How can you detect the presence of fecal coliforms in water?

Detecting the presence of fecal coliforms in water is crucial for assessing water quality and safety. The correct approach involves methods specifically designed to identify these bacteria, which are indicators of fecal contamination.

Membrane filtration and enzyme substrate tests are widely accepted methodologies for detecting fecal coliforms. Membrane filtration involves passing a water sample through a filter that traps bacteria, which is then placed on a selective growth medium to cultivate and identify coliform colonies. Enzyme substrate tests, on the other hand, utilize specific substrates that coliforms can metabolize, resulting in color changes or fluorescence, allowing for easy identification.

Both of these methods are essential because they are specifically tailored to detect the types of bacteria that are indicative of fecal pollution in water, which is of utmost importance for public health and environmental monitoring.

In contrast, gas chromatography is primarily used for analyzing volatile and semi-volatile organic compounds and is not suitable for bacterial detection. Measuring chemical oxygen demand assesses the organic matter present in water but does not provide specific information about fecal coliforms. Analyzing nutrient levels can give insights into overall water quality but does not directly indicate the presence of fecal contamination. Therefore, the methods focused on bacterial detection are most relevant in this