Coliforms

Definition

Coliforms are a group of Gram-negative, non-spore-forming bacteria that are commonly found in the environment and in the feces of warm-blooded animals. They are often used as indicator organisms to assess water quality and potential contamination.

5 Must Know Facts For Your Next Test

1. Coliforms include genera such as Escherichia, Enterobacter, Klebsiella, and Citrobacter.
2. They can ferment lactose with the production of acid and gas within 48 hours at 35°C.
3. Presence of coliforms in water is an indication of possible contamination by pathogenic microorganisms.
4. Total coliform count is a key parameter in water quality testing for public health safety.
5. Some coliform bacteria, such as Escherichia coli (E. coli), can cause serious foodborne illnesses.

Review Questions

• What characteristics do coliform bacteria share?
• Why are coliforms used as indicator organisms for water quality?
• Name two genera that belong to the group classified as coliforms.

Related terms

Escherichia coli (E. coli): A species of coliform bacteria that can be found in the intestines of humans and other animals; some strains can cause food poisoning.

Fecal Coliforms: A subset of total coliform bacteria that originate specifically from fecal matter.

Lactose Fermentation: A biochemical process where certain bacteria convert lactose into lactic acid and gas; used to identify coliforms.