5-10: Starch Hydrolysis (Amylase Test) Microbiology Homework

Suppose you had poured iodine on your plate and noticed clearings in the uninoculated area, as well as around both of your transferred cultures. Was integrity of the test compromised?

Most likely yes. If one of the three things above are true, then the test was compromised

Suppose you could selectively prevent production of a-amylase or ligo-1, 6- glucosidase in an organism that normally hydrolyses starch. Which enzyme would the organism miss the most?

Alpha-amylase because it causes hydrolyzation and is responsible for breaking down food.

How would you expect both positive and negative results to be affected if you were to add glucose to the medium?

The glucose would cause the starch breakdown to be slower resulting in a false negative

In many tests it is acceptable to read a positive result before the incubation time is completed. Why is this not the case with starch agar?

It take time for the starch to break down if amylase is present. If you were to read it as a positive results, it could be wrong because it hasn't been incubated for the proper amount of time

Suppose you had poured iodine on your plate and noticed clearings in the uninoculated area, as well as around both of your transferred cultures. What measures could be taken to avoid this problem in the future?

Make sure the starch is mixed properly, check for any contamination before you put the iodine in, things like that

Suppose you had poured iodine on your plate and noticed clearings in the uninoculated area, as well as around both of your transferred cultures. What are some possible explanations for this occurrence?

The starch was not mixed properly, there was contamination when you put the iodine in, and/or the test has been compromised and needs to be redone