Most biofuel comes from corn. The concern: will too many farmers switch to fuel crops? Fuel crops are more lucrative and less expensive to farm than food crop; and as biofuel becomes a mainstream alternative, the world may face major food shortages. Algae is a great biofuel alternative. This single-cell organism is capable of creating and storing natural oil in quantities up to 60% of its dry weight. It can grow in places corn can’t and in high stacks of containers that take up a lot less land than cornfields. The oil itself is a high-quality, almost-ready-for-combustion fuel. That’s what Drs. Yuval Ebenstein and Yael Michaeli already know. The next question: can we produce enough for commercial use?
"Biodiesel is fuel naturally produced by plants and organisms. Many see it as a green alternative to today's expendable fuels," says Dr. Ebenstein. "At present, the majority of biodiesel on the world market is produced from corn. But corn crops for fuel compete with food crops. Many farmers prefer to grow corn for fuel because of its profitability, which could lead to a food shortage. Algae are not food.
"They produce high-quality fuel, almost ready for combustion, and can be grown in areas unsuitable for agriculture, such as the desert. Moreover, quantities of algae can be grown in high stacks of containers that do not require much space, unlike field crops."
The algae studied are unicellular organisms capable of creating and storing natural oil in a quantity up to 60% of their dry weight. This oil is produced by the algae when under stress as a survival mechanism — a kind of energy store for times of shortage, very similar to fat stores in the human body. Properties discovered in the laboratory are promising: biodiesel produced by algae can power a car practically as is, without costly, polluting processing. So how can we produce a sufficient quantity for commercial use? This is the challenge facing the research team at Tel Aviv University today.
To make the process of generating oil in algae more efficient, researchers are developing in-depth understanding. They systematically alter parameters in the growing environment such as nutrition, temperature, cycles of light and dark, and the supply of essential materials nitrogen and iron, and examine optimal conditions for creating the maximum quantity of fuel.
Advanced optical imaging technology allows close monitoring of oil accumulation in the cell in real time. The oil is colored; making it is possible to identify the quantity formed, and the place where it is concentrated within the cell. Together with visual imaging, scientists seek to understand what occurs in the cell at the biological and genetic levels. To do so, they use a genetic analysis method called RTPCR (real-time polymer chain reaction). This method measures quantities of types of RNA found in the cell at a given time, helping researchers to identify proteins related to the fuel production process. Dr. Ebenstein explains: "RNAi genetic material that is a recipe for creating proteins in a cell. A high level of a particular type of RNA indicates that the cell is making an effort to create a matching a type of protein, in response to a change that we have made to environmental conditions. In this way, we identify proteins whose level increases significantly in response to specific environmental conditions, encouraging the production of fuel. Proteins identified as being significant in the oil production process are examined in depth, including genetic manipulations intended to increase output."
In the future, scientists hope to move out of the laboratory and partner with industry to promote commercial production of biological, algae-based fuel.
Dr. Yuval Ebenstein is a promising young scientist who returned to Tel Aviv in 2011 as part of the University's effort to bring Israel's best and brightest home. Dr. Ebenstein specializes in physical chemistry and biophysics, and developed innovative optical technologies for reading genetic information at UCLA. He was awarded a Rothschild scholarship and the prestigious International Human Frontiers Fellowship; and has published 20 research studies in leading journals.