Look up the following values. What are the minimum, optimum, and maximum pH levels for each of the four organisms examined? [2]
| Organism | Minimum pH | Optimal pH | Maximum pH |
|--------------|------------|------------|------------|
| E.coli | | | |
| A.faecalis | | | |
| L.acidophilus| | | |
| S.aureus | | | |
4. Which of the bacteria used in this exercise would grow in processed food that had a pH of 7? If the pH of the food was lowered to pH 4.5 during processing, how would that affect each bacterial species? [2]