Ontario Operator-in-Training (OIT) Practice Exam

The method known as filtration and culture testing is widely utilized to determine the presence of coliform bacteria in water. This approach involves passing a water sample through a filter that captures bacteria. The filter is then placed onto culture media specifically designed to promote the growth of coliform bacteria, allowing for their identification and quantification through incubation.

This method is effective because coliform bacteria can indicate the potential presence of more harmful pathogens, and by culturing, one can not only detect their presence but also assess their concentration in the sample. The growth on the culture medium can then be observed for characteristic colonies, which helps in confirming the presence of coliforms.

Other methods such as UV spectrophotometry or gas chromatography are not specifically designed for detecting bacteria and are primarily used for chemical analysis, while titration analysis focuses on determining the concentration of specific substances in water rather than microbial content. Thus, filtration and culture testing remains the standard choice for identifying coliform bacteria in water samples.