Synthesizing a Better Algae

Genetically modified algae increases biomass by up to 50 percent
By Erin Voegele | January 09, 2012

Those in the biofuel industry often think of algae as a future source of oil for conversion into biodiesel and hydrocarbon fuels. Researchers, however, say that algae may become an important source of feedstock for carbohydrate-based processing.

A team of researchers at Iowa State University has developed a technique that can increase the carbohydrate-based biomass of algae by up to 80 percent. A more energy intense version of the technique can also be used to increase the oil fraction of the biomass by approximately 50 percent.
According to the researchers, the improvements are made possible by expressing certain genes in algae that increase the amount of photosynthesis in the plant, leading to greater biomass production. A combination of two genes is used to create this increase in biomass as long as the algae is able to access sufficient carbon dioxide, says Martin Spalding, a professor in ISU’s Department of Genetics, Development and Cell Biology.

The two genes, LCIA and LCIB, are usually expressed in nature in environments that have relatively low levels of carbon dioxide. They allow the algae to capture and channel more carbon dioxide from the air into the cell, which keeps the algae alive and growing. The genes, however, shut down in environments with high carbon dioxide levels.

 The research conducted by Spalding’s team has shown that when these genes are expressed in areas of abundant carbon dioxide, the cells can produce significantly more biomass than would be otherwise possible. The researchers can also increase the oil production of algae cells by using some existing mutated genes, but that process requires more energy. The patent-pending technology is available for licensing.

—Erin Voegele