What type of bacteria is primarily responsible for coliform contamination in water?

Fecal coliform bacteria are primarily responsible for coliform contamination in water because they are a subset of the total coliform group that originates specifically from the intestines of warm-blooded animals. The presence of fecal coliforms, such as Escherichia coli (E. coli), in water indicates contamination with fecal matter, which poses a significant health risk as it can harbor pathogens harmful to human health.

These bacteria are widely used as an indicator organism in water quality testing because they are relatively easy to detect and serve as a reliable indicator of the potential presence of more harmful microorganisms. Their detection in water supplies often prompts further investigation and treatment measures to safeguard public health.

Other types of bacteria mentioned, like thermophilic and psychrophilic bacteria, do not specifically indicate fecal contamination; rather, they are categorized based on their temperature preferences for growth and do not directly relate to the health implications associated with fecal contamination in water. Actinomycetes, while they are significant in soil and organic matter decomposition, are not generally associated with indicating fecal pollution in water systems.