True Bacteria
KNOWN SPECIES
23,009
0.98% of our world's living things are true bacteria
CHARACTERISTICS
- microscopic
- single-celled organisms that lack a membrane-bounded nucleus within their cells
SIZE RANGE
microscopic to about 0.4 inch (0.05 micron to 1 centimeter)
WHERE THEY LIVE
in all environments, including inside other organisms
Here are just SOME of the world’s true bacteria:
![Sticker about size](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/size_color_sticker/5943306-3-eng-US/size_color_sticker_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/size_color_sticker/5943306-3-eng-US/size_color_sticker_full_990.png 600w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/size_color_sticker/5943306-3-eng-US/size_color_sticker_full_1468.png 600w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/size_color_sticker/5943306-3-eng-US/size_color_sticker_full_1980.png 600w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/size_color_sticker/5943306-3-eng-US/size_color_sticker_full_2475.png 600w)
SCIENTIFIC NAME:
Escherichia coli
![Elongated cluster of Escherichia](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/true_bacteria_escherichia/5939080-3-eng-US/true_bacteria_escherichia_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/true_bacteria_escherichia/5939080-3-eng-US/true_bacteria_escherichia_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/true_bacteria_escherichia/5939080-3-eng-US/true_bacteria_escherichia_full_1468.png 1468w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/true_bacteria_escherichia/5939080-3-eng-US/true_bacteria_escherichia_full_1980.png 1980w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/true_bacteria_escherichia/5939080-3-eng-US/true_bacteria_escherichia_full_2475.png 2382w)
SCIENTIFIC NAME:
Nodularia sp
![Cluster of Nodularia](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/true_bacteria_nodularia/5939076-3-eng-US/true_bacteria_nodularia_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/true_bacteria_nodularia/5939076-3-eng-US/true_bacteria_nodularia_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/true_bacteria_nodularia/5939076-3-eng-US/true_bacteria_nodularia_full_1468.png 1180w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/true_bacteria_nodularia/5939076-3-eng-US/true_bacteria_nodularia_full_1980.png 1180w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/true_bacteria_nodularia/5939076-3-eng-US/true_bacteria_nodularia_full_2475.png 1180w)
SCIENTIFIC NAME:
Salmonella enterica
![Individual Salmonella](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/true_bacteria_salmonella/5939084-4-eng-US/true_bacteria_salmonella_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/true_bacteria_salmonella/5939084-4-eng-US/true_bacteria_salmonella_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/true_bacteria_salmonella/5939084-4-eng-US/true_bacteria_salmonella_full_1468.png 1468w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/true_bacteria_salmonella/5939084-4-eng-US/true_bacteria_salmonella_full_1980.png 1980w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/true_bacteria_salmonella/5939084-4-eng-US/true_bacteria_salmonella_full_2475.png 2400w)
SCIENTIFIC NAME:
Staphylococcus sp
![cluster of staphylococcus](/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/true_bacteria_staphylococcus/5939088-3-eng-US/true_bacteria_staphylococcus_full_495.png 495w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/true_bacteria_staphylococcus/5939088-3-eng-US/true_bacteria_staphylococcus_full_990.png 990w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/true_bacteria_staphylococcus/5939088-3-eng-US/true_bacteria_staphylococcus_full_1468.png 1468w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/true_bacteria_staphylococcus/5939088-3-eng-US/true_bacteria_staphylococcus_full_1980.png 1800w,/var/ezflow_site/storage/images/media/amnh/images/explore/ology-images/biodiversity/tree-of-life/true-bacteria/true_bacteria_staphylococcus/5939088-3-eng-US/true_bacteria_staphylococcus_full_2475.png 1800w)
Guess what?
For perhaps 2 billion years, bacteria were the only living things on Earth! Although some species can cause disease, humans and other organisms need bacteria to survive.
Image Credits:
Escherichia coli, NIAID; Nodularia sp, © rmatth/CC BY-NC-SA; Salmonella enterica, Medical Illustrator: James Archer/CDC; Staphylococcus sp, Courtesy of Louis de Vos, BIODIC.