Production and monitoring of biomass and fucoxanthin with brown microalgae under outdoor conditions

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Fucoxanthin and docosahexaenoic acid production by cold-adapted Tisochrysis lutea

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Production and monitoring of biomass and fucoxanthin with brown microalgae under outdoor conditions

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Process optimization of fucoxanthin production with Tisochrysis lutea

To optimize fucoxanthin production in Tisochrysis lutea, the effect of different process parameters on fucoxanthin productivity (Pfx) were evaluated using batch and continuous experiments. In batch, the highest Pfx was found at 30 °C and 300 μmol m−2 s−1, allowing to design continuous experiments to optimize the dilution rate. The highest ever reported Pfx (9.43–9.81 mg L−1 d−1) was achieved at dilution rates of 0.53 and 0.80 d−1. Irradiance was varied (50–500 μmol m−2 s−1) to result in a range of absorbed light between 2.23 and 25.80 mol m−2 d−1 at a fixed dilution rate (0.53 d−1). These experiments validated the hypothesis that light absorbed can be used to predict fucoxanthin content, resulting in 2.23 mol m−2 d−1 triggering the highest fucoxanthin content (16.39 mg/g). The highest Pfx was found with 18.38 mol m−2 d−1. These results can be used to achieve high Pfx or fucoxanthin content during cultivation of Tisochrysis lutea.publishedVersionPaid Open Acces

Improved fucoxanthin and docosahexaenoic acid productivities of a sorted self-settling Tisochrysis lutea phenotype at pilot scale

This work aimed to select a Tisochrysis lutea phenotype with higher biomass and fucoxanthin productivities using fluorescence-activated cell sorting (FACS). A novel phenotype was obtained after 2 rounds of selection, based on high-fucoxanthin fluorescence. The resulting phenotype forms cell aggregates, has no flagella, and was stable after 15 months. Optimal temperature (30 °C) and light (300 µmol m−2 s−1) were obtained at laboratory scale, identical to the original strain. The biomass productivity was higher than the original strain: 1.9× at laboratory scale (0.4 L), and 4.5× under outdoor conditions (190 L). Moreover, compared to the original strain, the productivity of fucoxanthin increased 1.6–3.1× and docosahexaenoic acid 1.5–1.9×. These are the highest ever reported outdoor productivities, obtained with a robust new phenotype from a T. lutea monoculture isolated with FACS without genetic manipulation. The resulting phenotype shows high potential for industrial production.publishedVersio

Production and high throughput quantification of fucoxanthin and lipids in Tisochrysis lutea using single-cell fluorescence

This work aimed to investigate the accumulation of fucoxanthin and lipids in Tisochrysis lutea during growth (N+) and nitrogen-starvation (N−) and to correlate these products with single-cell emissions using fluorescence-activated cell sorting (FACS). Fucoxanthin content decreased 52.94% from N+ to N− in batch cultivation; increased 40.53% as dilution rate changed from 0.16 to 0.55 d−1 in continuous cultivation. Total lipids (N−) were constant (~250 mg/g), but the abundance of neutral lipids increased from 4.87% to 40.63%. Nile red can stain both polar and neutral lipids. However, in vivo, this differentiation is limited due to an overlapping of signals between 600 and 660 nm, caused by neutral lipids concentrations above 3.48% (W/W). Chlorophyll autofluorescence (720 nm) was reported for the first time as a proxy for fucoxanthin (R2 = 0.90) and polar lipids (R2 = 0.98). FACS can be used in high throughput quantification of pigments and lipids and to select and sort cells with high-fucoxanthin/lipids.publishedVersionPaid Open Acces

Light spectra as triggers for sorting improved strains of Tisochrysis lutea

It is known that microalgae respond to different light colors, but not at single-cell level. This work aimed to assess if different light colors could be used as triggers to sort over-producing cells. Six light spectra were used: red + green + blue (RGBL), blue (BL), red (RL), green (GL), blue + red (BRL) and blue + green (BGL). Fluorescence-activated cell sorting method was used to analyse single-cell fluorescence and sort cells. BGL and RGBL lead to the highest fucoxanthin production, while RL showed the lowest. Therefore, it was hypothesized that hyper-producing cells can be isolated efficiently under the adverse condition (RL). After exposure to all light colors for 14 days, the top 1% fucoxanthin producing cells were sorted. A sorted strain from RL showed higher (16–19%) growth rate and fucoxanthin productivity. This study showed how light spectra affected single-cell fucoxanthin and lipid contents and productivities. Also, it supplied an approach to sort for high-fucoxanthin or high-lipid cells.publishedVersionPaid Open Acces

Improved fucoxanthin and docosahexaenoic acid productivities of a sorted self-settling Tisochrysis lutea phenotype at pilot scale

This work aimed to select a Tisochrysis lutea phenotype with higher biomass and fucoxanthin productivities using fluorescence-activated cell sorting (FACS). A novel phenotype was obtained after 2 rounds of selection, based on high-fucoxanthin fluorescence. The resulting phenotype forms cell aggregates, has no flagella, and was stable after 15 months. Optimal temperature (30 °C) and light (300 µmol m−2 s−1) were obtained at laboratory scale, identical to the original strain. The biomass productivity was higher than the original strain: 1.9× at laboratory scale (0.4 L), and 4.5× under outdoor conditions (190 L). Moreover, compared to the original strain, the productivity of fucoxanthin increased 1.6–3.1× and docosahexaenoic acid 1.5–1.9×. These are the highest ever reported outdoor productivities, obtained with a robust new phenotype from a T. lutea monoculture isolated with FACS without genetic manipulation. The resulting phenotype shows high potential for industrial production.publishedVersio

Perspectives of fluorescence spectroscopy for online monitoring in microalgae industry

OSR‐2016‐CPF‐2907‐05 UIDB/50006/2020 UIDP/50006/2020 SFRH/BD/108894/2015Microalgae industrial production is viewed as a solution for alternative production of nutraceuticals, cosmetics, biofertilizers, and biopolymers. Throughout the years, several technological advances have been implemented, increasing the competitiveness of microalgae industry. However, online monitoring and real-time process control of a microalgae production factory still require further development. In this mini-review, non-destructive tools for online monitoring of cellular agriculture applications are described. Still, the focus is on the use of fluorescence spectroscopy to monitor several parameters (cell concentration, pigments, and lipids) in the microalgae industry. The development presented makes it the most promising solution for monitoring up-and downstream processes, different biological parameters simultaneously, and different microalgae species. The improvements needed for industrial application of this technology are also discussed.publishersversioninpres

Algae as food in Europe: an overview of species diversity and their application

ABSTRACT: Algae have been consumed for millennia in several parts of the world as food, food supplements, and additives, due to their unique organoleptic properties and nutritional and health benefits. Algae are sustainable sources of proteins, minerals, and fiber, with well-balanced essential amino acids, pigments, and fatty acids, among other relevant metabolites for human nutrition. This review covers the historical consumption of algae in Europe, developments in the current European market, challenges when introducing new species to the market, bottlenecks in production technology, consumer acceptance, and legislation. The current algae species that are consumed and commercialized in Europe were investigated, according to their status under the European Union (EU) Novel Food legislation, along with the market perspectives in terms of the current research and development initiatives, while evaluating the interest and potential in the European market. The regular consumption of more than 150 algae species was identified, of which only 20% are approved under the EU Novel Food legislation, which demonstrates that the current legislation is not broad enough and requires an urgent update. Finally, the potential of the European algae market growth was indicated by the analysis of the trends in research, technological advances, and market initiatives to promote algae commercialization and consumption.info:eu-repo/semantics/publishedVersio