Exercise 8: Lipase plate, Milk agar plate, and starch agar

What does the lipase plate detect?

Detects for the enzyme lipase = which hydrolyzes fats

Is lipase plate a selective or differential media?

Differential

What indicator is used for lipase plate?

Spirit blue

If an organisms is (+) for lipase, what will you see on the lipase plate?

The spirit blue dye is going to accumulate around the colony that is positive for lipase, results in intensification of blue color (+ = blue color)

If an organism if (-) for lipase , what will you see on lipase plate?

no color

is Milk agar plate a selective or differential media?

Differential

What does milk agar detect?

Detects for the enzyme caseinase = breaks down milk protein into amino acids

What do you need to remember about casein and what happens when it is broken down?

Casein gives milk its white color opacity and when broken down will lose its opacity and look clear

If an organisms is (+) for caseinase, what will you see in the milk agar plate?

(+) = clear zone around colony

If an organisms is (-) for caseinase, what will you see in the milk agar plate?

(-) = no clearning around colony

Is starch agar a differential or selective media?

Differential

What does starch agar detect?

Detects for the enzyme amylase = breaks down starch into simple sugars

For starch agar, to see result, what do you have to add?

Iodine added just around the edge of the colony

If an organisms is (+) for amylase, what will you see on the starch agar after adding iodine?

Since there is no starch for iodine to complex with so there is a clearing around the colony

If an organisms is (-) for amylase, what will you see on the starch agar plate after adding iodine?

Iodine will complex with starch and produce brown to eventually purple color around colony