A research team headed by Professor of Chemistry David Walt last month published a method of using the bacteria Escherichia coli (E. coli) to encode, deliver and decode messages that they said could lead to the evolution of methods in the area of secret message encoding.
Walt, alongside his head postdoctoral associate Manuel Palacios and a group of researchers from Tufts and Harvard University, developed the technique as a way to harness the bacteria, which is best known for its tendency to cause stomach sickness. They color tagged the bacteria, coding the different colors of fluorescent proteins in the E. coli to each represent a particular letter or number — a technique they dubbed InfoBiology.
According to the research paper published by Walt and his team of associates in the Sept. 26 issue of the Proceedings of the National Academy of Sciences (PNAS), InfoBiology is "a proof−of−principle method … [used] to write and encode data using arrays of genetically engineered strains of [E. coli] with fluorescent proteins (FPs) as phenotypic markers."
To translate the genetically engineered strains of E. coli bacteria with fluorescent proteins in order to convey a message with colored strains of bacteria, Walt and Palacios created a form of messages known as Steganography by Printed Arrays of Microbes (SPAM). The phenotype of the bacteria can be seen under ultraviolet light and are then decoded to reveal a message using a cipher.
According to Palacios, SPAM has the potential to expand awareness within the academic field regarding the ability to trace genetically modified organisms. It won't be put into use by the likes of the CIA anytime soon, though, he said.
"SPAM is mostly an academic exercise, a proof of principle," he said. Research team member and Postdoctoral Associate Mael Manesse agreed that the uses of this technique are primarily academic.
"We are more interested in creating biological watermarks to trace genetically modified organisms," Manesse said.
SPAM was developed in a collaborative effort between the Tufts group and a group of Harvard researchers working under Harvard Professor of Chemistry George Whitesides.
The research paper on InfoBiology, published by PNAS, describes the process of creating the SPAM bacteria message involving the growth of bacteria in a plate of agar, which is a seaweed−based gelatin, and then transferring the bacteria to a membrane that is sent to the person receiving the bacteria message. In order to decode the bacteria message on the membrane, the receiver must transfer the bacteria from the membrane back onto an agar plate. The receiver is then able to read the SPAM message by decoding the colors of bacteria on the plate under ultraviolet light, using the cipher as a color key.
Walt explained that the SPAM's usefulness lies not only in its ability to send encoded messages, but also in communicating through potentially compromised channels and deterring counterfeiting. SPAM allows for the transmission of messaging through an atmosphere where the message might be intercepted as well as preventing the message from being decoded by an interceptor thanks to the use of a unique cipher for decoding the particular message.
Palacios said the project was especially intriguing to him because it combined information technology with chemical systems, two of his interests.
"The simple question, of how much information there is in an atom, opens so many other questions," Palacios said.
Manesse said he was struck by the newfound possibilities of molecular biology.
"I was very interested in genetically engineering living organisms to express observable traits, in this case, fluorescent proteins, to encode a message or some data," Manesse said.
Although the research was published last month, Palacios said there is much to come in the future of the groundbreaking method.
"Usually the published paper is just the beginning of a new direction in a research program," he said. "I hope the program keeps going and other people give it continuity."
Manesse echoed Palacios' hopes and believes that the SPAM method is the start to newer projects.
"We're currently looking into bringing this project further by using different organisms such as yeast or spore−forming bacteria, making the system more robust," Manesse said.
Walt also believes that research is a continual process, leaving hope for new discoveries of biological message encoding.
"We are still doing some work on the project," he said.
