We first needed to collect all the proper materials to conduct the tests on our unknown bacterial sample. To begin the lab, we had to collect a nonpathogenic bacterial sample by swabbing an item or surface inside the biology building with a sterile cotton swab. Our lab group decided to swab a Sharpie permanent marker left at our lab station inside our lab room. We then opened a petri dish and smeared the swab across the surface of the agar several times. Once the bacteria was on the agar, we closed the lid immediately, hoping to prevent microorganisms in the air from contaminating our sample. We also collected a sample from the skin of a lab member, and another from the microorganisms in the air. Once our samples were placed in the agar,
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We first conducted the catalase test. We collected a microscope slide and placed it inside of an empty petri dish, attempting to rule out contamination. We then scoped a sample of our unknown bacteria from the LB agar (Luria Broth), then added a drop of 3% H202 (Hydrogen Peroxide). We observed the slide for a reaction to take place. If a reaction was observed, we knew that the species of our unknown bacteria was able to produce catalase to negate the effects of H202. For the second test, we tested the growth on Mannitol Salt Agar (MSA). To conduct this experiment, we needed to first create another live liquid sample using an isolated colony from the LB agar, and then transfer some of this culture into a MSA petri dish. We then added five sterile beads and shook them around the agar to distribute the bacterial cells. Once this was complete, we allowed the petri dish to incubate at 37°C for two days to allow the formation of new colonies. We then checked for growth/color change. If no color change was observed, we knew that the unknown bacteria was a salt-tolerant Gram-positive
We first conducted the catalase test. We collected a microscope slide and placed it inside of an empty petri dish, attempting to rule out contamination. We then scoped a sample of our unknown bacteria from the LB agar (Luria Broth), then added a drop of 3% H202 (Hydrogen Peroxide). We observed the slide for a reaction to take place. If a reaction was observed, we knew that the species of our unknown bacteria was able to produce catalase to negate the effects of H202. For the second test, we tested the growth on Mannitol Salt Agar (MSA). To conduct this experiment, we needed to first create another live liquid sample using an isolated colony from the LB agar, and then transfer some of this culture into a MSA petri dish. We then added five sterile beads and shook them around the agar to distribute the bacterial cells. Once this was complete, we allowed the petri dish to incubate at 37°C for two days to allow the formation of new colonies. We then checked for growth/color change. If no color change was observed, we knew that the unknown bacteria was a salt-tolerant Gram-positive