1. Based on the void area percentage of representative diatom samples determined using SEM image analyses (51.5% to 20.5%) and spectral simulation, the 1220 cm(-1)/1070 cm(-1) ratios of diatom samples are sometimes affected by the void effect, but the 950 cm(-1)/800 cm(-1) ratios can indicate real structural information of silica. This void effect should be carefully evaluated for IR micro-spectroscopy of micro-nano-porous materials. Maturity of diatom specimens may be evaluated from: (1) void area percentages determined by SEM; (2) average thicknesses determined by optical microscope; and (3) average values of 1220 cm(-1)/1070 cm(-1) peak height ratios (opposite trend to the void effect) determined by IR micro-spectroscopy. Microscopic heterogeneities of chemical structures of silica were obtained by IR micro-spectroscopic mapping of four representative diatoms. The 950 cm(-1)/800 cm(-1) ratios show that large regions of some diatoms consist of hydrated amorphous immature silica. The successful analysis of diatoms by IR micro-spectroscopic data with careful void effect evaluation may be applied to physicochemical structures of many other bionanomaterials.
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Affiliation(s)
- Leila Alipour
- Department of Earth and Space Science, Osaka University, Toyonaka, Japan
| | - Mai Hamamoto
- Department of Earth and Space Science, Osaka University, Toyonaka, Japan
| | - Satoru Nakashima
- Department of Earth and Space Science, Osaka University, Toyonaka, Japan
| | - Rika Harui
- Thermo Fisher Scientific Corp., Nishinakajima 6-3-14, Osaka, Japan
| | - Masanari Furiki
- Hitachi High Technologies Corp., Miyahara 3-3-31, Osaka, Japan
| | - Osamu Oku
- Micro World Service. Minami-Otsuka 1-3-25-301, Tokyo, Japan
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40
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Aitken ZH, Luo S, Reynolds SN, Thaulow C, Greer JR. Microstructure provides insights into evolutionary design and resilience of Coscinodiscus sp. frustule. Proc Natl Acad Sci U S A 2016; 113:2017-22. [PMID: 26858446 PMCID: PMC4776537 DOI: 10.1073/pnas.1519790113] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We conducted in situ three-point bending experiments on beams with roughly square cross-sections, which we fabricated from the frustule of Coscinodiscus sp. We observe failure by brittle fracture at an average stress of 1.1 GPa. Analysis of crack propagation and shell morphology reveals a differentiation in the function of the frustule layers with the basal layer pores, which deflect crack propagation. We calculated the relative density of the frustule to be ∼30% and show that at this density the frustule has the highest strength-to-density ratio of 1,702 kN⋅m/kg, a significant departure from all reported biologic materials. We also performed nanoindentation on both the single basal layer of the frustule as well as the girdle band and show that these components display similar mechanical properties that also agree well with bending tests. Transmission electron microscopy analysis reveals that the frustule is made almost entirely of amorphous silica with a nanocrystalline proximal layer. No flaws are observed within the frustule material down to 2 nm. Finite element simulations of the three-point bending experiments show that the basal layer carries most of the applied load whereas stresses within the cribrum and areolae layer are an order of magnitude lower. These results demonstrate the natural development of architecture in live organisms to simultaneously achieve light weight, strength, and exceptional structural integrity and may provide insight into evolutionary design.
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Affiliation(s)
- Zachary H Aitken
- Department of Mechanical and Civil Engineering, California Institute of Technology, Pasadena, CA 91125;
| | - Shi Luo
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125
| | - Stephanie N Reynolds
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Christian Thaulow
- Department of Engineering Design and Materials, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Julia R Greer
- Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125
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41
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Abstract
The wide variety of diatom frustule shapes and intricate architectures provide viable prototypes to guide the design and fabrication of nanodevices and nanostructured materials for applications ranging from sensors to nanotemplates. In this study, a combined experimental-simulation method was developed to probe the porous structure and mechanical behavior of two distinct marine diatom species, Coscinodiscus sp. (centric) and Synedra sp. (pennate), through ambient nanoindentation and finite element method analysis. These diatom frustule dimensions differed largely depending on diatom species with pore diameters d ranging from 0.3 to 3.0 μm. Young's modulus E and hardness H measurements of the diatom frustules were obtained via nanoindentation experiments. These values varied depending on diatom species (E between 1.1-10.6 GPa, H between 0.10-1.03 GPa for the Coscinodiscus sp.; and E between 13.7-18.6 GPa, H between 0.85-1.41 GPa for the Synedra sp.). Additionally, the mechanical response of diatom structures to uniform compression was examined. Predictive simulations were performed on the aforementioned diatom frustules, as well as another diatom structure (pennate Fragilariopsis kerguelensis), to correlate the mechanical response with specific morphology variables (e.g., pore or slit sizes). Results from calculated von Mises stress and displacement distributions unveil unique information on the effect that uniform loads have on these frustules, which can aid the design of tailored nanotemplates. A correlation between mechanical properties and porosity was established for selected frustules, and reported for the first time in this study.
