The possibility of using marine diatom-infecting viral promoters for the engineering of marine diatoms

Plant Science ◽  
2020 ◽  
Vol 296 ◽  
pp. 110475
Author(s):  
Takashi Kadono ◽  
Yuji Tomaru ◽  
Kengo Suzuki ◽  
Koji Yamada ◽  
Masao Adachi
Keyword(s):  
Marine Diatom ◽  
Marine Diatoms ◽  
Viral Promoters

Cenozoic Marine Diatom Biostratigraphy and Applications to Paleoclimatology and Paleoceanography

1995 ◽  
Vol 8 ◽  
pp. 107-118 ◽  
Author(s):  
John A. Barron ◽  
Jack G. Baldauf
Keyword(s):  
Marine Diatom ◽  
Paleoenvironmental Reconstruction ◽  
Photic Zone ◽  
Marine Diatoms ◽  
Sedimentary Sequences ◽  
Marine Food Chain ◽  
Current State ◽  
Aqueous Environments ◽  
Biostratigraphic Correlation ◽  
Marine Food

Diatoms, golden brown algae, are present in most aqueous environments. Within the marine environment marine diatoms occupy the photic zone and represent the lowest level of the marine food chain. Diatoms are either planktonic or benthic and possess an external siliceous skeleton or frustule, that is boxlike in structure. The size of diatom frustules ranges from less than 1 μm to more than 1,000 μm, but most frustules range in size from 10 to 100 μm. Diatoms are present in the geological record from at least the Cretaceous (Harwood and Nikolaev, this volume) and have numerous advantages for biostratigraphic correlation and paleoenvironmental reconstruction of marine sedimentary sequences. This chapter summarizes the current state of marine diatom biostratigraphy for the Cenozoic and provides examples of how marine diatoms are used in paleoenvironmental reconstructions. No attempt is made to illustrate the various diatom taxa discussed; the reader is referred to published references such as the syntheses of Fenner (1985) and Barron (1985).

scholarly journals Occurrence of structural aluminum (Al) in marine diatom biological silica: Visible evidence from microscopic analysis

2021 ◽  
Author(s):  
Qian Tian ◽  
Dong Liu ◽  
Peng Yuan ◽  
Mengyuan Li ◽  
Weifeng Yang ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Microscopic Analysis ◽  
Atomic Ratio ◽  
Marine Diatom ◽  
Biogeochemical Cycle ◽  
Homogeneous Distribution ◽  
Marine Diatoms ◽  
Mapping Analysis ◽  
Living Diatoms

Abstract. The global marine biogeochemical cycle of aluminum (Al) is believed to be driven by marine diatoms, due to the uptake of dissolved Al (DAl) by living diatoms from surface seawater. The occurrence of Al in diatom biogenic silica (BSi) can inhibit the dissolution of BSi, thus benefiting the effects of the ballast role of diatoms in the biological pump and forming a coupled Si-Al biogeochemical cycle. However, the occurrence mechanism of Al in marine diatoms is still unclear. In particular, whether or not Al is incorporated into the structure of BSi of living diatoms is unrevealed, resulting in difficulties in understanding the biogeochemical behaviors of Al. In this study, Thalassiosira weissflogii, a widely distributed marine diatom in marginal seas, was selected as the model to evaluate the occurrence of structural Al in BSi based on culturing experiments with the addition of DAl. The structural Al in BSi was detected by combining focused ion beam (FIB) scanning electron microscopy and energy dispersive X-ray spectroscopy (EDS) mapping analysis. Direct evidence of structural Al in living BSi was obtained for the first time. The distribution and content of this Al were revealed by the EDS-mapping analysis. The structural Al in the BSi exhibited a homogeneous distribution, and the average Al / Si atomic ratio obtained through the FIB-EDS mapping analysis was 0.011. The effects of structural Al on BSi dissolution-inhibition are discussed based on the content of this Al. The fundamental results indicate the significant contribution of marine diatoms to the biogeochemical migration of marine Al.

scholarly journals Artificial Intelligence Meets Marine Ecotoxicology: Applying Deep Learning to Bio-Optical Data from Marine Diatoms Exposed to Legacy and Emerging Contaminants

Biology ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 932
Author(s):  
Nuno M. Rodrigues ◽  
João E. Batista ◽  
Pedro Mariano ◽  
Vanessa Fonseca ◽  
Bernardo Duarte ◽  
...  
Keyword(s):  
Deep Learning ◽  
Emerging Contaminants ◽  
Test Organism ◽  
Large Datasets ◽  
Marine Diatom ◽  
Optical Data ◽  
Model Organisms ◽  
Total Production ◽  
Marine Diatoms ◽  
Wide Range

