Talk to any biofuels entrepreneur, and you are likely to hear a passionate riff on why their technology trumps all the up-and-comers.
Some, like San Diego-based Sapphire Energy, say you’ve got to harness free sunlight and the magic of photosynthesis, to grow oil-rich algae in open ponds at the scale of modern agriculture. Others, like South San Francisco-based Solazyme, say that will never work at commercial scale, and you need the controlled environment of industrial fermenters to keep out all kinds of curveballs Mother Nature might throw in the mix. The critics shoot back that the bioreactors will be too expensive to really scale up to meet energy needs for a world with a voracious appetite for energy, in a $7 trillion annual marketplace.
These are what you’d call engineering risks. But what about the basic science risks? Scientists have been working for a long time on various alternatives to fossil fuels as the fundamental unit of energy, without much success. No one person or institute has all the answers here, but Nitin Baliga, a professor at the Institute for Systems Biology in Seattle, runs a lab that works on a wide variety of relevant research projects with implications for human health, environmental cleanup, and biofuels.
The scientific challenge with biofuels has definitely been top of mind for me the past few weeks, as I get ready to moderate our next event, “Separating Hype from Reality in Alternative Fuels” at the ISB’s new headquarters in Seattle on May 19. Thinking through the challenges the past couple years has been sobering, Baliga says.
“I’ve become smarter about knowing what the challenges are,” Baliga says. “I’m not a pessimist yet, but my optimism is more guarded (than a couple years ago). I know now where it is more likely to work, and less likely to work. I do think there’s enormous potential that’s still really untapped, because we don’t understand how the systems work.”
When Baliga and his colleagues talk about systems, they are talking about not just studying one gene, one protein, or one organism in isolation. He’s talking about how whole networks of genes, or whole ecosystems in some cases, adjust and adapt in response to some new stimuli. One of his big discoveries from a couple years ago was about how a microbial cell will respond to a variety of environmental assaults, such as radiation and certain metals. Lately, he’s expanded on that idea to become interested in how whole communities of microbes adapt to change in the environment. For example, can you figure out how communities of microbes collaborate, compete, or even re-calibrate their genomes, when, say, the ocean becomes more acidic?
The U.S. Department of Energy and the National Science Foundation are interested in some of these fundamental questions, which might help us better predict what might happen, if say, engineered microbes were dumped into the Gulf of Mexico to clean up an oil spill. Oil companies have a different interest—like how efficient a microbe might be at converting sugars or sunlight into oil.
Baliga sees plenty of tricky scientific questions that need to be asked in all of those scenarios.
“Whichever organism you want to use for oil, whether it’s algae, cyanobacteria or something else, preferably you’d capture free solar energy, but then you run up against the efficiency of how much light energy gets sequestered, and how you harvest it. The first challenge in an open pond is that it’s hard to maintain monocultures.” That means you create a thriving pool for other species to hop in and do other things to compete for survival, doing things other than creating the desired stream of oil. “They take over,” Baliga says.
While a controlled bioreactor might keep the opportunistic species out of the pond, and create the desired stream of oils, they are expensive, and require energy to run themselves.
In the near term, Baliga says he sees promise in
