What is a key characteristic of coliform bacteria?

Coliform bacteria are a group of microorganisms commonly used as an indicator of water quality. Their presence in water suggests potential contamination by fecal matter, which can carry harmful pathogens. Because coliform bacteria primarily originate in the intestines of warm-blooded animals and humans, their detection in water supplies or recreational waters is a critical warning sign. This characteristic makes them crucial in assessing the safety of drinking water and understanding the level of sanitary risk posed by contaminated water sources. The presence of coliform bacteria signifies that the water could harbor other more dangerous organisms and is, therefore, of significant public health concern.

The other options do not accurately represent the fundamental role and characteristics of coliform bacteria. They are not exclusively related to marine environments, do not survive in extreme temperatures better than other bacteria, and while they may appear in some foods, their primary importance is linked to water contamination outlook rather than their presence in foods.