Increasing metabolic engineering efficiency using a conditionally quiescent fission yeast mutant

The proposed project aims to solve a major challenge in metabolic engineering.

In microbial metabolic engineering platforms, consumed nutrients are primarily invested into population growth instead of the production of chemicals of interest.

Our team is studying a temperature-sensitive mutant of fission yeast (Schizosaccharomyces pombe), which grows normally at 26C, but enters quiescence at 36C, while at the same time maintaining its metabolic activity.

Such an engineering platform could represent the holy grail of the metabolic engineering field - a chassis strain that can stop growing but keeps producing metabolites. Application of such pseudo-quiescent strain would be useful to both industrial and academic players.

To develop this mutant into a new metabolic engineering chassis, I will first design a molecular cloning toolkit to perform metabolic engineering in S. pombe, which will enable construction and expression of complex biosynthetic pathways. Second, I will characterize the phenotype of the pseudoquiescent S. pombe mutant using a multi-omics approach.

I will generate knowledge about mRNA, protein, metabolite and flux dynamics to delineate a genome-scale metabolic model of the chassis under pseudo-quiescence.

Then, I will assess the ability of the S. pombe mutant to overproduce 3 different high-value compounds (kavain via phenylalanine, theophylline via purine and artemisinin precursor via mevalonate).

Finally, I intend to reproduce the pseudo-quiescent mutant phenotype in other commonly used yeast species (Saccharomyces cerevisiae and Yarrowia lipolytica).

In the short term, this research will deliver a new type of a metabolic engineering chassis for the production of complex chemicals to the metabolic engineering community.

In the long term, it will contribute to the development of metabolic engineering as a competitive alternative of total synthesis of chemicals, leading to greener and renewable chemical industry.