Algae protein feedstock developed at UCLA
Photo: Yikun Tan, UCLA
March 8, 2011
BY Luke Geiver
James Liao, professor of chemical and bimolecular engineering at UCLA, has developed an algae process for biorefining that, when compared to current process methods focused on lipid extraction, is just the opposite. Liao, and his team from UCLA published their findings after three years of work, and he explained to Biodiesel Magazine what they found during their research. “Basically,” he said, “we’ve developed a technology that can use protein as a raw material for a biorefinery, and for making biofuels.”
The way people are currently utilizing algae, Liao said, is by artificially starving the algae to induce the strains to produce lipids, which will eventually be extracted and used as oil for biofuels. In this process, Liao explained, the algae species become sick and don’t grow as well or as fast as they otherwise may. “We reasoned that if we could use proteins as a resource instead of lipids,” he said, “we could bypass many of these difficulties.” Liao believes his approach to algae benefits from the fact that certain proteins that cannot be used for food are the main components in photosynthesis and carbon dioxide fixation. “The protein is a machine that harvests the energy that fixates the CO2,” he explained. “So if you want a cell to grow fast, you need the cell to have a lot of proteins. If we want the cell to fixate a lot of CO2, to grow very fast, to fixate a lot of sunlight, the cell needs a lot of proteins to do the job.”
Liao correlates the potential of algae proteins in banking terms. “Imagine if you had money in a bank and you keep taking the interest out,” he said. “That is what we are doing (with current algae approaches based on lipid extraction). We are taking the interest out as lipid or carbohydrates. Those things don’t add to your principle, they don’t keep making money,” he said, “then just take them out.”
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But, one of the noted problems with protein usage is the nitrogen content. Liao’s process, which has already been licensed by an unnamed company, takes out the nitrogen from the proteins and recycles it back into an algal growing pond. By altering the commonly used E. coli bacteria, Liao and his team developed an artificial metabolic system that converts the algal proteins. “The metabolic system is like fermentation,” he said. First the algal proteins are harvested then “cooked” for nearly an hour at 80 to 100 degrees Celsius, turning the algal proteins into a hyrdolysate. Then, those proteins are fed to the altered E. coli, which ferments the proteins into alcohols and, at the same time, secretes the ammonia for reuse.
“I think we’ve demonstrated the feasibility and we are ready for the next step test,” he said, adding that his study clearly shows that cellular nitrogen metabolism control is possible. “The beauty of this idea is that we can use any fast-growing algae that can be found in any native environment.” Liao and his team plan to continue the research and analyze any problems associated with scaling up the process to a commercial level. Although the team has already licensed the technology, they plan to continue the work, through possible funding by the licensee, until it is time to hand over the process.
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