BACKGROUND To make lignocellulosic fuel ethanol economically competitive with fossil fuels, it is necessary to reduce the production cost. One way to achieve this is by increasing the substrate concentration in the production process, and thus reduce the energy demand in the final distillation of the fermentation broth. However, increased substrate concentration in simultaneous saccharification...

Wheat straw hydrolysate produced by enzymatic hydrolysis of hydrothermal pretreated wheat straw at a very high solids concentration of 30% dry matter (w/w) was used for testing the effect of nutrients on their ability to improve fermentation performance of Saccharomyces cerevisiae. The nutrients tested were MgSO4 and nitrogen sources; (NH4)2SO4, urea, yeast extract, peptone and corn steep liquo...

The extraction yield, phenolic content, anthocyanin content and antioxidant activity of extracts from different varieties of red grapes, Cabernet Sauvignon, Merlot, Petit Verdot, Syrah, Tempranillo and Tintilla, using pressurized green solvents have been analyzed. Two techniques were studied and compared: supercritical fluid extraction (SFE) with CO2 + 20% ethanol and pressurized liquid extract...

The effects of the initial pH and air supply on the production of ethanol from D-xylose using the yeast Candida shehatae in a batch reactor were investigated. The initial pH was altered within the range of 2.5-6.5 and the specific aeration rate from 0.0-0.3 vv-1 min-1. The results showed that the most favorable initial pH for ethanol production was 4.5 and aeration via the stirring vortex of th...

The 2007 Energy Independence Security Act mandates the production of 16 billion gallons per year of cellulosic biofuel by 2022. These biofuels will be required to have life cycle assessment (LCA) greenhouse gas (GHG) emissions 60% below gasoline. Switchgrass is one potential feedstock for the production of cellulosic ethanol in Kansas. Emissions of the GHG nitrous oxide (N2O) from soils treated...

BACKGROUND Fermentative hydrogen (H2) production suffers from low carbon-to-H2 yield, to which problem, co-production of ethanol and H2 has been proposed as a solution. For improved co-production of H2 and ethanol, we developed Escherichia coli BW25113 ΔhycA ΔhyaAB ΔhybBC ΔldhA ΔfrdAB Δpta-ackA ΔpfkA (SH8*) and overexpressed Zwf and Gnd, the key enzymes in the pentose-phosphate (PP) pathway (SH...

Nine grain sorghum cultivars with a broad range of ethanol fermentation efficiencies were selected to characterize the changes in sorghum protein in digestibility, solubility, and microstructure during mashing and to relate those changes to ethanol fermentation quality of sorghum. Mashing reduced in vitro protein digestibility considerably, and a large amount of polymers cross-linked by disulfi...

BACKGROUND The production of ethyl alcohol by fermentation represents the largest scale application of Saccharomyces cerevisiae in industrial biotechnology. Increased worldwide demand for fuel bioethanol is anticipated over the next decade and will exceed 200 billion liters from further expansions. Our working hypothesis was that the drop in ATP level in S. cerevisiae cells during alcoholic fer...

Background: Cotton gin trash (CGT) is a lignocellulosic residue that can be used in the production of cellulosic ethanol. In a previous research, the sequential use of ultrasonication, liquid hot water, and ligninolytic enzymes was selected as pretreatment for the production of ethanol from CGT. However, an increment in the ethanol production is necessary. To accomplish that, this research eval...

Ethanol yields were 2.1 (P = 0.06) to 2.3 (P = 0.01) times higher in simultaneous saccharification and fermentation (SSF) reactions of microcrystalline cellulose when cellulase was physisorbed on silica nanoparticles compared to enzyme in solution. In SSF reactions, cellulose is hydrolyzed to glucose by cellulase while yeast simultaneously ferments glucose to ethanol. The 35°C temperature and t...