scholarly journals System Responses to Equal Doses of Photosynthetically Usable Radiation of Blue, Green, and Red Light in the Marine Diatom Phaeodactylum tricornutum

PLoS ONE ◽  
2014 ◽  
Vol 9 (12) ◽  
pp. e114211 ◽  
Author(s):  
Kristin Collier Valle ◽  
Marianne Nymark ◽  
Inga Aamot ◽  
Kasper Hancke ◽  
Per Winge ◽  
...  
Keyword(s):  
Phaeodactylum Tricornutum ◽  
Red Light ◽  
Marine Diatom

scholarly journals Combined artificial high-silicate medium and LED illumination promote carotenoid accumulation in the marine diatom Phaeodactylum tricornutum

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Zhiqian Yi ◽  
Yixi Su ◽  
Paulina Cherek ◽  
David R. Nelson ◽  
Jianping Lin ◽  
...  
Keyword(s):  
Light Intensity ◽  
Phaeodactylum Tricornutum ◽  
Red Light ◽  
Monochromatic Light ◽  
Biomass Productivity ◽  
Marine Diatom ◽  
Light Illumination ◽  
Scale Production ◽  
Red Led ◽  
High Silicate

Abstract Background Diatoms, which can accumulate large amounts of carotenoids, are a major group of microalgae and the dominant primary producer in marine environments. Phaeodactylum tricornutum, a model diatom species, acquires little silicon for its growth although silicon is known to contribute to gene regulation and play an important role in diatom intracellular metabolism. In this study, we explored the effects of artificial high-silicate medium (i.e. 3.0 mM sodium metasilicate) and LED illumination conditions on the growth rate and pigment accumulation in P. tricornutum, which is the only known species so far that can grow without silicate. It’s well known that light-emitting diodes (LEDs) as novel illuminants are emerging to be superior monochromatic light sources for algal cultivation with defined and efficient red and blue lights. Results Firstly, we cultivated P. tricornutum in a synthetic medium supplemented with either 0.3 mM or 3.0 mM silicate. The morphology and size of diatom cells were examined: the proportion of the oval and triradiate cells decreased while the fusiform cells increased with more silicate addition in high-silicate medium; the average length of fusiform cells also slightly changed from 14.33 µm in 0.3 mM silicate medium to 12.20 µm in 3.0 mM silicate medium. Then we cultivated P. tricornutum under various intensities of red light in combination with the two different levels of silicate in the medium. Higher biomass productivity also achieved in 3.0 mM silicate medium than in 0.3 mM silicate medium under red LED light irradiation at 128 μmol/m2/s or higher light intensity. Increasing silicate reversed the down-regulation of fucoxanthin and chlorophyll a under high red-light illumination (i.e. 255 μmol/m2/s). When doubling the light intensity, fucoxanthin content decreased under red light but increased under combined red and blue (50:50) lights while chlorophyll a content reduced under both conditions. Fucoxanthin accumulation and biomass productivity increased with enhanced red and blue (50:50) lights. Conclusion High-silicate medium and blue light increased biomass and fucoxanthin production in P. tricornutum under high light conditions and this strategy may be beneficial for large-scale production of fucoxanthin in diatoms.

scholarly journals Chemical Mutagenesis and Fluorescence-Based High-Throughput Screening for Enhanced Accumulation of Carotenoids in a Model Marine Diatom Phaeodactylum tricornutum

Marine Drugs ◽  
2018 ◽  
Vol 16 (8) ◽  
pp. 272 ◽  
Author(s):  
Zhiqian Yi ◽  
Yixi Su ◽  
Maonian Xu ◽  
Andreas Bergmann ◽  
Saevar Ingthorsson ◽  
...  
Keyword(s):  
High Throughput ◽  
Metabolic Pathways ◽  
Phaeodactylum Tricornutum ◽  
Mass Spectrometry Data ◽  
Marine Diatom ◽  
Chemical Mutagenesis ◽  
Carotenoid Content ◽  
Enzymatic Reactions ◽  
Wild Type ◽  
A Genome

Diatoms are a major group of unicellular algae that are rich in lipids and carotenoids. However, sustained research efforts are needed to improve the strain performance for high product yields towards commercialization. In this study, we generated a number of mutants of the model diatom Phaeodactylum tricornutum, a cosmopolitan species that has also been found in Nordic region, using the chemical mutagens ethyl methanesulfonate (EMS) and N-methyl-N′-nitro-N-nitrosoguanidine (NTG). We found that both chlorophyll a and neutral lipids had a significant correlation with carotenoid content and these correlations were better during exponential growth than in the stationary growth phase. Then, we studied P. tricornutum common metabolic pathways and analyzed correlated enzymatic reactions between fucoxanthin synthesis and pigmentation or lipid metabolism through a genome-scale metabolic model. The integration of the computational results with liquid chromatography-mass spectrometry data revealed key compounds underlying the correlative metabolic pathways. Approximately 1000 strains were screened using fluorescence-based high-throughput method and five mutants selected had 33% or higher total carotenoids than the wild type, in which four strains remained stable in the long term and the top mutant exhibited an increase of 69.3% in fucoxanthin content compared to the wild type. The platform described in this study may be applied to the screening of other high performing diatom strains for industrial applications.

Structural basis for blue-green light harvesting and energy dissipation in diatoms

Science ◽  
2019 ◽  
Vol 363 (6427) ◽  
pp. eaav0365 ◽  
Author(s):  
Wenda Wang ◽  
Long-Jiang Yu ◽  
Caizhe Xu ◽  
Takashi Tomizaki ◽  
Songhao Zhao ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Phaeodactylum Tricornutum ◽  
Light Harvesting ◽  
Green Light ◽  
Marine Diatom ◽  
Structural Basis ◽  
Aquatic Environments ◽  
Efficient Energy Transfer ◽  
Chl A ◽  
Photosynthetic Organisms

Diatoms are abundant photosynthetic organisms in aquatic environments and contribute 40% of its primary productivity. An important factor that contributes to the success of diatoms is their fucoxanthin chlorophyll a/c-binding proteins (FCPs), which have exceptional light-harvesting and photoprotection capabilities. Here, we report the crystal structure of an FCP from the marine diatom Phaeodactylum tricornutum, which reveals the binding of seven chlorophylls (Chls) a, two Chls c, seven fucoxanthins (Fxs), and probably one diadinoxanthin within the protein scaffold. Efficient energy transfer pathways can be found between Chl a and c, and each Fx is surrounded by Chls, enabling the energy transfer and quenching via Fx highly efficient. The structure provides a basis for elucidating the mechanisms of blue-green light harvesting, energy transfer, and dissipation in diatoms.

The roles of silicon in combating cadmium challenge in the Marine diatom Phaeodactylum tricornutum

2020 ◽  
Vol 389 ◽  
pp. 121903 ◽  
Author(s):  
Jie Ma ◽  
Beibei Zhou ◽  
Qiaoguo Tan ◽  
Li Zhang ◽  
Ke Pan
Keyword(s):  
Phaeodactylum Tricornutum ◽  
Marine Diatom
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