title: Mixed culture syngas fermentation and conversion of carboxylic acids into alcohols.
abstract: Higher alcohols such as n-butanol and n-hexanol have higher energy density than ethanol, are more compatible with current fuel infrastructure, and can be upgraded to jet and diesel fuels. Several organisms are known to convert syngas to ethanol, but very few can produce higher alcohols alone. As a potential solution, mixed culture fermentation between the syngas fermenting Alkalibaculum bacchi strain CP15 and propionic acid producer Clostridium propionicum was studied. The monoculture of CP15 produced only ethanol from syngas without initial addition of organic acids to the fermentation medium. However, the mixed culture produced ethanol, n-propanol and n-butanol from syngas. The addition of propionic acid, butyric acid and hexanoic acid to the mixed culture resulted in a 50% higher conversion efficiency of these acids to their respective alcohols compared to CP15 monoculture. These findings illustrate the great potential of mixed culture syngas fermentation in production of higher alcohols.
authors: Department of Biosystems and Agricultural Engineering, Oklahoma State University, Stillwater, OK 74078, USA.
authors: Kan
authors: K
authors: Liu
authors: Department of Biosystems and Agricultural Engineering, Oklahoma State University, Stillwater, OK 74078, USA. Electronic address: hasan.atiyeh@okstate.edu.
authors: Hasan K
authors: HK
authors: Atiyeh
authors: Microbiology and Plant Biology, University of Oklahoma, 770 Van Vleet Oval, Norman, OK 73019, USA.
authors: Bradley S
authors: BS
authors: Stevenson
authors: Microbiology and Plant Biology, University of Oklahoma, 770 Van Vleet Oval, Norman, OK 73019, USA.
authors: Ralph S
authors: RS
authors: Tanner
authors: Department of Biosystems and Agricultural Engineering, Oklahoma State University, Stillwater, OK 74078, USA.
authors: Mark R
authors: MR
authors: Wilkins
authors: Department of Biosystems and Agricultural Engineering, Oklahoma State University, Stillwater, OK 74078, USA.
authors: Raymond L
authors: RL
authors: Huhnke
mesh_terms: D019342:Acetic Acid / Q000378:metabolism; D000438:Alcohols / Q000378:metabolism*; D001419:Bacteria / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology; D002244:Carbon / Q000378:metabolism; D002264:Carboxylic Acids / Q000378:metabolism*; D003013:Clostridium / Q000254:growth & development; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D005740:Gases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D011422:Propionates / Q000378:metabolism; D013816:Thermodynamics
chemical_list: D000438:Alcohols; D002264:Carboxylic Acids; D005740:Gases; D011422:Propionates; D000431:Ethanol; D002244:Carbon; C029658:propionic acid; D019342:Acetic Acid
keywords: Drop-in biofuel; Mixed culture syngas fermentation; n-Butanol; n-Hexanol; n-Propanol