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Addressing the need for alternative transportation fuels: The Joint BioEnergy Institute

Joint BioEnergy Institute, Department of Chemical Engineering, University of California, Berkeley, California 94720, USA.
ACS Chemical Biology (Impact Factor: 5.36). 02/2008; 3(1):17-20. DOI: 10.1021/cb700267s
Source: PubMed

ABSTRACT Today, carbon-rich fossil fuels, primarily oil, coal, and natural gas, provide 85% of the energy consumed in the U.S. As world demand increases, oil reserves may become rapidly depleted. Fossil fuel use increases CO emissions and raises the risk of global warming. The high energy content of liquid hydrocarbon fuels makes them the preferred energy source for all modes of transportation. In the U.S. alone, transportation consumes >13.8 million barrels of oil per day and generates 0.5 gigatons of carbon per year. This release of greenhouse gases has spurred research into alternative, nonfossil energy sources. Among the options (nuclear, concentrated solar thermal, geothermal, hydroelectric, wind, solar, and biomass), only biomass has the potential to provide a high-energy-content transportation fuel. Biomass is a renewable resource that can be converted into carbon-neutral transporation fuels. Currently, biofuels such as ethanol are produced largely from grains, but there is a large, untapped resource (estimated at more than a billion tons per year) of plant biomass that could be utilized as a renewable, domestic source of liquid fuels. Well-established processes convert the starch content of the grain into sugars that can be fermented to ethanol. The energy efficiency of starch-based biofuels is however not optimal, while plant cell walls (lignocellulose) represent a huge untapped source of energy. Plant-derived biomass contains cellulose, which is more difficult to convert to sugars; hemicellulose, which contains a diversity of carbohydrates that have to be efficiently degraded by microorganisms to fuels; and lignin, which is recalcitrant to degradation and prevents cost-effective fermentation. The development of cost-effective and energy-efficient processes to transform lignocellulosic biomass into fuels is hampered by significant roadblocks, including the lack of specifically developed energy crops, the difficulty in separating biomass components, low activity of enzymes used to deconstruct biomass, and the inhibitory effect of fuels and processing byproducts on organisms responsible for producing fuels from biomass monomers. The Joint BioEnergy Institute (JBEI) is a U.S. Department of Energy (DOE) Bioenergy Research Center that will address these roadblocks in biofuels production. JBEI draws on the expertise and capabilities of three national laboratories (Lawrence Berkeley National Laboratory (LBNL), Sandia National Laboratories (SNL), and Lawrence Livermore National Laboratory (LLNL)), two leading U.S. universities (University of California campuses at Berkeley (UCB) and Davis (UCD)), and a foundation (Carnegie Institute for Science, Stanford) to develop the scientific and technological base needed to convert the energy stored in lignocellulose into transportation fuels and commodity chemicals. Established scientists from the participating organizations are leading teams of researchers to solve the key scientific problems and develop the tools and infrastructure that will enable other researchers and companies to rapidly develop new biofuels and scale production to meet U.S. transportation needs and to develop and rapidly transition new technologies to the commercial sector. JBEI's biomass-to-biofuels research approach is based in three interrelated scientific divisions and a technologies division. The Feedstocks Division will develop improved plant energy crops to serve as the raw materials for biofuels. The Deconstruction Division will investigate the conversion of this lignocellulosic plant material to sugar and aromatics. The Fuels Synthesis Division will create microbes that can efficiently convert sugar and aromatics into ethanol and other biofuels. JBEI's cross-cutting Technologies Division will develop and optimize a set of enabling technologies including high-throughput, chipbased, and omics platforms; tools for synthetic biology; multi-scale imaging facilities; and integrated data analysis to support and integrate JBEI's scientific program.

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    • "The main contributors to the high cost of cell wall–derived glucose are low sugar density of the biomass, cell wall recalcitrance to enzymatic hydrolysis and medium content in cellulose. Each factor either impacts transportation or requires intensive use of energy and chemicals for processing (Blanch et al., 2008; Klein-Marcuschamer et al., 2010; Searcy et al., 2007). Therefore, enhancement of polysaccharide accumulation in raw biomass and improvement of biomass digestibility will have important beneficial impacts on the cost of lignocellulosic biofuels production (Blanch et al., 2011; Klein-Marcuschamer et al., 2010). "
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    • "Development of efficient processes for converting renewable lignocellulosic biomass into biofuels requires microorganisms that produce target biofuels such as ethanol at high yields, titers, and productivities (Blanch et al., 2008). It is a challenging task to engineer microorganisms to perform well in the presence of compounds derived from biomass hydrolyzates, which typically contain mixtures of hexoses and pentoses together with inhibitors such as organic acids (e.g., ferulic acid, acetic acid), furan derivatives (e.g., furfural, hydroxymethylfurfural), and phenolic compounds. "
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