Development of an integrated circuit from bacteria

Scientists have succeeded in developing an integrated biological electrical circuit by programming bacteria so that they change the expression of their genes for the entire population, i.e. sort of the biological equivalent of a printed circuit in computers

[Translation by Dr. Nachmani Moshe]
Scientists have succeeded in developing an integrated biological electrical circuit by programming bacteria so that they change the expression of their genes for the entire population, that is, sort of the biological equivalent of a printed circuit in computers.
___________________________________________________________
Scientists from Rice University have succeeded in creating a living electrical circuit from various types of bacteria that cooperate with each other and cause changes in protein expression. The project, described in the prestigious scientific journal Science, presents, for the first time ever, a biological equivalent to a computerized circuit. The goal of the researchers is to change biological systems by controlling how bacteria affect each other.

The human stomach contains many types of bacteria, says biologist Matthew Bennett of Rice University. "Naturally, together they create a diverse collection. One of the ideas is to engineer bacteria that can be inserted into the stomach, and thus form part of the diverse collection there. Their activity together in cooperation will result in a greater impact than if they were to act separately."
The researchers were able to create two strains of bacteria that underwent a genetic modification responsible for regulating the production of proteins essential in intercellular signaling processes, which allows cells to cooperate together. The ability to change DNA and thereby cause cells to produce specific proteins has already become a useful operation, for example, by engineering bacteria that can produce biofuels and useful chemicals.
"The main focus in the field of synthetic biology is the ability to engineer single cells," says the lead researcher. "But today we are moving towards multi-cell systems. We want the cells to adjust their activities in order to produce a response we want". The researchers achieved their goal by genetically modifying the common bacterium Escherichia coli. By producing and mixing two genetically different populations, they encouraged the bacteria to cooperate with each other. The bacteria worked together even though they performed opposite tasks: one population increased the expression of certain genes, and the other population inhibited the expression of the genes. Together, the two populations created regular oscillations - rhythmic peaks and troughs - of gene transcription in the common bacterial population. The two new strains of the bacteria produced molecules responsible for intercellular signaling and thereby activated linked positive and negative feedback cycles that affected gene production in the entire population. The researchers made sure that the two new strains produced fluorescent genes so that their activities could be monitored. In addition, the bacteria were placed into microfluidic devices where they could be more easily monitored during each experiment.
The lead researcher claims that his research could help scientists understand how cells communicate with each other, an important factor in any attempt to fight disease. "In our body there are many different types of cells, from skin cells and liver cells to pancreatic cells, and they all still coordinate their activity so that our body functions properly," he explains. "To do this, they send small signaling molecules that are produced in one cell type and affect another cell type. We used this principle and integrated it into extremely simple organisms to test if we could understand and build multicellular systems from scratch." "One of the possible applications is to develop yogurt that includes genetically engineered bacteria," said the researcher. "The patient feeds on the yogurt and the doctor can control the bacterial population with the help of the patient's diet. Certain combinations of molecules in our food can turn on or off the systems in the engineered bacteria and have a controlled effect on the content of the bacteria in our stomach."

Article Summary

The news about the study