Matters Microbial

Matters Microbial #134: Could Alien Life Use Different Chemistry?
July 14, 2026 Today Dr. Morgan Sobol, Assistant Professor in the Department of Biology at Texas State University, joins the Quality Quorum today to discuss how microbes on early earth began interacting with elements like nitrogen, making life possible here and perhaps elsewhere in the universe! You will learn about the fundamental and amazing enzyme nitrogenase!
Host: Mark O. Martin
Guest: Morgan Sobol
Download MM134 (37 MB MP3, 62 mins)
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Links for this episode
The website for ASM Microbe, the annual meeting of microbiologists.
The "live" #MattersMicrobial session recorded at ASM Microbe, with Dr. Hannah Reich.
An essential article about "A World Without Microbes."
A video version of "A World Without Microbes."
An introduction to microbial ecology.
An overview of the enzyme that fixes carbon dioxide into organic matter, Rubisco.
An overview of the enzyme that converts practically inert dinitrogen gas into bioavailable ammonia, nitrogenase.
A short essay on metalloenzymes, including nitrogenase.
An overview of nitrogen fixing microbes, and the strategies they use.
A review editorial describing the burgeoning field of astrobiology.
A link to a NASA program exploring early evolution of microbial life.
An article on the microbially caused Great Oxidation Event that changed our atmosphere eons ago, making life like forms like ours possible.  
An article exploring the evolution of microbial nitrogen fixation.
An abstract by Dr. Sobol and colleagues, discussing the evolution of nitrogen fixation in an ancient ecological context. 
A lovely article about the microbiology of Yellowstone National Park.
Dr. Sobol's faculty website.
Dr. Sobol's interesting research group website.
Intro music is by Reber Clark
Send your questions and comments to mattersmicrobial@gmail.com

Matters Microbial #133: The Microbial Partnerships That Help Corals Survive
June 29, 2026 Dr. Hannah Reich of the Department of Environmental Biology at the State University of New York's College of Environmental Science and Forestry joins the #QualityQuorum to discuss how microalgal interactions (including with bacteria) are fundamental contributors to large scale ecosystem processes including the ocean carbon pump, the duration of algal blooms, and the evolutionary success of coral reefs.
 
Host: Mark O. Martin
Guest: Hannah Reich
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Links for this episode
An essay on the coral holobiont.
A discussion of the phycosphere.
A discussion of the rhizosphere.
A review of the roles of iron in microbial biology.
An overview of siderophores in the microbial world.
An article about iron, the warming oceans, and coral. 
A VERY recent article by Dr. Reich and colleagues regarding siderophores in the coral holobiont.
A very nice short video by Dr. Reich explaining her work at ESF.  
Dr. Reich's faculty website.
Dr. Reich's fascinating laboratory group website.
Intro music is by Reber Clark
Send your questions and comments to mattersmicrobial@gmail.com

Matters Microbial #132: What 83,000 Generations of Bacteria Reveal About Evolution
June 17, 2026 Today Dr. Jeffrey Barrick, John A. Hannah Distinguished Professor of the Department of Microbiology, Genetics, & Immunology and the Department of Entomology at Michigan State University, joins the quality quorum today to discuss how microbes can be used to study evolution itself. He will also discuss the impressive and ongoing LTEE program, the experiments that originate from it, and what they tell us about evolution.
Host: Mark O. Martin
Guest: Jeffrey Barrick
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Links for this episode
Here is a link to an article about the late great Abigail Salyers.
Here is what I wrote about Dr. Salyers. I learned so much from her.
 An article about the contributions of Dr. Theodosius Dobzhansky to the study of evolution.
The concept of contingency during evolution.
An overview of microbial evolution.
A link to "Microbes and Evolution," a book discussed during this podcast.
A link to "A Primer for Experimental Evolution," a book discussed during this podcast.
The concept of Growth Advantage in Stationary Phase (GASP).
A video about the MEGA plate experiment by Dr. Michael Baym and colleagues. This is a "must watch."
An video about Dr. Richard Lenski, originator of the LTEE.
Dr. Lenski's website. 
The LTEE (long term evolutionary experiment) website.  There is so much here to explore.
An excellent introduction to the LTEE.
An article about the amazing " climbing citrate mountain" innovation during LTEE described in the podcast.
A video by Dr. Lenski about LTEE.
A video by Dr. Barrick that is worth your time.
Dr. Barrick's faculty website at Michigan State University.
Dr. Barrick's research laboratory website.
Intro music is by Reber Clark
Send your questions and comments to mattersmicrobial@gmail.com

