Modifications of this procedure include the use of hot plates instead of Bunsen burners, and heating t-butyl alcohol to 60-65 ℃ instead of 50 ℃. Other modifications include the use of weighing boats to measure an amount of unknown instead of weighing paper, and completing one run of unknown 2 instead of two runs of unknown 2. Summary of
Unknown #10 produced no identifiable macroscopic characteristics as a broth, so the first step was to Gram stain a loopful to determine the microscopic characteristics. Gram staining not only helped identify Unknown #10’s microscopic morphology but it also helped ensure the specimen was a pure culture—no other bacteria were visible when Unknown #10 was Gram stained and observed under the microscope. Unknown #10’s key microscopic morphology was that it was a very small, Gram negative bacillus. Though bacilli can possibly form endospores, no empty white centers were visible which suggested that Unknown #10 was not an endospore forming bacteria. No quick endospore stain was performed to validate this assumption since only one assigned organism was endospore forming and unlike Unknown #10, that organism was Gram positive.
The tube was placed back in incubation for 96 more hours to observe any more positives. 2.10 Catalase Test A trypticase soy agar plate was used and after incubation, four drops of 3% Hydrogen Peroxide was added to the plate to flow over the bacterial growth. A presence of bubbling was observed. 2.11 Starch Hydrolysis
Transformation was successful in the plates where the bacteria consumed the pGLO plasmid. In the first plate that the bacterium was plated on it included the LB broth and of ampicillin antibiotic (amp), 2 colonies were present. The second plate of bacteria was grown with the presence of LB broth, ampicillin, arabinose sugar (ara), and 22 colonies were observed. But a green fluorescent glow of the colonies was only present in plate 2. Plates 3 and 4 were the control plates.
The purpose of this lab was to perform a procedure known as genetic transformation which allowed us to genetically engineer E. Coli to be ampicillin resistance. Before the lab we expected that lysogeny broth and minus DNA will have growth but no glow. The lysogeny broth, ampicillin, and
Identification of bacteria within Unknown Culture #21 In this experiment, an unknown culture of two different types of bacteria was assigned to each person, a number of tests were performed to isolate and identify these bacterial cells. Based on knowledge from the previous experiments completed in lab, a basic understanding of each type of bacteria was used to create a flow chart that would aid the process of identifying the unknown bacteria within the culture. A gram stain that is performed initially will narrow down the types of tests certain bacteria will and will not respond to. In addition to the gram stain, some of the tests that were used include, a catalase test, an Eosin methylene blue (EMB) agar test, a bile esculin test, and a 6.5% sodium chloride (NaCl) test.
Escherichia Coli 0157: H7 This paper will specialize on a specific type of bacterial foodborne illness caused by the bacteria Escherichia Coli. E. coli was discovered by Theodore von Escherich in 1885. E.coli is a natural found bacteria that lies throughout the intestinal tract of warm blooded animals and comes in many forms only one of which is deadly. This form is E. coli 0157:H7 which can be caused by direct exposure to fecal matter to kill this rouge
Gelatin hydrolysis test is used to detect the ability of an organism to produce gelatinase (proteolytic enzyme) that liquefy gelatin. This process takes place in two sequential reactions. In the first reaction, gelatinase degrade gelatin to polypeptides. Then, the polypeptides are further converted into amino acids. The bacterial cells can then take up these amino acids and use them in their metabolic processes.
The media used in this experiment was Trypticase nitrate broth. The reagents used (A and B) were sulfanilic acid and alpha-naphthylamine (respectively). Using aseptic technique, the bacterium (16A and 16B) were inoculated into labeled broth test tubes. The tubes were incubated for 48 hours at 37 degrees Celsius. When the incubation was complete 5 drops of reagent A and 5 drops of reagent B were added to each of the broths.
A scale of zero to five was used to describe the reactions, with zero being no reaction at all, one being a slow reaction, and five being a very fast reaction. The materials used were a test tube rack, six test tubes, a test tube clamp, forceps, a graduated cylinder, four small pieces of liver, one piece of potato, one piece of hamburger meat, approximately forty milliliters of hydrogen peroxide in a forty milliliter beaker, a splint, and matches. An ice bath and boiling water was required for testing, where a hot plate was used to boil the water. Each test tube given a label, which were “cold”, “room”, “hot”, “warm”, “potato”, “meat”, and