E. coli
Escherichia coli
Escherichia coli is a Gram-negative, rod-shaped, facultatively anaerobic bacterium commonly found in the lower intestine of warm-blooded organisms. Most E. coli strains are harmless and form part of the normal gut microbiota, though some serotypes can cause serious food poisoning or infections. It is a key model organism in microbiology and molecular biology, frequently used in biotechnology for recombinant protein production.
Details
Identification
Gram-negative staining, rod-shaped morphology, peritrichous flagella for motility, ability to ferment lactose with the production of acid and gas.
Social behavior
Can form biofilms and communicate with other bacteria via quorum sensing to regulate population-dependent gene expression.
Diet
Utilizes a wide variety of organic carbon sources such as glucose, lactose, and amino acids through fermentation or aerobic respiration.
Overwintering
Can persist in cooler environments outside the host in a state of reduced metabolic activity.
Ecology
Ecological role
Important symbiont in the gut that produces vitamin K2 and prevents the growth of pathogenic bacteria through niche competition.
Natural predators
Bacteriophages, protozoa (such as amoebae and ciliates), and the host organism's immune system.
Competitor species
Other members of the gut microbiota such as Enterococcus species, Bacteroides species, and other enterobacteria.
Ecosystem service
Support of digestion and nutrient absorption in the host organism; decomposition of organic substances in aquatic systems.
Threats
Antibiotics, disinfectants, extreme pH levels, and UV radiation outside the host.
Scientific profile
Profile
Habitat
Natural habitat is the intestine of endotherms. As a facultative anaerobe, it can persist in the environment (water, soil, sediments), making it a key indicator of fecal input.
Ecological role
In the intestinal tract, it acts as a commensal, produces vitamin K2, and contributes to colonization resistance against pathogenic germs. In the environment, it serves as a biological indicator of anthropogenic pressure.