A major international research project that seeks to develop new bacterial strains capable of converting waste rice straw into biofuel will receive over $2 million of UK funding, with matched resource from the Department of Biotechnology (DBT) in India.

Researchers from the University of Nottingham and the International Centre for Genetic Engineering and Biotechnology (ICGEB) in India will collaborate to engineer enzymes, bacteria and bioconversion processes using synthetic biology toward the production of advanced biofuels from rice straw, the left over from rice harvests. Waste rice straw is typically burned by farmers in large quantities in order to dispose it. The team aims to develop an enzyme cocktail optimized for deconstructing rice straw into the necessary raw materials for biofuel production.

Researchers at the U.S. Department of Energy's Oak Ridge National Laboratory (ORNL) have identified two fundamental processes - cellulose dehydration and lignin-hemicellulose phase separation - responsible for the morphological changes in biomass during pretreatment processes used in breaking down woody plant materials for biofuel production.

Pretreatment processes use extremely high temperature and pressure to break apart the protective lignin and hemicellulose polymers that surround cellulose fibers in the biomass. Once released, cellulose can be enzymatically degraded into simpler sugars, and then fermented into ethanol. Understanding the mechanism of biomass breakdown during pretreatment will lead to more efficient conversion of biomass into ethanol.

By integrating experimental techniques including neutron scattering and X-ray analysis with supercomputer simulations, ORNL scientists found that water molecules trapped between cellulose fibers are pushed out as the biomass heats up during pretreatment. This loss of water causes the cellulose fibers to move closer together and become more crystalline, making them harder to break down. The team also discovered that lignin and hemicelluloses polymers separate into different phases during pretreatment.

With these findings, the researchers conclude that they need to find a balance which avoids cellulose dehydration but allows phase separation, in order to improve the pretreatment process. But how that could be done still requires further research.

Researchers at Scripps Institution of Oceanography at the University of California San Diego have developed a metabolic engineering approach to increase the yield of biofuel-relevant lipids in a microscopic marine algae species without affecting its growth.

Algae mainly produce lipid oils, the fat molecules that store energy that can be produced for fuel, when they are starved for nutrients. Limited nutrition, however, reduces algal growth. With a robust diet, algae grow well, but they produce carbohydrates instead of the desired lipids. To address this problem, Scripps researchers employed a targeted metabolic manipulation that would result in increased lipid yields and sustained biomass accumulation. Specifically, they metabolically engineered a "knock-down" of fat-reducing enzymes called lipases to increase algal lipid yields without compromising growth.

The team used a data set of genetic expression (called transcriptomics) obtained from a group of microalgae known as diatoms (Thalassiosira pseudonana) to target the lipase enzyme. The target enzyme's ubiquity suggests that this approach can be applied broadly to improve the economic feasibility of algal biofuels in other groups of microalgae.

In Australia, researchers have finished determining the sugar content of the leaves of agave, also known as tequila plant, moving closer to the next step - finding a way to convert the plant material into biofuel.

Central Queensland University researchers have found the tequila leaves to have strong potential as bio-ethanol source. In Mexico, the stem of the tequila plant is used to produce alcohol worth up to $200 a liter and the leaves are just left on the ground as mulch. The Australian team is currently working toward the development of a technology for converting the tequila leaves into bio-ethanol.