Bacteria Make Diesel from Biomass

Newly engineered E. coli streamline the conversion of cellulose into fuel.

Engineered bacteria have been rewired with the genetic machinery necessary to convert cellulose into a range of chemicals, including diesel fuel. The bacteria, developed by South San Francisco company LS9 in collaboration with researchers at the University of California, Berkeley, make the necessary enzymes for every step along the synthesis pathway and can convert biomass into fuel without the need for additional processing. LS9 has demonstrated the bacteria in pilot-scale reactors and plans to scale the process to a commercial level later this year.

Jay Keasling, professor of chemical engineering and bioengineering at UC Berkeley and one of LS9's founders, and scientists at LS9 report engineering E. coli bacteria to synthesize and excrete the enzyme hemicellulase, which breaks down cellulose into sugars. The bacteria can then convert those sugars into a variety of chemicals--diesel fuel among them. The final products are excreted by the bacteria and then float to the top of the fermentation vat before being siphoned off.

Using these methods, it's possible to create a range of fuels from biomass, but LS9 is focusing on diesel rather than fuels similar to gasoline for the time being, says Stephen del Cardayre, the company's vice president of research and development. Diesel specifications are easier to meet and the market for diesel is growing by 2 to 4 percent a year, while that for gasoline is flat. Last May, LS9 partnered with Procter & Gamble to develop fuels as well as commodity chemicals.



LS9's process is built on E. coli bacteria's metabolic machinery for converting sugars into fatty acids, which they then use to make other molecules. The advantage of working with E. coli is that the organism, a workhorse of molecular biology, is well known and easy to grow, says Keasling. And the bacterium's fatty acid pathway is more efficient at turning feedstocks into fuel than metabolic pathways used by other synthetic biology companies.

Fatty acids are a large class of molecules that can form the basis of many commodity chemicals and fuels that are conventionally derived from petroleum. These metabolic pathways are complex networks, and taking advantage of them required changing several of the bacterium's existing genes as well as adding new ones. After years of engineering, says Keasling, "we can get the molecule we want specifically."

Del Cardayre says LS9 has tested the diesel-production process at its 1,000-liter pilot-scale plant in South San Francisco using sugarcane as a feedstock. The company will scale the process to a commercial level at a 75,000-liter plant this year.

LS9 isn't the only company turning sugarcane into diesel: last year, another synthetic biology company founded by Keasling, Amyris Biotechnologies of Emeryville, CA, opened a demonstration plant in Campinis, Brazil. Amyris's process is based around yeast engineered to convert sugars into hydrocarbon-fuel precursors. Del Cardayre says LS9 may open a plant in Brazil as well, but because the new bacteria can convert cellulose, not just sugar, the company isn't tied to sugarcane or any other feedstock.

Jim Collins, professor of biomedical engineering at Boston University, says the question now is whether LS9's process will be cost-effective on a large scale. "As you go from 10 gallons to thousands of gallons, the biology changes, and analyses that worked well in the lab no longer work," notes Collins, because the microbes' environment changes. "The interesting question in the next few years is, which company can get their yields high enough, and get their processes up to scale to keep costs down," says Collins.

Experts Break Mobile Phone Security

A researcher has shown that attacks on a long-standing mobile phone standard are possible.

The algorithm used to protect the security of communications on 80 percent of cell phones in the world can be relatively easily cracked to intercept calls, according to cryptographers at the 26th Chaos Communication Congress, a computer conference in Berlin. A German researcher presented an attack on the Global System for Mobile Communications (GSM)--showing it's possible to eavesdrop on cell phone calls and intercept SMS messages. Mobile phones worldwide use GSM, though in the United States many carriers, including Verizon and Sprint PCS, use a competing standard.

Karsten Nohl, who has a PhD in computer science from the University of Virginia, says he demonstrated the GSM attack to encourage people to develop a more sophisticated means of protection. GSM encryption was introduced in 1987, and first showed cracks in the 1990s. Nohl points to a series of academic papers illustrating problems with A5/1, which is used to protect GSM calls.

