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Detangling Algae Enzyme Behavior for Future Fuels
Seen around SLAC: EV Hookups

SLAC Today

Wednesday - May 5, 2010

Detangling Algae Enzyme Behavior for Future Fuels

Structure of a unique enzyme that naturally produces hydrogen gas. Click to view the cluster at the enzyme's active site. (Image courtesy David Mulder.)

Environmentalists dream of a world that runs on hydrogen, but cranking out the gas is expensive and often uses precious metals. Using the Stanford Synchrotron Radiation Lightsource's bright X-rays, scientists have uncovered insights into how a complicated enzyme that naturally produces hydrogen gas is assembled in nature. The finding could be a key step in understanding how microorganisms could cheaply mass-produce hydrogen for energy sources such as fuel cells.

Enzymes, proteins that jump-start chemical reactions, are found in microorganisms all over the planet, turning nitrogen into life-essential amino acids, converting carbon dioxide from gas to solid, and giving off hydrogen. Scientists knew a particular hydrogen-producing enzyme, found in algae, worked by shuffling around iron and sulfur, but didn't know specific about how they are assembled in the enzyme.

"If you want to genetically engineer an algae to make more of an enzyme and mass-produce it, you need to know how it is assembled," said John Peters, a chemist at Montana State University.

Under flashes of X-ray light at the SSRL, a team of Montana chemists took microscopic snapshots of the enzyme. By watching X-rays diffract from crystals of the enzyme, the chemists concluded last week in Nature that clusters of iron are assembled step by step to make the active hydrogen producing enzyme.

"This is a significant advancement," said Peters, who co-authored the paper. Now, the insights may help scientists build something that mimics the biological structure and make their own synthetic enzyme, or mass-produce algae with large amounts of the enzyme in giant pools, he said.

The finding hints at how Earth's earliest ancestors evolved. Organisms too primitive to make their own iron-sulfide clusters could have piggy-backed on minerals that could.

Read more about the work in the SSRL Scientific Highlight and Montana State University news release.

(Photo - SLACmobiles)
(Photos by Shawne Workman.)


Plugged into a weatherproof outlet behind SLAC's Test Laboratory, what looks like an oversized green-and-silver go-cart waits with its load of tools and paint supplies. It's part of a fleet of pint-sized economobiles that have carried people, materials, and equipment around SLAC National Accelerator Laboratory since the lab’s early days.

It all started with trikes.

"The linac was full of threewheeled bicycles way back when," said SLAC fleet services garage supervisor Al Manuel. In the mid-60s, he says, SLACers pedaled tricycles up and down the Klystron Gallery that serves the lab's two-mile linear accelerator.  Read more in Symmetry magazine...

(Photo by Julie Karceski.)

Seen around SLAC: EV Hookups

The newly-completed LCLS office building is offering SLAC another way to get a little greener: in the parking lot, there is a row of hookups designated for SLAC's electric cars. SLAC has a fleet of electric cars for driving around the site, and hookups to charge the cars at Buildings 120, 41, 35 and 81, too. This is part of a project to achieve LEED Gold Certification. The idea is to make a changeover from remaining gasoline and diesel powered SLAC fleet cars to have a completely electric fleet.


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