Microbiology Series: Episode 7
Microbe Structures for Environmental Fitness

In this introductory episode, I will talk about some of the various structures or processes that microbes can use to persist in environments outside of human (or other) hosts. This includes being able to withstand low nutrient availability, a lack of adherence sites, exposures to toxic chemicals, exposures to predators, and environmental extremes. So, let’s find out how they can survive these conditions and what that means for humans!
Transcript:
Transcript of Ep7
Sources:
Engleberg, N. C., DiRita, V. J., & Imperiale, M. J. (2022). Schaechter’s mechanisms of microbial disease (6th ed.). Wolters Kluwer.
Madigan, M. T., Bender, K. S., Buckley, D. H., Sattley, W. M., Stahl, D. A., & Brock, T. D. (2012). Brock Biology of Microorganisms (13th ed.). Pearson Education.
Tortora, G. J., Funke, B. R., & Case, C. L. (2013). Microbiology: An Introduction (11th ed.). Pearson Education.
Smith, A. C., & Hussey, M. A. (2005, September 30). Gram stain protocols. American Society for Microbiology. https://asm.org/getattachment/5c95a063-326b-4b2f-98ce-001de9a5ece3/gram-stain-protocol-2886.pdf
Gaynes, R. (2017, May). The discovery of penicillin—new insights after more than 75 years of clinical use. Emerging Infectious Diseases. https://pmc.ncbi.nlm.nih.gov/articles/PMC5403050/
Cornell College of Agriculture and Life Sciences. (n.d.). Bacterial Endospores. Cornell CALS. https://cals.cornell.edu/microbiology/research/active-research-labs/angert-lab/epulopiscium/bacterial-endospores
Basta, M., & Annamaraju, P. (2023, January 30). Bacterial Spores. StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK556071
Rohde, M. (2019, May 24). The Gram-positive Bacterial Cell Wall. Microbiology Spectrum. https://pmc.ncbi.nlm.nih.gov/articles/PMC11086966/#:~:text=Therefore%2C%20bacterial%20cell%20walls%20deserve,disease%20in%20animals%20and%20humans.
Beveridge, T. J. (1999, August). Structures of Gram-negative Cell Walls and Their Derived Membrane Vesicles. Journal of Bacteriology. https://pmc.ncbi.nlm.nih.gov/articles/PMC93954/#:~:text=Gram%2Dnegative%20cell%20walls%20are,back%20to%20the%20Archean%20eon.
Libretexts. (2024, November 23). 4.4D: Mycoplasmas and Other Cell-Wall-Deficient Bacteria. Biology LibreTexts. https://bio.libretexts.org/Bookshelves/Microbiology/Microbiology_(Boundless)/04%3A_Cell_Structure_of_Bacteria_Archaea_and_Eukaryotes/4.04%3A_Cell_Walls_of_Prokaryotes/4.4D%3A_Mycoplasmas_and_Other_Cell-Wall-Deficient_Bacteria#:~:text=Consistent%20with%20this%20very%20limited,Key%20Points
Jarlier, V., & Nikaido, H. (1994, October 1). Mycobacterial Cell Wall: Structure and Role in Natural Resistance to Antibiotics. Oxford Academic: FEMS Microbiology Letters. https://academic.oup.com/femsle/article/123/1-2/11/426815
Pereira, A. C. C., Ramos, B., Reis, A. C. c., & Cunha, M. V. V. (2020, September 9). Non-tuberculous Mycobacteria: Molecular and physiological bases of virulence and adaptation to ecological niches. Microorganisms. https://pmc.ncbi.nlm.nih.gov/articles/PMC7563442/#:~:text=The%20diversion%20of%20energy%20(ATP,coli%20PolIII%CE%B1%20%5B78%5D.
Hett, E. C., & Rubin, E. J. (2008, March). Bacterial Growth and Cell Division: A Mycobacterial Perspective. Microbiology and Molecular Biology Reviews. https://pmc.ncbi.nlm.nih.gov/articles/PMC2268284/#:~:text=the%20nonsporulating%20M.-,tuberculosis%20is%20its%20ability%20to%20remain%20dormant%20within%20an%20individual,%2Drich%20gram%2Dpositive%20organisms.
