Which group of bacteria is commonly used as an indicator of water quality?

Total coliforms are a group of bacteria that are commonly used as indicators of water quality due to their presence in the intestines of warm-blooded animals and their ability to survive in the environment. When detected in water samples, total coliforms raise concerns about the potential presence of harmful pathogens that can influence human health. Their presence suggests that the water may be contaminated with fecal material or other pollutants, which can ultimately affect the safety of drinking water and recreational swimming areas.

The use of total coliforms as indicator bacteria is advantageous because they are relatively easy to detect using standard laboratory methods. Monitoring their levels helps water quality managers determine whether further testing is needed for pathogenic bacteria or if remediation actions should be taken to protect public health.

In contrast, strict anaerobes do not play a significant role in indicating water quality as they thrive in the absence of oxygen and are not commonly found in surface water. While facultative anaerobes can survive in both aerobic and anaerobic conditions, they are not used specifically as indicators for water quality. Pseudomonads, although they may be present in various environments and sometimes indicate potential contamination, are not widely accepted as a standard indicator group for assessing water quality like total coliforms.