The yeast should not ferment the sugar in the presence of oxygen. This is not true. Answers to questions for Activity 3 1. The aerated flask should grow best. As the bacteria grew they started using the sugar for fermentation creating acids.
Growth is affected by many factors including nutrients, temperature, oxygen, pH, and growth itself.
In this experiment the bacteria changed the pH of their environment. The pH needs to be adjusted by addition of acids or bases . 5.A small inoculum in a large volume of medium will take too long to grow therefore the cell numbers need to be increased step-wise. This is continued until a large enough inoculum is grown. The products must be removed from the cells and culture media and chemically purified.