Although science is becoming ever more complex, Chemistry Professor Virginia Cornish decided to do something relatively simple – at least from a scientific point of view – to solve a big problem.
The problem was cholera, which infects about 4 million people annually and kills at least 100,000, most of them children under age 5 and the very poor. Inspired by a research proposal from one of her doctoral students, Cornish, the Helena Rubinstein Professor of Chemistry, has set her lab to engineering a simple yeast – not unlike the kind used to make beer or bread – to detect the bacteria that causes cholera.
“If we can buy Fleischmann’s Yeast in the grocery store, why not make a freeze-dried yeast available that can detect cholera?” asked Cornish. “We want to enable a nontechnical person, in the simplest setting, to be able to safely and easily use this—not in a lab but in their home.”
Cornish’s lab focuses on synthetic biology, the science of building biomolecules and guiding cell evolution. The last century saw tremendous strides in the field of synthetic chemistry, with scientists learning to build molecules composed of about 100 atoms to make drugs in large quantities. The discovery of DNA, and the wealth of powerful techniques in molecular biology that followed, revolutionized biological research allowing researchers to manipulate sophisticated biomolecules such as antibodies. The new field of synthetic biology now attempts to bring together biologists, chemists and engineers to design and construct living cells to take on new challenges from disease detection to clean energy.
Cornish’s research has been funded with a starter grant of $100,000 from the Bill and Melinda Gates Foundation, whose officials hope to find a tool for developing nations to quickly and cheaply determine the presence of cholera and other diarrheal diseases. These diseases are often easily treatable but are extremely dangerous, spread rapidly and can kill within hours due to severe dehydration if not treated properly.
The idea for the project began with Nili Ostrov, a Ph.D. candidate in Chemistry who seized on the idea of using synthetic biology to create a sensor, or test, for cholera for her 4th year original research proposal requirement.
So how do you turn humble baker’s yeast into a disease-detecting machine? The team will engineer a receptor on the yeast that can detect the target bacteria. If the bacteria is found, the receptor will activate signaling molecules incorporated into the yeast cells to make lycopene—the organic pigment that gives tomatoes their red color. Then the water or other bacteria-laden substance will turn a bright red, indicating that it is contaminated and needs to be disposed of in a safe manner.
Their funding began last December and by next June, Cornish’s team hopes to show that the yeast can recognize and signal at least one target pathogen in a simple system. That will enable them to apply for a grant of $1 million from Gates to continue the work, conduct field trials and ultimately bring the sensor to the countries where it is needed most.
“The beauty of yeast is that it’s a living system that propagates itself,” said Cornish. “If we can create this and give it to a country that needs it, they can make as much as they want. If you can brew beer, you can produce this.”
The researchers have been consulting with colleagues at the Mailman School of Public Health, who put them in touch with the U.S. Centers for Disease Control and Prevention. The CDC was excited about the potential of the research and urged the Columbia team to explore creating sensors to detect diseases similar to cholera. CDC officials also encouraged the team to create sensors that could detect diseases in feces as well as water so the yeasts could be used for testing whether people are infected.
By Angela Retzky
To view Dr. Cornish's technologies, please click here.