Are marine algae just as good as fresh water algae in producing biofuels? Yes, according to biologists at University of California San Diego. In a research study published in Algal Research, scientists genetically engineered marine algae to produce five different kinds of industrially important enzymes. The same process, say the researchers, could be used to enhance the yield of petroleum-like compounds from salt water algae.
Researchers say this discovery is important because it expands the kinds of environments in which algae can be conceivably grown for biofuels. For example, algal biofuels could be produced in the ocean, in brackish water of tidelands, or on agricultural land where crops can no longer grow due to the high salt content of the soil.
“What our research shows is that we can achieve in marine species exactly what we’ve already done in fresh water species,” said Stephen Mayfield, a professor of biology at UC San Diego, who headed the research project. “There are about 10 million acres of land across the United States where crops can no longer be grown that could be used to produce algae for biofuels. Marine species of algae tend to tolerate a range of salt environments, but many fresh water species don’t do the reverse. They don’t tolerate any salt in the environment.”
“The algal community has worked on fresh water species of algae for 40 years,” added Mayfield, who also directs the San Diego Center for Algae Biotechnology. “We know how to grow them, manipulate them genetically, express recombinant proteins—all of the things required to make biofuels viable. It was always assumed that we could do the same thing in marine species, but there was always some debate in the community as to whether that could really be done.”
The timing of the research was fortuitous – in October, the National Academy of Sciences committee published a report concluding that the production of algal biofuels might be limited by fresh water. “But now we’ve done it,” said Mayfield. “What this means is that you can use ocean water to grow the algae that will be used to produce biofuels. And once you can use ocean water, you are no longer limited by the constraints associated with fresh water. Ocean water is simply not a limited resource on this planet.”
In addition to expanding this research, the scientists would like to determine whether whole algae, post-oil extraction, could be sued as a feed additive to improve animal feeds.