Want to keep learning?

This content is taken from the University of Reading's online course, Small and Mighty: Introduction to Microbiology. Join the course to learn more.

Skip to 0 minutes and 10 seconds In this step, I’m with Dr. Renee Lee, an environmental microbiologist, to discuss her research on how microbes affect global processes. Hi, Renee. I’ve heard that your research revolves around microorganisms and climate change. Could you talk to me a little bit more about that? Yeah. That’s right, Glenn. I’m interested, actually, in the interaction between biology and the environment, particularly the discipline geology. Biology and geology comes together to form the subdiscipline called biogeochemistry. And microorganisms are particularly important in modifying our climate or actually contributing to things in our climate. So things like cyanobacteria is particularly important. Because with cyanobacteria, there wouldn’t be oxygen in our environment today. I’m also interested in protists, which are unicellular eukaryotes that photosynthesize and calcify.

Skip to 1 minute and 4 seconds These things are known as coccolithophores. And coccolithophores are dominant in our oceans. They form magnificent blooms of billions of cells, which can be seen from satellite imagery. And these organisms are prolific photosynthesizers. So what they do is they fix carbon dioxide from the environment in the process of photosynthesis, and they form organic matter. As they die, they sediment into the bottom of the ocean, thereby fixing the carbon dioxide. So this then fixes a few gigatons of carbon dioxide per year. So that essentially is a carbon sink that– Yes, it is. So you’ve talked about the length of these coccolithophores with our current climate. Is there any link of these organisms with our past climate?

Skip to 1 minute and 51 seconds Here, I have a sample of a piece of chalk that I’ve got from the White Cliffs of Dover. These coccolithophores can be cultured in the lab environment. So we grow them in different flasks in different conditions and we study how they photosynthesize and how they fix carbon dioxide. So you can measure its photosynthetic capacity, you can measure how much carbon they fix, and you can see how important they are in our global carbon cycle. If you were to take a chip off this chalk and, say, smash it and put it under the microscope, you’ll see remnants of these coccolithophores or these coccoliths. So these coccoliths are used by climate scientists to kind of look into the past.

Skip to 2 minutes and 34 seconds In fact, it is a window into the past climate. And by measuring isotopic fractionation, it gives us a signature that can tell us what the carbon dioxide level is like in the past. It can even tell us about the temperature in the past. And when I mention the past, this can be in the Jurassic or a few millions of years ago. So these organisms are not only important for our global climate, but it actually gives us the opportunity to figure out what it was like in the past. Thank you very much for meeting with me here today. Yup. Thank you, once again.

Meet Dr Renee Lee

In this video, I join environmental microbiologist Dr Renee Lee in our teaching lab. Renee discusses the relationship between microbes in our oceans and the global climate, both past and present, and how microbes impact climate change.

Share this video:

This video is from the free online course:

Small and Mighty: Introduction to Microbiology

University of Reading

Get a taste of this course

Find out what this course is like by previewing some of the course steps before you join: