biology essay

Submitted By krtalbert
Words: 548
Pages: 3

Rico Duncan
Microbiology Lab
Thursday 12:30

Lab report antibiotic

Introduction ` The first antibiotic, penicillin was discover in 1929 by sir alexander fleming. He made the discovery will observing a staphylococci agar that was contained by penicillin mold. Sir Alexander flemming discover that the mold had a space or an area where the staphylococcus didn’t grow. That single observation lead to a multiple array of antibiotics that we use today. Since this discovery, we have found way to synthesis antibiotics from all source natural, synthetic, or both,. From year of antibiotic use, many bacteria have develop resistance that allow them to be unaffected .This emergences of resistance is what drives researcher to discover more effective antibiotics. In order to survive, organisms must rely on defense mechanisms that allow them to repair or escape the oxidative damage of hydrogen peroxide (H2O2). Some bacteria produce the enzyme catalase which facilitates cellular detoxification. Catalase neutralizes the bactericidal effects of hydrogen peroxide and its concentration in bacteria has been correlated with pathogenicity

Method’s and materials For the antibiotic experiment we needed a Bunsen burner, Escherichia coli Sample plate, Bacillus cereus plate, ruler, pincer ,place mate , antibiotic disk : penicillin, chloramphenicol, gentamicin, tetracycline, ampicillin, streptomycin, and control disk. Frist, we laid the Escherichia coli plate on the place mate in order to see where the disk would go. Next, we placed the control disk in the center spot. We always sterilized the pincer by placing it over the flame and we allowed it to cool. After, we placed the other antibiotic in their respective spots. We sterilized after each application. Incubate o/n 32 degrees .We repeated the same steps for the Bacillus cereus plate. For the catalase experiment we needed a Bunsen burner, PBs, inoculating loop, 3 slides, hydrogen peroxide, and samples of Bacillus cereus, Escherichia coli, and Enterococcus faecalis. Frist we add a drop of PBs to a slide. Then, we used the sterilized inoculating loop to place a sample of Bacillus cereus on to the slide. We added a drop of hydrogen peroxide and we watched for a reaction. We repeated the step using Escherichia coli, and Enterococcus faecalis. We made sure to