Large-Scale Farming of Cyanobacteria Could Provide a New Source of Biofuel

One might not cook with this sugar, but from a biofuels viewpoint, it is very sweet. A class of three single-celled, algae-like organisms has been patented by a Bay Area company which when grown together releases high amounts of sugar that is just right for producing biofuels. HelioBioSys Inc. is being helped by Sandia National Laboratories to find out whether large-scale farming of these organisms would be effective.

Algae have been subjected to a great deal of research because of the huge demand for domestically produced and clean renewable energy.

Algae do not compete with food crops for water, land, or other resources and hence they are considered a desirable biofuel source. However, the water used for growing these organisms is not generally suited for agriculture. Usually, the aim of algae farms is to generate large amounts of biomass, which can then be harvested and transformed into bio-based products, including chemicals and fuels.

On the other hand, HelioBioSys is experimenting with another group of organisms known as cyanobacteria. These organisms were mistaken for algae until the early 1900s. Similar to algae, colonies of marine cyanobacteria multiply in water and have wrongly been known as “blue-green algae.” However, unlike algae, these cyanobacteria release plenty of sugars directly into the water where they grow or multiply.

Sandia Biochemist Ryan Davis believes that 1 gram of biomass per liter (0.04 ounces per quarter gallon) may be grown from a typical algae operation. Moreover, small-scale testing performed on cyanobacteria demonstrates that these organisms are capable of producing 4 to 7 grams of sugar for each liter of biomass (up to 0.25 ounces per quarter gallon) — an increased concentration of up to 700%. Hence, in terms of the amounts of sugar obtained, growing cyanobacteria is much more efficient than growing biomass.

When compared to extracting lipids from large quantities of algae mass, it was noted that extracting sugar from water is a much simpler and thus a less costly process. Compared to biomass, sugar can be easily converted into a wide range of fuels and chemicals. Besides, cyanobacteria do not need extra fertilizer to make their sugars. Such cost savings could make biofuels on par with petroleum.

However, before this, the unusual sugar production by cyanobacteria needs to be further understood so that the sugar can be maximized.

In other words, we’re trying to deconstruct the magic sauce in this cyanobacteria consortium and learn what conditions are optimal for large-scale growth.

Ryan Davis, Biochemist, Sandia National Laboratories

From the lab to large-scale farming in Sandia’s open raceway test beds

David Smernoff and Rocco Mancinelli, Founders of  HelioBioSys Inc., opted to grow a group of three cyanobacteria instead of focusing on one organism (which is typical in algae cultivation) since communal systems resemble nature more closely.

According to Smernoff and Mancinelli, cyanobacteria in communities are stronger and hence may probably endure changes in the contamination, environment and predation. Sandia is helping them test this idea.

In closed, sterile, controlled laboratories, the cyanobacteria have already been shown to be effective. Now, Sandia Scientists are growing these organisms in large raceway systems that look like long bath tubs. Although the raceway systems are indoors, they are exposed to the air, which means predation may prove to be an even bigger challenge.

Davis explains, “Giant bowls of sugar water generally don’t last long in nature.” However, this is where Sandia’s expertise in algae cultivation could be helpful, he said. “We can understand where we can prevent bacterial overload, and stop the sugars from being consumed by things we don’t want to grow.”

Cyanobacteria, unlike true algae, have a unique ability to “fix” nitrogen from the air or atmosphere, which helps to support their growth. This means cyanobacteria can literally pull their own fertilizer out of the atmosphere, preventing the need for expensive additional fertilizers.

Davis and his group are attempting to understand whether all the three cyanobacteria execute a particular function for the consortium, for example producing most of the sugars or fixing the nitrogen. Although the cyanobacteria need sunlight for growth, Davis believes that one of the cyanobacteria may serve as a sunscreen, guarding the community against light levels that become very high.

Sandia Researchers are also assessing the other aspects, such as micronutrient needs or whether there are specific triggers for sugar production that could be regulated. If the Sandia study proves to be successful, the next step would be to test the cyanobacteria outdoors in larger ponds. Once the technology is proved outdoors, HelioBioSys hopes to sell or license the technology.

Special Department of Energy program makes collaboration possible

Smernoff and Mancinelli are both Microbiologists with extraordinary backgrounds. They were co-workers at NASA, where they worked on advanced systems that could support human life extraterrestrially. With the help of HelioBioSys, both are presently working on clean energy systems that could have positive environmental effects that support human life on Earth.

In spite of their remarkable history and mission, Smernoff and Mancinelli say that without the Small Business Vouchers program of the Department of Energy, getting cyanobacteria-based sugars to market would not have been possible.

Raising the funds for us to do the research that Sandia can do, with their equipment and facilities and expertise, would otherwise be impossible. So to have this program and let a small company like ours access those resources is invaluable.

David Smernoff, Founder of  HelioBioSys Inc.

As part of the program, HelioBioSys has also teamed up with Lawrence Berkeley National Laboratory, who has agreed to send its tangential flow filtration unit in Sandia’s test beds. The unit is basically a box with a porous membrane through which molecules of a specific size alone can pass through. This will enable the Sandia Researchers to rapidly separate and filter the sugars from the marine water.

In addition, the Berkeley laboratory is investigating the feasibility of these sugars for conversion to biofuels. Apart from biofuels, sugars generated by marine cyanobacteria could also be used as the source material for many products that are presently obtained from petroleum. These comprise of pharmaceuticals, plastics, fabrics, nylon, roof shingles, asphalt, shoe polish, adhesives, etc.

As this study draws to a close by the end of the year, the country may be closer to a sweet future driven by the oldest of microorganisms.