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.
