Increased renewable production of aromatic chemicals by improving the management of oxidative stress and protein misfolding

Research Project, 2024 – 2026

In a biobased economy, microorganisms as yeast are a sustainable alternative to chemical synthesis of a wide variety of compounds. Plant dry matter unsuitable for food and feed, lignocellulosic biomass, is the most abundantly available raw material on earth. Yeast cell factories metabolizing lignocellulose to biochemicals, however, face both oxidative and acetic acid stress, that target several aspects of protein synthesis, folding and degradation (proteostasis). Our pilot study shows that tolerance to acetic acid is improved by altering the regulation of protein degradation. Here we will utilise the applicants’ expertises in oxidant proteostasis and cell factory engineering as well as cutting edge tools and knowledge to develop tolerant yeast cell factories. A library of strains with altered gene expression will be constructed using CRISPR interference/activation and adaptive laboratory evolution. The metabolic status of cells with improved lignocellulose tolerance will be monitored in high throughput using genetic biosensors for oxidants and acid, several already established. As a proof-of-concept we will focus on combining lignocellulose resistance with the production of violacein, a high-value compound suggested to inhibit the growth of tumor cells and pathogens. A thorough understanding of cellular regulation is needed for the development of cell factories for biochemical conversion of renewable carbon, here provided by the unique and broad expertise of the applicants.