Question

1- What was the starting concentration of Nalidixic acid used for the MIC experiment? a. 32 µg/ml b. 1024 µg/ml c. 512 µg/ml d. 2048 µg/ml

2-A species of bacteria underwent the Hugh and Liefsens test, following incubation both tubes were showing a colour change from green to yellow. This means that the species of bacteria being tested is a: a. Oxidiser b. Non-utiliser c. Fermenter d. None of these

3- What is the pH indicator included in the selective and differential agar used for membrane filtration examination of water? a. Methyl red b. Phenol red c. Bromocresol purple d. Phenolphthalein

Microbiology

Answer 1

1 The starting concentration of Nalidixic acid used for MIC experiment is 2048 µg/ml

2 If the species of bacteria underwent the Hugh and Leifson's test and both the tubes changed color change from green to yellow. This means that the bacteria is fermenting and acting as a fermenter.

3. The pH indicator included in the selective and differential agar used for membrane filtration examination of water is Phenol red.