초록
<P><B>Abstract</B></P> <P>Some clostridia produce alcohols (ethanol, butanol, hexanol) from gases (CO, CO<SUB>2</SUB>, H<SUB>2</SUB>) and others from carbohydrates (<I>e.g</I>., glucose). <I>C. carboxidivorans</I> can metabolize both gases as well as glucose. However, its bioconversion profile on glucose had not been reported. It was observed that <I>C. carboxidivorans</I> does not follow a typical solventogenic stage when grown on glucose. Indeed, at pH 6.2, it produced first a broad range of acids (acetic, butyric, hexanoic, formic, and lactic acids), several of which are generally not found, under similar conditions, during gas fermentation. Medium acidification did not allow the conversion of fatty acids into solvents. Production of some alcohols from glucose was observed in <I>C. carboxidivorans</I> but at high pH rather than under acidic conditions, and the total concentration of those solvents was low. At high pH, formic acid was produced first and later converted to acetic acid, but organic acids were not metabolized at low pH.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>C. carboxidivorans</I> can metabolize both gasses (CO/CO<SUB>2</SUB>/H<SUB>2</SUB>) as well as glucose. </LI> <LI> At pH 6.2 glucose is converted to acetic, butyric, caproic, formic, and lactic acids. </LI> <LI> Besides organic acids, minor amounts of alcohols are produced at high pH (6.2). </LI> <LI> Acidification down to pH 5.2 does not stimulate the conversion of acids into solvents. </LI> <LI> <I>C. carboxidivorans</I> uses formic acid while simultaneously producing acetic acid. </LI> </UL> </P>