Nohl says that despite these concerns, people trust GSM with ever more sensitive data. In particular, there have been recent moves to use the standard for mobile banking, payments, and authentication.

Working with a group of hackers, Nohl generated and published a "rainbow table" for A5/1. This table is an optimized set of codes that would allow an attacker to quickly find the key protecting a given phone conversation. The group also cracked another algorithm that protects conversations by shifting communications between mobile phones and base stations to a variety of different frequencies during a call.

"It would be a good time to start transitioning GSM systems to more advanced cryptographic algorithms," says David Wagner, a professor at the University of California at Berkeley who was involved in work in the early 2000s that proved it was possible to break A5/1. "We should be grateful. We don't always get advance warning that it's time to upgrade a security system before the bad guys start taking advantage of it."

Wagner says the research brings no surprises. It simply demonstrates that attacking GSM's encryption is more feasible than previously realized. "The bottom line for cell phone users is about the same," he says. "Interception of GSM calls is possible, but takes serious technical sophistication." Intelligence agencies, however, are probably following this closely, Wagner adds, since they're in a position to use these techniques to decrypt GSM calls en masse, and may already be doing so.

The GSM Association, a London-based organization that "represents the interest of the worldwide mobile communications industry," begs to differ. "All in all, we consider this research, which appears to be motivated in part by commercial considerations, to be a long way from being a practical attack on GSM," the organization said in a statement. "Before a practical attack could be attempted, the GSM call has to be identified and recorded from the radio interface. So far, this aspect of the methodology has not been explained in any detail, and we strongly suspect that the teams attempting to develop an intercept capability have underestimated its practical complexity."

Plastic Logic Device Showcases Organic Transistors

Today at the Consumer Electronics Show in Las Vegas, Plastic Logic announced the details of the first consumer product based on organic transistors, a technology that's been limited to the lab for the past 20 years. The company's thin, lightweight e-reader, called the Que, uses organic transistors to power a black and white, touch-sensitive display made by E Ink, an electronic paper company. Such transistors can be built on lightweight plastic backings.

For the Que, the organic transistors mean a large and lightweight touch-sensitive display measuring 27 centimeters. Que users can annotate documents, by either scribbling directly on them with a finger, or using a touch-screen-based keyboard to type in notes. The two models announced today were a version with 4 gigabytes of onboard memory, retailing for $649 and the 3G-enabled version, with 8 gigabytes of memory for $799. The 8 gigabyte version should be able to store about 75,000 documents. Both weigh roughly 0.5 kilograms.

The home page on the Que features a calendar display that synches with Microsoft Exchange, and Que is working on creating wireless email and calendar. The company is partnering with Barnes and Noble to create a dedicated store, with business-oriented books and periodicals (including Technology Review) available.

To enhance the presentation of newspapers and magazines, Plastic Logic has partnered with Adobe to create the so-called truVue standard, which creates templates designed to give periodicals more of the look and feel of pages from a print issue. Subscriptions are downloaded using either WiFi or over AT&Ts 3G network.

Organic transistors can be made at much lower temperatures than those made with conventional silicon, which means it's possible to print them on top of lightweight, flexible plastic instead of glass. The Que's display is based on an array of one million organic transistors built on a plastic backing. This plastic array, which replaces the rigid, heavy, silicon-on-glass array in most displays, including those in other e-readers on the market, drives the pixels of the E Ink display. Though the display itself is flexible, it's encased in rigid plastic. The advantage of the flexible plastic display is that it's nearly unbreakable.

Plastic Logic was spun out of Cambridge University in 2000, the same year the Nobel Prize in chemistry was awarded to the three researchers who made the first electrically conductive polymers in the late 1970s (none of these researchers are associated with Plastic Logic). The first organic transistors, which performed poorly compared with silicon, were made in Japan and England in the late 1980s.