Welcome to BIO121/ESS120: Introduction to Environmental and Ecological Microbiology at UC Merced! This page provides additional online content associated with the course, including short video lectures by Professor Beman, additional videos and interactives, and additional reading materials.
Microbial Diversity and Symbioses
When we look at microbes and global change, it can be a little overwhelming. This week we examine some of the more uplifting aspects of microbiology: microbial diversity and the symbioses that they form with large organisms. Both of these are active areas of scientific discovery—and there are broad discoveries being made, not just minor ones! These discoveries include new forms of life, new genes/enzymes, and amazing tricks that microbes perform. Because this is interesting stuff, there is a fair amount of content!
9.1 Introduction to Microbial Diversity. In this video lecture, I’ll cover some of the different aspects of microbial diversity that scientists typically examine. With microbes, it is not just about species diversity! There is diversity of all kinds to examine, although their total species diversity is remarkable. As always, pause, rewind, rewatch, and take notes.
[OPTIONAL] If you are interested, this interactive gives you an idea of how we examine microbial diversity in the lab:
https://www.biointeractive.org/classroom-resources/bacterial-identification-virtual-lab
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9.2 Community Diversity. This short article provides some brief background on how we characterize diversity in ecological communities of all kinds (not just microbes). Some of this may be review, but it helps with some of the concepts that we apply to microbes:
https://www.nature.com/scitable/knowledge/library/characterizing-communities-13241173/
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9.3 Abundance and Diversity. This article provides a little more information of patterns in species abundances and how this is an important part of biodiversity. This idea is particularly important for microbes, because we now know that there are a few very abundant groups of microbes in many ecosystems—we discussed some of these—and many, many, many, many rare groups. In order to understand the total diversity, we need to think about this pattern and what it means for sampling and studying microbial communities:
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9.4 Microbial Diversity. This video lecture is by Diane Newman, an outstanding scientist and professor at Caltech. This is a full lecture, so you may want to pause at some points. Before you started this class, a lot of this probably would be hard to follow; but now I think you will understand all of it!
I like this lecture because she covers all aspects of microbial diversity and weaves it together into a nice story with good visuals:
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9.5 Introduction to Symbiosis. This video lecture gives you an introduction to some of the amazing symbioses that microbes form with larger organisms. Scientists are discovering and understanding more of these each day, and many are amazing. This lecture is a little longer, and pause, rewind, rewatch, and take notes.
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9.6 Coral Bleaching. In previous lectures, I covered the coral-algae symbiosis. This is a nice visualization from the HHMI that shows this from the reef down to the chloroplast level, and is narrated by an excellent scientist, Stephen Palumbi. This may also help you visualize how photosynthesis more broadly works. And, unfortunately, this symbiosis can break down under high temperatures and light levels:
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9.7 Symbiosis and the Bobtail Squid. This is a video lecture from another excellent scientists, Margaret McFall-Ngai at the University of Hawai’i. She works on a surprisingly interesting symbiosis involving a cute little squid! I know it sounds weird at first, but it is really interesting in multiple ways. She also provides some more background on symbiosis:
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9.8 Symbiosis in Hydrothermal Vent Tube Worms. This is a final video on another cool symbiosis, the bacteria that support hydrothermal vent tube worms. This is from the HHMI and is narrated by Ed Yong, who is an excellent science writer. If you are interested in symbioses and microbiomes (including humans), he wrote an fantastic book called ‘I Contain Multitudes’ that is worth reading. He has also written some amazing articles on the pandemic for The Atlantic Monthly. He interviews one of the scientists, Colleen Cavanaugh, who has worked extensively on this symbiosis. It is, in a lot of ways, otherworldly to us!
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Beman Lab, University of California, Merced 