Researchers at North Carolina State University have developed a simple, effective and relatively inexpensive technique for removing lignin from the plant material used to make biofuels, which may drive down the cost of biofuel production.
Lignin, nature’s way of protecting plant cell walls, is difficult to break down or remove from plant materials called “biomass,” such as the non-edible parts of the corn plant. However, that lignin needs to be extracted in order to reach the energy-rich cellulose that is used to make biofuels. (more…)
The first dynamic regulatory system that prevents the build-up of toxic metabolites in engineered microbes has been reported by a team of researchers with the U.S. Department of Energy (DOE)’s Joint BioEnergy Institute (JBEI). The JBEI researchers used their system to double the production in Escherichia coli (E. coli) of amorphadiene, a precursor to the premier antimalarial drug artemisinin.
Using genome-wide transcriptional analysis, the JBEI researchers identified native regions of DNA – called “promoters” – in E. coli that respond to toxic metabolites by promoting the expression of protective genes. They then developed a system based on these promoters for regulating artificial metabolic pathways engineered into the E.coli to enable the bacterium to produce amorphadiene. (more…)
New Technique Identifies Populations Within a Microbial Community Responsible for Biomass Deconstruction
One of the keys to commercialization of advanced biofuels is the development of cost-competitive ways to extract fermentable sugars from lignocellulosic biomass. The use of enzymes from thermophiles – microbes that thrive at extremely high temperatures and alkaline conditions – holds promise for achieving this. Finding the most effective of these microbial enzymes, however, has been a challenge. That challenge has now been met by a collaboration led by researchers with the U.S. Department of Energy (DOE)’s Joint BioEnergy Institute (JBEI).
Working with a compost-derived consortium of thermophillic bacterium adapted to grow on switchgrass, a leading potential fuel crop, and using a combination of metagenomic and metaproteomic technologies, the collaboration has identified individual microbial species whose enzymes were the most active in deconstructing the switchgrass biomass. Major institutes in addition to JBEI participating in this collaboration included DOE’s Joint Genome Institute (JGI), and EMSL, the Environmental Molecular Sciences Laboratory, a national scientific user facility at Pacific Northwest National Laboratory (PNNL). (more…)
Digesting lignin, a highly stable polymer that accounts for up to a third of biomass, is a limiting step to producing a variety of biofuels. Researchers at Brown have figured out the microscopic chemical switch that allows Streptomyces bacteria to get to work, breaking lignin down into its constituent parts.
PROVIDENCE, R.I. [Brown University] — Microorganisms that can break down plant biomass into the precursors of biodiesel or other commodity chemicals might one day be used to produce alternatives to petroleum. But the potential of this “biorefinery” technology is limited by the fact that most microorganisms cannot break down lignin, a highly stable polymer that makes up as much as a third of plant biomass.
Streptomyces bacteria are among few microorganisms known to degrade and consume lignin. Now a group of researchers at Brown University has unlocked the genetic and molecular mechanisms behind a key part of that process. The results are published in the journal Nucleic Acids Research. (more…)
Researchers Show Ionic Liquids Effective for Pre-Treating Mixed Blends of Biofuel Feedstocks
Winemakers have long known that blending different grape varietals can favorably balance the flavor characteristics of the wine they produce. In the future, makers of advanced biofuels might use a similar strategy, blending different feedstock varieties to balance the energy characteristics of the transportation fuel they produce.
A collaborative study by researchers with the U.S. Department of Energy (DOE)’s Joint BioEnergy Institute (JBEI), a bioenergy research center led by Berkeley Lab, and the Idaho National Laboratory (INL) has shown that an ionic liquid proven to be effective for pre-treating individual biofuel feedstocks is also effective at pre-treating multiple different feedstocks that have been mixed and densified into a blend. (more…)
Joint BioEnergy Institute Researchers Find New Access to Abundant Biomass for Advanced Biofuels
After cellulose, xylan is the most abundant biomass material on Earth, and therefore represents an enormous potential source of stored solar energy for the production of advance biofuels. A major roadblock, however, has been extracting xylan from plant cell walls. Researchers with the U.S. Department of Energy (DOE)’s Joint BioEnergy Institute (JBEI) have taken a significant step towards removing this roadblock by identifying a gene in rice plants whose suppression improves both the extraction of xylan and the overall release of the sugars needed to make biofuels.
The newly identified gene – dubbed XAX1 – acts to make xylan less extractable from plant cell walls. JBEI researchers, working with a mutant variety of rice plant – dubbed xax1 – in which the XAX1 gene has been “knocked-out” found that not only was xylan more extractable, but saccharification – the breakdown of carbohydrates into releasable sugars – also improved by better than 60-percent. Increased saccharification is key to more efficient production of advanced biofuels. (more…)
*Joint BioEnergy Institute (JBEI) Researchers Reach Milestone on the Road to Biofuels*
A milestone has been reached on the road to developing advanced biofuels that can replace gasoline, diesel and jet fuels with a domestically-produced clean, green, renewable alternative.
Researchers with the U.S. Department of Energy (DOE)’s Joint BioEnergy Institute (JBEI) have engineered the first strains of Escherichia colibacteria that can digest switchgrass biomass and synthesize its sugars into all three of those transportation fuels. What’s more, the microbes are able to do this without any help from enzyme additives. (more…)
