Microbiology of synthesis gas fermentation for biofuel production.
A significant portion of biomass sources like straw and wood is poorly degradable and cannot be converted to biofuels by microorganisms. The gasification of this waste material to produce synthesis gas (or syngas) could offer a solution to this problem, as microorganisms that convert CO and H2) (the essential components of syngas) to multicarbon compounds are available. These are predominantly mesophilic microorganisms that produce short-chain fatty acids and alcohols from CO and H2. Additionally, hydrogen can be produced by carboxydotrophic hydrogenogenic bacteria that convert CO and H2O to H2 and CO2. The production of ethanol through syngas fermentation is already available as a commercial process. The use of thermophilic microorganisms for these processes could offer some advantages; however, to date, few thermophiles are known that grow well on syngas and produce organic compounds. The identification of new isolates that would broaden the product range of syngas fermentations is desirable. Metabolic engineering could be employed to broaden the variety of available products, although genetic tools for such engineering are currently unavailable. Nevertheless, syngas fermenting microorganisms possess advantageous characteristics for biofuel production and hold potential for future engineering efforts.
Henstra
Anne M
AM
Laboratory of Microbiology, Wageningen University, H. v. Suchtelenweg 4, 6703 CT, Wageningen, The Netherlands. anne-meint.henstra@wur.nl
Sipma
Jan
J
Rinzema
Arjen
A
Stams
Alfons J M
AJ
D000105:Acetyl Coenzyme A / Q000378:metabolism; D000445:Aldehyde Oxidoreductases / Q000378:metabolism; D001105:Archaea / Q000378:metabolism*; D001419:Bacteria / Q000378:metabolism*; D018533:Biomass; D005285:Fermentation; D005740:Gases; D009097:Multienzyme Complexes / Q000378:metabolism
D005740:Gases; D009097:Multienzyme Complexes; D000105:Acetyl Coenzyme A; D000445:Aldehyde Oxidoreductases; C019823:carbon monoxide dehydrogenase