November 23, 2005
Bacteria Can Take Pictures of Themselves
SAN FRANCISCO -- The notorious E. coli bug made its film debut Wednesday. That's when researchers at the University of California, San Francisco and the University of Texas announced in the journal Nature that they had created photographs of themselves by programming the bacteria - best known for outbreaks of food poisoning - to make pictures in much the same way Kodak film produces images.
It's the latest advance in "synthetic biology," a disputed research movement launched largely by engineers and chemists bent on genetically manipulating microscopic bugs into acting like tiny machines, creating new, powerful and inexpensive ways to make drugs, plastics and even alternatives to fossil fuel.
The field seeks to go beyond traditional genetic engineering feats where a single gene is spliced into bacteria and other cells to manufacture drugs. Synthetic biologists are trying to create complex systems that function as logically and reliably as computers.
Mainstream biologists, however, scoff that biology - life itself - is too unpredictable and prone to genetic mutation to understand, let alone tame and turn into miniature factories.
Bioethicists, meanwhile, fret that synthetic biologists are attempting to create new living creatures and are inventing technology that can readily be used by terrorists.
Still, a growing number of engineers are jumping into the nascent field, whose chief goals include breaking down microbes and other living things into smaller components and reassembling those parts into useful machines.
"There is kind of a hacker culture behind all of this," said Chris Voigt, a University of California, San Francisco researcher who, at 29, was the senior author on the bacteria-as-film paper in Nature.
Voigt and colleagues took from algae light-sensitive genes that emit black compounds and spliced them into a batch of E. coli bacteria. The organisms were then spread on a petri dish that resembles a cookie sheet and placed in an incubator. A high-powered projector cast photographic images of the researchers through a hole on top of the incubator, exposing some of the bacteria to light.
The result: Ghostly images like traditional black-and-white photographs of the researchers responsible for the invention, at a resolution Voigt said was about 100 megapixels, or 10 times sharper than high-end printers.
The work, though, isn't intended for commercial markets.
"They aren't going to put Kodak out of business any time soon," said Massachusetts Institute of Technology researcher Drew Endy, a leading synthetic biologist.
Instead, the creation will be used as a sensor to start and stop more complex genetic engineering experiments. The idea is to create a genetically engineered cell that lays dormant until a laser is shined on it, prompting it into action.
Such an accomplishment would add to the growing success of a field that is making strides around the world, in such projects as:
-- Scientists in Israel made the world's smallest computer by engineering DNA to carry out mathematical functions.
-- J. Craig Venter, the entrepreneurial scientist who mapped the human genome and launched the Rockville, Md.-based research institute named after himself, is attempting to create novel organisms that can produce alternative fuels.
-- With a $42.6 million grant that originated at the Bill and Melinda Gates Foundation, Berkeley researchers are engineering the E. coli bug with genes from the wormwood plant and yeast to create a new malaria drug.
Even as they wrestle with scientific hurdles like controlling genetic mutations, thorny ethical issues are cropping up.
It's cheap and easy to buy individual genes online. They cost about $1 each, down from the $18 apiece charged just a few years ago. Researchers last year created a synthetic polio virus by simply stitching together these mail-order genes.
National security experts and even synthetic biologists themselves are concerned that rogue scientists could create new biological weapons - like deadly viruses that lack natural foes. They also worry about innocent mistakes: organisms that could potentially create havoc if allowed to reproduce outside the lab.
Researchers are casting about for ways to self-police the field before it really takes off. Leaders in the field have organized a second national conference to grapple with these issues this coming May and the Arthur P. Sloan Foundation in June handed out a $570,000 grant to study the social implications of the new field.
"This is powerful work and we live in an age that many tools and technologies can be turned into weaponry," said Laurie Zoloth, a bioethicist at Northwestern University. "You always have the problem of dual-use in every new technology. Steel can be used to make sewing needles or spears."