Posted on 11/25/2005 4:46:09 AM PST by PatrickHenry
The photos were created by projecting light on "biological film" -- billions of genetically engineered E. coli growing in dishes of agar, a standard jello-like growth medium for bacteria.
The work is published in this week’s issue of Nature (Nov. 24, 2005), devoted entirely to the emerging field of synthetic biology. The new field focuses on identifying genes that control key traits and then engineering microbes to activate the genes in novel combinations to create useful tools for medicine and technology.
The students produced the innovative bacterial images and a bacterial camera as part of MIT's intercollegiate Genetically Engineered Machine (iGEM) competition. The project won "best part" for the genetically engineered light receptor developed by UCSF graduate students working with Chris Voigt, PhD, assistant professor of pharmaceutical chemistry at UCSF and a leader in synthetic biology.
"Our living photographs are a somewhat playful example of how devices quite useful to technology and medicine can be created in the new field of synthetic biology," Voigt said.
"Essentially, we engineer the bug to give it new capabilities by combining different gene-based skills that it or other organisms already have."
The bacterial photograph could allow material to be printed with incredibly high precision, Voigt said.
"We estimate that the resolution of these photographs is about 100 Megapixels, or about ten times better than high-resolution printers. The difference is that we can print gene expression." Anselm Levskaya, a UCSF biophysics graduate student, led the effort to "build the bug," while the University of Texas team figured out how to create the photographs. Levskaya is the Nature paper’s lead author and Voigt the senior author.
"With the growing number of sequenced microbes, we can search through nature's large trove of tools to find ones that fit the job," Levskaya said. "In our case, searching for light-sensing domains led us to use a photosynthetic bacterium." The students produced ghostlike, living photos of many things, including themselves and their advisors.
Like pixels on a computer screen switching between white and black, each bacterium either produced black pigment or didn’t, based on whether it was growing in a dark or light place in the dish. The resulting images are a collection of all the bacteria responding to the pattern of light.
E. coli live in the dark confines of the human gut and wouldn’t normally sense light, so the students had to engineer the unicellular machines to work as a photo-capturing surface. Levskaya and Voigt first engineered the bacteria to sense light by adding a light receptor protein from a photosynthetic blue-green algae to the E. coli cell surface. The microbe’s metabolism was modified to produce a chemical that gave the protein sensor the ability to see light in its new microbial host.
The light sensor was also genetically modified so that light turns off a gene that ultimately controls the production of a colored compound.
To create the actual photographs, the Texas students optimized pigments and growth media, and used a unique light projector largely designed and built by Aaron Chevalier, a physics undergraduate. They added a chemical compound to the agar so that those bacteria that are in the dark produce black pigment and those that are in the light do not.
The device projects the pattern of light, such as an image of a person, onto the dish of bacteria growing at body temperature in an incubator. After about 12 to15 hours of exposure (the time it takes for a bacterial population to grow and fill-up the Petri dish), the light projector is removed.
What's left is a permanent living photograph.
The biological technologies these students are building could be applied in a variety of ways beyond making photos. For example some genes produce plastics or precipitate metals. By activating these genes in the light, high-resolution materials could be printed. In addition, the activation of genes can differentiate cells, so one day this strategy could be used to build tissues based on patterns of light, the scientist-engineers say.
The students are following up the living photograph with another innovation—bacteria that can find and create a line around the edges of an image, a process that requires the bacteria to communicate with each other.
The project's faculty advisors at the University Texas were Edward Marcotte, assistant professor of biochemistry, and Andrew Ellington, professor of chemistry. Other students and researchers who participated in the project at the University of Texas were Laura Lavery, Zachary Booth Simpson, Matthew Levy, Eric Davidson and Alexander Scouras; and Jeff Tabor, a doctoral student at the Institute for Cell and Molecular Biology in Austin.
Voigt is also an investigator in the department of synthetic biology at UC’s Lawrence Berkeley Laboratory. He organized an international conference on synthetic biology last summer, sponsored by the National Science Foundation, UC’s QB3 institute, the Lawrence Berkeley Lab and the University of Oxford:
Voight Lab
UCSF is a leading university that consistently defines health care worldwide by conducting advanced biomedical research, educating graduate students in the life sciences, and providing complex patient care.
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Amazing!
AHA Intelligent Design
I hope this is the result of careless editing and not "Goodspeak".
Why don't they do something useful, like modifying them to produce petroleum?
Sounds like a contradiction unless the bacteria are immortal and the medium is non-degradable.
The bacteria wouldn't live forever, but the image could, if treated the correct way.
I suspect the true value of this would be processes to lay down patterns of other materials, metal, plastic, whatever.
What this demonstrates is that we understand how biology works on a very low level. And a major part of that understanding is evolution.
I don't know the procedures the students used to produce the bacteria, but I suspect that a part of it was a "selection" process, not unlike "natural selection". Since selection conditions exist everywhere, the fact that selection can be used to generate a new bacteria is more evidence that natural selection in the environment changes life forms.
I imagine that is potential resolution based on the size of the bacteria. The sample image isn't sharp at all.
The Laws of Reproducible Results:
Anything found in the wild is evidence of Intelligent Design; and your theories mean nothing unless you can actually produce something in the lab.Anything people deliberately do in a lab is obviously evidence of Intelligent Design; and such tinkering tells us nothing about what happens in the wild.
Looks like you found the perfect Catch-22 PH.
I suspect they had some light scattering through the medium. If such a thing were done commercially, you'd seek to have only one layer of bacteria in a very thin medium so light scattering was minimized. I doubt they'd get to 100meg pixels, but it might be pretty good.
There are others:
The universe is made for life, therefore ID.A good creationist always has a handy argument.
Life can't arise naturally, therefore ID.
Yeast can make alcohol, why not a genetically created critter that can create crude oil.. or even gasoline.. maybe feeding on COAL..
Well, I thought it was interesting, but not every thread is a winner. Thanks anyway for the tip.
Echoes of the novel Prey (Michael Crichton)...
Thanks for the ping!
e. coli????
EEEEEEWWWWWWWWWWWW!!!!!!!
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