You are in charge of water quality for your city's water treatment plant. Of the methods at your disposal, which will be the most efficient and cheapest method of determining the number of viable bacteria in the water coming out of your plant?
A) Direct counts using a microscope and a counting chamber.
B) Using a Coulter counter machine.
C) Performing serial dilutions and doing spread plate counts.
D) Using membrane filtration followed by placing the membrane in a growth medium for colony counts after incubation.
E) Biochemical analysis of secondary metabolites in the water that are given off by bacteria.

Question

You are in charge of water quality for your city's water treatment plant. Of the methods at your disposal, which will be the most efficient and cheapest method of determining the number of viable bacteria in the water coming out of your plant?
A) Direct counts using a microscope and a counting chamber.
B) Using a Coulter counter machine.
C) Performing serial dilutions and doing spread plate counts.
D) Using membrane filtration followed by placing the membrane in a growth medium for colony counts after incubation.
E) Biochemical analysis of secondary metabolites in the water that are given off by bacteria.

Quizplus · Accepted Answer

Membrane filtration followed by placing the membrane in a growth medium for colony counts after incubation is both efficient and cost-effective for determining the number of viable bacteria in water. This method concentrates the bacteria present in large volumes of water onto a filter, which is then placed on a growth medium. After incubation, the colonies that grow can be counted, providing a direct measure of the number of viable bacteria in the water sample. This method is preferred for water quality testing because it is specific for viable bacteria, relatively simple, and does not require expensive equipment.

You Are in Charge of Water Quality for Your City's