Genetically Altered Algae Increases Biomass for Biofuels

Martin Spalding (Bob Elbert, Iowa State Univ.)

An Iowa State University biologist has developed a process for genetically altering a strain of algae to increase its biomass content by up to 80 percent. This discovery, which can lead to enhanced production of biofuels from non-food sources, is available for licensing from the university’s technology transfer office.

Martin Spalding (pictured right), leads a team in Iowa State’s Department of Genetics, Development, and Cell Biology in Ames, that found a way of expressing certain genes in algae that increase the amount of photosynthesis in the plant, which leads to more biomass. When the two genes in Chlamydomonas reinhardti, a type of algae, are expressed (activated), they result in increased biomass production and photosynthesis under conditions amenable to industrial biofuel production.

Spaulding says in its natural form, algae are limited from growing faster because they don’t get enough carbon dioxide from the atmosphere. To get sufficient CO2, two genes in algae — LCIA and LCIB — are expressed to help capture and channel more carbon dioxide from the air into the cells to keep the algae alive and growing.

LCIA and LCIB, however, work only in low concentrations of carbon dioxide. In higher CO2 concentrations, such as in soil near plant roots that are expiring carbon dioxide, the two genes shut down because the plant is already getting enough carbon dioxide.

Spalding’s team altered the behavior of the two genes to keep them operating even in the presence of more atmospheric CO2. The excess biomass then, through its natural photosynthesis process, becomes starch and increases the biomass starch by around 80 percent.

By using some existing mutated genes, Spalding can instruct the algae to make oil instead of starch. This process requires more energy and the process results in around a 50 percent increase in oil biomass.

Iowa State’s technology transfer office, the Iowa State University Research Foundation, says a patent is pending on the process, which became available for licensing earlier this month.

Read more: Process Turns Algae into Renewable Fuel, Cleans Wastewater

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