Efficient biofuel production from plants and microalgae

These collaborative projects are funded by Chevron Technology Ventures (CTV) LLC and the collaborators include John Labavitch (UCD Department of Plant Sciences), Jean Van der Gheynst (UCD Department of Agricultural Engineering) and Ann Powell.

In one project, the overall objective of this project is to modify the rice straw hemicellulosic xylan in order to enhance its bioconversion to fermentable sugars by reducing the need for expensive lignocellulose pre-treatments.  Our strategy is aimed at expressing in rice plants microbial genes that code for xylan-digesting enzymes (XDEs).  The XDE-carrying constructs have been designed such that XDE gene expression is targeted to different cellular locations and controlled developmentally so that xylans in the cell wall can perform their normal structural roles up until the time that this “imposed” biological lignocellulose pre-treatment would be initiated.  We have developed several rice transgenic lines carrying a thermostable fungal xylanase.  We are currently analyzing the expression of this xylanase in the transgenic rice plants as well as assessing its impact on the rice cell wall.

In the second project, microalgae are being examined for their potential to produce starch for use in biofuels. Microalgae are able to fix CO2 and releaseO2 by photosynthetic activity. They also produce a large amount of biomass that can contain high concentrations of starch and oil. In addition, the microalgal cell wall is composed of sugars and proteins. These sugars can be used for producing biofuels by fermentation. Currently, however, most researchers have focused on using algal lipid because it can be directly converted into biodiesel via esterification processes. Our work is directed towards to using starch and sugar from microalgal cell walls for biofuel production.

Ravi Barabote, a postdoc is working on the rice and wheat straw project and Orn-a-ma Tanadul, a Horticulture and Agronomy PhD student from Thailand, is working on the microalgae project

[progress reports]