bacterial intelligence shown to be DNA driven (Animals)

by David Turell @, Monday, October 09, 2017, 17:27 (15 days ago) @ David Turell

New research altering bacterial DNA can make the bugs do what the scientist wants:
Researchers at Duke University have turned bacteria into the builders of useful devices by programming them with a synthetic gene circuit.

"As a bacterial colony grows into the shape of a hemisphere, the gene circuit triggers the production of a type of protein to distribute within the colony that can recruit inorganic materials. When supplied with gold nanoparticles by researchers, the system forms a golden shell around the bacterial colony, the size and shape of which can be controlled by altering the growth environment.

"The result is a device that can be used as a pressure sensor, proving that the process can create working devices.

"While other experiments have successfully grown materials using bacterial processes, they have relied entirely on externally controlling where the bacteria grow and have been limited to two dimensions. In the new study, researchers at Duke demonstrate the production of a composite structure by programming the cells themselves and controlling their access to nutrients, but still leaving the bacteria free to grow in three dimensions.


"The genetic circuit is like a biological package of instructions that researchers embed into a bacterium's DNA. The directions first tell the bacteria to produce a protein called T7 RNA polymerase (T7RNAP), which then activates its own expression in a positive feedback loop. It also produces a small molecule called AHL that can diffuse into the environment like a messenger.

"As the cells multiply and grow outward, the concentration of the small messenger molecule hits a critical concentration threshold, triggering the production of two more proteins called T7 lysozyme and curli. The former inhibits the production of T7RNAP while the latter acts as sort of biological Velcro that can latch onto inorganic compounds.

"The dynamic interaction of these feedback loops causes the bacterial colony to grow in a dome-shaped pattern until it runs out of food. It also causes the bacteria on the outside of the dome to produce the biological Velcro, which grabs onto gold nanoparticles supplied by the researchers, forming a shell about the size of your average freckle.

"The researchers were able to alter the size and shape of the dome by controlling the properties of the porous membrane it grows on. For example, changing the size of the pores or how much the membrane repels water affects how many nutrients are passed to the cells, altering their growth pattern.

"'We're demonstrating one way of fabricating a 3-D structure based entirely on the principal of self-organization," said Stefan Zauscher, the Sternberg Family Professor of Mechanical Engineering & Materials Science at Duke. "That 3-D structure is then used as a scaffold to generate a device with well-defined physical properties. This approach is inspired by nature, and because nature doesn't do this on its own, we've manipulated nature to do it for us."

Comment: These scientists act like God might. If the instructions are put into bacterial DNA the bacteria act automatically to respond to them. Bacteria are automatic responders obviously. Note I have subverted the point of the article to support my theories, just as I have a perfect right to use Shapiro in my interpretations.

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