429909 Systems and Synthetic Biology of Photosynthetic Organisms for Biorenewable Chemicals

Sunday, November 8, 2015
Exhibit Hall 1 (Salt Palace Convention Center)
Rajib Saha, Department of Biology, Washington University, St. Louis, MO

Background: In the FY 2016 Budget, the Department of Energy (DOE) requests $10.7 billion including $2.72 billion for Energy Efficiency and Renewable Energy (EERE), and $645 million for renewable energy generation technologies. In addition, National Science Foundation (NSF) recently set a goal of pertaining crops the ability to fix nitrogen instead of using expensive, chemically synthesized, and artificial fertilizers. To this end, NSF started a novel research program in order to revolutionize current farming methods and awarded $12 million to four different groups from the US and the UK. Photosynthetic organisms such as cyanobacteria and plants derive energy from light and carbon from atmospheric carbon dioxide, and, thus, lie in the core of achieving these goals. However, the feasibility of utilizing these organisms hinges on the development of efficient platforms and genetic toolkits by systems and synthetic biology approaches.

Motivation: The scope and breadth of genome-scale metabolic reconstructions have continued to expand over the last decade. However, only a limited number of efforts exist on photosynthetic metabolism reconstruction. In addition, less well studied are the similarities and differences in their metabolism and diurnal behavior. The unique demands of living on light as a primary nutrient make the use of many established gene expression control systems difficult or impossible to apply in cyanobacteria. Hence, developing an effective genetic toolkit to regulate gene expressions would facilitate biotechnological applications in cyanobacteria.

My Research: My postdoctoral work at the Pakrasi Lab (Washington University in St. Louis) is aimed at developing an efficient system for regulating gene expression and also, applying bioinformatics approaches to explore cyanobacterial physiology. My doctoral work at the Maranas Lab (The Pennsylvania State University) involved reconstruction and analysis of genome-scale metabolic models of photosynthetic organisms. This poster will focus on three broad topics of my research that can widely be applied to develop platforms for producing biorenewables:

  • Reconstruction of genome-scale metabolic models:  Developed high-quality genome-scale models for Cyanothece sp. ATCC 51142 (iCyt773), Synechocystis sp. PCC 6803 (iSyn731), and Zea mays (a global model iRS1543 and a leaf-specific model).
  • Development of engineered riboswitch:  Combined a theophylline-responsive riboswitch with the T7 control system to demonstrate better regulation of gene expression than that of the existing systems.
  • Application of bioinformatics approaches to analyze cyanobacterial physiology: Analyzed microarray data to shed light on the global coordination of cellular processes over light/dark cycle in Synechocystis sp. PCC 6803 and also studied RNAseq data to find regulatory RNAs in the nif cluster of Cyanothece sp. ATCC 51142.

Extended Abstract: File Uploaded