Deep-sea hydrothermal vents harbor diverse microbes whose enzymes can be used in diagnostic tests, like the ones to detect the novel coronavirus and other pandemics like AIDS and SARS. (Video acquired from the submersible Alvin at the East Pacific Rise near 9° 50’N at 2510 meters depth. © WHOI-NDSF, Alvin Group, National Science Foundation)
The test being used to diagnose the novel coronavirus—and other pandemics like AIDS and SARS—was developed with the help of an enzyme isolated from a microbe found in marine hydrothermal vents as well as freshwater hot springs.
Biomedical breakthroughs sometimes happen in the most unlikely places. Take the deep ocean, for example, where mineral-laden fluid superheated by magma gushes from hydrothermal vents. Under extreme pressure and acidity, at times with no oxygen to speak of, microbes not only survive there, they thrive. This incredible adaptation offers insight into how life evolved billions of years ago—and how modern humans may be able to fight infections and disease.
“We’ve found marine microorganisms that produce antimicrobials—basically chemical weapons that help them fight off other organisms, and molecular mechanisms that help them resist viruses,” says Virginia (Ginny) Edgcomb, a WHOI microbiologist who investigates fungi and bacteria living in the deep sea and deep subsurface biosphere. These microbes feed on tough compounds like hydrocarbons and produce antimicrobial compounds. “Almost every antibiotic we have was produced by microorganisms. Who knows—maybe we’ll find new antimicrobials when we start to look in deep ocean habitats.”
The deep ocean has already given us compounds to treat cancer, inflammation, and nerve damage. But breakthroughs have also come from the ocean depths in the form of diagnostic tools. Case in point: the test being used to diagnose the novel coronavirus—and other pandemics like AIDS and SARS—was developed with the help of an enzyme isolated from a microbe found in marine hydrothermal vents as well as freshwater hot springs.
The pathway to developing this test started back in 1969 when scientists discovered a bacterium, Thermus aquaticus, living in the extreme temperatures of a hot spring in Yellowstone National Park. Two decades later, WHOI biologist Carl Wirsen and colleagues discovered new strains of bacteria on a hydrothermal vent off of Italy that could withstand even greater extremes (including heat, pressure, and lack of oxygen). More heat-loving microbes have since been found in hydrothermal vent communities across the globe to depths as great as 5000 meters beneath the sea surface.
By the mid-1980s, the unassuming microbes had enabled a major advance in the emerging field of genetics. Scientists found that their enzymes remained stable, even at the temperatures required to perform a revolutionary procedure known as polymerase chain reaction (PCR). With enzymes recovered from the microbes, it became possible to make millions of copies of a single DNA sequence in just a few hours, essentially upgrading geneticists’ tools from carbon-copy paper to state-of-the-art Xerox machinery. A technique using these enzymes, termed DNA polymerases, as well as enzymes isolated from viruses, now make it possible to quickly test for viruses, including coronaviruses like SARS (avian flu) and COVID-19.
Identifying microbial processes in the deep ocean is an essential first step for discerning human applications, says WHOI microbiologist Julie Huber.
“A lot of people think of the deep sea as a desert,” she says. “To our naked eye, it looks like there’s nothing there. But hydrothermal vents have a remarkable diversity of microbes, including genetic diversity. There’s huge potential there. What I can do as a basic science researcher is describe them and make their genome available. And folks in applied science can take that data and turn it into something useful.”
Edgcomb says the coronavirus outbreak underscores the importance of funding basic exploratory research, which may help lead to a cure or diagnostic tool in the future.
“You need to have people exploring different habitats in order to continue feeding the pipeline of medically-relevant enzymes (proteins),” she says. “This is a tough lesson to learn, with this pandemic, but I do hope people realize that the more we can learn more about microbes, the better off we are.”