Fermentative production of 1-propanol from d-glucose, l-rhamnose and glycerol using recombinant Escherichia coli

Biochemical analysis of cross-feeding behaviour between two common gut commensals when cultivated on plant-derived arabinogalactan

In this paper, we reveal and characterize cross-feeding behaviour between the common gut commensal Bacteroides cellulosilyticus (Baccell) and certain bifidobacterial strains, including Bifidobacterium breve UCC2003, when grown on a medium containing Larch Wood Arabinogalactan (LW-AG). We furthermore show that cross-feeding is dependent on the release of β-1,3-galacto-di/trisaccharides (β-1,3-GOS), and identified that the bga gene cluster of B. breve UCC2003 allows β-1,3-GOS metabolism. The product of bgaB is presumed to be responsible for the import of β-1,3-GOS, while the bgaA gene product, a glycoside hydrolase family 2 member, was shown to hydrolyse both β-1,3-galactobiose and β-1,3-galactotriose into galactose monomers. This study advances our understanding of strain-specific syntrophic interactions between two glycan degraders in the human gut in the presence of AG-type dietary polysaccharides.

Synthetic Biology and Metabolic Engineering Employing Escherichia coli for C2-C6 Bioalcohol Production

Biofuel production from renewable and sustainable resources is playing an increasingly important role within the fuel industry. Among biofuels, bioethanol has been most widely used as an additive for gasoline. Higher alcohols can be blended at a higher volume compared to ethanol and generate lower greenhouse gas (GHG) emissions without a need to change current fuel infrastructures. Thus, these fuels have the potential to replace fossil fuels in support of more environmentally friendly processes. This review summarizes the efforts to enhance bioalcohol production in engineered Escherichia coli over the last 5 years and analyzes the current challenges for increasing productivities for industrial applications.

Deoxydehydration of glycerol in presence of rhenium compounds: reactivity and mechanistic aspects

Re compounds in different oxidation states are activated during a delay time into an active Re alkoxide precipitate catalysing the DODH of glycerol.

Transfer and analysis of Salmonella pdu genes in a range of Gram-negative bacteria demonstrate exogenous microcompartment expression across a variety of species

Bacterial microcompartments (MCPs) are protein organelles that typically house toxic or volatile reaction intermediates involved in metabolic pathways. Engineering bacteria to express exogenous MCPs will allow these cells to gain useful functions involving molecule compartmentalization. We cloned a 38 kb region from the Salmonella enterica serovar Typhimurium genome containing the pdu 1,2 propanediol (1,2 PD) utilization and cob/cbi genes using the FRT‐Capture strategy to clone and transfer large genomic segments. We transferred this clone to a range of Gram‐negative bacteria and found the clone to be functional for 1,2 PD metabolism in a variety of species including S. Typhimurium Δpdu, Escherichia coli, Salmonella bongori, Klebsiella pneumoniae, Cronobacter sakazakii, Serratia marcescens, and different Pseudomonas species. We successfully isolated MCPs expressed from the clone from several, but not all, of these strains, and we observed this utilizing a range of different media and in the absence of protease inhibitor. We also present a mini‐prep protocol that allows rapid, small‐scale screening of strains for MCP production. To date, this is the first analysis of cloned, exogenous microcompartment expression across several different Gram‐negative backgrounds and provides a foundation for MCP use in a variety of bacterial species using a full, intact clone.