Question

Part i: you are given a broth culture that is growing an unknown organism. what is the first test you will do

Answer 1

First, you can inspect the broth specimen. If the bacteria are aerobic, which need oxygen to live, the bacteria will grow in the upper part of the broth. Anaerobic bacteria will grow on the bottom part. The bubble can be produced if the bacteria do fermentation.
Doing gram stain microscopic examination also help much since knowing the gram classification and the morphology of the bacteria.