Life Of Navin

Bacteria have been turned into "living computers" and used to successfully solve a mathematical problem.Karmella Haynes and colleagues from the biology and the mathematics departments of Davidson College, North Carolina and Missouri Western State University, Missouri published their results in the Journal of Biological Engineering.
The feat by the American team has shown that living cell computing is feasible, opening the door to a number of applications such as data storage.

The research is part of an effort in "synthetic biology" to improve on four billion years of evolution and turn bacteria into living machines to do our calculations for us. The Team added genes to an innocuous form of the bacterium Escherichia coli, widely used in genetics research, creating bacterial computers able to solve a mathematical problem. The showcased the power of the living computer through the solution of a problem called the "Burnt Pancake" problem. The problem is fitting considering that the bacteria are found in the Human gut.

In this experiment, the researchers used fragments of DNA as the pancakes, and added genes from a different type of bacterium to enable the E. coli to flip the DNA 'pancakes'. They also included a gene that made the bacteria resistant to an antibiotic, but only when the DNA fragments had been flipped into the correct order.

"The system offers several potential advantages over conventional computers" says Dr Haynes. "A single flask can hold billions of bacteria, each of which could potentially contain several copies of the DNA used for computing. These 'bacterial computers' could act in parallel with each other, meaning that solutions could potentially be reached quicker than with conventional computers, using less space and at a lower cost."

Bacterial computing also has the potential to utilize repair mechanisms and, of course, can evolve after repeated use. This is an elaborate version of conventional genetic engineering methods that have been used for three decades.

The team recently participated in the International Genetically Engineered Machine Competition (iGEM). Through the efforts of hundreds of competitors they are developing a library of DNA snippets, each with a specific function, that have been engineered to snap together with other library parts like genetic Lego bricks.

These "biobricks" are created according to strict guidelines so that each one is compatible with others in the collection, which is officially called the Registry of Standard Biological Parts. The registry contains about 2,000 biobricks.

Three years ago, a team at Princeton University programmed the e.Coli to communicate with each other and produce various motifs. In one experiment, the cells glowed green when they sensed a higher concentration of a certain signal chemical and red when they sensed a lower concentration.

Together, in a Petri dish, they formed a bull's-eye pattern -- a green circle inside a red one. Earlier work inserted three interacting genes (dubbed a repressilator) in a way that gave the e.coli a green twinkle so they can blink on and off (sort of like Christmas lights). And a team at Boston University made a genetic switch, endowing each modified bacterium with a rudimentary digital memory. Using the switch, they have wired up bacteria to assemble and form communities called biofilms under the glow of ultraviolet light.