This Miniature 'Mona Lisa' Replica Is Created Using Genetically Modified Bacteria
Scientists have used genetically modified E. coli bacteria to recreate images of some of the world's most famous paintings. The arty researchers were experimenting with the ways that can unite different attributes in order to control large populations of bacteria.
They have ambitious plans to develop microscopic transport devices or perhaps even 3D printing bacteria. “I think it’s an interesting proof of concept of possibly using bacteria as bricks to build structure on the microscale cheaply and easily,” study author Roberto Di Leonardo from the Sapienza University of Roma told Gizmodo.
Light-sensitive proteins used in combination with E. coli
The researchers were curious about how to combine the special attributes of different organisms together. In this case, they combined the light-sensitive protein proteorhodopsin with the E. coli’s flagellum. Proteorhodopsin can be thought of as a solar panel for cells and flagellum can be considered as a teeny tiny motor.
By combining the two, the scientist hoped to create a system that would move faster with the more light it received. To create the images, the proteorhodopsin-producing gene was first spliced into the bacteria.
Then a projector was modified with a microscope lens instead of its regular lens. Images were projected onto a stage that held the bacteria, two micrometers per pixel.
The theory was that slower-moving bacteria, receiving less light from the projected image would clump together and form black shades while the ones receiving lots of light would move further apart. The clumped and moving bacteria would then form the resulting image.
They describe it in the introduction to their published research saying, “Swimming bacteria, much like cars in city traffic, are known to accumulate in areas where their speed decreases. By controlling swimming speed with proteorhodopsin, researchers can manipulate the local density of bacteria simply by projecting different patterns of light.”
Images were created by projecting light in particular patterns that encouraged bacterial movement
According to the paper published by the researchers, the tactic worked pretty well except that the bacteria were slow to change positions, resulting in fuzzy images. To correct this, the scientists set up a system where every 20 seconds, the bacterial positions were compared to the final desired image.
Places, where the bacteria were slow to move away, were brightened up so the bacteria would clear away more quickly. The places that needed to be darker, were dimmed even further to encourage denser clumping.
The researchers admit that there is a long way to go before light reactive bacteria are taking over our jobs but the authors say this is just the first step towards further research.
“This could be extremely valuable for building the next generation of microscopic devices. For example, bacteria could be made to surround a larger object such as a machine part or a drug carrier, and then used as living propellers to transport it where it is needed."
The research was published in eLife.