Student team perfects 'cell-free' way to produce complex biomolecules

Creating a new molecular chip capable of synthesizing biopharmaceutical drugs and even jet fuels at markedly lower cost, Cornell's International Genetically Engineered Machines (iGEM) team won a gold medal at a recent competition.

At the iGem Americas competition in Indianapolis, Oct. 8-10, the Cornell iGEM team, composed all of undergraduates, was one of 20 to win the top prize. They will now advance to the iGem synthetic biology world competition at the Massachusetts Institute of Technology in early November.

Pushing the boundaries of synthetic biology, the engineering process of creating complex biomechanical systems from a composite of genetic parts known as "biobricks," the Cornell "biofactory" successfully created wafer-sized microfluidic devices that use enzymes rather than cells to synthesize chemicals that are in demand by industry.

Splitting E. coli bacteria by a light-induced lysis process to extract these enzymes, the team attached them -- using the biotin-avidin binding mechanism -- to a biofluidic pathway through which inactive compounds flow through to be converted into substances of use to industry.

"Currently, these chemicals are produced or modified by living bacterial cells encapsulated in giant cell reactors," said iGem senior adviser Malinka Walaliyadde '12. "The problem with [using cells, rather than enzymes] is that a lot of unnecessary products, or side-products, are also produced and have to be removed -- this purification process can be extremely expensive. … We can place the bacterial enzymes in this microfluidic device in exactly the right order to ensure maximum efficiency of useful chemical production and minimum side-product production."

A strategic advantage held by the iGem team was its interdisciplinary nature, according to Xiling Shen, faculty adviser and assistant professor of electrical and computer engineering.

The 13-member iGem team has students with majors ranging from biological and chemical engineering to materials science and engineering physics, Shen said, a variety that not only helped inform the project's proposal, but also allowed the team to proceed at a rapid clip since initial planning work began in April.

"These members contributed in a huge way by creating detailed computer models and allowing us to make use of Cornell's diverse engineering facilities to fabricate our micro-fluidic devices," Walaliyadde said. "[And] because Cornell is a leader in nanofabrication, we were able to use the Cornell Nanofabrication Facility to augment the biology portion of our project and actually make microfluidic chips that we could test our enzymes with."

Now, the team is working to further reduce the cost of manufacturing the device, as part of their preparation for the world competition.

Shashwat Samudra '14 is a writer intern for the Cornell Chronicle.

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