Scientists Synthesize Bacteria Into Biofuels
A breakthrough with the bacteria Escherichia coli (E. coli) could make it cheaper to produce fuel from switchgrass, an ad vanced biofuel with the potential to replace gasoline on a gallonfor- gallon basis. Researchers at the U.S. Department of Energy’s Joint BioEnergy Institute (JBEI) have engineered the first strains of the bacteria to digest switchgrass biomass and synthesize its sugars into all three types of transportation fuels -- gasoline, diesel, and jet fuels.
Unlike corn grain used to produce ethanol, which contains simple sugars, switchgrass biomass contains complex sugars, cellulose, and hemicellulose, bound in lignin. These complex sugars are not only difficult to extract from the switchgrass, but have to be converted or hydrolyzed into simple sugars before they can be synthesized into fuels.
JBEI researchers have demonstrated that engineered E.coli strains can both digest switchgrass and synthesize its sugars. They first pre-treat the biomass with an ionic liquid (molten salt) to dissolve it, then use the E.coli to both digest the dissolved biomass and produce hydrocarbons that have the properties of petrochemical fuels.
While this is not the first demonstration of E. coli producing gasoline and diesel from sugars, it is the first demonstration of E. coli producing all three forms of transportation fuels. Switch-grass can be used not only to produce fuels with a larger energy content than ethanol, but also has other favorable characteristics that make it a highly desirable plant for biofuel production. This non-food crop is a perennial grass that is both salt- and drought-tolerant, can flourish on marginal cropland, does not compete with food crops, and requires little fertilization.
Learn more at www.doe.gov/articles/advanced-biofuels-how-scientists-are-engineeringbacteria-help-drive-america.
Next Generation of Crash Test Dummies
Crash test dummies continue to be the accepted standard test device in the auto industry for evaluating the severity of an impact to vehicle occupants and pedestrians in a car crash. But while traditional dummies can measure the force and acceleration that is applied to a body during a crash, they cannot simulate the tissue injuries that result from these impacts.
Toyota Motor Corporation and Toyota Central R&D Labs partnered to develop THUMS (Total HUman Model for Safety), an experimental virtual model of the human body that includes not just the exterior shape, but also internal structures like organs, bone, ligaments, tendons, and muscle. This approach to crash testing simulates the in juries sustained in actual car crashes. As a result, the model is able to detect and predict the most common injuries reported in accident data analysis.
Toyota Motor Corp. began developing THUMS in 1997 with a goal of improving the quality of data gathered from crash testing. THUMS has two million distinct parts, including bones, ligaments, tendons, and the muscular systems. Toyota is using THUMS data to help develop advanced safety technologies for airbags, seatbelt systems, and vehicle body structures. THUMS currently includes a model for an adult male of average body size, and Toyota is working to create a female model and extend the system to different body sizes.
Ford also has been working to develop the first digital human child model for virtual crash testing. The work on Ford’s adult human body model took 11 years to complete. Digital models are used in research, not in vehicle development, so they don’t take the place of crash dummies, which measure the effect of forces on the body. Instead, they are used as a way to understand how to further improve restraint system effectiveness through better understanding of injury mechanisms.
The digital model is constructed component-by-component – brain, skull, neck, ribcage, upper and lower extremities, etc. – with extensive research included on each part. After gathering such data through medical scans and anatomical texts, the researchers build a model section-by-section, creating regions of the body. The brain in Ford’s adult human digital model was constructed as a separate component, detailed down to the brain stem, the gray matter, and the fluid between the layers.