Engineered Microalgae Yields More Biofuel-Relevant Lipids

Researchers at Scripps Institution of Oceanography at the University of California San Diego have developed a metabolic engineering approach to increase the yield of biofuel-relevant lipids in a microscopic marine algae species without affecting its growth.

Algae mainly produce lipid oils, the fat molecules that store energy that can be produced for fuel, when they are starved for nutrients. Limited nutrition, however, reduces algal growth. With a robust diet, algae grow well, but they produce carbohydrates instead of the desired lipids. To address this problem, Scripps researchers employed a targeted metabolic manipulation that would result in increased lipid yields and sustained biomass accumulation. Specifically, they metabolically engineered a "knock-down" of fat-reducing enzymes called lipases to increase algal lipid yields without compromising growth.

The team used a data set of genetic expression (called transcriptomics) obtained from a group of microalgae known as diatoms (Thalassiosira pseudonana) to target the lipase enzyme. The target enzyme's ubiquity suggests that this approach can be applied broadly to improve the economic feasibility of algal biofuels in other groups of microalgae.