Reciprocal regulation of NagC and quorum sensing systems and their roles in expression and biofilm formation in .

Biofilm formation by is regulated by quorum sensing (QS) and dependent on the haemin storage locus , required for the extracellular polysaccharide poly--acetylglucosamine (poly-GlcNAc) production. In NagC regulates both GlcNAc biosynthesis and metabolism with GlcNAc acting as a signal that co-ordinates these and other activities. However, the contribution of NagC and GlcNAc to biofilm development in is not known.

Energy Conservation in the Acetogenic Bacterium .

In times of global warming caused by the extensive use of fossil fuels, the need to capture gaseous carbon compounds is growing bigger. Several groups of microorganisms can fix the greenhouse gas CO. Out of these, acetogenic bacteria are role models in their ability to reduce CO with hydrogen to acetate, which makes acetogens prime candidates for genetic modification towards biotechnological production of value-added compounds from CO, such as biofuels.

Homologous production, one-step purification, and proof of Na transport by the Rnf complex from Acetobacterium woodii, a model for acetogenic conversion of C1 substrates to biofuels.

Background: Capture and storage of the energy carrier hydrogen as well as of the greenhouse gas carbon dioxide are two major problems that mankind faces currently. Chemical catalysts have been developed, but only recently a group of anaerobic bacteria that convert hydrogen and carbon dioxide to acetate, formate, or biofuels such as ethanol has come into focus, the acetogenic bacteria. These biocatalysts produce the liquid organic hydrogen carrier formic acid from H + CO or even carbon monoxide with highest rates ever reported.

Revealing formate production from carbon monoxide in wild type and mutants of Rnf- and Ech-containing acetogens, Acetobacterium woodii and Thermoanaerobacter kivui.

Acetogenic bacteria have gained much attraction in recent years as they can produce different biofuels and biochemicals from H plus CO or even CO alone, therefore opening a promising alternative route for the production of biofuels from renewable sources compared to existing sugar-based routes. However, CO metabolism still raises questions concerning the biochemistry and bioenergetics in many acetogens. In this study, we focused on the two acetogenic bacteria Acetobacterium woodii and Thermoanaerobacter kivui which, so far, are the only identified acetogens harbouring a H -dependent CO reductase and furthermore belong to different classes of 'Rnf'- and 'Ech-acetogens'.

The Rnf complex from the acetogenic bacterium Acetobacterium woodii: Purification and characterization of RnfC and RnfB.

rnf genes are widespread in anaerobic bacteria and hypothesized to encode a respiratory enzyme that couples exergonic reduction of NAD with reduced ferredoxin as a reductant to vectorial ion (Na, H) translocation across the cytoplasmic membrane. However, despite its importance for the physiology of these bacteria, little is known about the subunit composition and the function of subunits. Here, we have purified the entire Rnf complex from the acetogen Acetobacterium woodii or after its production in Escherichia coli.

It does not always take two to tango: "Syntrophy" via hydrogen cycling in one bacterial cell.

Interspecies hydrogen transfer in anoxic ecosystems is essential for the complete microbial breakdown of organic matter to methane. Acetogenic bacteria are key players in anaerobic food webs and have been considered as prime candidates for hydrogen cycling. We have tested this hypothesis by mutational analysis of the hydrogenase in the model acetogen Acetobacterium woodii.

Regulation of lactate metabolism in the acetogenic bacterium Acetobacterium woodii.

Acetogenic bacteria compete in an energy-limited environment by coupling different metabolic routes to their central metabolism of CO fixation. The underlying regulatory mechanisms are often still not understood. In this work, we analysed how lactate metabolism is regulated in the model acetogen Acetobacterium woodii.

The Rnf Complex Is an Energy-Coupled Transhydrogenase Essential To Reversibly Link Cellular NADH and Ferredoxin Pools in the Acetogen Acetobacterium woodii.

The Rnf complex is a respiratory enzyme that catalyzes the oxidation of reduced ferredoxin to the reduction of NAD, and the negative free energy change of this reaction is used to generate a transmembrane ion gradient. In one class of anaerobic acetogenic bacteria, the Rnf complex is believed to be essential for energy conservation and autotrophic growth. We describe here a methodology for markerless mutagenesis in the model bacterium of this class, , which enabled us to delete the genes and to test their role.

Full validation of therapeutic antibody sequences by middle-up mass measurements and middle-down protein sequencing.

The regulatory bodies request full sequence data assessment both for innovator and biosimilar monoclonal antibodies (mAbs). Full sequence coverage is typically used to verify the integrity of the analytical data obtained following the combination of multiple LC-MS/MS datasets from orthogonal protease digests (so called "bottom-up" approaches). Top-down or middle-down mass spectrometric approaches have the potential to minimize artifacts, reduce overall analysis time and provide orthogonality to this traditional approach.

Endemic Mimosa species from Mexico prefer alphaproteobacterial rhizobial symbionts.

The legume genus Mimosa has > 500 species, with two major centres of diversity, Brazil (c. 350 spp.) and Mexico (c.