Student and faculty researchers at Missouri Western State University and Davidson College in North Carolina have created ‘living computers’ by genetically altering bacteria. The findings of the research, published in the “Journal of Biological Engineering,” demonstrate that computing in living cells is feasible, opening the door to a number of applications including data storage and as a tool for manipulating genes for genetic engineering.
A research team from the biology and the mathematics departments of Western and Davidson added genes to E. coli bacteria, creating bacterial computers able to solve a classic mathematical puzzle known as the burnt pancake problem.
The research was part of Western and Davidson’s entry in the 2006 international Genetically Engineered Machine (iGEM) competition, where the combined teams won five awards, including Best Presentation by the Western students.
The burnt pancake problem involves a stack of pancakes of different sizes, each of which has a golden side and a burnt side. The aim is to sort the stack so the largest pancake is on the bottom and all pancakes are golden side up. Each flip reverses the order and the orientation (i.e. which side of the pancake is facing up) of one or several consecutive pancakes. The aim is to stack them properly in the fewest number of flips.
In this experiment, the researchers used fragments of DNA as the pancakes. They 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 time required to reach the mathematical solution reflects the minimum number of flips needed to solve the burnt pancake problem.
“Our project illustrates the concept of using bacterial cells as parallel processors to solve mathematical problems that are difficult for conventional computers to manage,” said Dr. Eckdahl, , professor of biology. “The project is an important contribution to the emerging field of synthetic biology, which uses engineering principles and the tools of molecular biology to design and build biological machines with applications in medicine, energy and technology.”
“It is very exciting that our undergraduate students have opportunities to work at the cutting edge of applied research and to learn that the quality of their work is as high as anywhere in the world,” said Dr. Poet, associate professor of mathematics.