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Affiliation(s)
- Miguel Diaz Moreno
- Materials Science and Engineering, School of Engineering, University of California Merced, 5200 N. Lake Road, Merced, CA 95343, USA
| | - Kaka Ma
- Department of Chemical Engineering and Materials Science, College of Engineering, University of California Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Julie Schoenung
- Department of Chemical Engineering and Materials Science, College of Engineering, University of California Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Lilian P Dávila
- Materials Science and Engineering, School of Engineering, University of California Merced, 5200 N. Lake Road, Merced, CA 95343, USA.
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Tanaka A, De Martino A, Amato A, Montsant A, Mathieu B, Rostaing P, Tirichine L, Bowler C. Ultrastructure and Membrane Traffic During Cell Division in the Marine Pennate Diatom Phaeodactylum tricornutum. Protist 2015; 166:506-21. [PMID: 26386358 PMCID: PMC4710849 DOI: 10.1016/j.protis.2015.07.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Revised: 06/05/2015] [Accepted: 07/30/2015] [Indexed: 12/14/2022]
Abstract
The marine pennate diatom Phaeodactylum tricornutum has become a model for diatom biology, due to its ease of culture and accessibility to reverse genetics approaches. While several features underlying the molecular mechanisms of cell division have been described, morphological analyses are less advanced than they are in other diatoms. We therefore examined cell ultrastructure changes prior to and during cytokinesis. Following chloroplast division, cleavage furrows are formed at both longitudinal ends of the cell and are accompanied by significant vesicle transport. Although neither spindle nor microtubules were observed, the nucleus appeared to be split by the furrow after duplication of the Golgi apparatus. Finally, centripetal cytokinesis was completed by fusion of the furrows. Additionally, F-actin formed a ring structure and its diameter became smaller, accompanying the ingrowing furrows. To further analyse vesicular transport during cytokinesis, we generated transgenic cells expressing yellow fluorescent protein (YFP) fusions with putative diatom orthologs of small GTPase Sec4 and t-SNARE protein SyntaxinA. Time-lapse observations revealed that SyntaxinA-YFP localization expands from both cell tips toward the center, whereas Sec4-YFP was found in the Golgi and subsequently relocalizes to the future division plane. This work provides fundamental new information about cell replication processes in P. tricornutum.
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Affiliation(s)
- Atsuko Tanaka
- Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, 46 rue d'Ulm, F-75005 Paris, France
| | - Alessandra De Martino
- Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, 46 rue d'Ulm, F-75005 Paris, France
| | - Alberto Amato
- Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, 46 rue d'Ulm, F-75005 Paris, France
| | - Anton Montsant
- Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, 46 rue d'Ulm, F-75005 Paris, France
| | - Benjamin Mathieu
- Imaging Platform, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR8197 INSERM U1024, 46, rue d'Ulm, 75230 Paris Cedex 05, France
| | - Philippe Rostaing
- Neuroscience Section, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR8197 INSERM U1024, 46, rue d'Ulm, 75230 Paris Cedex 05, France
| | - Leila Tirichine
- Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, 46 rue d'Ulm, F-75005 Paris, France
| | - Chris Bowler
- Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, 46 rue d'Ulm, F-75005 Paris, France.
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43
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Abstract
Traditionally, biodiversity has often been estimated on the basis of abundance partly due to the need for complicated measurements of biomass. Here, we conducted robust measurements of the community composition and of the size structure of diatoms in the North Pacific to evaluate the importance of biomass on the biodiversity. We found that the two most useful evenness indices increased in most cases where small species were numerically dominant when calculations were based on biomass compared with those on abundance. Size-abundance spectra of diatoms revealed that numerically dominant small species rarely dominated in terms of biomass. On the other hand, intermediate to large diatom species generally played a dominant role in terms of biomass in diatom community. The results suggest that the size of the dominant species is a crucial factor in determining the role of diatoms in the ecosystem functioning. Because such size variability can also be observed in other organisms, we need to pay attention to the effect of size structures on biodiversity.
