Better Bugs to Make Plastics

A startup that has successfully engineered bacteria to make common industrial chemicals is now using its technology to engineer organisms to make renewable fuel.

OPX Biotechnologies, based in Boulder, Colorado, says its strains of E. coli can be used to convert sugar to acrylic acid–a key component of paints, diapers, and adhesives–at lower costs than making it from petroleum. The bacteria-based process produces 75 percent fewer carbon-dioxide emissions than making the same amount from oil, and a single commercial plant using the process could reduce petroleum consumption by over 500,000 barrels per year.

The technology has been demonstrated in a pilot plant with a 200-liter fermentation tank, and the company plans to build a 20,000 liter system starting next year. Then it plans to build a commercial plant in 2014 that can produce 100 million pounds of acrylic. So far the company has raised $22.4 million of venture capital. The company is also working on a process that employs bacteria to convert carbon dioxide and hydrogen into diesel fuel. The U.S. Department of Energy’s Advanced Research Projects Agency for Energy (ARPA-E) recently gave the company a $6 million grant to demonstrate the technology in a pilot plant within three years.

The company is one of dozens of startups that have sprung up to make chemicals from plant matter rather than petroleum. It’s something researchers have been trying to do for decades, but only recently have they had any success with commercial-scale production. For example, in 2007, DuPont started commercial production of propanediol (used for plastics and cosmetics) made from corn sugar.

OPX’s approach to engineering strains of microorganisms is faster and cheaper than conventional methods, says CEO Charles Eggert. The company has developed a novel way of generating mutations that lets it track which genes are responsible for performance changes. Rather than hoping that all of the best changes are combined at random in a single strain, which is the case with the conventional approach, the OPX researchers use this detailed information to select genetic changes from a variety of randomly created strains and combine them into one.

Commercializing the technology will be challenging. The company still needs to produce acrylic acid at costs at or below the costs for conventional petroleum-based acrylic acid. Eggert says this is possible based on the performance of OPX’s organisms, but costs are often greater than expected. For one thing, it’s difficult for bio-based approaches to produce a product with the 99.99 percent purity levels that industrial customers require, says Robert Kirschbaum, vice president of open innovation at Netherlands-based DSM, a major producer of chemicals, including acrylic acid. If the chemical is not pure enough, a company must buy expensive purification equipment, which throws off its cost estimates.

For its ARPA-E diesel project, OPX is using its technology to engineer a bacteria, cupriavidus necator, to produce fatty acids to make biodiesel. This could be mixed with petroleum-based diesel for use in vehicles. OPX could use carbon dioxide emitted from power plants and hydrogen from a variety of sources, including natural gas. The goal of the ARPA-E project is to use hydrogen generated from renewable sources, such as water splitting using electricity from solar panels.