title: Continuous syngas fermentation for the production of ethanol, n-propanol and n-butanol.
abstract: Syngas fermentation to fuels is a technology on the verge of commercialization. Low cost of fermentation medium is important for process feasibility. The use of corn steep liquor (CSL) instead of yeast extract (YE) in Alkalibaculum bacchi strain CP15 bottle fermentations reduced the medium cost by 27% and produced 78% more ethanol. When continuous fermentation was performed in a 7-L fermentor, 6g/L ethanol was obtained in the YE and YE-free media. When CSL medium was used in continuous fermentation, the maximum produced concentrations of ethanol, n-propanol and n-butanol were 8 g/L, 6 g/L and 1 g/L, respectively. n-Propanol and n-butanol were not typical products of strain CP15. A 16S rRNA gene-based survey revealed a mixed culture in the fermentor dominated by A. bacchi strain CP15 (56%) and Clostridium propionicum (34%). The mixed culture presents an opportunity for higher alcohols production from syngas.
authors.affiliation: Department of Biosystems and Agricultural Engineering, Oklahoma State University, Stillwater, OK 74078, USA.
authors.forename: Kan
authors.initials: K
authors.lastname: Liu
authors.forename: Hasan K
authors.initials: HK
authors.lastname: Atiyeh
authors.forename: Bradley S
authors.initials: BS
authors.lastname: Stevenson
authors.forename: Ralph S
authors.initials: RS
authors.lastname: Tanner
authors.forename: Mark R
authors.initials: MR
authors.lastname: Wilkins
authors.forename: Raymond L
authors.initials: RL
authors.lastname: Huhnke
mesh_terms: D020001:1-Butanol / Q000378:metabolism*; D000433:1-Propanol / Q000378:metabolism*; D019342:Acetic Acid / Q000378:metabolism; D019149:Bioreactors / Q000382:microbiology; D002244:Carbon / Q000378:metabolism; D003470:Culture Media / Q000494:pharmacology; D000431:Ethanol / Q000378:metabolism*; D005051:Eubacterium / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D005285:Fermentation / Q000187:drug effects; D005740:Gases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration / Q000187:drug effects
chemical_list: D003470:Culture Media; D005740:Gases; D000431:Ethanol; D002244:Carbon; D020001:1-Butanol; D000433:1-Propanol; D019342:Acetic Acid
keywords: Alkalibaculum bacchi; Continuous syngas fermentation; Ethanol; n-Butanol; n-Propanol