Gao, S., Jin, W., Quan, Y., Li, Y., Shen, Y., Yuan, S., Yi, L., Wang, Y., & Wang, Y. (2024, March 13). Bacterial Capsules: Occurrence, Mechanism, and Function. Nature News. https://www.nature.com/articles/s41522-024-00497-6
Waites, K. B., & Ambalavanan, N. (2025, May 15). Mycoplasma hominis and Ureaplasma Infections. UpToDate. https://www.uptodate.com/contents/mycoplasma-hominis-and-ureaplasma-infections
To, K., Cao, R., Yegiazaryan, A., Owens, J., & Venketaraman, V. (2020, August 6). General Overview of Nontuberculous Mycobacteria Opportunistic Pathogens: Mycobacterium avium and Mycobacterium abscessus. Journal of Clinical Medicine. https://pmc.ncbi.nlm.nih.gov/articles/PMC7463534/#:~:text=NTM%20are%20ubiquitous%20in%20the,abscessus.
Nucci, A., Le Bris, J., Diaz-Diaz, S., Torres-Elizalde, L., Rocha, E. P. C., & Rendueles, O. (2025b, October 8). Phenotypic Heterogeneity of Capsule Production Across Opportunistic Pathogens. American Society for Microbiology. https://pmc.ncbi.nlm.nih.gov/articles/PMC12505892/#:~:text=The%20bacterial%20extracellular%20capsule%20is,in%20ON/OFF%20phase%20variation.
Li, G., Cortez, M. H., & Weitz, J. S. (2019, August 1). When to be Temperate: On the Fitness Benefits of Lysis vs. Lysogeny. Virus Evolution. https://www.biorxiv.org/
Goel , T., Beckett, S. J., & Weitz, J. S. (2025, April 29). Eco-evolutionary Dynamics of Temperate Phages in Periodic Environments. Virus Evolution. https://academic.oup.com/ve/article/11/1/veaf019/8121540
Komarova, N. L. (2007, December 21). Viral Reproductive Strategies: How can Lytic Viruses be Evolutionarily Competitive?. Journal of Theoretical Biology. https://www.researchgate.net/publication/351163114_httpswwwsciencedirectcomsciencearticleabspiiS1051200421000968
Erez, Z., Steinberger-Levy, I., Shamir, M., Doron, S., Stokar-Avihail, A., Peleg, Y., Melamed, S., Leavitt, A., Savidor, A., Albeck, S., Amitai, G., & Sorek, R. (2017, January 26). Communication Between Viruses Guides Lysis-Lysogeny Decisions. Nature. https://pmc.ncbi.nlm.nih.gov/articles/PMC5378303/#:~:text=Temperate%20viruses%20can%20become%20dormant,the%20lytic%20or%20lysogenic%20cycle.
Fehringer, M., & Vogl, T. (2025, January 7). Molecular Mimicry in the Pathogenesis of Autoimmune Rheumatic Diseases. Journal of Translational Autoimmunity. https://pmc.ncbi.nlm.nih.gov/articles/PMC11773492/#:~:text=The%20peptide%20triggering%20molecular%20mimicry,RF%20on%20IgG1Fc%20%5B157%5D.
Ene, I. V., & Bennett, R. J. (2014, April). The Cryptic Sexual Strategies of Human Fungal Pathogens. Nature Reviews: Microbiology. https://pmc.ncbi.nlm.nih.gov/articles/PMC4102497/
Nielsen, K., & Heitman, J. (2007). Sex and Virulence of Human Pathogenic Fungi. Advances in Genetics. https://pubmed.ncbi.nlm.nih.gov/17352904/#:~:text=Recent%20studies%20with%20engineered%20pairs,into%20successful%20pathogens%20in%20humans.
Gauthier, G., & Klein, B. S. (2008, September). Insights into Fungal Morphogenesis and Immune Evasion: Fungal Conidia, when Situated in Mammalian Lungs, may Switch from Mold to Pathogenic Yeasts or Spore-Forming Spherules. Microbe (Washington, D.C.). https://pmc.ncbi.nlm.nih.gov/articles/PMC2902187/#:~:text=Once%20situated%20in%20lungs%2C%20the,of%20particular%20interest%20to%20us.