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Affiliation(s)
- Koji Sugie
- Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Hokkaido, Japan
- CREST, Japan Science and Technology Agency, Sapporo, Hokkaido, Japan
- * E-mail:
| | - Koji Suzuki
- Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Hokkaido, Japan
- CREST, Japan Science and Technology Agency, Sapporo, Hokkaido, Japan
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44
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Samylina OS, Sapozhnikov FV, Gaĭnanova OI, Riabova AV, Nikitin MA, Sorokin DI. [Algo-bacterial communities of the Kulunda steppe (Altai region, Russia) soda lakes]. Mikrobiologiia 2015; 84:107-119. [PMID: 25916153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The composition and macroscopic structure of the floating oxygenic phototrophic communities from Kulunda steppe soda lakes (Petukhovskoe sodovoe, Tanatara VI, and Gorchiny 3) was described based on the data of the 2011 and 2012 expeditions (Winogradsky Institute of Microbiology). The algo-bacterial community with a green alga Ctenocladus circinnatus as an edificator was the typical one. Filamentous Geitlerinema sp. and Nodosilinea sp. were the dominant cyanobacteria. Apart from C. circinnatus, the algological component of the community contained unicellular green algae Dunaliella viridis and cf. Chlorella minutissima, as well as diatoms (Anomeoneis sphaerophora, Brchysira brebissonii, Brachysira zellensis, Mastogloia pusilla var. subcapitata, Nitzschia amphibia, Nitzschia communis, and Nitzschia sp.1). The latter have not been previously identified in the lakes under study. In all lakes, a considerable increase in salinity was found to result in changes in the composition and macroscopic structure of algo-bacterial communities.
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45
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De Tommasi E, De Luca AC, Lavanga L, Dardano P, De Stefano M, De Stefano L, Langella C, Rendina I, Dholakia K, Mazilu M. Biologically enabled sub-diffractive focusing. Opt Express 2014; 22:27214-27. [PMID: 25401872 DOI: 10.1364/oe.22.027214] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Evolution shows that photonic structures are a constituent part of many animals and flora. These elements produce structural color and are useful in predator-prey interactions between animals and in the exploitation of light for photosynthetic organisms. In particular, diatoms have evolved patterned hydrated silica external valves able to confine light with extraordinary efficiency. Their evolution was probably guided by the necessity to survive in harsh conditions of sunlight deprivation. Here, we exploit such diatom valves, in conjunction with structured illumination, to realize a biological super-resolving lens to achieve sub-diffractive focusing in the far field. More precisely, we consider a single diatom valve of Arachnoidiscus genus which shows symmetries and fine features. By characterizing and using the transmission properties of this valve using the optical eigenmode technique, we are able to confine light to a tiny spot with unprecedented precision in terms of resolution limit ratio, corresponding in this case to 0.21λ/NA.
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Sullivan T, McGuinness K, O'Connor NE, Regan F. Characterization and anti-settlement aspects of surface micro-structures from Cancer pagurus. Bioinspir Biomim 2014; 9:046003. [PMID: 25291692 DOI: 10.1088/1748-3182/9/4/046003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Tuning surface and material properties to inhibit or prevent settlement and attachment of microorganisms is of interest for applications such as antifouling technologies. Here, optimization of nano- and microscale structures on immersed surfaces can be utilized to improve cell removal while reducing adhesion strength and the likelihood of initial cellular attachment. Engineered surfaces capable of controlling cellular behaviour under natural conditions are challenging to design due to the diversity of attaching cell types in environments such as marine waters, where many variations in cell shape, size and adhesion strategy exist. Nevertheless, understanding interactions between a cell and a potential substrate for adhesion, including topographically driven settlement cues, offers a route to designing surfaces capable of controlling cell settlement. Biomimetic design of artificial surfaces, based upon microscale features from natural surfaces, can be utilized as model surfaces to understand cell-surface interactions. The microscale surface features of the carapace from the crustacean Cancer pagurus has been previously found to influence the rate of attachment of particular organisms when compared to smooth controls. However, the nature of microscale topographic features from C. pagurus have not been examined in sufficient detail to allow design of biomimetic surfaces. In this work, the spatial distribution, chemical composition, size and shape descriptors of microscale surface features from C. pagurus are characterized in detail for the first time. Additionally, the influence of topography from C. pagurus on the settlement of marine diatoms is examined under field conditions.
