I added a few drops of 3% Hydrogen Peroxide and it resulted in bubble formation. The positive gram stain and positive catalase test indicated that the organism belonged to the Staphylococcus Genus, which meant it was now time to pinpoint the species based on differential and selective biochemical tests. To ensure that my genus identification was correct I performed a Bile Esculin Slant with a fish tail streak on my unknown bacteria. This test resulted in neither growth nor a black precipitate; therefore I could conclude that my unknown was not Streptococci or Enterococci but indeed Staphylococcus. Next I observed the isolation streak on my Blood Agar Plate and found pinpoint, round, entire and flat colony morphology as well as an alpha hemolytic reaction pattern, indicating red blood cell ion leakage which is characteristic of S. epidermidis.
It is for this reason that Identification of bacteria is very important in the many areas of microbiology (Singh, 2009). There are many reasons for identifying an unknown bacterium. The reasons range from medical purposes, such as determining if the unknown could cause ailments in living things or knowing what microorganisms are needed to make antibiotics to other purposes such as knowing the exact microorganism has to be used to make certain foods (Burton, 2003). Throughout this report we will be addressing the differences in methods of identifying unknown microorganisms and differentiate between the results of these techniques by explaining how each outcome was achieved. The main aim of these experiments is to determine whether the unknown microorganisms are of Gram-Positive or Gram Negative nature and ultimately to determine exactly what kind on microorganism the unknowns are.
In determining this unknown bacteria, number two, many tests were performed. The tests that helped identify this bacteria were gram-stain, motility, Simmons citrate, lactose testing, and methyl red testing. All of the tests that were stated and recorded on the comparative analysis chart also tribute to uncovering the unknown bacteria, but they were not the critical tests needed. In the gram-stain tests, the bacteria was indicated as negative and the shape of the bacteria were rods. Motility was noted under the microscope by evidence of the bacteria moving around on the slide.
The purpose of these tests were to determine how the bacterium reacted to glucose with and without oxygen. My findings reported a gram stain negative along with positive tests for glucose oxidation and fermentation. Next I performed an Indole Production Test. This test determines whether the microbe produces indole from the amino acid tryptophan. The results from this test were negative.
This was confirmed by the lab manual in page 30 which contains the list of the different Rf values by decreasing value. Introduction: Chemist use many ways of separating and determine want components are in different materials. One of this ways is by dissolving the material in solvent this will only get the mixture of components for example the spinach had to be grind up with hexane to get the organic material separated from the pigments that will be separated even further. Next using a solvent and a polar compound like alumina, the pigments separated from the organic material could be run in a column in which those will be separated even more using polarity. As a more polar solvent is use to push the different rings of pigment, these are collected in their own test tubes to then be run in a TLC which will determine the polarity using the Rf values and then comparing them to the table in the organic lab manual ones.
Explain. After 30 minutes, the Benedict’s test is positive. Explain. The biuret reagent will change the color if in the presence of the protein. The starch is not protein, so the biuret test is negative.
Why are the specimens to be stained suspended in sterile saline or distilled water? Usage of sterile water to avoid false result by microorganisms having in the water and same reason for distilled also to avoid impurities like crystals of some metal ions to avoid other microorganism. 4. How does a stained preparation compare with a hanging drop for studying the morphology and motility of bacteria? The hanging drop is the classical method for viewing unstained microorganisms.
Animal cells have membrane bound organelles, bacteria do not so that makes them much bigger than a bacteria cell. Part B: Gram Stain Materials & Methods: Materials: * Watch the “Gram Stain “ video * Answer the questions and include them in the lab report. Questions & Answers: 1. This procedure is used to separate what two types of bacteria? A. Gram negative and gram positive.
In this experiment there were main 4 hypothesis made according to each agar plate each with a different types of genes on them. There are two genes that are on the agar plate and not in the solution it is the ampicillin and the arabinose genes. The ampicillin gene (amp) is a gene which acts like an antibiotic that kill the bacteria but when used with the pGLO plasmid it lets it survive because of the ampicillin resistant. The arabinose
Selective Media Lab Report Introduction Biological media acts as food for the bacteria and allows the growth of bacteria. There are two types growth media, selective media and differential media. Selective media used is when trying to promote the growth of only one bacteria, while differential media is used when trying to distinguish one media from another growing on the same plate. This experiment uses one type of differential media, Blood agar, which is differential for detecting hemolytic activity. Three types of selective media are used: Phenyl Ethyl Alcohol (PEA) are both selective for gram positive agar and Deoxycholate Citrate Agar (DCA) is selective for enteric pathogens.