Oral Presentation 18th International Congress on Photobiology 2024

Engineering solar lipid production in oleaginous microalgae: a focus on the prospects and challenges on the path to optimization and industrialization.   (#196)

SARAH D'ADAMO 1 , Rene Wijffels 1 , Maria Barbosa 1
  1. WAGENINGEN UNIVERSITY AND RESEARCH, WAGENINGEN, THE NETHERLANDS, Netherlands

Over the past seven decades, microalgae have garnered attention as promising candidates for industrial exploitation in food and biofuels due to their high productivity, versatility in growing in fresh and seawater, and independence from fertile land1.  Harnessing their potential for producing proteins, hydrocarbons, and fatty acids holds promising prospects for various industries. However, to ensure economic viability, optimization in solar energy conversion, carbon capture, and metabolic flux partitioning is imperative2-3. Our analyses showed that solar to lipid conversion is still one of the major causes of the high costs of bulk lipid production4-5. So, how do we optimize this process? Here we report some considerations and some strategies that we perform, aimed at increasing the lipid productivities, by taking advantage of the natural genetic variability, by inducing mutations in a parental population, by targeted genetic engineering5,6. Our recent research focuses on genetically domesticating robust, oleaginous marine microalgae, particularly Nannochloropsis oceanica, known for its high triacylglycerides (TAGs) and omega-3 eicosapentaenoic acid (EPA) content. Strategies such as genetic engineering, induced mutations, and leveraging natural genetic variability are being employed to enhance lipid productivities3,7. This talk provides insights on the developed cutting-edge tools like CRISPR-Cas systems for precise gene editing and the exceptional high-gene expression system based on RNA polymerase I activity8-10. Additionally, we will discuss successful applications of high-throughput screening techniques to identify and select new mutant lines with increased lipid phenotype11-14. Moreover, we discuss the targeted genetic engineering efforts to tailor the lipid composition of N. oceanica for specific applications, such as replacing tropical oils and incorporating novel lipid classes like medium-chain fatty acids15. Overall, this forward-thinking approach underscores the significant role microalgae could play in sustainable industrial applications. are innovative strategies that could significantly impact various industries.

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  2. Remmers IM, D’Adamo S*, Martens DE, et al. Orchestration of transcriptome, proteome and metabolome in the diatom Phaeodactylum tricornutum during nitrogen limitation. Algal Res. 2018;35(July):33-49. doi:10.1016/j.algal.2018.08.012
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  4. Barbosa MJ, Janssen M, Sudfeld C, D’Adamo S and Wijffels RH. Hypes, hopes, and the way forward for microalgal biotechnology. Trends in Biotechnology, 2023https://doi.org/10.1016/j.tibtech.2022.12.017
  5. Remmers IM, Wijffels RH, Barbosa MJ, Lamers PP. Can We Approach Theoretical Lipid Yields in Microalgae ? Trends Biotechnol. 2017;36(3):265-276. doi:10.1016/j.tibtech.2017.10.020
  6. Remmers IM, Wijffels RH, Barbosa MJ, Lamers PP. Can We Approach Theoretical Lipid Yields in Microalgae ? Trends Biotechnol. 2017;36(3):265-276. doi:10.1016/j.tibtech.2017.10.020
  7. Ruiz J, Olivieri G, Vree J de, et al. Towards industrial products from microalgae. 2016;9(10):3036-3043. doi:10.1039/C6EE01493C
  8. Muñoz, Camilo F; Südfeld, Christian; Naduthodi, Mihris IS; Weusthuis, Ruud A; Barbosa, Maria J; Wijffels, René H; D’Adamo, Sarah; Genetic engineering of microalgae for enhanced lipid production, Biotechnology advances, 52, 107836, 2021, Elsevier.
  9. Naduthodi MiS, Mohanraju P, Südfeld C, D'Adamo S, Barbosa MJ, J van der Oost. CRISPR – Cas ribonucleoprotein mediated homology ‑ directed repair for efficient targeted genome editing in microalgae Nannochloropsis oceanica IMET1. Biotechnol Biofuels 2019; 1–11. https://doi.org/10.1186/s13068-019-1401-3
  10. Naduthodi MIS, Südfeld C, Avitzigiannis EK, D'Adamo S, Barbosa MJ, J van der Oost Comprehensive Genome Engineering Toolbox for Microalgae Nannochloropsis oceanica Based on CRISPR-Cas Systems. ACS Synth Biol. 2021;10(12):3369-3378. doi:10.1021/acssynbio.1c00329
  11. Südfeld C, Pozo-Rodríguez A, Manjavacas Díez SA, Wijffels RH, Barbosa MJ, D’Adamo S. The nucleolus as a genomic safe harbor for strong gene expression in Nannochloropsis oceanica. Plant cell, Volume 15, Issue 2, 2022, Pages 340-353 https://doi.org/10.1016/j.molp.2021.11.003
  12. Optimization of high-throughput lipid screening of the microalga Nannochloropsis oceanica using BODIPY 505 / 515. Volume 53, March 2021, 102138, https://doi.org/10.1016/j.algal.2020.102138
  13. Südfeld C, Hubáček M, Figueiredo D, Naduthodi MIS, van der Oost J, Wijffels RH, Barbosa MJ, D'Adamo S. High-throughput insertional mutagenesis reveals novel targets for enhancing lipid accumulation in Nannochloropsis oceanica. Metab Eng. 2021;66(May):239–58 https://doi.org/10.1016/j.ymben.2021.04.012
  14. Südfeld C, Kiyani A, Wefelmeier K, Wijffels RH, Barbosa MJ, D'Adamo S. Expression of glycerol-3- phosphate acyltransferase increases non-polar lipid accumulation in Nannochloropsis oceanica. Microbial Cell Factories volume 22, Article number: 12 (2023) https://doi.org/10.1186/ s12934-022-01987-y
  15. Südfeld C, Kiyani A, Buckens H, Hubáček M, Wijffels RH, Barbosa MJ, D'Adamo S. Accumulation of medium chain fatty acids in Nannochloropsis oceanica by heterologous expression of Cuphea palustris thioesterase FatB1 Algal Research Volume 64, May 2022, 102665, https://doi.org/10.1016/j.algal.2022.102665