Virginia Marine Resource Bulletin
Volume 42, Number 1, Winter 2010
By Phil Marsosudiro
Serendipity has a long history in science and technology. Alexander Fleming discovered penicillin by accident when he noticed a petri dish in which bacteria were not growing as expected. Sticky notes, microwave ovens, and even the chocolate chip were conceived while their inventors were trying to achieve something else. And in 2004, the career path of Virginia Tech professor Zhiyou Wen was radically altered by a chance conversation.
At the time, Dr. Wen was a postdoctoral researcher at Washington State University, studying ways to process animal waste. During a visit to the Washington State Department of Ecology with his advisor, an agricultural staffer happened to mention the Washington biodiesel industry and the glut of glycerol it produced as a byproduct. The staffer wondered out loud, “What are we going to do with all this glycerol?”
The question meant nothing to Wen until two days later when a lightbulb flashed in his mind. He remembered reading that glycerol (also called glycerine) is great feedstock for several species of algae. Wen suspected that some of those species might be great sources of DHA and EPA—two omega-3 fatty acids commonly found in fish oil that Americans have recently started to clamor for in their diets. Could he possibly meet consumer demand by growing algae from a biodiesel byproduct? Today, Wen is on the road to an answer, with funding from Virginia Sea Grant, the Virginia Agricultural Council, and several other agencies.
“We are only at the beginning of the race,” says Wen, now an assistant professor of biological systems engineering at Virginia Tech in Blacksburg, “but the early results are promising. The DHA we are producing in the lab from crude glycerol has the same quality as commercially available DHA. Our first aquaculture tests verified that fish will feed on our product and accumulate the DHA, just like when they feed on algae in the wild.” With luck, Wen will find a way to produce high-quality DHA and EPA in bulk for aquaculture, animal feedstock, and even human consumption.
Omega-3 fatty acids are compounds found naturally in fatty fish, such as salmon or tuna. Because most Americans don’t consume enough fish to meet their needs, the pharmaceutical and food industries have responded by selling omega-3s in fish oil capsules and additives that they incorporate into everything from farmed fish to salad dressings.
In 2008, North Americans consumed more than 59 billion pounds of omega-3s, according to industry analysts, and as more benefits of these fatty acids to cardiovascular health emerge, use is expected to grow.
Dr. Wen’s colleague, Dr. Michael Schwarz of the Virginia Seafood Agricultural Research and Extension Center (VSAREC), a Virginia Tech facility in Hampton, explains, “the increased demand has put money in the market… Many groups are looking at different ways to produce omega-3s, such as from algae grown in ponds or indoor systems, yeasts, bacteria, or from genetically modified plant sources such as flaxseed etc.”
The key to taking advantage of this opportunity, according to Schwarz, is to find a method that is inexpensive and yields a consistent and high-purity product. By producing omega-3s from a cheap and abundant byproduct of the biodiesel industry, Wen hopes to do just that.
“Crude glycerol is easy to find,” says Wen. Biodiesel production generates more than a hundred million gallons of waste product each year, and 70 percent is glycerol.
At this early stage, Wen is searching for the best combinations of algae and fermentation techniques to create the fatty acids. Until recently, it was believed that algae could only produce DHA, but Wen has found a way to produce EPA from algae.
“We worked on many species and failed many times,” he says, “but eventually we found a species that can grow on crude glycerol and produce a high level of EPA. This result is very promising, and Virginia Tech owns the patent rights on this process.”
Wen begins by preparing a batch of crude glycerol—several gallons that he’ll need to grow multiple batches of algae. He dilutes the biodiesel waste product with water and neutralizes it with acid. After a few minutes, liquid settles out into layers.” The bottom 70 percent or so is the crude glycerol we want,” Wen says.
Next he combines the glycerol, algae, and nutrients in a fermenter, a glass chamber that is about twice the size of a gallon of milk and is equipped with a stirrer, thermometer, pH probes, and other instruments. Then he waits while the algae grow.
