title: Homeoviscous response of Clostridium pasteurianum to butanol toxicity during glycerol fermentation.
abstract: Clostridium pasteurianum ATCC 6013 achieves high n-butanol production when glycerol is used as the sole carbon source. In this study, the homeoviscous membrane response of C. pasteurianum ATCC 6013 has been examined through n-butanol challenge experiments. Homeoviscous response is a critical aspect of n-butanol tolerance and has not been examined in detail for C. pasteurianum. Lipid membrane compositions were examined for glycerol fermentations with n-butanol production, and during cell growth in the absence of n-butanol production, using gas chromatography-mass spectrometry (GC-MS) and proton nuclear magnetic resonance ((1)H-NMR). Membrane stabilization due to homeoviscous response was further examined by surface pressure-area (π-A) analysis of membrane extract monolayers. C. pasteurianum was found to exert a homeoviscous response that was comprised of an increase lipid tail length and a decrease in the percentage of unsaturated fatty acids with increasing n-butanol challenge. This led to a more rigid or stable membrane that counteracted n-butanol fluidization. This is the first report on the changes in the membrane lipid composition during n-butanol production by C. pasteurianum ATCC 6013, which is a versatile microorganism that has the potential to be engineered as an industrial n-butanol producer using crude glycerol.
authors.affiliation: Biotechnology Science and Engineering Program, University of Alabama in Huntsville, 301 Sparkman Dr NW, MSB 333, Huntsville, AL 35899, USA.
authors.forename: Keerthi P
authors.initials: KP
authors.lastname: Venkataramanan
authors.affiliation: Department of Chemical Engineering, University of Rhode Island, 16 Greenhouse Rd., 205 Crawford Hall, Kingston, RI 02881, USA.
authors.forename: Yogi
authors.initials: Y
authors.lastname: Kurniawan
authors.affiliation: Department of Chemical and Materials Engineering, University of Alabama in Huntsville, 301 Sparkman Dr NW, EB 130, Huntsville, AL 35899, USA.
authors.forename: Judy J
authors.initials: JJ
authors.lastname: Boatman
authors.affiliation: Department of Chemical and Materials Engineering, University of Alabama in Huntsville, 301 Sparkman Dr NW, EB 130, Huntsville, AL 35899, USA.
authors.forename: Cassandra H
authors.initials: CH
authors.lastname: Haynes
authors.affiliation: Department of Chemical and Materials Engineering, University of Alabama in Huntsville, 301 Sparkman Dr NW, EB 130, Huntsville, AL 35899, USA.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Taconi
authors.affiliation: Department of Cell and Molecular Biology, University of Rhode Island, 120 Flagg Rd., 393 CBLS, Kingston, RI 02881, USA.
authors.forename: Lenore
authors.initials: L
authors.lastname: Martin
authors.affiliation: Department of Chemical Engineering, University of Rhode Island, 16 Greenhouse Rd., 205 Crawford Hall, Kingston, RI 02881, USA. Electronic address: bothun@egr.uri.edu.
authors.forename: Geoffrey D
authors.initials: GD
authors.lastname: Bothun
authors.affiliation: Department of Chemistry, University of Alabama in Huntsville, 301 Sparkman Dr NW, MSB 333, Huntsville, AL 35899, USA. Electronic address: scholzc@uah.edu.
authors.forename: Carmen
authors.initials: C
authors.lastname: Scholz
mesh_terms: D020001:1-Butanol / Q000378:metabolism / Q000633:toxicity*; D003013:Clostridium / Q000145:classification / Q000502:physiology*; D003470:Culture Media / Q000737:chemistry; D005285:Fermentation; D008401:Gas Chromatography-Mass Spectrometry; D005990:Glycerol / Q000378:metabolism*; D008563:Membrane Lipids / Q000378:metabolism*; D066244:Proton Magnetic Resonance Spectroscopy
chemical_list: D003470:Culture Media; D008563:Membrane Lipids; D020001:1-Butanol; D005990:Glycerol
keywords: Butanol; Clostridium pasteurianum; Fermentation; Glycerol; Homeoviscous response; Lipid composition