Finding New Antibiotics Using Soil

Finding New Antibiotics Using Soil


[Music]>>My name is Paris Vigil and this is my microbiology soil research. In summary, this is … Sorry, can I start over? OK. This is my first time presenting, let me just … all right. Hi, my name is Paris Vigil, and this is my
microbiology soil research. In a nutshell, in today’s world, there’s a very underrated problem: antibiotic resistance. A lot of people are resistant to different kinds of
antibiotics, and it’s really expensive to produce these
antibiotics in pharmaceutical companies, so that’s why they use people like us to try and
find antibiotics within things like soil. First of all, we started with serial dilutions. We
and mixed it in a test-tube. Then through different series, we took less and
less soil and water, diluting the soil and water
combination. After we did the serial dilutions, we moved it to a
master plate. I guess I should talk about where
I got my soil. I originally collected my soil from residential
backyard area in Lawrence, Kansas, but my soil
did not produce any antibiotic properties, so I adopted my bacteria from Anna Kawase.
From there, I was able to follow through with my
experiment. After I obtained her bacteria from a master plate, I grew it on [another] master plate, and then I was able to take it and perform various tests. The first one would be gram staining, taking the
bacteria and staining it with crystal violet. If [it’s] done correctly, gram-positive [bacteria
are] purple and gram-negative [are] pink. Mine was gram-variable, which means it was gram-positive and gram-negative. If you look closely, there’s purple and pink within
the organisms you can see under the microscope. Afterward, we did an endospore staining, and
this is done with malachite green. If done
correctly, spores will form and will turn green. After that, we went ahead and did a Kirby Bauer sensitivity test. This was to tell whether or not our bacteria was susceptible to different kinds of antibiotics. Mine ended up being susceptible to vancomycin and ciprofloxacin, and my measurements for the zones of inhibition came out to be about 24 mm for inhibition came out to be about 24 mm for the vancomycin and 35 mm for ciprofloxacin. There was no zone of inhibition for the trimethoprim. We then did various biochemical tests. The first one was a catalase test. This is just mixing our bacteria with hydrogen peroxide. If it bubbled, that means it tested positive, so mine tested positive. Our biochemical tests followed a flow chart. I don’t that pictured, but the flow chart is the PP ID flow chart, I think that’s what it’s called. The bacillus SPP ID flow chart, excuse me. After I did the catalase test, I did a starch hydrolysis test. This is growing my bacteria on a plate and then covering it with iodine. You can see here that a little red ring formed. This indicates that it tested positive. Afterward, we did a VP test and a citrate test. They tested negative. Once I was following the flow chart, I came up with the conclusion that my bacteria – hopefully I don’t butcher its name – was Bacillus Badius. To further my research, I performed more PCR tests in the lab, but we were unable to find the specific sequence that we wanted, due to not having a specific primer made for our bacteria. We used more of a universal primer. I would like to further my research by getting a primer specifically for my bacteria, and I would also like to collect my own soil sample from the area that Anna got her soil, so I’m able to do the experiment from beginning to end. That is my research in a nutshell.

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