High-throughput techniques for understanding and industrializing fast-growing cyanobacteria

Cyanobacteria are model organisms for photosynthesis. They also have several biotechnology applications, such as sustainable protein and producers of chemicals. To date, industrial use is not economically viable.

However, the discovery of fast-growing, high-cell density strains such as Synechococcus PCC 11901 has shown that photosynthesis can operate faster than previously known.

We will elucidate mechansims behind this exceptional growth, findings that could accelerate its industrial use and inform crop science.

In a first part, a 4-year Ph.D. project, we will create genome-wide mutant libraries, where all genes are targeted for both repression and overexpression. Libraries will be cultivated in competitive growth in multiple conditions, and tracked via deep sequencing.

Outcomes include: a correlation of gene dose and cell growth for every gene, estimated flux control coeffficents in the Calvin cycle, and tradeoffs between growth speed and robustness. We will also screen the libraries for production of 3-hydroxybutryate, a biofuel precursor, using a novel platform.

In the second part, a 2-year postdoc will develop cell lysate assays as a tool for rapid optimization of synthetic metabolic pathways. In a first test, we will combinatorially screen enzyme ratios in the 5-step n-butanol pathway.

This project advances our understanding of fast photosynthesis (basic science), and will provide novel metabolic engineering strategies for cyanobacteria-produced fuels (applied science).