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Escherichia coli, known as E. coli or simply ecoli, is commonly found in the lower intestines of most warm-blooded organisms. Humans are subject to the ecoli bacteria within 40 hours of birth. Most of the strains are harmless and benefit their hosts by producing vitamin K. By their presence and location they also prevent pathogenic bacteria from taking up residence. However, a number of strains are responsible for different types of infections, most notably food poisoning. The bacterium was discovered in 1885 by a German pediatrician named Theodor Escherich.
Some ecoli characteristics include its lack of retaining crystal violet dye in Gram staining, its process of making ATP aerobically in oxygen, and a lack of ability to create endospores. Ecoli are rod-shaped and are approximately two micrometers long. Ecoli produce lactate, ethanol, acetate, succinate, and carbon dioxide. The bacteria are generally found with hydrogen-consuming organisms that make methane. The optimal temperature for growth of ecoli is 37-degrees Celsius. Most possess flagella that allow them to swim.
Above left: E. Coli. (Supplied by the National Institutes of Health; Public Domain; http://upload.wikimedia.org/wikipedia/commons/3/32/EscherichiaColi_NIAID.jpg)
