Stephanie Carr, Hartwick College – Microbes

Microbes are a rich area of study.

Stephanie Carr, assistant professor of biology at Hartwick College, discusses thinking small to find big answers.

Dr. Stephanie Carr is an assistant professor of biology at Hartwick College. As a microbiologist and a geochemist, Stephanie aims to understand how microorganisms impact our environment. Stephanie focuses on discovering how microorganisms survive extreme conditions, such as the oxygen-free and nutrient-limiting environments at the bottom of the ocean. The seafloor covers 70% of our planet, and the microorganisms in the seafloor live by recycling the elements of the ocean. Learning about these organisms is an important step towards understanding our planet. Dr. Carr earned her Ph.D. at the Colorado School of Mines. Her most recent research on Hydrothermarchaeota will be published this year in the International Society for Microbial Ecology Journal.



What are microorganisms doing for you? Microbes live everywhere, but we often forget about them because they are too small to see without a microscope. The truth is, microbes impact our everyday lives in many ways, including making us sick which is the case for Salmonella.  Others make useful and valuable products. The antibiotic streptomycin, for example, comes from a microbe called Streptomyces. Microbes living in the ocean produce large amounts of oxygen, while others living underground produce methane, which is a greenhouse but also a natural gas that can be burned for fuel. It’s safe to say that microbes impact our lives every day.

But did you know that scientists have only characterized a small fraction of the planet’s microbes? This is because it is hard to grow most microbes in the lab, just like it is hard to grow some plants indoors. But just because they are hard to grow, doesn’t make them any less important.

In my research, we use DNA analyses to understand the function of microbes that can’t grow in the lab. For example, Hydrothermarchaeota. These unique microbes are found beneath the ocean floor. We can’t grow them in the lab (yet), but based on the genomes we collected, we can hypothesize that these organisms eat carbon monoxide. We also found DNA for early-evolved proteins that suggest that these organisms may help us understand how life evolved on Earth, and how life might evolve on other planets where carbon monoxide is plentiful. And now that we have studied the genomes of Hydrothermarchaeota, we have a better guess as to what food and nutrients they need, and a better chance of growing these microbes in the lab, where we can continue to investigate how their growth may impact our lives.