Matters Microbial #131: What Cystic Fibrosis Reveals About Hidden Microbial Lives
June 3, 2026 Today Dr. Sam Brown, Professor of Biological Sciences at Georgia Tech University, joins the quality quorum today to discuss the social lives of bacterial pathogens. He will also discuss VERY recent research from his lab group exploring the specialist/generalist problem in Pseudomonas aeruginosa, and thoughts on cryptic convergent specialization!
Host: Mark O. Martin
Guest: Sam Brown
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Links for this episode
An overview of behavioral ecology.
An article describing evolutionary trade offs and game theory.
A video describing Tinbergen's "Four Whys" involving behavioral ecology.
A wonderful essay by Carl Zimmer relating lake ecology and microbial ecology in humans. 
A Pseudomonas plush toy from Giant Microbes.
The Pseudomonas contaminated eyedrops story told by Dr. Brown, as summarized by the CDC.
An essay about sociomicrobiology.
An overview of quorum sensing.
An overview of biofilms.
An article describing specialization versus generalism in ecology. 
A description of a "confusion matrix" in data analysis.
A somewhat dated overview of PCA (principle component analysis).
The article about convergent cryptic specialization under discussion today on this podcast from Dr. Brown's research group (first author Mehlferber).
A VERY interesting article from Dr. Brown's research team describing eco-evolutionary aspects of polymicrobial infections.
Dr. Brown's faculty website.
Dr. Brown's laboratory group website.
Intro music is by Reber Clark
Send your questions and comments to mattersmicrobial@gmail.com

Matters Microbial #130: The Holobiont — Animals, Microbes, and Ecology
May 19, 2026 Today Dr. Kevin Kohl, Associate Professor of Biological Sciences at the University of Pittsburgh, joins the #QualityQuorum to discuss how he and his colleagues study the interplay between animals, their resident gut microbes, and the overarching concept of the holobiont.
Host: Mark O. Martin
Guest: Kevin Kohl
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Links for this episode
The One Health Microbiome Center at Pennsylvania State University.
A very fine essay on the holobiont concept for non-microbiologists.
A general introductory overview of the holobiont concept.
The holobiont concept and the coral symbiosis. 
A partial history of the development of the holobiont concept.
Dr. Casadevall suggests that context and thus outcomes describes the term "pathogen," and a similar analysis applies to the holobiont.
A very short description of the holobiont concept. 
Another overview of the holobiont concept in general, coauthored by Dr. Kohl. 
Some basic rules for thinking about the holobiont concept.
A video introduction to the holobiont concept, by Dr. Seth Bordenstein.
I highly recommend this essay by the science writer Carl Zimmer, "The Human Lake," to think of the connections between lake ecology and microbial interactions with humans.
Another wonderful article recommended by Dr. Kohl, by Dr. Margaret McFall-Ngai and coauthors, detailing the impact microbes have on animals over evolution and development. 
The wood rat – creosote – microbiome connection to the holobiont concept, discussed on this podcast (coauthored by Dr. Kohl).
The fascinating work by Dr. Kohl and colleagues showing the relationship between tadpole development and pond microbes discussed in this podcast.
 A must read article by Dr. Kohl and colleagues, "Through the microbial looking glass: our shifting understanding of the holobiont and microbes as mediators of organismal biology," illustrates the development and influence of the holobiont concept.
Dr. Richard Prum's book, "Performance All the Way Down," was discussed during this podcast. There is also a video where Dr. Prum discusses the ideas in this book, describing gene regulation as a performance. 
Dr. Kohl's faculty website.
Dr. Kohl's (very interesting) research website.
Intro music is by Reber Clark
Send your questions and comments to mattersmicrobial@gmail.com