Over recent decades, the world has experienced the adverse consequences of uncontrolled development of multiple human activities. In recent years, the total production of chemicals has been composed of environmentally harmful compounds, the majority of which have significant environmental impacts. These emerging contaminants (ECs) include a wide range of man-made chemicals (such as pesticides, cosmetics, personal and household care products, pharmaceuticals), which are of worldwide use. Among these, several ECs raised concerns regarding their ecotoxicological effects and how to assess them efficiently. This is of particular interest if marine diatoms are considered as potential target species, due to their widespread distribution, being the most abundant phytoplankton group in the oceans, and also being responsible for key ecological roles. Bio-optical ecotoxicity methods appear as reliable, fast, and high-throughput screening (HTS) techniques, providing large datasets with biological relevance on the mode of action of these ECs in phototrophic organisms, such as diatoms. However, from the large datasets produced, only a small amount of data are normally extracted for physiological evaluation, leaving out a large amount of information on the ECs exposure. In the present paper, we use all the available information and evaluate the application of several machine learning and deep learning algorithms to predict the exposure of model organisms to different ECs under different doses, using a model marine diatom (Phaeodactylum tricornutum) as a test organism. The results show that 2D convolutional neural networks are the best method to predict the type of EC to which the cultures were exposed, achieving a median accuracy of 97.65%, while Rocket is the best at predicting which concentration the cultures were subjected to, achieving a median accuracy of 100%.

scholarly journals Effects of environmental parameters on chytrid infection prevalence of four marine diatoms: a laboratory case study

2017 ◽  
Vol 60 (4) ◽  
Author(s):  
Bettina Scholz ◽  
Wim Vyverman ◽  
Frithjof C. Küpper ◽  
Halldór G. Ólafsson ◽  
Ulf Karsten
Keyword(s):  
Environmental Factors ◽  
Host Species ◽  
Environmental Parameters ◽  
Coastal Areas ◽  
Marine Diatom ◽  
Infection Prevalence ◽  
Marine Diatoms ◽  
North West ◽  
Infection Susceptibility

AbstractThe influence of environmental factors on the infection susceptibility of four different marine diatom host species to chytrid infection was tested under laboratory conditions, using host and parasite isolates obtained from diverse coastal areas in north-west Iceland in 2015. Specifically, a total of 120 monoclonal marine diatom host cultures of

scholarly journals Checklist of marine diatoms from the Turkish coastal waters with updated nomenclature

2021 ◽  
Vol 4 (1) ◽  
pp. 88-115
Author(s):  
Aydın Kaleli ◽  
Reyhan Akçaalan
Keyword(s):  
Coastal Waters ◽  
Benthic Diatom ◽  
Marine Phytoplankton ◽  
Marine Diatom ◽  
Marine Diatoms ◽  
The Past ◽  
Detailed List

Marine diatom research in the coastal waters of Turkey started nearly two centuries ago. In the last decades, in-creasing numbers of contri-butions extended the knowledge of the marine phytoplankton. While sev-eral studies dedicated to planktonic forms and the checklists published con-cerning on the phytoplank-ton, relatively low numbers of benthic diatom studies were performed. Therefore, this is the first detailed list of the marine diatoms in-cluding both planktonic and benthic forms in Turkish coasts. This paper brings up the checklist of the past re-search referring to the au-thors in the last two centu-ries within the scope of the latest nomenclature. A total of 767 taxa (species, varie-ties and forms) belonging to 183 genera were listed. This study focussed into the study areas according to the reviewed literature and showed that many areas are yet to be investigated.

scholarly journals Environmental fluctuations accelerate molecular evolution of thermal tolerance in a marine diatom

2017 ◽  
Author(s):  
C.-Elisa Schaum ◽  
A. Buckling ◽  
N. Smirnoff ◽  
D. J. Studholme ◽  
G. Yvon-Durocher
Keyword(s):  
Thermal Tolerance ◽  
Cellular Response ◽  
Redox Homeostasis ◽  
Thalassiosira Pseudonana ◽  
Marine Diatom ◽  
Marine Diatoms ◽  
Phenotypic Changes ◽  
Evolutionary Rescue ◽  
Fluctuating Environments ◽  
Significant Genetic Divergence

Diatoms contribute roughly 20% of global primary production, but the factors determining their ability to adapt to global warming are unknown. Here we quantify the capacity for adaptation to warming in the marine diatom Thalassiosira pseudonana. We found that evolutionary rescue under severe warming was slow but adaptation to more realistic scenarios, where temperature increases were moderate or where they fluctuated between benign and severe conditions, was rapid. Adaption to warming was linked to major phenotypic changes in metabolism and elemental composition. Whole genome re-sequencing identified significant genetic divergence both among populations adapted to the different warming regimes and between the evolved and ancestral lineages. Consistent with the phenotypic changes, the most rapidly evolving genes were associated with transcriptional regulation, cellular response to oxidative stress and redox homeostasis. These results demonstrate that evolution of thermal tolerance in marine diatoms can be rapid, particularly in fluctuating environments, and is underpinned by major genomic and phenotypic divergence.

scholarly journals Inhibition Effects of Jakarta Bay Sediments to the Growth of Marine Diatom (Chaetoceros Gracilis)

2019 ◽  
Vol 33 (2) ◽  
Author(s):  
Triyoni Purbonegoro ◽  
Muhammad Reza Cordova ◽  
Rachma Puspitasari ◽  
Dwi Hindarti
Keyword(s):  
Heavy Metals ◽  
Marine Organism ◽  
Sediment Toxicity ◽  
Sediment Quality ◽  
Marine Diatom ◽  
Growth Responses ◽  
Marine Diatoms ◽  
Chaetoceros Gracilis ◽  
Port Area ◽  
The Impact

