**5. Cultural requirements of** *Escherichia coli*

*E. coli* cells may grow on a solid or in a liquid growth medium under laboratory conditions. It may be grown in a basic minimum of media, which includes glucose as a carbon and energy source, ammonium salts as a nitrogen source, other salts, and trace elements [18]. As *E. coli* have simple nutritional requirements it can be

**Figure 2.** *Antigenic structure of E. coli [17].*

easily cultured on a common medium, such as Nutrient agar, Mac Conkey agar, and EMB agar [19].

*E. coli* can grow at temperatures ranging from 10°C to 40°C, although the optimum temperature for most strains is 37°C (98.6°F), however, some laboratory strains can proliferate at temperatures as high as 49°C (120.2°F) [20]. *E. coli* can survive at 4.5–9.5 pH but the maximum growth is observed at 7.0, i.e., neutral pH. Also, the pH requirements vary with the strains of *E. coli*; [21]. The cultural characteristics of *E. coli* are presented in **Table 1**.
