Genetics researchers at Iowa State University have discovered how to make algae produce between 50 and 80 percent more biomass, a finding that could foster the production of algal biofuel. The modification on the part of the scientists involves expressing, or activating, two genes that promote photosynthesis.
In nature, algal growth is governed by the amount of carbon dioxide available. In relatively low carbon environments, two genes — LCIA and LCIB — are expressed to capture more CO2 and direct it into the cells, promoting growth. However, when algae live in an environment with enough CO2 to promote growth, the two genes shut down. The researchers found that expressing them, even in carbon-rich environments, significantly increases growth.
“Based on some prior research we had done, we expected to see an increase, probably in the 10 to 20 percent range” researcher Martin Spalding said in a statement. “But we were surprised to see this big of an increase.”
Expressing them individually yielded a 10 to 15 percent increase in biomass. Expressing them together boosted it 50 to 80 percent. The excess biomass naturally becomes starch, increasing the biomass around 80 percent. Using existing mutated genes, Spalding can direct the algae to make oil instead. That requires more energy, increasing biomass just 50 percent.
Researchers in many fields are attracted to algae as a source of bio-fuel because it grows quickly and thrives in many different environments, from seawater to sewage. This sort of research is especially important when one takes into account the Energy Independence and Security Act requirement that bio-fuels replace more than 10 percent of our current petroleum consumption by 2022.
“There is no doubt in my mind that this brings us closer [to affordable, domestic biofuel],” Spalding said.
Spalding is a professor in the Department of Genetics, Development, and Cell Biology and associate dean for research and graduate studies in the College of Liberal Arts and Sciences.
