P159: Isopropanol production from cellobiose by E. coli

Efficient bio-production from lignocellulosic biomass is required for the purpose of developing an inexpensive, practical bio-refinery process. As one approach to address this problem, we genetically engineered E. coli to produce isopropanol directly from cellobiose via the cellobiose degradation by Beta-Glucosidase (BGL) on the cell surface. We introduced the synthetic pathway for isopropanol production (thl (thiolase from Clostridium acetobutylicum ATCC824), atoAD (CoA transferase from Escherichia coli MG1655), adc (acetoacetate decarboxylase from C. acetobutylicum) and cbadh (secondary alcohol dehydrogenase from C. beijerinckii NRRL B593) and the BGL protein from Thermobifida fusca YX (Tfu0937) fused to the anchor protein Blc (Tfu-Blc) into E. coli BW25113 and compared their isopropanol production in the presence of cellobiose. This strain consumed cellobiose and produced 69.0±11.6 mM isopropanol at 21 h of fermentation. To our knowledge, this is the first report of the production of a bioproduct from cellobiose using E. coli.