After working with a research group that studied microbes in extreme salinity, like the Dead Sea, Enalls knew he wanted to study microbes “in strange places, doing strange things,” inspiring him to get his Ph.D. in organismic and evolutionary biology. Now in his work at EESA, his research focuses on the interrelationship of a microbe and its environment in extreme ecosystems such as hydrothermal vents.

Question: What made you interested in microbes? Was there a specific class, research experience, or professor that sparked your passion?

Answer: When I first started as a biology undergraduate student at Rider University, I wanted to go to medical school because I thought that was the only path to take. I joined a couple of medical school clubs, did some internships at hospitals, and then realized that I didn’t like being in medicine. I definitely respect the field, but I knew it wasn’t for me. I was in a panic because I didn’t know what else there was to do outside of medicine, but I turned on the TV to the Science Channel one night as a documentary was on. Scientists were doing research in the field in cave sites with very low pH, studying both the environment and the microbes that lived in this acidic water. I was a bit surprised that biologists were out here in the field, working in a super cool environment studying these very weird microbes. I really wanted to know, could I do that? How can I be that person one day? Luckily, at my undergrad, Dr. Kelly Bidle worked with microbes that like living in really salty environments – places that are 10 times saltier than the ocean, like the Dead Sea. Working with her and her research group was my jumpstart into strange microbes in strange places, doing strange things. And since then, I’ve moved on to working in other extreme environments such as the deep sea and contaminated sediments.

Question: Has there been something else that has reinforced your passion for your work? Any specific course of field work experience?

Answer: Early in my time in graduate school at Harvard University, I took  a microbial diversity summer course at the Marine Biological Labs near Cape Cod in Massachusetts. The entire goal of the summer was to work with a bunch of different microbes and learn how to isolate them from their environments. We really got our hands dirty in the field and were able to take some water and sediment samples back to the lab and work directly with microbes found in them. After taking that course, I had a much greater appreciation for microbes and I really wanted to continue to study and work with them.

I also had more opportunities to do field work as part of my graduate studies working with Dr. Peter Girguis. Since I was a part of a deep sea biology lab, many of our study sites were at the bottom of the ocean. We lived on research vessels, which are large ships, for a couple weeks at a time during our expeditions. Since our field sites were usually about one or two kilometers below sea level, we typically used remote operated vehicles and collected seawater and sediments to work with them either shipboard or back in the lab. Having these unique experiences  further kickstarted my interests in microbes found in  unique environments and understanding how they influence their habitats.

Question: How do microscopic organisms contribute to the overall ecosystem? What are you studying about microbes specifically? Is there a certain research question you’re trying to answer?

Answer: Microbes have very diverse metabolisms, and because of that they can be found in almost any environment on Earth–from places as far up as clouds in the atmosphere to as low as deep sea hydrothermal vents. Microbes are involved in biogeochemical cycling, which is how different elements flow between earth’s lithosphere, the hydrosphere, or the atmosphere. Microbes are directly involved in transforming these elements and mediating these processes through their metabolisms.

One specific example of this is methane. Microbes produce a good portion of the methane on Earth. Methane is a very potent greenhouse gas, it’s a bit stronger than CO2 in its ability to retain heat. There are also microbes that can consume methane and they tend to thrive in subsurface and soil environments. One of my projects here at Berkeley Lab with Dr. Romy Chakraborty involves trying to understand the dynamics between methane producing organisms and other organisms that co-occur in similar locations within sediments. Some of these microbes can share electrons between each other using conductive minerals as wires,  and these electrons are used to power their respective metabolisms. Looking at microbe-mineral interactions can help us understand the biological controls on methane and its  production not only in these specific natural settings, but also as it accumulates into the atmosphere.