Formic Acid Formation by $Clostridium$ $ljungdahlii$ at Elevated Pressures of Carbon Dioxide and Hydrogen

Oswald, Florian; Stoll, I. Katharina; Zwick, Michaela; Herbig, Sophia; Sauer, Jörg; Boukis, Nikolaos; Neumann, Anke

Abstract:
Low productivities of bioprocesses using gaseous carbon and energy sources are usually caused by the low solubility of those gases (e.g., H2 and CO). It has been suggested that increasing the partial pressure of those gases will result in higher dissolved concentrations and should, therefore, be helpful to overcome this obstacle. Investigations of the late 1980s with mixtures of hydrogen and carbon monoxide showed inhibitory effects of carbon monoxide partial pressures above 0.8 bar. Avoiding any effects of carbon monoxide, we investigate growth and product formation of Clostridium ljungdahlii at absolute process pressures of 1, 4, and 7 bar in batch stirred tank reactor cultivations with carbon dioxide and hydrogen as sole gaseous carbon and energy source. With increasing process pressure, the product spectrum shifts from mainly acetic acid and ethanol to almost only formic acid at a total system pressure of 7 bar. On the other hand, no significant changes in overall product yield can be observed. By keeping the amount of substance flow rate constant instead of the volumetric gas feed rate when increasing the process pressure, we increased the overall product yield of 7.5 times of what has been previously reported in the literature. ... mehr

 Zugehörige Institution(en) am KIT Institut für Bio- und Lebensmitteltechnik (BLT)Institut für Katalyseforschung und -technologie (IKFT) Publikationstyp Zeitschriftenaufsatz Publikationsdatum 12.02.2018 Sprache Englisch Identifikator ISSN: 2296-4185 urn:nbn:de:swb:90-810507 KITopen-ID: 1000081050 HGF-Programm 35.13.03 (POF III, LK 01) Behandlung und Veredelung Erschienen in Frontiers in Bioengineering and Biotechnology Verlag Frontiers Media Band 6 Seiten Art.Nr. 6 Bemerkung zur Veröffentlichung Gefördert durch den KIT-Publikationsfonds Schlagwörter Clostridium ljungdahlii; high-pressure fermentation; acetogenic bacteria; acetic acid; formic acid; mass transfer Nachgewiesen in ScopusWeb of ScienceDimensions
KIT – Die Forschungsuniversität in der Helmholtz-Gemeinschaft
KITopen Landing Page