Research

Our research focuses on engineering microbial cell-based systems to perform complex tasks and to produce renewable fuels, chemicals, and advanced materials.

 

Dynamic Regulatory Systems: (synthetic biology, metabolic engineering)

Nature uses a suite of delicate regulatory systems to control both gene expression and pathway flux in response to environmental signals. When engineering microbial cells to produce fuels, chemicals, and materials, it is important to rewire the natural regulatory network, which was evolved for cell growth and replication, but not to over-produce any target compound. We are interested in developing tools to dissect the complex regulatory network of natural systems and to design synthetic regulatory systems that allow cell to control engineered pathways dynamically (Fig left). In addition, non-genetic, cell-to-cell variations in protein and metabolite concentrations cause large heterogeneity in single cell biosynthetic performance and dramatically affect ensemble product yields and titers (Fig right). We are interested in understanding the origin of metabolic noise and developing tools to regulate metabolic variation.

Advanced Biofuels (metabolic engineering & synthetic biology)

To meet the increasing demands of sustainable transportation energy, we aim to engineer microbes to produce advanced biofuels that could be readily used in current engines. One of the biggest challenges is to biosynthesize non-natural molecules that have structures exactly the same or highly similar to the fuels currently derived from petroleum. We are interested in constructing novel metabolic pathways to produce these compounds. In addition, we are also developing synthetic biology tools to improve the titer, yield, and productivity of the advanced biofuels.

Advanced Materials (synthetic biology)
Most synthetic polymers are currently derived from petroleum. Increasing concerns over petroleum’s environmental impacts and declining supply demand the development of state-of-the-art technologies to manufacture polymers from renewable feedstocks. On the other hand, nature has evolved various types of materials with delicate nano-scale structural that endow desirable material properties at the macro-scale. We aim to harness the biosynthetic machinery to establish a cell-based platform for the production of advanced biomaterials with precisely defined structures, which are impossible or impractical to synthesize by other means.

 

cyanoCyanobacteria for biofuels (synbio & metabolic eng)

Cyanobacteria can thrive at low nutrient, high salinity water and use sunlight energy to fix CO2 into organic compounds. These microbes are ideal hosts for biofuel production. However, the available tools to engineer cyanobacteria are very limited. We aim to develop synthetic biology toolkits for use in these organisms, and introduce heterologous pathways for the production of advanced biofuel in cyanobacteria.