Heterozygous expression of insulin in Nannochloropsis

As of 2024, more than 90% of the global insulin supply is controlled by just three conglomerates. Patents and license agreements restrict the use of optimised expression vehicles such as E. coli, S. cerevisiae, or P. pastoris, by the small/medium scale enterprises (SMEs) who can decentralise insulin production and cater to local demands. Project HERO (HEterozygous expRession of insulin in NannOchloropsis) aims to develop a novel microalgal platform technology for sustainable and accessible transgenic insulin production using Nannochloropsis oceanica as the model organism. The project builds upon the applicant’s recent discovery that N. oceanica (an ω-3 lipid rich, phototrophic microalgae) secretes the protease serine decarboxylase (SDC) during nitrogen scarcity. In this project, the transcriptome and secretome of N. oceanica under varying nitrogen concentrations will be comprehensively profiled after which, state-of-the-art plasmid designing techniques and CRISPR transformation pipelines will be used to insert the genes for insulin in the microalgal genome and express it as a fusion-protein with SDC. Controlled auto-proteolysis of the fusion-protein will greatly simplify and decrease steps in downstream insulin processing, thereby reducing overall water consumption and production costs. Moreover under nitrogen starvation, N. oceanica naturally over-produces high-value ω-3 lipids through biochemical pathways independent to SDC secretion. This offers the biorefinery benefits of multi-stream production (insulin and lipids) to further offset production costs. Finally, the engineered N. oceanica strain will be cultivated at pilot scale (100 L) to assess insulin yields, perform lifecycle analysis and establish its commercialisation potential.By empowering local SMEs to economically and sustainably produce insulin and supply them to their local communities, Project HERO intends to help democratise access to this life-saving drug to people across all financial tiers.