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Affiliation(s)
- T Sullivan
- MESTECH: Marine and Environmental Sensing Technology Hub, Dublin City University, Glasnevin, Dublin 9, Ireland
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Zimmermann J, Abarca N, Enk N, Skibbe O, Kusber WH, Jahn R. Taxonomic reference libraries for environmental barcoding: a best practice example from diatom research. PLoS One 2014; 9:e108793. [PMID: 25265556 PMCID: PMC4180937 DOI: 10.1371/journal.pone.0108793] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [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: 05/13/2014] [Accepted: 08/14/2014] [Indexed: 01/12/2023] Open
Abstract
DNA barcoding uses a short fragment of a DNA sequence to identify a taxon. After obtaining the target sequence it is compared to reference sequences stored in a database to assign an organism name to it. The quality of data in the reference database is the key to the success of the analysis. In the here presented study, multiple types of data have been combined and critically examined in order to create best practice guidelines for taxonomic reference libraries for environmental barcoding. 70 unialgal diatom strains from Berlin waters have been established and cultured to obtain morphological and molecular data. The strains were sequenced for 18S V4 rDNA (the pre-Barcode for protists) as well as rbcL data, and identified by microscopy. LM and for some strains also SEM pictures were taken and physical vouchers deposited at the BGBM. 37 freshwater taxa from 15 naviculoid diatom genera were identified. Four taxa from the genera Amphora, Mayamaea, Planothidium and Stauroneis are described here as new. Names, molecular, morphological and habitat data as well as additional images of living cells are also available electronically in the AlgaTerra Information System. All reference sequences (or reference barcodes) presented here are linked to voucher specimens in order to provide a complete chain of evidence back to the formal taxonomic literature.
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Affiliation(s)
- Jonas Zimmermann
- Botanic Garden and Botanical Museum Berlin-Dahlem, Freie Universität Berlin, Berlin, Germany
- Justus-Liebig-Universität Giessen, AG Spezielle Botanik, Giessen, Hessen, Germany
| | - Nelida Abarca
- Botanic Garden and Botanical Museum Berlin-Dahlem, Freie Universität Berlin, Berlin, Germany
| | - Neela Enk
- Botanic Garden and Botanical Museum Berlin-Dahlem, Freie Universität Berlin, Berlin, Germany
| | - Oliver Skibbe
- Botanic Garden and Botanical Museum Berlin-Dahlem, Freie Universität Berlin, Berlin, Germany
- Larger than life - micro and nature photography, http://www.larger-than-life.de, Berlin Germany
| | - Wolf-Henning Kusber
- Botanic Garden and Botanical Museum Berlin-Dahlem, Freie Universität Berlin, Berlin, Germany
| | - Regine Jahn
- Botanic Garden and Botanical Museum Berlin-Dahlem, Freie Universität Berlin, Berlin, Germany
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Müller M, Mey T, Niemeyer J, Mann K. Table-top soft x-ray microscope using laser-induced plasma from a pulsed gas jet. Opt Express 2014; 22:23489-23495. [PMID: 25321818 DOI: 10.1364/oe.22.023489] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
An extremely compact soft x-ray microscope operating in the "water window" region at the wavelength λ = 2.88 nm is presented, making use of a long-term stable and nearly debris-free laser-induced plasma from a pulsed nitrogen gas jet target. The well characterized soft x-ray radiation is focused by an ellipsoidal grazing incidence condenser mirror. Imaging of a sample onto a CCD camera is achieved with a Fresnel zone plate using magnifications up to 500x. The spatial resolution of the recorded microscopic images is about 100 nm as demonstrated for a Siemens star test pattern.
