Butanol and hexanol production in Clostridium carboxidivorans syngas fermentation: Medium development and culture techniques.
Clostridium carboxidivorans was grown on model syngas (CO:H2:CO2 [70:20:10]) in a defined nutrient medium with concentrations of nitrogen, phosphate and trace metals formulated to enhance production of higher alcohols. C. carboxidivorans was successfully grown in a limited defined medium (no yeast extract, no MES buffer and minimal complex chemical inputs) using an improved fermentation protocol. Low partial pressure of CO in the headspace, coupled with restricted mass transfer for CO and H2, was required for successful fermentation. In the absence of substrate inhibition (particularly from CO), growth limitation increased production of alcohols, especially butanol and hexanol. Concentrations of butanol (over 1.0g/L), hexanol (up to 1.0g/L) and ethanol (over 3.0g/L) were achieved in bottle fermentations. Minimal medium and controlled supply of CO and H2 should be used in characterizing candidate butanol and hexanol producing strains to select for commercial potential.
Biosystems and Agricultural Engineering Department, Oklahoma State University, Stillwater, OK, United States.
John R
JR
Phillips
Biosystems and Agricultural Engineering Department, Oklahoma State University, Stillwater, OK, United States. Electronic address: hasan.atiyeh@okstate.edu.
Hasan K
HK
Atiyeh
Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, United States.
Ralph S
RS
Tanner
Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, United States.
Juan R
JR
Torres
Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, United States.
Jyotisna
J
Saxena
Biosystems and Agricultural Engineering Department, Oklahoma State University, Stillwater, OK, United States.
Mark R
MR
Wilkins
Biosystems and Agricultural Engineering Department, Oklahoma State University, Stillwater, OK, United States.
Raymond L
RL
Huhnke
D019149:Bioreactors / Q000382:microbiology; D000440:Butanols / Q000302:isolation & purification / Q000378:metabolism*; D002248:Carbon Monoxide / Q000378:metabolism*; D018929:Cell Culture Techniques / Q000379:methods; D003013:Clostridium / Q000145:classification / Q000378:metabolism*; D005285:Fermentation / Q000502:physiology; D000441:Hexanols / Q000302:isolation & purification / Q000378:metabolism*; D006859:Hydrogen / Q000378:metabolism*; D013045:Species Specificity
D000440:Butanols; D000441:Hexanols; D002248:Carbon Monoxide; D006859:Hydrogen
Butanol; Culture techniques; Hexanol; Medium development; Syngas fermentation