Investments move Proterro sucrose pilot project forward

By Sue Retka Schill | December 18, 2012

With new funding in hand, Proterro Inc. is poised to take its sucrose-producing process to the pilot stage, using full scale-bioreactors. The company is projecting the process can produce fermentation-ready sugar at a cost of less than 5 cents per pound, according to CEO Kef Kasdin, who said the projection was based on detailed and robust economic modeling that includes depreciation and operating costs. 

Proterro announced Dec. 18 that it has closed on a $3.5 million financing round led by current investor Braemar Energy Ventures. Cultivian Ventures and Middleland Capital joined as new investors, with other existing investors, Battelle Ventures and its affiliate, Innovation Valley Partners, also participating in the round.

“This capital infusion will support our continued work on optimizing the genetic engineering of the microorganism and adding to our patent portfolio,” Kasdin said. “The funds also will enable us to accelerate the path to business partnerships, through piloting a full-scale photobioreactor and completing designs for our demonstration-scale facility.” She expects the pilot-scale facility will be running in the first half of next year, testing a handful of the company’s solid-state reactors. “And then we’ll be ready to build the demo facility with up to 100 of these.”

Two years ago, Proterro announced it had achieved proof of concept utilizing engineered sucrose-producing cyanobacteria and had successfully scaled a prototype bioreactor up to a square meter size. This spring the company achieved continuous production for three months, Kasdin said, and began work on designing a full-scale reactor.

“CO2 is our feedstock,” Kasdin said. “We are an efficient user of carbon dioxide. We don’t need pure CO2, and we don’t need a lot.” The company sees co-location with an ethanol plant to provide CO2 and utilize the sugars as a distinct possibility. “We could look at other emitters of CO2, such as power plants,” she added.

“These engineered cyanobacteria, which require a combination of only water, carbon dioxide, sunlight and nutrients to produce sucrose in a biosynthetic process at consistently high yields, are unique to us,” she said. “They are why we can say that we are the only company that ‘makes’ sugar – others must ‘extract’ it from crops, which has proven to be a far more expensive proposition.”

“This gives us a solid technical foundation with respect to intellectual property,” added John Aikens, Proterro chief technology officer and a co-inventor with Robert Turner on a patent application that was recently awarded. Aikens noted that, in addition to this newly allowed patent, Proterro has five more U.S. patent applications and multiple foreign patent applications pending.

 “What’s holding back the adoption of biofuels and biobased chemicals is the high cost of producing and delivering feedstock today,” said Ron Meeusen, Cultivian’s founder, who joins the Proterro board of directors, following the company’s investment.

“Proterro’s novel process for developing sucrose differentiates the company from all other approaches, which extract sugars from biomass,” echoed Bill Lese, managing partner at Braemar Energy Ventures.