Matters Microbial

Matters Microbial #137: The Living Skin of Our Planet
August 25, 2026 Today Dr. Estelle Couradeau, Assistant Professor in the Department of Ecosystem Science and Management and the Huck Institutes of the Life Sciences at the Pennsylvania State University,  joins the quality quorum today to discuss the role that the soil microbiome can play in terms of agriculture, moderating temperature, and protecting specific environments.
 
Host: Mark O. Martin
Guest: Estelle Couradeau
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Links for this episode
The Erskine Foundation fellowship website.
An overview of Paenibacillus.  
An article discussing the fascinating colonial morphology often found with Paenbacillus. 
A blog post that demonstrates that the odd appearance of Paenibacillus can be used by other microbes for dispersal! 
Dr. Jo Handelsman's essential book, "A World Without Soil."
A fine video describing the soil microbiome.
The complexity of soil with regard to where and how microbes can live.
Science journalist Carl Zimmer's indispensable essay likening the microbial ecology of lakes to the human body:  "The Human Lake."
An overview of dormancy in microbes.
The "BonCat" (bio-orthogonal non-canonical amino acid tagging) technique for detecting living microbes in a sample without cultivation.
An overview of flow cytometry in microbiology.
An essay suggesting that marine bacteria are involved in the production of clouds.
An article about climate change and microbes.
An article about cyanobacteria and "sunscreen."
A review article about the "biocrust" concept.
A video overview of beautiful and fascinating microbial fossils:  stromatolites.
A video by Dr. Couradeau describing her research.
Articles by Dr. Couradeau and colleagues asking which microbes are active in soil:  here, here, and here.
Articles by Dr. Couradeau and colleagues asking if microbes can change the temperature of a desert:  here and here.
Articles by Dr. Couradeau and colleagues that explore the hidden microbiomes of Andean páramo wetlands:  here and here.
Dr. Couradeau's faculty website.
Dr. Couradeau's research website.
Intro music is by Reber Clark
Send your questions and comments to mattersmicrobial@gmail.com

Matters Microbial #136: When Bacteria Open the Wrong Door
August 11, 2026 Today Dr. Michael D.L. Johnson, Associate Professor of Immunobiology at the University of Arizona,  joins the quality quorum today to discuss copper, microbiology, and a possible new strategy to fight bacteria that cause disease.
Host: Mark O. Martin
Guest: Michael D. L. Johnson
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Links for this episode
A link to Hartiful, the Etsy artist who custom creates glow in the dark (and many other kinds) pins.
A link to the essential science artist Beatrice the Biologist.
A link to World Microbiome Day.
A link to Micropia, the microbiology museum in Amsterdam.  
A recent article on the growing threat of antibiotic resistance among disease causing bacteria.
A video demonstrating the Kirby Bauer procedure, which shows antimicrobial effects and zones of inhibition.
A link to an earlier #MattersMicrobial episode with Dr. Michael Schmidt describing copper and microbes.
A review article describing the impact that copper can have on microbes.
 A review article on Streptococcus pneumoniae, the organism with which Dr. Johnson works.
An video celebrating the role that S. pneumoniae had in determining that DNA was the genetic material prior to World War 2.
An overview of siderophores that help microbes obtain needed iron.
An article about redox activity and copper and microbes.
The relationship between metal toxicity and antimicrobial activity.
The role that copper plays in agriculture.
The differences between Gram positive and Gram negative bacteria.
An article on efflux pumps and metal toxicity in microbes.
An article describing how iron binding proteins also bind copper.
An article describing how zinc interacts with microbes.
A wonderful description of Dr. Johnson's "Trojan Horse" approach to battle disease causing microbes.
A relevant review article by Dr. Johnson and his colleagues discussing copper and microbes.
An overview of the "Hypothesis Fund," which supports unusual ideas in science.
A video of Dr. Johnson describing his research.
Dr. Johnson's faculty website.
Dr. Johnson's research laboratory website.
Intro music is by Reber Clark
Send your questions and comments to mattersmicrobial@gmail.com

Matters Microbial #135: Biofilms in Motion—The Adorable Zorbs
July 30, 2026 Host: Mark O. Martin
Guest: Jo Handelsmann, Shruthi Magesh
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Links for this episode
Here is a link to the Etsy shop where one can buy the wonderful "THIS IS WHAT A MICROBIOLOGIST LOOKS LIKE" enamel pins.
Here is a link to the World Microbiome Day website.
Here is a link to the interesting work of Contamination Club.
The story of Alexander Fleming's famous contaminant that led to the discovery of penicillin. 
Here is a link to Dr. Handelsman's recent book, "A World Without Soil."  Highly recommended. 
The website for Dr. Handelsman's wonderful "Tiny Earth" program, helping students worldwide to screen soil for antimicrobial production (and learning about microbial diversity).  
An overview of the microbial complexity of soil.  
A video overview of biofilms.
A video overview of types of bacterial motility.
A video overview of "gliding motility" among bacteria.
Some bacteria can "hitchhike" or are carried by other bacteria, such as Paenibacillus. 
Learning about an odd sport involving "zorbs."
An introductory essay on "zorbing" and motility.
Another introductory essay on "co-zorbing," the topic of today's discussion.
A description of Flavobacterium johnsoniae, which carries out "zorbing." 
The original article on THOR ("The Hitchhikers of the Rhizosphere") by Dr. Handelsman and colleagues.
The original "zorb" paper by Dr. Handelsman and colleagues that was discussed during today's podcast.
The "co-zorb" paper by Dr. Handelsman, Dr. Magesh, and colleagues that was discussed during today's podcast.
A fascinating video by Dr. Handelsman and her path to becoming a microbial scientist. Highly recommended..  
Dr. Handelsman's faculty website.
The website for the Wisconsin Institute for Discovery.
Dr. Handelsman's research laboratory website.
Intro music is by Reber Clark
Send your questions and comments to mattersmicrobial@gmail.com

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