MIT engineers have transformed the genome of the bacterium E. coli into a long-term storage device for memory:

Once an exposure is recorded through this process, the memory is stored for the lifetime of the bacterial population and is passed on from generation to generation.

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Environmental applications for this type of sensor include monitoring the ocean for carbon dioxide levels, acidity, or pollutants. In addition, the bacteria could potentially be designed to live in the human digestive tract to monitor someone’s dietary intake, such as how much sugar or fat is being consumed, or to detect inflammation from irritable bowel disease.

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Another possible application is engineering brain cells of living animals or human cells grown in a petri dish to allow researchers to track whether a certain disease marker is expressed or whether a neuron is active at a certain time. “If you could turn the DNA inside a cell into a little memory device on its own and then link that to something you care about, you can write that information and then later extract it,” Lu says.