Response of CO ₂ -starved diatom Phaeodactylum tricornutum to light intensity transition

Abstract

In this study, we investigated the responses of cells acclimated to 300 µmol m s photon flux density to an increase (1000 µmol m s) or decrease (30 µmol m s) in photon flux densities. The light shift occurred abruptly after 5 days of growth and the acclimation to new conditions was followed during the next 6 days at the physiological and molecular levels. The molecular data reflect a rearrangement of carbon metabolism towards the production of phosphoenolpyruvic acid (PEP) and/or pyruvate. These intermediates were used differently by the cell as a function of the photon flux density: under low light, photosynthesis was depressed while respiration was increased. Under high light, lipids and proteins accumulated. Of great interest, under high light, the genes coding for the synthesis of aromatic amino acids and phenolic compounds were upregulated suggesting that the shikimate pathway was activated.This article is part of the themed issue 'The peculiar carbon metabolism in diatoms'.

The lipid biochemistry of eukaryotic algae

“…Also in Chlamydomonas, extended (24h) dark periods cause TAG accumulation [430]. Prolonged darkness in Phaeodactylum tricornutum has also been studied in detail and information about nuclear transcriptional activity, pigment content and photosynthesis reported during darkness and following re-illumination [443].…”

Protective Action of Ostreococcus Tauri and Phaeodactylum Tricornutum Extracts towards Benzo[a]Pyrene-Induced Cytotoxicity in Endothelial Cells

“…The total pigment amount was determined spectroscopically using a double beam Lambda 25 UV/VIS spectrometer (PerkinElmer). The concentration of chlorophyll (Chl) a, Chl c and total carotenoids in the PT were calculated according to Heydarizadeh et al [103], whereas the Chl a, Chl b and total carotenoids in the OT were calculated according to Lichtenthaler et al [104].…”

Microalgae Water Bioremediation: Trends and Hot Topics

“…In this assay, a 94% flocculation activity, at a pH 11, was registered within the co-culture of the mentioned microorganisms [60]. Furthermore, there is evidence that some microalgae species, like Phaeodactylum tricornutum (Bacillariophyta), also present the ability to flocculate as a response to several abiotic factors, such as light, pH, temperature or carbon dioxide concentration [61,62].…”