Simultaneous saccharification and cofermentation of dilute-acid pretreated yellow poplar hardwood to ethanol using xylose-fermenting Zymomonas mobilis.
Simultaneous saccharification and cofermentation (SSCF) was carried out at approximately 15% total solids using conditioned dilute-acid pretreated yellow poplar feedstock, an adapted variant of National Renewable Energy Laboratory (NREL) xylose-fermenting Zymomonas mobilis and either commercial or NREL-produced cellulase enzyme preparations. In 7 d, at a cellulase loading of 12 filter paper units per gram cellulose (FPU/g), the integrated system produced more than 3% w/v ethanol and achieved 54% conversion of all potentially available biomass sugars (total sugars) entering SSCF. A control SSCF employing Sigmacell cellulose and a commercial cellulase at an enzyme loading of 14 FPU/g achieved 65% conversion of total sugars to ethanol.
McMillan
J D
JD
Biotechnology Center for Fuels and Chemicals, National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, CO 80401-3393, USA. jim_mcmillan@nrel.gov
Newman
M M
MM
Templeton
D W
DW
Mohagheghi
A
A