Dr. Mark O. Martin, Associate professor of biology at the University of Puget Sound in Tacoma, Washington is a distinguished educator with a well-known social media presence. He discusses how he became interested in microbiology and what drives his varied research foci, including #Microbialcentricity, bacterial predation, bioluminescence, tardigrades, microbial midwives and more. In the process, he delves into his passion for using art and other creative approaches to facilitate learning in the classroom, and shares some experience-driven wisdom about building confidence in STEM.
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Ashley's Biggest Takeaways
Undomesticated MicrobesWhen it comes to studying unusual microbes in the lab (or undomesticated microbes, as Martin affectionately calls them) good tools are hard to find. Keeping an open mind will help. In other words, if you’re looking at an unusual organism, don’t expect to see what you’ve seen before. All organisms are not E. coli.
After a while, one starts to get a feeling for the organism they work with, what’s normal and what’s abnormal for that species. In this sense, familiarity breeds knowledge.
There is no bad question. Often times it is the unusual questions that feed new questions that generate discovery.
Microbial Midwives
Sceloporus virgatus, is a species of lizard that is a close relative to a Blue Belly lizard, Sceloporus occidentalis. One unique aspect of this species, is that the S. virgatus females, not the males, demonstrate bright spots of color, and the intensity of color is associated with the fecundity and viability of its offspring.
Eggs dissected and incubated out of gravid females tend to be susceptible to fungal and bacterial infection, while those that are naturally laid do not. It turns out, microbes are at the center (#Microbialcenricity) of this phenomenon. Certain microbes found in the cloaca of these lizards produce antifungal compounds that protect the eggs from infection, and different populations of microbes appear in different areas of the G.I. tract.
Bacterial Predation
Bdellovibrio stands for curved leech. They are very much like a bacteria phage, but they have an innate metabolism. They are bacteria, but they can only live at the expense of other bacteria.
Bdellovibrio cruise through liquid at 50 cell lengths per second, collide with other bacteria and use Type IV pilli to shoehorn their way into the periplasm—compartment between the inner and outer membrane—of its host. This organism, about 1/3 the size of E. coli will shoehorn itself into an area that is literally 40 nm wide and grow at the expense of the host.
Bdellovibrio modifies the outer cell wall so that further Bdellovibrio’s can’t gain access. It is still unknown what receptor, or if there is a receptor that is recognized.
Tardigrades
Tardigrades undergo a process called cryptobiosis, where they go from a regular, active state, to a tun state, in which they draw in their legs, their body dries out and their metabolism drops—allowing the organism to survive extreme conditions (sort of like a cyst).
Martin is investigating whether the microbiome comes with it, or is left behind.
Featured Quotes:
“Even though my background was different from many people’s, maybe I could be a scientist. And it also taught me that sometimes the best way to answer a question is with simple approaches.”“I want to teach my students about the centrality of microbes to everything.”
“There’s so much microbiology everywhere and in everything. We don’t center it in our educational system, and I really think we should. On so many levels. There are echoes of even the most complex behaviors in eukaryotes, even multicellular eukaryotes—like my family—that we can trace back to microbial antecedents that I think are a really good way to look at biology.”
“First evolved; last extinct is really true about the microbial world.”
“The beginner’s mind is open to opportunities, but the experienced mind is closed to what’s new. There aren’t any bad questions.”
“I really encourage students to ask the unusual questions. Mostly if one person has an unusual question, it’s really worth talking about.”
“If you have a known genome and you are able to get relatively inexpensive sequencing, you can find out what genes have changed.
“I have many questions about Bdellovibrio and many questions about Ensifer, and there are so many others. I think predation is the rule.”
“Tardigrade is like an exemplar of what we all should be because it is a multiple extremophile.”
“I have tardigrades in my lab at all times.”
“The worst thing in modern society is this bizarre idea that there’s only one way to do things. There are lots of ways to do anything. For example, I tend to talk a lot about personal struggles that I’ve had. I’ve had people tell me that that’s too open, but I’ve also had people say that they’ve found it to be powerful and helpful to them. So the most important thing is to just be yourself.”
“The value of social media, beyond a sounding board—that message in a bottle that you throw out electronically—is that I’ve had so much help in microbiology and in pedagogy from people that read something that I’ve tweeted out about, and then they’ll contact me with their ideas.”
“I have an international reach through Twitter.”
“Be a nice human. Ask for help. You’re not alone. As microbiologists, we know we’re never alone.”
Links for This Episode
- Vertically transmitted microbiome protects eggs from fungal infection and egg failure
- The effects of Sceloporus virgatus cloacal microbiota on the growth of pathogenic fungi
- Sex-specific asymmetry within the cloacal microbiota of the striped plateau lizard, Sceloporus virgatus
- Predatory Prokaryotes: An Emerging Research
Opportunity (pdf) - Carleton College #LuxArt 2019
