Images of Bacteria

The 'exhibits' of our museum contain text only. This enables easy access for every visitor. Not everybody has the fastest of computers. But the beauty of bacteria becomes apparent first when you see them.

There are different ways of looking at bacteria. Bacteria growing in a liquid will generally make the liquid cloudy, and sometimes change color, but by the look of such a broth it is hard to determine what type of bacteria are growing in it. View the different colors of bacterial cultures (Source: USGS).

More typically, bacteria are plated out on dishes filled with a solidified medium. Agar (a polycarbohydrate similar to gelatin) is usually used to produce a solid medium plate. Bacteria are put on and care is taken to spread them out so thin that single cells cover the plate. How to produce single colony streaks (Source: Microbiology Course University of Leicester). Each cell will start growing into a colony. The morphology (shape, color, shine, etc.) is often characteristic of the bacterial family or species.

Look at colony morphology at the following sites:

The Artistry of Microorganisms (Source: Bacterial Cybernetics Group)
Artistry of bacterial colonies and the antibiotic crisis (UN World Health Report)
Quick-time movies of growing colonies (Source: Catalan Polytech Uni)
Quick-time movies of bacterial movement (Source: Microbiology at Leicester)
Bacteriologists at work: different enteric bacteria on different agar plates(Source: Albert Einstein Coll. Med.) Learn why different agar plates are in use (Source: Albert Einstein Coll. Med.)

A special form of bacterial growth is biofilms. These films are a continuous layer of growing organisms and often contain different species. How does a biofilm form? (Source: Uni Edinburgh).

Hands-on: here are some experimental procedures

fractal structures in bacterial colonies (Source: Bath Uni)
For more choices of do-it-yourself bacteriology see another exhibit of our museum.

Sometimes scientists change the appearance of a bacterial colony on purpose. Introduction of a gene that produces Green Fluorescent Protein makes bacteria...green and fluorescent. (Source: Uni Cornell Uni Biomedical Engineering).

A bacteriologist will not only observe colonies on agar plates, but probably also look at the bacteria down a microscope. The color and appearance are sometimes manipulated by chemical stains, for instance the Gram Stain, which will differentiate gram-positive bacteria (the ones that stain deep purple) from the gram-negative ones. The Gram stain explained (Source: Austin Community College).

Listed below are the best picture galleries of Bacteria available on the web:

Photo Gallery of pathogenic bacteria, an excellent collection site by N. Chamberlain, sorted by bacterial species
Cyonobacterial image gallery (Source: Cyanosite)
Gram-stained images of medically important bacteria (Source: Loyola Uni Medical Center)
Bacterial colonies and cell shapes (Source: The Microbial World)
Photo Gallery of microorganisms (Source: Cells Alive)
One of the best sites for pictures: Dennis Konkel Microscopy. Search this site (Source: D. Kunkel), which contains an extensive collection of electron-microscopic pictures, by bacterial species name or keywords.
An Internet Gallery of bacteria (Source: Wadsworth Center)
Types of bacteria Have a look inside! (Source: Kloschly)
Bacterial images sorted by species (Source: Buckman laboratories)

The content of this page is copyright of the Virtual Museum of Bacteria and was written by Dr. T. M. Wassenaar (curator), with support of the Foundation for Bacteriology (Dr. M.J. Blaser, President).
Special Feature files cover various aspects of bacteria, bacteriology, and bacterial diseases and are produced with support from

The Waksman Foundation for Microbiology.

Page last modified: 08 Mar 2005

This page will no longer be updated. We apologize for inactive links.