Features

Dr. Jonathan Trent, Bioengineering Research Scientist, Ames Research Center

ImageDr. Jonathan Trent is an expert in the use of extremophile proteins to create nanoscale electronic devices. An extremophile is a life form capable of surviving in the harshest conditions on earth including severe heat, bitter cold, and extremely acidic or alkaline environments. The recipient of a 2006 Nano 50 Award as one of the leading innovators in the field of nanotechnology, Dr. Trent also leads the GREEN (Global Research into Energy and the Environment at NASA) Team at Ames Research Center.

NASA Tech Briefs: You currently work in the Bioengineering Branch of NASA’s Ames Research Center. What is that branch’s mission and what types of projects do they typically get involved in?

Dr. Jonathan Trent: The Bioengineering Branch is primarily focused on what could be called “advanced life support.” Advanced life support involves a lot of different activities, but they are all related to keeping people alive in space. Most of what the scientists do in the Branch is related to space suits, and air, water, and waste purification and recycling. Some years ago the branch chief, Mark Kliss, decided that he wanted to extend the purview of the branch to include nanotech and he invited the protein nanotech group that I had assembled to be part of his Branch.

NTB: You’ve done extensive research in the area of so-called ‘thermophiles,” or “extremophiles,” life forms that can somehow survive in extreme conditions such as those found in the acidic hot springs of Wyoming’s Yellowstone National Park, where temperatures can exceed 150 degrees F. Tell us about your work in that area and what you’ve learned from it.

Dr. Trent: My interest in extremophiles goes back over 20 years. When I was a graduate student, studying marine science, hot springs were discovered at the bottom of the deep ocean called deep sea hydrothermal vents, where the water temperatures can reach more than 400°C (750°F)—the hydrostatic pressure keeps the water from boiling, like a pressure cooker. I became very interested in temperature and pressure effects on microbes and when some of my colleagues published a paper suggesting that high pressures could allow microbes to live at super high temperatures, such as 250°C, which is about 480°F, I got involved in a big controversy. These scientists claimed that anywhere there is liquid water, bacteria can grow and they used samples from a hydrothermal vent at 2,600 meters depth off the coast of Mexico to do experiments that they claimed gave evidence for bacterial growth at 250°C and 265 atmospheres pressure. I knew enough about pressure effects on microbes and molecules to know that their claim about liquid water was wrong and I was very skeptical about their results, so I did experiments in our deep-sea simulation lab and I was able to replicate their results without a culture. In other words, I demonstrated that their results could be explained by artifacts that occur under their experimental conditions and there was no reason to believe bacteria were actually growing at these super high temperatures and pressures. The debate was decided for the scientific community when some biophysicists showed the instability of fundamental macromolecules at 250°C and 265 atmospheres pressure, indicating that life as we know it is impossible at that temperature and pressure doesn’t make a big difference.

Although I’m interested in the discovery of new species of extremophiles, particularly those living in hot springs and the deep sea, I’m more interested in understanding the biochemical adaptations that allow these organisms to thrive under conditions that would instantly kill most familiar organisms?

NTB: How many types of extremophiles have you and your team discovered to date?