Founders of PetroAlgae, with its home office in Melbourne, started growing algae in Fellsmere in 2006, on former wholesale greenhouse land, after getting special cultures from the University of Arizona, Tennant said.

Since then, he said, the company has expanded from the lab to small-scale outdoor production with 35 of the company’s 100 employees.

Algae as paste. PetroAlgae workers will extract the oil

Tennant pointed to a series of vertical plastic tubes filled with clear water, light green water and darker green water, and bubbling with what he said was carbon-dioxide, the fuel for any plant.The tubes represented clean water, day-old algae and 3-day-old algae, he said.

PetroAlgae Vice President Fred Tennant says, after it sells the technology to alternate-fuel companies and they make enough oil to bring diesel prices down at filling stations.

“We’re working on a small scale of a commercial station, but big enough to show (clients) how they can take this and do it on 10,000 acres,” he said on a recent tour.

He has spent recent months flying to international board meetings to pitch the idea of growing algae — instead of corn or soybeans — to make biodiesel fuel and wean off the world’s dwindling supplies of fossil fuel.