Microbiology: A Systems Approach 4th Edition by Marjorie Kelly Cowan

Exercise 34

From chapter 3, figure 3.5 b. If this MacConkey agar plate was inoculated with well water, would you report that coliforms were present in the water
Figure 3.5 b: Examples of media that are both selective and differential. (b) MacConkey agar selects against gram-positive bacteria. It also differentiates between lactose-fermenting bacteria (indicated by a pink-red reaction in the center of the colony) and lactose-negative bacteria (indicated by an off-white colony with no dye reaction).