Really, this is about scum. Green, slimy, don't-swim-in-the-water scum. OK, the people who make their living working with the stuff probably prefer the technical names for all that green sludge: algae and cyanobacteria. The two groups of organisms are actually as different as people are from worms, but they're commonly lumped together under the same terminology. Nonetheless, it's this very slime that might save the world.
How? Well, take global climate change as a given: melting ice caps, the opening of the Northwest Passage, increased global temperatures. Global warming is on, and if the thousands of climate-change scientists at the United Nations are right, it's all because humanity has been extracting too much carbon from the ground (as oil and coal), burning it and putting that carbon into the atmosphere. Algae can save us by re-absorbing some of that carbon and turning it into useful things.
Algae, it turns out, is the most efficient organism in the world at converting sunlight into other stuff—50 times more efficient than most terrestrial plants. Even better, when algae absorbs sunlight and nutrients, its output takes the form of lipids and protein. Lipids are hydrocarbons, just like oil. As it happens, San Diego is a center for investigating how to turn algae into useful things, whether it's fuel, cancer cures or plastics.
As it happens, algae and cyanobacteria come in thousands—if not millions—of different forms. Up at the Scripps Institution of Oceanography (SIO) in La Jolla, Bill Gerwick keeps what amounts to a cyanobacteria library—shelves of Erlenmeyer flasks of delicate branching plants floating in salt water, racks of test tubes with little bits of fluffy green plant and a machine that shakes beakers of algae like a grocery-store coin-horse to encourage it to grow (algae, like some people, thrive when agitated). Gerwick has amassed his collection thanks to his jetsetting lifestyle as an algae bioprospector. Every year he travels the world sampling different forms of algae to try to find those whose particular lipids and proteins might be useful to humanity. At the time of this writing, he's on Palmyra Atoll, an island some 1,000 miles south of Hawaii.
Samples in hand, Gerwick or his students test them to see if they make anything useful, like, say, a cure for cancer. On a trip to Curacao, Gerwick found algae that produced a compound that actually stops animal cells from dividing too rapidly. He called it Curacin A and promptly sent it off to Novartis, the Massachusetts-based drug company that's contracted by the National Cancer Institute to test new leads. The chemical showed promise and has now been designated a “lead” toward a cure for some types of cancer. The next step will be animal testing to find out what form of cancer it might cure, but the line for such testing is long. It may be years before Curacin A gets its chance to shine.
Meanwhile, over at Scripps Research Institute, Stephen Mayfield, one of Gerwick's compatriots (though not exactly a colleague since SRI and SIO are independent), has figured out a way to turn algae into a chemical factory for known pharmaceuticals.
“The technology we're going to develop will allow us to make therapeutics so cheap that protein-based therapeutic drugs in the next 10 years will become available to everybody,” Mayfield said.
He cited the example of Avastin, a breast-cancer treatment made by Genentech that can cost $116,000 for a regimen, far more than some insurance companies will pay. He believes he can reduce costs to a tenth of that. How? By saving money on factories. All the expensive equipment used to actually produce the drug can cost as much as $600 million. But producing algae essentially requires a lot of water, sunlight and a facility to extract the chemical from the slime, all of which can be done cheaply. Mayfield modifies the genes of algae to get it to make the desired chemical. He already has algae that makes one drug (he wouldn't say which) that has reached the stage of animal testing. And since the algae-made drug is chemically identical to Genentech's, he sees no reason that the drug should fail the tests.
He's using pretty much the same type of manipulation to produce biofuel. Working with UCSD professor Steven Briggs, he's devised an algae that makes crude oil. Sapphire Energy, a company that Mayfield and Briggs run together, has received $50 million in venture capital to scale up its technology to help supply the 23.1 million gallons of fuel Americans use every day. They're racing against hundreds of other companies looking to exploit algae for biofuel. Unlike electricity or hydrogen, algae-based fuel could be inserted directly into our current gasoline-based infrastructure. Not even our cars would have to change. It could be refined in existing factories and pumped through existing infrastructure into current automobiles.
“The goal, of course, has to be to replace imported oil,” Briggs said, “ultimately to replace even domestic oil, so that we can go to what we call a carbon-free economy.”
For Briggs, biofuel is a crucial goal, but not the only one.
“A large part of a barrel of oil is used for chemicals, not fuel,” he said. “So, if we're going to replace petroleum, we have to replace this non-fuel part of it that makes plastics and solvents—just thousands of other products.”
To that end, Briggs is working on creating a form of algae that would produce plastic feedstock. His lab hasn't published anything yet, so he wouldn't go into details on his current success, but thinks the line of inquiry is promising.
Whether making industrial chemicals or oil, algae will have to produce the crude oil at an astonishing scale never before imagined, and there are serious obstacles— algae-eating organisms, getting sunlight to algae below the surface and managing nutrients for maximum production. Essentially, scientists have to figure out how to domesticate algae.That's where a researcher like SIO professor Greg Mitchell comes in. He's an ecologist who calls himself “an enthusiastic supporter” of algae as a source for fuel and other products. In his lab, he tries to figure out what combination of light, water and nutrients will cause algae to produce the most biomass at the highest rate. In a way, he's an algae gardener. His plan at the moment is to try to grow algae on our most useless waste, thus converting it to something useful. He has a plan to grow algae in sewage tanks and even to trap emissions from smokestacks to feed his garden. Society produces all this nutrient-rich waste and then it gets dumped into the ocean (millions of gallons of treated sewage in San Diego alone). Why not put that waste to use?
The race is on to solve these problems—and quickly. Scientists just discovered that the arctic ice cap is melting faster than previously believed. If algae is to save the world, it must do so soon.
As Mayfield said: “We have to do in 10 years what we did for corn over 10,000.”
Full disclosure: Eric Wolff is married to an SIO graduate student, but she does not work in this field or with these professors. Tips or comments? Write to firstname.lastname@example.org and email@example.com.