EBI Personnel Directory Nadler, Dana
The goal is to develop new experimental systems to study cellulosome degradation of cellulosic biomass. The program includes discovering new thermophilic organisms as enzyme sources and/or for biofuel production, protein engineering and kinetic modeling of improved cellulases, cellular engineering for improved solvent tolerance, and bioprocess engineering to optimize fermentation.
The high-throughput construction of metabolically engineered organisms is hindered by our inability to rapidly assay the presence of most small molecules. Recently, biosensors fashioned around the green fluorescent protein (GFP) have been developed to sense a number of important chemicals such as calcium and ATP, but little attempt has been made to develop this work in the biofuel space. If available, a fluorescent biosensor of biofuels or biofuel intermediates would have an enormous impact on our ability to construct and evolve production strains with superior yields and rates. To this end, this project will engineer GFP-based biosensors of various biofuels (medium and long-chain esters, alcohols, and alkanes) and their intermediates in fatty acid metabolism. A number of bacterial transcription factors (TFs) are known to bind these molecules. The group will characterize the binding specificity of five relevant TFs against a panel of biofuels and intermediates to assess their suitability for biosensor engineering. For each TF, a library of GFP-TF chimeras will be constructed, and high-throughput screening will be used to identify variants with biosensor activity against the intended molecules. A small number of the best biosensors will be optimized and used in a proof of principle experiment to screen for novel mutations to improve the flux and yield of biofuel-producing strains.