DOI: 10.5061/dryad.v6wwpzh4j
title: Potential for the production of carotenoids of interest in the polar diatom Fragilariopsis cylindrus

description: Carotenoid xanthophyll pigments are receiving growing interest in various
 industrial fields due to their broad and diverse bioactive and health
 beneficial properties. Fucoxanthin (Fx) and the inter-convertible couple
 diadinoxanthin–diatoxanthin (Ddx+Dtx) are acknowledged as some of the most
 promising xanthophylls; they are mainly synthesized by diatoms
 (Bacillariophyta). While temperate strains of diatoms have been widely
 investigated, recent years showed a growing interest in using polar
 strains, which are better adapted to the natural growth conditions of
 Nordic countries. The aim of the present study was to explore the
 potential of the polar diatom Fragilariopsis cylindrus in producing Fx and
 Ddx+Dtx by means of the manipulation of the growth light climate
 (daylength, light intensity and spectrum) and temperature. We further
 compared its best capacity to the strongest xanthophyll production levels
 reported for temperate counterparts grown under comparable conditions. In
 our hands, the best growing conditions for F. cylindrus were a
 semi-continuous growth at 7 °C and under a 12 h light:12 h dark
 photoperiod of monochromatic blue light (445 nm) at a PUR of 11.7 μmol
 photons m−2 s−1. This allowed the highest Fx productivity of 43.80 µg L−1
 day−1 and the highest Fx yield of 7.53 µg Wh−1, more than two times higher
 than under ‘white’ light. For Ddx+Dtx, the highest productivity (4.55 µg
 L−1 day−1) was reached under the same conditions of ‘white light’ and at 0
 °C. Our results show that F. cylindrus, and potentially other polar diatom
 strains, are very well suited for Fx and Ddx+Dtx production under
 conditions of low temperature and light intensity, reaching similar
 productivity levels as model temperate counterparts such as Phaeodactylum
 tricornutum. The present work supports the possibility of using polar
 diatoms as an efficient cold and low light-adapted bioresource for
 xanthophyll pigments, especially usable in Nordic countries.
description: # Potential for the Production of Carotenoids of Interest in the Polar
 Diatom Fragilariopsis cylindrus
 [https://doi.org/10.5061/dryad.v6wwpzh4j](https://doi.org/10.5061/dryad.v6wwpzh4j) The polar diatoms Fragilariopsis cylindrus (CCMP3323) cultures were grown in sterilize natural sea water enriches with f or f/2 medium , at 0 °C and 7 °C under different photoperiods (12h light : 12h dark, 18h light : 6h dark, and continuous light), light intensities (5.8, 11.7, 23.4 µmol photons m−2 s−1 of photosynthetically usable radiation)  and 3 light spectra (artificial ‘white’ light spectrum, monochromatique blue 445nm and red light 660nm). Importantly, and contrary to many studies conducted in the field, cultures were kept optically thin, in order to control the light field inside the reactors, by a daily dilution with fresh f/2 medium (semi-continuous cultivation) to maintain a cell concentration of 1 millions cells mL−1. The so-called ‘white’ light spectrum used here was built to be as close as possible to the spectrum observed at the horizon of bottom sea ice. The monochromatic blue and red lights had a full width half maximum of 20 nm centred at 450 and 660 nm, respectively. The emission spectrum of the light source as well as the spectrum at the bottom sea ice, and the typical absorption spectrum of Fragilariopsis cylinders are available in the dataset.  Cultures were acclimated under each set of condition for at least 3 weeks before sampling  for performing cell counts, analysing elemental and pigment composition as well as photosynthetic performance (i.e., rapid light curves, Water-PAM). The dataset contains the growth rate, pigments content, elemental composition, and photosynthetic performance, of Fragilariopsis cylindrus in all the conditions we tested for each culture (3 biological replicate). For more details on methods and experimental plan, see the Material and Methods section of the associated paper. ## Description of the data and file structure The dataset contain 5 sheets, the first associated the column name used and the parameter proper naming from the original paper as well as their units and definition. This table is also available below.   