Jakarta Bay coastal ecosystem is known suffered from water pollution and habitat degradation. Solid and fluid waste from households and several industrial areas flow and ended up in the bay. Ecotoxicological studies are needed to assess the effects of pollutant on marine organism, including phytoplankton as the primary producer. Therefore chemical analysis and toxicity test were performed to investigate the impact of Jakarta Bay Sediments to marine diatoms Chaetoceros gracilis. Heavy metals concentration especially Cu, Pb, Cd, and Hg in the sediments were lower than in previous studies. It could be related to the stricter environmental regulations which started enforced at the end of 1990s. Meanwhile, PAH and pesticide were higher than in previous studies. Increasing activities and maritime traffic in surrounding area of Tanjung Priok Port area and most likely comes from other adjacent harbors (Muara Baru, Muara Angke, and Marina Ancol harbor) and the massive usage of the pesticide compound in the households of the Jakarta City area were suspected to be the reasons. Estuaries area and locations <10 km were identified and predicted would produce harmful effects since the concentration of Zn and Hg in those area exceeded Probable Effects Level (PEL) of Sediment Quality Guidelines (SQG). The growth responses of Chaetoceros gracilis were varied greatly. Most of the sites (24 from 31 sites) showed inhibition effects on the growth of diatoms, ranged from 1.75-35.33 % (17.75±9.59 %) relative to control, with the highest inhibition value was at Cengkareng Drain estuary (M2). The relationship between the concentration of contaminants and the inhibition response could not be clearly explained, however, there is an assumption that low concentrations of some heavy metals were suspected to give adverse effects on diatom’s growth.Keywords: sediment, toxicity, marine diatoms, Chaetoceros gracilis, Jakarta BayEkosistem Teluk Jakarta dikenal mengalami pencemaran air dan degradasi habitat. Limbah cair dan padat berasal dari perumahan dan industri mengalir dan berakhir di teluk tersebut. Kajian ekotoksikologi diperlukan untuk mengetahui pengaruh pencemar terhadap organisme laut termasuk fitoplankton sebagai produsen primer. Analisis kimia dan uji toksisitas dilakukan untuk mengetahui dampak sedimen Teluk Jakarta terhadap diatom laut Chaetoceros gracilis. Konsentrasi logam berat terutama Cu, Pb, Cd, dan Hg dalam sedimen lebih rendah dari penelitian sebelumnya. Hal tersebut berkaitan dengan peraturan lingkungan ketat yang mulai diberlakukan pada akhir 1990-an. Namun demikian, konsentrasi PAH dan pestisida lebih tinggi dari penelitian sebelumnya. Hal tersebut diduga kuat akibat dari peningkatan aktivitas dan lalu lintas maritim di daerah sekitar Pelabuhan Tanjung Priok, juga kemungkinan besar berasal dari pelabuhan lain yang berdekatan (Muara Baru, Muara Angke, dan pelabuhan Marina Ancol) serta akibat penggunaan besar-besaran senyawa pestisida kegiatan rumah tangga di wilayah Kota Jakarta. Daerah dan lokasi estuaria <10 km diidentifikasi dan diprediksi akan menghasilkan efek berbahaya karena konsentrasi Zn dan Hg di area tersebut melebihi Probable Effects Level (PEL) dari Pedoman Kualitas Sedimen (SQG). Respon pertumbuhan diatom laut Chaetoceros gracilis sangat bervariasi. Sebagian besar stasiun (24 dari 31 stasiun) menunjukkan efek penghambatan pada pertumbuhan diatom, berkisar antara 1,75-35,33% (17,75 ± 9,59%) relatif terhadap kontrol, dengan nilai penghambatan tertinggi di muara Sungai Cengkareng (M2). Hubungan antara konsentrasi kontaminan dan respon penghambatan tidak dapat dijelaskan dengan lebih pasti namun terdapat asumsi konsentrasi rendah dari beberapa logam berat diduga memberikan efek buruk pada pertumbuhan diatom.Kata Kunci: sedimen, toksisitas, diatom laut, Chaetoceros gracilis, Teluk Jakarta

Diatoms in the Early Valdai (Weichselian) sediments in Lake Ladoga basin

2019 ◽  
pp. 225-228
Author(s):  
Anna V. Ludikova
Keyword(s):  
Species Diversity ◽  
High Energy ◽  
Lake Ladoga ◽  
Diatom Assemblages ◽  
Marine Diatoms ◽  
Selective Preservation

The pioneer diatom study of the Early Weichselian (Valdai) sediments in Lake Ladoga basin was performed. The specifics of the diatom assemblages (co-occurrence of ecologically incompatible taxa, poor species diversity, low diatom concentration and selective preservation) suggest that during the Early Weichselian time intense erosion of previously deposited marine Eemian (Mikulino) sediments prevailed, which resulted in re-deposition of marine diatoms. The sedimentation took place in high-energy environments unfavorable for diatom accumulation and preservation.

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