Plant breeding and biotechnology for innovative biofuels feedstocks and increased productivity
Plant breeding and biotechnology can be used to improve energy crops to increase yield, improve tolerance to pests and drought, to alter the characteristics of the plants (e.g. percentage of lignin, oil content, cell structure) making it more efficient to convert them to liquid biofuels. Plants may also be modified to produce specific chemicals, or to express enzymes that facilitate bioindustrial processing. See below for examples.
Reseachers at Michigan State University have identified a switch that regulates photosynthesis, and enables 'balanced plant metabolism'. A greater understanding of this switch mechanism could help to develop food and fuel crops that are more resiliant to environmental stress. (April 2015)
Syngenta has developed Enogen® corn (with 'corn Amylase trait') that increases the efficiency of ethanol production by 8% [Ref: Western Plains Energy]. The variety is currently supplied to 9 commercial ethanol plants in the US [Source: Syngenta April 2015]. See also Cellerate Process Technology.
Reseachers at the University of Manchester have manipulated two genes (PXY and CLE) in poplar trees to make them grow larger and faster (April 2015).
Virginia Tech has received a $1.4m grant (August 2014) to investigate optimising yields fom Populus spp. on poorer soils and under various environmental stresses. See also Hybrid Poplar for Bioenergy and Biomaterials Feedstock Production on Appalachian Reclaimed Mine Land (Amy Brunner et al, 2009).
In October 2013, UCLA published details of a synthetic glycolytic pathway (non-oxidative glycolysis, or NOG) that converts all six glucose carbon atoms into three molecules of acetyl-CoA (as opposed to the 4 carbon atoms converted naturally). This would potentially increase conversion efficiency of feedstock to ethanol by 50%. [Source: Nature, October 2013, Synthetic non-oxidative glycolysis enables complete carbon conservation].
In 2013, VIB Department of Plant Systems Biology, Gent, Belgium carried out a field trial in poplar trees in which the CCR-enzyme was suppressed to reduce the synthesis of lignin, and facilitate production of greater yields of ethanol. The technique is now being further developed to improve consistency and efficiency.
In July 2012, a paper published in Plant Cell by scientists at the Brookhaven National Laboratory suggest that a new enzyme (Engineered Monolignol 4-O-Methyltransferase) can reduce lignin content in cell walls making them easier to breakdown and convert into biofuels.
In September 2012, Purdue University, US, announced it has receieved a $5.2m grant to develop plants that produce phenylethanol, by modifying the metabolic route that normally converts phenyalanine to lignin. Initial research will be carried out using Arabidopsis, but the technique could eventually be applied to energy crops such as Switchgrass.
Partly supported by the PETRO program, Chromatin has engineered sweet sorghum to accumulate the fuel precursor farnesene (20%), a molecule that can be blended into diesel fuel.
Arcadia Biosciences, in collaboration with the University of California-Davis, is developing plants that produce vegetable oil in their leaves and stems (as opposed to seeds). Various projects are also looking at improving oil yields from modified strains of Camelina, and producing oils from modified Tobacco plants. University of Florida is working to increase the amount of turpentine in harvested pine from 4% to 20% of its dry weight.
Samuel Roberts Noble Foundation has also developed novel strains of switchgrass that contain lower amounts of lignin and hence boost biofuel yields by over a third [Source: Proceedings of the National Academy of Sciences].
Agrivida, Medford, Mass., uses protein-engineering expertise to produce low cost sugars from cellulosic feedstocks, such as corn stover, sorghum and switchgrass. Agrivida is developing both seeds engineered with pretreatment and cellulose-degrading traits, and processing techniques for activating the plants' cell wall-degrading enzymes in industrial and agricultural processes.
Research at Oregon State University suggest that modified trees with reduced height offer traits that could be beneficial for SRC and bioenergy.
In Singapore, Temasek Life Sciences Laboratory and JOil Pte Ltd. have developed Jatropha strains with 75% oleic acid content, compared to the typical 45% percent.
In the UK, the Centre for Novel Agriculturual Products, CNAP also carries out research on increasing biomass for biofuel production, biomass oils, and biorenewable products.