It takes three or four days to grow each batch, which Dr. Wen runs through a centrifuge to separate the algal biomass from the liquid. He then freeze-dries the biomass to obtain a dry powder full of DHA or EPA. This is the product that industry wants tons of.
“But right now, the process is very small,” says Wen. “Running 24 hours a day, 7 days a week for three months, we end up with less than two pounds of DHA.” Not quite tons.
The Path to Market
Dr. Wen has proven that his glycerol-fed algae can produce high-quality omega-3 fatty acids, free of heavy metals like mercury and lead, which are a concern with fish-derived omega-3s. But can Wen’s process be done at industrial quantities?
“Scalability is one important factor in getting this process commercially viable, along with many other factors such as production speed, cost, quality, and consistency,” says Dr. Schwarz. There are many questions, each of which requires rigorous testing and validation. Fortunately, Schwarz and his Virginia Tech colleagues can test some applications for Dr. Wen’s omega-3s at their labs at the VSAREC in Hampton.
“For aquaculture, we can test Dr. Wen’s product in fish feed to see how it affects growth, food conversion ratios, stress reduction, etc. We can also look at how well his DHA gets retained by the fish we feed it to and its subsequent effects on final product quality, safety, shelf-life, and consumer acceptance. All of these things are on the table, even while we collaborate with other Virginia researchers who might examine Dr. Wen’s product for use in other land-based agriculture such as poultry or dairy production,” Schwarz says.
Serendipity may have started this scientific project, but Wen and his team will need continued effort to convert the science into a commercial venture. Only then will their DHA and EPA make it into grocery stores and pharmacy shelves.
“Of course we’d be glad to find industry partners who can expand and use our process,” Wen says. “Everything takes time, and there are many steps. But some people are already excited about the project. When I first described the project to a biodiesel producer, he was so excited. ‘How many truckloads do you need?’ he asked, ‘It’s all free.’ I felt bad to tell him we only needed a few gallons.”
But if all goes well at the Virginia Tech labs, Dr. Wen will need the truckloads soon.
BOX: All about Omega-3s
Americans are paying attention to omega-3 fatty acids, now that scientists and healthcare professionals have convinced them just how important omega-3’s are for cardiovascular health and more. In their various forms, DHA, EPA, and ALA, play an essential role in reducing cholesterol, preventing problems with blood clotting, and assisting brain development in babies. Scientists are also examining their possible benefits for health issues as varied as depression, arthritis, and attention deficit disorder.
“The easiest way for people to get their DHA and EPA is through a couple of capsules in the morning and at night. Lots of people don’t like to eat fish, but capsules are easy,” says Damon Dickinson of Omega Protein, Inc., the nation’s largest fish oil producer. “Many grocery products have omega-3s added during production,” says Dickinson, who lists eggs, buttery spreads, salad dressings, and power bars as examples. “The food industry knows that consumers are looking for ways to get more omega-3s in their diets.”
Omega-3 supplements are added to feedstocks for farmed fish and eggs and are also finding use in feedstocks for poultry and beef, to produce meats that have omega-3 content much higher than would occur naturally in grain-fed animals.
Dickinson quotes market studies showing that “growth in the last several years has been on the order of 35% a year, as people have been catching on,” and that’s driving the emergence of a multi-billion dollar market.
Fish oil is the dominant source for DHA and EPA, today, and will likely remain so into the foreseeable future.
“Fish oil, like fish meal, is basically a global commodity, and the fisheries associated with this product, such as menhaden, are probably some of the best managed fisheries in the world,” says Schwarz at Virginia Tech. “Fish oil producers work very hard to make sure they don’t overfish themselves out of business.”
However, some stakeholders argue that the menhaden fisheries are a problem, either because of overfishing or because of the underestimated importance of menhaden to other marine life that feed on them.
While these questions have not been definitively answered, the market would likely embrace alternative sources of DHA and EPA if they can be produced at lower cost and environmental impact. If, in addition, the new sources came with some environmental benefit—such as Dr. Wen’s use of an overabundant industrial byproduct—they would be appreciated even more.