Brock and Freeze

AWARDEES: Thomas Brock and Hudson Freeze

SCIENCE: Thermus Aquaticus

FEDERAL FUNDING AGENCY: National Science Foundation

Most people go to Yellowstone to explore the outdoors, watch geysers, and look for moose, elk, and bears.  But in 1966, two scientists went to the park with a very different mission, not knowing that their quest would transform human medicine and so much more.

Funded by the National Science Foundation, Thomas Brock, a microbiologist, and his undergraduate research assistant, Hudson Freeze, went to Yellowstone to study thermophiles – heat-loving bacteria that thrive in extreme temperatures.  They were curious about how organisms survived in extreme environmental conditions.  Among the bacteria they collected at the park were microorganisms they would name Thermus aquaticus.  And those bacteria – Taq, as they were ultimately nicknamed – helped launch the field of biotechnology and the ongoing genomics revolution.

From new drugs and vaccines to diagnostic tests, biotechnology has enabled life-saving advances in human health.  How did these obscure bacteria, found in a natural hot spring, have such an enormous impact?

Since the discovery of DNA as the material encoding our genetic blueprint, scientists had wanted to study and exploit this complicated molecule to improve human health.  They needed a lot of material, however, and cells contain only a minute amount of DNA.  In theory, scientists knew how to “amplify” DNA, effectively replicating what goes on in the cells of living creatures.  They could unravel the DNA and use enzymes that occur in all DNA, called polymerases, which act like photocopiers, to generate many copies of a tiny piece of DNA.  Unfortunately, the way to unravel (or denature) the DNA in the lab is to subject it to very high temperatures, but the polymerase enzymes stopped working or fell apart at those temperatures.  Scientists could keep adding fresh enzyme, but it was a laborious and inefficient process.

Brock and Hudson’s discovery provided a key solution to this problem.  Like most organisms, Thermus aquaticus contained DNA and therefore also had the complement of enzymes needed to replicate that DNA, including polymerase.  Because the bacteria were adapted to living in water at extremely high, near boiling, temperatures, Taq polymerase could take the heat, remaining active at the temperature used to denature DNA.  In 1983, Nobel Prize winning biochemist Kary Mullis exploited this attribute of Taq to create a technology called the polymerase chain reaction (PCR), which allowed generation of unlimited copies of any fragment of DNA, large or small.  Six years later, the journal Science named Taq polymerase the “Molecule of the Year.”  In 2007, a publication on the history of PCR produced by the American Association for the Advancement of Science noted that “few technologies in the life sciences can claim to have been as pivotal as [PCR].”

The ability to amplify copies of DNA through PCR has led to accurate genetic tests for a wide variety of diseases and conditions, advanced forensic science to analyze crime scene evidence, and helped make possible the sequencing of the human genome.  Knowledge generated via PCR has led to cutting edge drugs and vaccines for diseases ranging from cancer to kidney disease.

All of this because two scientists with an NSF grant followed their insatiable curiosity to a hot spring in Yellowstone National Park!

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