Description | Escherichia coli, a ubiquitous and well-studied microorganism, belongs to the family Enterobacteriaceae. This gram-negative, rod-shaped bacterium thrives in temperatures ranging from 7°C to 50°C, making it a mesophilic microbe. Its metabolism is heterotrophic, relying on organic compounds for energy and growth. E. coli is a chemoheterotroph, utilizing carbon-rich molecules as its energy source. This microbe produces energy through the process of cellular respiration, where it converts glucose into ATP. The E. coli genome has been extensively sequenced, revealing a single circular chromosome of approximately 4.6 million base pairs. The gram-negative staining pattern of E. coli is characterized by a thin peptidoglycan layer, which is surrounded by an outer membrane containing lipopolysaccharides. E. coli typically appears as a straight or slightly curved rod, measuring 2-4 μm in length and 0.5-1 μm in width. It has been isolated from various body sites in all possible species, including the human gut, urinary tract, and bloodstream. Oxygen preference for E. coli is facultative anaerobic, meaning it can grow in both aerobic and anaerobic environments, but prefers aerobic conditions. In hosts, E. coli plays a crucial role in the human gut microbiome, aiding in nutrient absorption and immune system development. In the environment, E. coli can contaminate food and water, causing gastrointestinal illnesses in humans. Despite its potential pathogenicity, E. coli has also been engineered for biotechnological applications, such as the production of recombinant proteins and biofuels. Furthermore, studies on E. coli have led to a deeper understanding of bacterial physiology, genetic regulation, and molecular biology, making it a valuable model organism in scientific research. |
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