SGT discovers green algae ‘lipid trigger'

By Lisa Gibson
California-based Sustainable Green Technologies has found the elusive "lipid trigger" allowing for increased production of green algae oil for biodiesel production, according to the company.

The secret ingredient is the waste stream from the company's patented biohydrogen-producing bioreactor. SGT's scientists were looking for ways to use the waste stream when they discovered it sparked algae growth and increased lipid production and storage when combined with green algae in a bioreactor, according to the company. An increase in lipid production means an increase in the amount of oil extracted from the algae.

Usually, algae store excess solar energy in the form of starch and in smaller amounts as lipid droplets. This breakthrough allows the plants to "flip a switch" and turn on massive production and storage of oils instead of starch, creating "obese algae," according to SGT.

The start-up company produces biohydrogen for energy using waste products like glycerol from biodiesel production, sugars from sugarcane and sugar beets, office paper once it is turned to glucose by enzymes, and brewery wastes, among others. The waste stream from that process now will be used to increase algae oil production for the company's biodiesel plant, whose waste stream will go right back into the biohydrogen bioreactor, according to the company. "It closed the loop for us," said Jim Siegrist, vice president of marketing and sales for SGT.

The biodiesel plant does not run on algae oil yet, but the company is in the process of converting the facility, he said. SGT has an application pending with the U.S. DOE for $15 million, but Siegrist does not expect to hear back with a definitive answer for about three months, he said. Once the plant is converted, it will run on the electricity produced when SGT's biohydrogen is put into fuel cells. "It's a nice, completely closed system," Siegrist said.

SGT is in discussions with potential partners, including a 3 MMgy biodiesel plant and a golf course interested in finding green uses for the algae in its ponds, according to Siegrist. The company already has one partnership with Pacific Fuel Cell Corp., he added.

-Lisa Gibson