Simplified process for ethanol production from sugarcane bagasse using hydrolysate-resistant Escherichia coli strain MM160.
Hexose and pentose sugars from phosphoric acid pretreated sugarcane bagasse were co-fermented to ethanol in a single vessel (SScF), eliminating process steps for solid-liquid separation and sugar cleanup. An initial liquefaction step (L) with cellulase was included to improve mixing and saccharification (L+SScF), analogous to a corn ethanol process. Fermentation was enabled by the development of a hydrolysate-resistant mutant of Escherichia coli LY180, designated MM160. Strain MM160 was more resistant than the parent to inhibitors (furfural, 5-hydroxymethylfurfural, and acetate) formed during pretreatment. Bagasse slurries containing 10% and 14% dry weight (fiber plus solubles) were tested using pretreatment temperatures of 160-190°C (1% phosphoric acid, 10 min). Enzymatic saccharification and inhibitor production both increased with pretreatment temperature. The highest titer (30 g/L ethanol) and yield (0.21 g ethanol/g bagasse dry weight) were obtained after incubation for 122 h using 14% dry weight slurries of pretreated bagasse (180°C).
Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA.
C C
CC
Geddes
M T
MT
Mullinnix
I U
IU
Nieves
J J
JJ
Peterson
R W
RW
Hoffman
S W
SW
York
L P
LP
Yomano
E N
EN
Miller
K T
KT
Shanmugam
L O
LO
Ingram
D002480:Cellulase / Q000737:chemistry; D002482:Cellulose / Q000737:chemistry / Q000378:metabolism*; D004926:Escherichia coli / Q000145:classification* / Q000235:genetics / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D009154:Mutation; D011492:Protein Hydrolysates / Q000378:metabolism*; D031786:Saccharum / Q000378:metabolism* / Q000382:microbiology*; D013045:Species Specificity
D011492:Protein Hydrolysates; D000431:Ethanol; D002482:Cellulose; C027433:bagasse; D002480:Cellulase