Learn More
Biofuels are an attractive means to prevent a further increase of carbon dioxide emissions. Currently, gasoline is blended with ethanol at various percentages. However, butanol has several advantages over ethanol, such as higher energy content, lower water absorption, better blending ability, and use in conventional combustion engines without modification.(More)
Clostridium ljungdahlii is an anaerobic homoacetogen, able to ferment sugars, other organic compounds, or CO(2)/H(2) and synthesis gas (CO/H(2)). The latter feature makes it an interesting microbe for the biotech industry, as important bulk chemicals and proteins can be produced at the expense of CO(2), thus combining industrial needs with sustained(More)
Propionibacterium acnes is a major inhabitant of adult human skin, where it resides within sebaceous follicles, usually as a harmless commensal although it has been implicated in acne vulgaris formation. The entire genome sequence of this Gram-positive bacterium encodes 2333 putative genes and revealed numerous gene products involved in degrading host(More)
Clostridium acetobutylicum is an anaerobic, spore-forming bacterium with the ability to ferment starch and sugars into solvents. In the past, it has been used for industrial production of acetone and butanol, until cheap crude oil rendered petrochemical synthesis more economically feasible. Both economic (price of crude oil) and environmental aspects(More)
Clostridial acetone/butanol fermentation used to rank second only to ethanol fermentation by yeast in its scale of production and thus is one of the largest biotechnological processes known. Its decline since about 1950 has been caused by increasing substrate costs and the availability of much cheaper feedstocks for chemical solvent synthesis by the(More)
The sol operon of Clostridium acetobutylicum is the essential transcription unit for formation of the solvents butanol and acetone. The recent proposal that transcriptional regulation of this operon is controlled by the repressor Orf5/SolR (R. V. Nair, E. M. Green, D. E. Watson, G. N. Bennett, and E. T. Papoutsakis, J. Bacteriol. 181:319-330, 1999) was(More)
At the end of the exponential growth phase the Gram-positive bacterium Clostridium acetobutylicum performs a metabolic switch from classical sugar fermentation accompanied by the production of acetate and butyrate to reinternalization and oxidation of these acids to acetone and butanol. Protein synthesis in acidogenic and solventogenic C. acetobutylicum(More)
Acetogenic anaerobic bacteria are defined as organisms employing the Wood-Ljungdahl pathway to synthesize acetyl-CoA from CO(2) or CO. Their autotrophic mode of metabolism offers the biotechnological chance to combine use of abundantly available substrates with reduction of greenhouse gases. Several companies have already established pilot and demonstration(More)
UNLABELLED Most acetogens can reduce CO2 with H2 to acetic acid via the Wood-Ljungdahl pathway, in which the ATP required for formate activation is regenerated in the acetate kinase reaction. However, a few acetogens, such as Clostridium autoethanogenum, Clostridium ljungdahlii, and Clostridium ragsdalei, also form large amounts of ethanol from CO2 and H2.(More)
Clostridium acetobutylicum is able to switch from acidogenic growth to solventogenic growth. We used phosphate-limited continuous cultures that established acidogenic growth at pH 5.8 and solventogenic growth at pH 4.5. These cultures allowed a detailed transcriptomic study of the switch from acidogenesis to solventogenesis that is not superimposed by(More)