Biological production of alcohols from coal through indirect liquefaction

Clostridium ljungdahlii sp. nov., an Acetogenic Species in Clostridial rRNA Homology Group I

“…C. ljungdahlii is the first known acetogenic member of rRNA homology group I, which includes solvent-producing species, such as Clostridium acetobutylicum, Clostridium beijerinckii, and Clostridium butyricum ( 5 , 15). A comparative biochemical study of these species could be helpful for improving the conversion of synthesis gas to ethanol catalyzed by C. ljungdahlii (2,25).…”

Syngas Fermentation: A Microbial Conversion Process of Gaseous Substrates to Various Products

“…The first acetogen reported to produce ethanol from syngas was Clostridium ljungdahlii [25,26]. Shortly thereafter, Butyribacterium methylotrophicum was reported to produce butanol and ethanol from CO [27].…”

“…The production of acetic acid and ethanol from syngas is represented in the literature by the stoichiometry for a single reductant, production from either CO or H2 with CO2 [2,25,55,[58][59][60]. The pure component stoichiometry and associated Gibbs free energy, ΔG°, are given in Table 2, Equations (1) and (5) for the production of acetic acid and Equations (6) and (12) for the production of ethanol.…”

“…The potential of the oxidation-reduction reactions of the pathway can be estimated by Equation (26) using E • calculated from Equation (25). Then, Equation (26) can be rearranged to calculate the mass action ratio as in Equation (27).…”

A review of conversion processes for bioethanol production with a focus on syngas fermentation

“…The main disadvantages of syngas fermentation are (i) low solubility and mass transfer limitations of the CO and H2 gaseous substrates, (ii) slow reactions resulting in long residence times, (iii) low metabolic energy is produced when the microorganisms grow on gaseous substrate instead of sugar substrates resulting in slow growth, low cell density and low solvent production (Barik et al, 1988;Vega et al, 1989).…”