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49
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Unnep R, Nagy G, Markó M, Garab G. Monitoring thylakoid ultrastructural changes in vivo using small-angle neutron scattering. Plant Physiol Biochem 2014; 81:197-207. [PMID: 24629664 DOI: 10.1016/j.plaphy.2014.02.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [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: 12/17/2013] [Accepted: 02/08/2014] [Indexed: 05/01/2023]
Abstract
The light reactions of oxygenic photosynthesis take place in the thylakoid membranes, flattened vesicles, which contain the two photosystems and also embed the cytochrome b6f complex and the ATP synthase. In general, the thylakoid membranes are assembled into multilamellar membrane systems, which warrant an optimal light capturing efficiency. In nature, they show astounding variations, primarily due to large variations in their protein composition, which is controlled by multilevel regulatory mechanisms during long-term acclimation and short-term adaptation processes and also influenced by biotic or abiotic stresses - indicating a substantial degree of flexibility in the membrane ultrastructure. The better understanding of the dynamic features of this membrane system requires the use of non-invasive techniques, such as small angle neutron scattering (SANS), which is capable of providing accurate, statistically and spatially averaged information on the repeat distances of periodically organized thylakoid membranes under physiologically relevant conditions with time resolutions of seconds and minutes. In this review, after a short section on the basic properties of neutrons, we outline the fundamental principles of SANS measurements, its strengths and weaknesses in comparison to complementary structure investigation techniques. Then we overview recent results on isolated plant thylakoid membranes, and on living cyanobacterial and algal cells as well as on whole leaves. Special attention is paid to light-induced reversible ultrastructural changes in vivo, which, in cyanobacterial and diatom cells, were uncovered with the aid of SANS measurements; we also discuss the role of membrane reorganizations in light adaptation and photoprotection mechanisms.
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Affiliation(s)
- Renáta Unnep
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, POB 49, H-1525 Budapest, Hungary
| | - Gergely Nagy
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, POB 49, H-1525 Budapest, Hungary; Laboratory for Neutron Scattering, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Márton Markó
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, POB 49, H-1525 Budapest, Hungary; Laboratory for Neutron Scattering, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, POB 521, H-6701 Szeged, Hungary.
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50
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Ferrara MA, Dardano P, De Stefano L, Rea I, Coppola G, Rendina I, Congestri R, Antonucci A, De Stefano M, De Tommasi E. Optical properties of diatom nanostructured biosilica in Arachnoidiscus sp: micro-optics from mother nature. PLoS One 2014; 9:e103750. [PMID: 25076045 PMCID: PMC4116236 DOI: 10.1371/journal.pone.0103750] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [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: 05/19/2014] [Accepted: 07/02/2014] [Indexed: 11/23/2022] Open
Abstract
Some natural structures show three-dimensional morphologies on the micro- and nano- scale, characterized by levels of symmetry and complexity well far beyond those fabricated by best technologies available. This is the case of diatoms, unicellular microalgae, whose protoplasm is enclosed in a nanoporous microshell, made of hydrogenated amorphous silica, called frustule. We have studied the optical properties of Arachnoidiscus sp. single valves both in visible and ultraviolet range. We found photonic effects due to diffraction by ordered pattern of pores and slits, accordingly to an elaborated theoretical model. For the first time, we experimentally revealed spatial separation of focused light in different spots, which could be the basis of a micro-bio-spectrometer. Characterization of such intricate structures can be of great inspiration for photonic devices of next generation.
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Affiliation(s)
- Maria Antonietta Ferrara
- Institute for Microelectronic and Microsystems, Department of Naples, National Research Council, Naples, Italy
- * E-mail:
| | - Principia Dardano
- Institute for Microelectronic and Microsystems, Department of Naples, National Research Council, Naples, Italy
| | - Luca De Stefano
- Institute for Microelectronic and Microsystems, Department of Naples, National Research Council, Naples, Italy
| | - Ilaria Rea
- Institute for Microelectronic and Microsystems, Department of Naples, National Research Council, Naples, Italy
| | - Giuseppe Coppola
- Institute for Microelectronic and Microsystems, Department of Naples, National Research Council, Naples, Italy
| | - Ivo Rendina
- Institute for Microelectronic and Microsystems, Department of Naples, National Research Council, Naples, Italy
| | - Roberta Congestri
- Laboratory of Biology of Algae, Department of Biology, University of Rome “Tor Vergata”, Rome, Italy
| | - Alessandra Antonucci
- Department of Environmental, biological, and Pharmaceutical Sciences and Technologies, Second University of Naples, Caserta, Italy
| | - Mario De Stefano
- Department of Environmental, biological, and Pharmaceutical Sciences and Technologies, Second University of Naples, Caserta, Italy
| | - Edoardo De Tommasi
- Institute for Microelectronic and Microsystems, Department of Naples, National Research Council, Naples, Italy
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