Week Twelve

Last week, we noted bacterial growth from the plastic pieces collected for month 3. We streaked them on MacConkey agar. The goal was to verify our gram stain results, as growth on Mac plates would help further indicate that the bacteria are gram-negative, bacilli. And something interesting that I learned is that the MAC agar will have a color change reaction. When I first saw them they were a distinguishable red/purple color. And I learned that the plates can change depending on the microbe living on it. It can go from its original red color to a clear/yellow, because the agar is made of pH indicator and lactose... cool stuff :P