4-01: Thermobifida fusca ß-glucosidase attachment to ethanologenic Escherichia coli outer membrane employing the type V secretion system

The attachment of the β-glucosidase BglC from Thermobifida fusca to the outer membrane of the ethanologenic Escherichia coli strain MS04 (MG1655 ΔpflB, ΔadhE, ΔfrdA, ΔxylFGH, ΔldhA, PpflB::pdc_Zm-adhB_Zm; evolved in the presence of xylose and acetate) was performed using the AIDA-I system, with the purpose to produce ethanol from cellobiose and to reduce the addition of cellulases from pre-treated agricultural residues. Whole cell protease treatment, SDS-PAGE and western blot analysis demonstrated that BglC was attached to the external surface of the outer membrane. E. coli MS04 transformed with plasmid pAIDABglCRHis fermented 40 g/L cellobiose in mineral medium in 60 hours with an ethanol yield of 81% of the theoretical maximum. This study shows the potential of BglC and the type V secretion system (AIDA-I) as tools in the lignocellulosic bio-commodities production.