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bioRxiv · 10.1101/2025.04.28.651004

Could microalgae serve as an alternative to replace unsustainable palm oil?

Abstract

Palm oil is the worlds most widely used vegetable oil with a significant impact on the environment. Microalgae produce a variety of fatty acids whose composition is influenced by growth conditions. We selected a set of ten algal strains that naturally produce oils similar in composition to palm oil, and we analyzed the effects of varying light intensity on their growth and fatty acid production and composition while maintaining temperatureThe optimum irradiance in terms of biomass accumulation was determined to be 400 {micro}mol photons m-2 s-1 for most of the microalgae, except for C. moewusii CCALA 242 and CCALA 243, where the optimum illuminance was determined to be 100 and 50 {micro}mol photons m-2 s-1, respectively. The growth of Scenedesmus and Desmodesmus strains improved with increasing light intensity and mostly reached the growth rates approximately twice as high as the C. moewusii strains at higher light intensities. In the presence of NaCl, the growth of C. moewusii CCALA 244 and D. subspicatus CCALA 467 was similar or better than under the non-stress conditions. In contrast, the growth of D. communis CCALA 463 was reduced and biomass productivity decreased. In C. moewusii CCALA 244, salinity improved total fatty acid production 5-fold and had a particular effect on the production of palmitic acid, stearic acid, oleic acid and linolenic acid. The lab-scale growth could be successfully recapitulated in large-scale photobioreactor, although the total fatty acid productivity was lower. Interestingly, D. communis CCALA 463 showed a 3.5-fold improvement in growth in the large-scale photobioreactor as well as improved total fatty acid productivity. Eight of the ten microalgal strains used were capable of heterotrophic growth. Although specific growth rates were higher in heterotrophy, biomass productivity and total fatty acid productivity were lower than in the case of high light intensities of the autotrophic treatment.

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BibTeXRIS

Sterbova, K. x., Bisova, K. x., Manoel, J. A. C., Masojidek, J. x.. 2025-04-28. Could microalgae serve as an alternative to replace unsustainable palm oil?. https://doi.org/10.1101/2025.04.28.651004

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