What method is used to determine coliform bacteria presence in water?

What method is used to determine coliform bacteria presence in water?

• A. Distillation
• B. Membrane filtration or multiple-tube fermentation
• C. Ultraviolet light testing
• D. Water color comparison

Answer: (B)

The presence of coliform bacteria in water is primarily determined through methods such as membrane filtration and multiple-tube fermentation. These techniques are specifically designed to isolate and quantify bacteria in water samples. Membrane filtration involves passing a measured volume of water through a filter that captures bacteria. The filter is then placed on a selective medium that encourages the growth of coliform bacteria, allowing for enumeration based on colony growth. This method provides a clear indication of the viability and count of coliforms present in the sample. Multiple-tube fermentation is another reliable method wherein various samples of water are inoculated into tubes containing a nutrient broth that promotes bacterial growth. The tubes are then analyzed for gas production or color change, which indicates the presence of coliform bacteria. This method helps in estimating the most probable number (MPN) of bacteria in the water. In contrast, distillation is a process used to purify water and does not specifically test for bacteria. Ultraviolet light testing is primarily used for disinfection and not for directly measuring bacterial counts. Water color comparison is a qualitative method that may indicate certain contaminants but does not provide specific information about coliform presence. Thus, membrane filtration and multiple-tube fermentation are the most accurate and commonly used methods for detecting

The presence of coliform bacteria in water is primarily determined through methods such as membrane filtration and multiple-tube fermentation. These techniques are specifically designed to isolate and quantify bacteria in water samples.

Membrane filtration involves passing a measured volume of water through a filter that captures bacteria. The filter is then placed on a selective medium that encourages the growth of coliform bacteria, allowing for enumeration based on colony growth. This method provides a clear indication of the viability and count of coliforms present in the sample.

Multiple-tube fermentation is another reliable method wherein various samples of water are inoculated into tubes containing a nutrient broth that promotes bacterial growth. The tubes are then analyzed for gas production or color change, which indicates the presence of coliform bacteria. This method helps in estimating the most probable number (MPN) of bacteria in the water.

In contrast, distillation is a process used to purify water and does not specifically test for bacteria. Ultraviolet light testing is primarily used for disinfection and not for directly measuring bacterial counts. Water color comparison is a qualitative method that may indicate certain contaminants but does not provide specific information about coliform presence. Thus, membrane filtration and multiple-tube fermentation are the most accurate and commonly used methods for detecting