Selecting for a high lipid accumulating microalgae culture by dual growth limitation in a continuous bioreactor

Selecting for a high lipid accumulating microalgae culture by dual growth limitation in a continuous bioreactor

Policastro, G. (TU Delft BT/Environmental Biotechnology; Università degli Studi di Napoli Federico II)
Ebrahimi, S. (TU Delft BT/Environmental Biotechnology; Sahand University of Technology)
Weissbrodt, D.G. (TU Delft BT/Environmental Biotechnology; Norwegian University of Science and Technology (NTNU))
Fabbricino, Massimiliano (Università degli Studi di Napoli Federico II)
van Loosdrecht, Mark C.M. (TU Delft BT/Environmental Biotechnology)

2024

A dual-growth-limited continuous operated bioreactor (chemostat) was used to enhance lipid accumulation in an enrichment culture of microalgae. The light intensity and nitrogen concentration where both limiting factors resulting in high lipid accumulation in the mixed culture. Both conditions of light and nitrogen excess and deficiency were tested. Strategies to selectively enrich for a phototrophic lipid-storing community, based on the use of different nitrogen sources (ammonium vs. nitrate) and vitamin B supplementation in the growth medium, were evaluated. The dual limitation of both nitrogen and light enhanced the accumulation of storage compounds. Ammoniacal nitrogen was the preferred nitrogen source. Vitamin B supplementation led to a doubling of the lipid productivity. The availability of vitamins played a key role in selecting an efficient lipid-storing community, primarily consisting of Trebouxiophyceae (with an 82 % relative abundance among eukaryotic microorganisms). The obtained lipid volumetric productivity (387 mg L⁻¹ d⁻¹) was among the highest reported in literature for microalgae bioreactors. Lipid production by the microalgae enrichment surpassed the efficiencies reported for continuous microalgae pure cultures, highlighting the benefits of mixed-culture photo-biotechnologies for fuels and food ingredients in the circular economy.

Ammonium
Dual growth limitation
Lipid production
Mixed culture microalgae
Vitamin B

http://resolver.tudelft.nl/uuid:6231852e-42cc-469b-9e77-f9134726cf38

https://doi.org/10.1016/j.scitotenv.2023.169213

2024-06-12

0048-9697

Science of the Total Environment, 912

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

Institutional Repository

journal article

© 2024 G. Policastro, S. Ebrahimi, D.G. Weissbrodt, Massimiliano Fabbricino, Mark C.M. van Loosdrecht