Exploração de vias de biossíntese e sinalização de fitohormonas em microalgas para aumentar a sua produtividade de biomassa e produtos de alta valor acrescentado

In recent years, the European microalgae industry has expanded and gained considerable interest as an emerging sector of the Blue Bioeconomy [7–9]. However, despite the recent advances in industrial microalgae production technologies, several abiotic and biotic stress factors still negatively impact microalgae productivity, leading to lower economic viability which is one of the current shortcomings of the sector. Moreover, not much is understood about the molecular factors regulating the production of valuable bioactive compounds by microalgae, hindering their exploration and future valorization of microalgae industrial processes. Novel biological insights are needed to provide solutions to increase microalgae productivity and stress resistance, and, thus, potentiate the EU microalgae sector [7,9]. Enhancing the productivity, and resilience of microalgae could be achieved by exploring methods to regulate or influence the biosynthesis and signaling pathways of microalgae phytohormones, a group of chemical messengers that tightly regulate a wide range of aspects of microalgae physiology, including cell division, photosynthetic efficiency, nutrient uptake, stress tolerance as well as the regulation of interactions with other microorganisms. Amongst phytohormones, ethylene (ET) and its direct precursor, 1-aminocyclopropane-1-carboxylate (ACC), and auxins such as indole-3-acetate (IAA), are known to strongly impact several developmental processes of multiple algae species [12,14,15,28,29], indicating that the manipulation/modulation of these phytohormones concentrations in microalgae can be useful targets for the development of improved strains and novel cultivation strategies aiming at increased microalgae productivity. In the EpicAlgaeBoost project proposal, we aim to explore ET/ACC and IAA biosynthesis and signaling pathways in industrially relevant microalgae such as Chlorella and Phaeodactylum, to boost their productivity (biomass and high-value compounds) and stress resistance. To accomplish this the team proposes an ambitious and multidisciplinary research plan, with three main scientific objectives: 1) engineer microalgae strains presenting modified ET/ACC and IAA biosynthesis, transport and signaling profiles linked to increased productivity and stress resistance using cutting-edge CRISPR-Cas genome editing tools and other omics toolboxes [30–32]; 2) explore and develop new cultivation strategies to increase microalgae biomass and value-added products based on the modulation of microalgae ET/ACC and IAA levels using chemical signaling mechanisms, 3) design new co-cultivation schemes based on selected ACC and IAA-modulating bacteria to promote microalgae growth and stress resistance. Novel scientific knowledge regarding the molecular and biochemical aspects of microalgae physiology, bioactive compound biosynthesis, and its regulation by phytohormones will be obtained. Moreover, the innovative cultivation strategies developed during the project are expected to potentiate microalgae productivity by 10-20%, bringing solutions with clear real-world potential applications to the European microalgae industry. The project also encompasses a comprehensive strategy for disseminating, demonstrating, and valuing the results to maximize the project’s impact on target groups (scientific community, industry stakeholders, and general audience), contributing to the advancement of the field and the EU algae sector.