In the 2nd 3rd and 4th sheet, there is the data of the various experiment where each raw is a parameter and each raw a replicate.  In the 5th sheet there is the various light spectrums and F. cylindrus absorption spectrum normalized in column and in raw the value for each wavelength from 400 to 700nm.  | Column Name | Corresponding Parameter | Unit / Factor | Definition | | :---------------- | :------------------------------------------- | :----------------------------------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Light\_spectrum | Spectrum | WIT=‘White’; RB= 445nm; RED = 660nm | | | PAR | PAR | μmol photons m−2 s−1 | photosynthetically available radiation | | PUR | PUR | μmol photons m−2 s−1 | photosynthetically usable radiation | | Day\_Lenght | Photoperiod | hour | Light hour for a 24h photoperiod | | Temp\_C | Temperature | Celcius | | | Culturing\_medium | Culturing medium | F2 = f/2 F=f | | | Culture\_name | Unique name ID for each biological replicat  | | | | P\_Wh | Power consumption | W h-1 | Daily energy consumption for a 2.7L bioreactor | | Fx\_dw | Fx cont. | mg g-1 | Fucoxanthin content per dry weight of algae cells | | DdDt\_dw | Ddx+Dtx cont. | mg g-1 | Diadinoxanthin+Diatoxanthin  content per dry weight of algae cells | | Fx\_Prod | Fx prod. | µg L-1 d-1 | Fucoxanthin productivity | | DdDt\_Prod | Ddx+Dtx cont. | mg g-1 | Diadinoxanthin+Diatoxanthin content | | GrowthRate | µ | d-1 | Growth rate  | | Chla\_Cell | Cellular Chl *a* | pg cell-1 | Intracellular Chlorophyll *a* content | | C\_Cell | Cellular C | pg cell-1 | Intracellular Carbon content | | Chla\_C  | Chl *a*/C | g g-1 | Chl *a* : Carbon ratio | | C\_N | C/N | g g-1 | Carbon :Nitrogen ratio | | Fv\_Fm | FV/FM | No units | Maximum photosynthetic efficiency of PSII;   | | alpha | a | μmol electrons m−2 s−1 per μmol photons m−2 s−1  | Light usage efficiency  | | rETRmax | rETRmax | μmol electrons m−2 s−1 | rETR-E curve asymptote | | ek | Ek  | μmol photons m−2 s−1 | Light saturation coefficient  | | Eopt | Eopt  | μmol photons m−2 s−1 | Light intensity for reaching rETRmax  | | NPQeff | NPQgE | rel. unit. | Non-photochemical quenching  | | NPQmax | NPQmax | rel. unit. | NPQ-E curve asymptote | | Ypsii | YPSII | rel. unit. | Quantum yield of photochemical energy conversion in PSII  | | Ynpq | YNPQ | rel. unit. | Quantum yield of regulated non-photochemical energy loss in PSII | | Yno | YNO | rel. unit. | Quantum yield of non-regulated non-photochemical energy loss in PSII | | Time | Time | Day | Time since the begining of the experiment  | | Cell | Cells | cells mL-1 | Algae cellular density | | Fx | Fucoxanthine | µg L-1 | Volumetric Fucoxanthine concentration | | Ddx | Diadinoxanthin | µg L-1 | Volumetric Diadinoxanthin concentration | | Dtx | Diatoxanthin | µg L-1 | Volumetric Diatoxanthin concentration | | wl\_nm | Wavelenght | nm | | | Under\_Ice | Under ice light spectrum | rel. unit. | Average of the under sea-ice solar spectrum measured from May 27 2015 to June 4 2015 at 1m under untouched snow coverage and sea ice in the West Baffin Bay (67.48°N 63.79°W) normalized to it's maximum intensity (481nm) . Data are available at: Green Edge project LEFE-CYBER repository ([http://www.obs-vlfr.fr/proof/php/GREENEDGE/greenedge.php](http://www.obs-vlfr.fr/proof/php/GREENEDGE/greenedge.php)). | | WIT | White light emission spectrum | rel. unit. | Emission spectrum of the LED array used to reproduced a Under Ice solar spectrum normalizet to it's maximum intensity (475nm) | | RB | Monochromatique blue light (445nm) spectrum | rel. unit. | Emission spectrum of the royal blue LED (LXML-PR01, 445 nm), normalizet to it's maximum intensity (445nm) | | RED | Monochromatique red light (660nm) spectrum | rel. unit. | Emission spectrum of the far red LED (LXM3-PD01, 660 nm), normalizet to it's maximum intensity (662nm) | | Abs\_Fcyl | Fragilariopsis cylindrus absorption spectrum | rel. unit. | Absorbtion spectrumn of Fragilariopsis cylindrus grown under 30µmol μmol photons m−2 s−1 ( PAR) of the 'white' liht at 0°C in f/2 media, normalised to it's maximum intensity (435nm). |