TY - JOUR
T1 - Fermentation of dried distillers' grains and solubles (DDGS) hydrolysates to solvents and value-added products by solventogenic clostridia
AU - Ezeji, Thaddeus
AU - Blaschek, Hans P.
N1 - Funding Information:
These studies were supported by grants from the United States Department of Energy (DOE) DE-FG36-046014220 to grant to the Midwest Consortium. We would also like to thank Drs. M. Ladisch and B. Dale for providing us with liquid hot water (LHW) and AFEX pretreated DDGS and to the other members of the Midwest Consortium.
PY - 2008/8
Y1 - 2008/8
N2 - Pretreatment and hydrolysis of lignocellulosic biomass using either dilute acid, liquid hot water (LHW), or ammonium fiber expansion (AFEX) results in a complex mixture of sugars such as hexoses (glucose, galactose, mannose), and pentoses (xylose, arabinose). A detailed description of the utilization of representative mixed sugar streams (pentoses and hexoses) and their sugar preferences by the solventogenic clostridia (Clostridium beijerinckii BA101, C. acetobutylicum 260, C. acetobutylicum 824, Clostridium saccharobutylicum 262, and C. butylicum 592) is presented. In these experiments, all the sugars were utilized concurrently throughout the fermentation, although the rate of sugar utilization was sugar specific. For all clostridia tested, the rate of glucose utilization was higher than for the other sugars in the mixture. In addition, the availability of excess fermentable sugars in the bioreactor is necessary for both the onset and the maintenance of solvent production otherwise the fermentation will become acidogenic leading to premature termination of the fermentation process. During an investigation on the effect of some of the known lignocellulosic hydrolysate inhibitors on the growth and ABE production by clostridia, ferulic and p-coumaric acids were found to be potent inhibitors of growth and ABE production. Interestingly, furfural and HMF were not inhibitory to the solventogenic clostridia; rather they had a stimulatory effect on growth and ABE production at concentrations up to 2.0 g/L.
AB - Pretreatment and hydrolysis of lignocellulosic biomass using either dilute acid, liquid hot water (LHW), or ammonium fiber expansion (AFEX) results in a complex mixture of sugars such as hexoses (glucose, galactose, mannose), and pentoses (xylose, arabinose). A detailed description of the utilization of representative mixed sugar streams (pentoses and hexoses) and their sugar preferences by the solventogenic clostridia (Clostridium beijerinckii BA101, C. acetobutylicum 260, C. acetobutylicum 824, Clostridium saccharobutylicum 262, and C. butylicum 592) is presented. In these experiments, all the sugars were utilized concurrently throughout the fermentation, although the rate of sugar utilization was sugar specific. For all clostridia tested, the rate of glucose utilization was higher than for the other sugars in the mixture. In addition, the availability of excess fermentable sugars in the bioreactor is necessary for both the onset and the maintenance of solvent production otherwise the fermentation will become acidogenic leading to premature termination of the fermentation process. During an investigation on the effect of some of the known lignocellulosic hydrolysate inhibitors on the growth and ABE production by clostridia, ferulic and p-coumaric acids were found to be potent inhibitors of growth and ABE production. Interestingly, furfural and HMF were not inhibitory to the solventogenic clostridia; rather they had a stimulatory effect on growth and ABE production at concentrations up to 2.0 g/L.
KW - Butanol
KW - Coumaric
KW - DDGS
KW - Ferulic
KW - Syringaldehyde
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U2 - 10.1016/j.biortech.2007.09.032
DO - 10.1016/j.biortech.2007.09.032
M3 - Article
C2 - 17967532
AN - SCOPUS:42649128257
SN - 0960-8524
VL - 99
SP - 5232
EP - 5242
JO - Bioresource Technology
JF - Bioresource Technology
IS - 12
ER -