Scientists at Scripps Institution of Oceanography (SIO), in a partnership with Southern California Gas Co. (SoCalGas), are busy at work proving that it is indeed easy to be green. The subject of the collaborative effort is one that swimmers, surfers and other ocean lovers are familiar with. It is abundantly available, as is the scientific talent needed to study it, in San Diego. It is often mislabeled — unfairly, according to one researcher — as slimy or scummy. It is marine algae, and it could be the answer to the country’s oil-addiction woes and skyrocketing gas prices. SIO, a member organization of the San Diego Center for Algae Biotechnology, has been the center of studies for several years on the use of algae as a clean, renewable biofuel. Researchers are hoping they can take the advantages of algae one step further, by leveraging its natural ability to absorb CO2 in the environment and convert it into oil-rich biomass or biomethane, or refined into fossil fuel replacements. Furthermore, the biomass left over after oils used for biodiesel are extracted can be used as a safe, protein-rich animal feed. As part of the increased efforts to harness the potential benefits of algae, Scripps and SoCalGas are designing an innovative system to investigate how algae could most effectively capture industrial CO2 from sources like natural gas power plants, large engines used in natural gas compression and water pumping, and boilers used to produce steam for industrial processes like enhanced oil recovery. “We can farm algae on land or in the water, and we can take waste nutrients, such as feed-lot waste and waters from feed lots, and feed them to the algae,” said Dominick Mendola, a senior development engineer in the laboratory of Greg Mitchell, a Scripps research biologist who is exploring marine algae for its potential as a new biofuel source. “When we add into the water carbon dioxide gas from the exhaust of an engine or a power plant, then we have the perfect crop, because we’re recycling CO2, converting oils into transportation oils, and the carbohydrates can be digested to produce methane gas while the proteins can be ex-tracted and made into animal feed. We’re trying to use all the parts.” Algae, as compared to other sources of biofuel like corn and soybeans, is five to 10 times more efficient in converting light energy into a natural biomass oil product. Plus, it can be grown in harsh conditions — like a barren desert, using seawater — making it superior to terrestrial plants that need nutrient-rich soil and valuable fresh water for irrigation. “Terrestrial plants have to produce cellulose and lignin to hold themselves up to the sunlight. Floating plants don’t have to do that, so they don’t have to spend energy on that,” Mendola said. “Because they don’t have that extra cellulose and lignin, they’re soft and easy to digest, and easier to break down and convert into biofuel. Though we do have to break the cell wall and get the oils out, it’s still easier than crushing bamboo or grass.” The path to an algae-cum-biofuel-dependent society is not yet entirely paved, however. Various challenges have arisen, most notably the problem of getting algae to grow while still producing the lipid oils that can be converted into biodiesel. Algae, it turns out, generally only produce those lipids when starved for nutrients. When starved for nutrients, however, algae don’t grow well. Given a healthy diet, algae produce carbohydrates, not lipids. Thus, some Scripps researchers are investigating, as reported in UCSD’s Explorations Now magazine, how genes are turned on in lipid production, to identify which genes are induced when lipids are produced. Another challenge researchers are facing is one of money. Right now, Mendola said, producing a gallon of algae biofuel is still three times as expensive as fossil fuel oil. That number, however, is a promising one, he said. “We’re all encouraged that it’s only two to three times as expensive at this point,” he said. “We can get that number down by economy of scale — the larger [the farm], the more economy of scale you will realize. We have to have some breakthroughs in harvesting, but there are some very smart people who are looking at new methods and procedures, and we all have a lot of faith that we’ll be able to shave the cost down in time.” If and when the research gets to the point at which it can support a large-scale algal biofuel industry, scientists have no doubt it has the potential to change the landscape of biofuels and the future of how we power our cars, trucks and aircraft. “It won’t save all of the universe, but it will definitely help,” Mendola said. “We’re here to show that algae is a very productive plant, much more so than terrestrial plants. It’s way far and above as a producer of oil than corn, soy, palm, etc. We still have to refine the systems, select algal strains that are good producers on a reliable basis and get the cost down. But we just started.”