Thursday, 23 January 2014

Time For Biofuel from Yeast Cells

Now Biofuel can be obtained from genetically engineered yeast cells and ordinary table sugar. Researchers at The University of Texas at Austin's Cockrell School of Engineering have managed to derive oils and fats, known as lipids, from yeast cells that can be used in place of petroleum-derived products as renewable energy source. Assistant professor Hal Alper, in the Cockrell School's McKetta Department of Chemical Engineering calls the biofuel produced by this process "a renewable version of sweet crude" Since yeast cells grow on sugars. Through the process of fermentation, culturing cells to convert sugar into products such as alcohol, gases or acids, highest concentration of oils and fats were reported by the researchers. The UT Austin research team managed to rewire yeast cells to enable up to 90 percent of the cell mass to convert to lipids, which can then be used to produce biodiesel. This process has wide scope to produce a variety of items made with petroleum or oils, from nylon to nutrition supplements to fuels, since fatty materials are building blocks for most household products. Yeast strain of Yarrowia lipolytica was used for this process.
Biofuels and chemicals produced from living organisms represent a promising portion of the renewable energy market.

The biofuel formulated is similar in composition to biodiesel made from soybean oil. The advantages of using the yeast cells to produce commercial-grade biodiesel are that yeast cells can be grown anywhere, do not compete with land resources and are easier to genetically alter than other sources of biofuel.
"This is a remarkable demonstration of the power of metabolic engineering."
Researchers believe this process to be capable of  industry-scale production.
In a large-scale engineering effort of over four years, the researchers genetically modified Yarrowia lipolytica by both removing and over expressing specific genes that influence lipid production. The team also found  optimum culturing conditions that differ from standard conditions. Traditional methods rely on nitrogen starvation to trick yeast cells into storing fat and materials. Alper's research provides a mechanism for growing lipids without nitrogen starvation that will make it extremely advantageous for industrial process. As compared to the other platforms that yield approximately 50 percent lipid content, this platform yields about 90 percent lipid contant.
Alper and his team are continuing to find ways to further enhance the lipid production levels and develop new products using this engineered yeast.