Skip to content
The Microbial Menagerie
Menu
  • Home
  • About
    • Blog News and Updates
    • About Jennifer
    • My Other Writing
    • Write a Guest Post
    • Contact Me
    • Privacy Policy and Disclosures
  • Microbes and Microbiologists
    • Meet a Microbiologist
    • Meet a Microbe
    • Microbiology Poems
  • Microbiome
    • Human Microbiome
    • Built Environments
  • Fermented Foods
    • Bread
    • Cheese
    • Kefir
    • All Fermented Foods
  • Diseases and Immunity
    • COVID-19
    • Antimicrobial Resistance
    • Vaccines
    • Infectious Diseases
  • Other
    • Agar Plates
    • Applied Microbiology
    • Fungi
    • Microbes in the Environment
    • Microbial Physiology
    • Microbiology Research Updates
    • Science Communication
    • Microbiology History
    • Microbiology Books
Menu

A Bacterium You Can See With the Naked Eye

Posted on September 27, 2017July 19, 2022 by Jennifer Tsang

It is commonly believed that bacteria are microscopic – stealthy and hidden from the naked eye. But the bacterium, Epulopiscium fishelsoni, is a microbial behemoth you can see with the human eye alone. First discovered in the intestines of a brown surgeonfish in the Red Sea in 1985, this giant bacterium was first classified as a protist because of its large size. In 1993, rRNA sequencing revealed that this organism is actually a bacterium.

Epulopiscium varies between 10- to 20-fold in length and has a volume more than 2,000 times that of a typical bacterium. They range from 200 – 700 microns in length, about the size of a grain of table salt. But being big does have its downsides.

Challenges That Come With an Increased Cell Size

As cell size increases, both the surface area and volume increases. The trouble comes because volume increases much faster than surface area. This increased volume poses challenges to giant bacteria that the typical bacterium does not face.

A Epulopisicium cell. Image credit: Alan Cann.

With a small size, bacteria can use simple diffusion to transport molecules and nutrients inside their cell membranes and within the cell. When the cell size increases, diffusion becomes much too slow to be functional. To overcome the diffusion problem, the Epulopiscium cell membrane is wrinkly instead of a flat, smooth surface. The wrinkles lend to more surface area of the membrane where diffusion and transport of molecules into the cell can take place.

Large cells, such as those within eukaryotic organisms, evolved internal structures to more efficiently transport molecules within the cell. Epulopiscium cells, however, do not contain these structures. But they have evolved other ways to deal with the transport problem.

Epulopiscium lives in the intestine of surgeonfish. Image credit: Paul Asman and Jill Lenoble.

Thousands of Genome Copies Help With Local Gene Expression

In 2008, researchers found an extremely large amount of DNA within the cell. Epulopisicium cells can contain anywhere between 85 pg and 250 pg of DNA, or about 14 to 42 times as much DNA as a human cell. An E. coli cell contains 0.017 pg of DNA meaning Epulopsicium contains 5,000 to 15,000 times as much DNA as the typical bacterium. This immense amount of DNA is not just one chromosome – each cell contains thousands of copies of its genome. This means that copies of the same gene are scattered about the cell resulting in gene expression that can happen locally, without the need of large-scale diffusion.

Epulopiscium is yet another example of the diverse lifestyles of microbes and reminds us that we find microbes in the most obscure places and in the most astounding forms. Epulopsicium defies the conventional view of microbe and leaves us wondering:  how big is too big for a bacterium?

Loading

Share this:

  • Click to share on Twitter (Opens in new window)
  • Click to share on Facebook (Opens in new window)
  • Click to share on LinkedIn (Opens in new window)
  • Click to share on Pinterest (Opens in new window)
  • Click to share on Reddit (Opens in new window)
  • Click to email a link to a friend (Opens in new window)
  • Click to print (Opens in new window)

Related

8 thoughts on “A Bacterium You Can See With the Naked Eye”

  1. David says:
    February 25, 2020 at 05:52

    So was the bacteria being cell fish?

    Reply
    1. Don Joe says:
      March 31, 2020 at 22:15

      No, it seems they in fact have a symbiotic relationship.

      Reply
    2. teerlla says:
      April 4, 2020 at 23:29

      lol

      Reply
    3. Alexander Tan says:
      April 7, 2021 at 06:36

      HAHAHAHA LMAO UR SO FUNNY xD

      Reply
  2. ٪ÞRØłłəř¾ says:
    April 4, 2020 at 23:56

    some people have a form of extrasensory perception which gives them the ability* to see all forms of bacteria, viruses, and other microbial life (parasitic and mutualistic); unfortunately differentiating the ‘good guys’ from ‘bad guys’ is rare. *see Mysophobia

    Reply
  3. Pihu says:
    November 22, 2020 at 12:06

    Microorganism to be seen naked eye. Because these are very small in size. These organisms can be seen with of microscope and lens.

    Reply
  4. Marion k May says:
    September 30, 2021 at 10:30

    I saw a living bacteria move across my unlit phone screen last night. I watched it for a minute. It was kind of interesting and kind of scared me at the same time. But it was not long or as narrow as the one they are showing.

    Reply
  5. J says:
    April 21, 2024 at 13:14

    All phobias are irrational by definition. If science ever proves that there are people who can truly “sense” something that was previously unperceivable, they wouldn’t call it *something*-phobia. Or the name would be changed if it was initially classified as a phobia.

    Believing that people with mysophobia can sense microorganisms is akin to believing that schizophrenics aren’t hallucinating but are actually perceiving “ghosts/spirits/alternate realities”. Either one (or both) may very well end up being true in the future and you’re free to believe anything, but don’t word those beliefs like they’re facts.

    Reply

Leave a ReplyCancel reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Support the blog!

If you've enjoyed reading the blog, please support me on Ko-fi

Stay in Touch

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

Join us on social

  • Facebook
  • Twitter
  • LinkedIn

Categories

Agar Plates Animal Microbiome Antimicrobial Resistance Applied Microbiology Blog News and Updates Built Environments COVID-19 Fermented Foods Fungi Human Microbiome Infectious Diseases Meet a Microbe Meet a Microbiologist Microbes in the Environment Microbial Physiology Microbiology Books Microbiology History Microbiology Poems Microbiology Research Updates Science Communication Vaccines

Top Posts

  • A Microbiologist’s Guide to Yogurt + Instant Pot Yogurt Recipe
  • Blood and Bacteria: Blood Agar Reveals How Microbes “Consume” Blood
  • Knitting and Crocheting Microbes
  • A Bacterium You Can See With the Naked Eye
  • Fanny Hesse, the Woman Who Introduced Agar to Microbiology

Recent Posts

  • Why do we get more colds and respiratory illnesses in the wintertime?
  • Boo! How Bacterial Ghosts Can Help Treat Disease
  • When should I get my flu shot? Here’s what science says.
  • Meet a Microbe: Anaplasma phagocytophilum
  • The Snotty Science Behind Daycare Respiratory Illness Transmission

Archives

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

© 2025 The Microbial Menagerie | Powered by Minimalist Blog WordPress Theme
 

Loading Comments...