Yin Li

Professor, Institute of Microbiology, Chinese Academy of Sciences

Summary of my work

My current research interest is focused on developing microbial cell factories active in converting carbon dioxide into a range of chemicals, fuels, and other materials. We have discovered and developed the strongest cyanobacterial promoter to date that enables up to 15% soluble heterologous protein to be produced in cyanobacteria, a level comparable to protein production in dedicated host microbes. We have introduced a synthetic acetone pathway into cyanobacteria, which opens the gate of using carbon dioxide as raw materials to produce ketone compounds.

We also made significant a progress in increasing the efficiency of carbon fixation. Photosynthetic fixation of carbon dioxide is the ultimate source of organic carbon on earth and thus is essential for crop production and carbon sequestration. Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyzes the first step of photosynthetic fixation of carbon dioxide. However, the carboxylation efficiency and the selectivity between carbon dioxide and oxygen of Rubisco are very low. We developed an efficient selection system, with which Rubisco mutants with 85% increased activity towards carbon dioxide were obtained - the best improvement for Rubisco activity achieved to date.

While at Cornell, my objective is to integrate the expertise and knowledge from Cornell on biofuel, biorefinery, bioprocess engineering, and industrial ecosystems with my research on photosynthetic biotechnology. This integration will bring new understandings, new tools, and new strategies that would significantly increase our knowledge on the biological conversion of carbon dioxide into chemicals desired.

Impacts in China

The energy crises and global warming call for sustainable, renewable, carbon-neutral alternatives (for instance bio-based chemicals and fuels) to gradually reduce our dependency on fossil resources. Presently, most bio-based chemicals and fuels are produced from agricultural crops or residues, which leads to concerns about food security and land shortage. In many developing countries including China, a large population shares relatively limited water, land, mineral and oil resources, but the emissions of greenhouse gases including carbon dioxide and the discharge of wastes are continuously increasing. Biological fixation and conversion of carbon dioxide into useful product is therefore of great scientific significance and potential practical importance. In this regards, the knowledge generated from my study at Cornell will have fundamental scientific merits and potential strong social impacts to China.