Preview

Litmus Milk Procedural

Satisfactory Essays
Open Document
Open Document
342 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Litmus Milk Procedural
Sarah St. Vincent
Olivia Almeida
December 10, 2012
Biomedical

LITMUS MILK

Litmus milk is a complex medium that can potentially distinguish many species of bacteria. Litmus milk has several components that can be metabolized: lactose (milk sugar); casein (milk protein); and litmus (a pH indicator). If lactose is fermented, the solution should turn pink. If gas is produced during fermentation, you may be able to see bubbles or cracks in the milky medium. If lactose is not fermented and proteins are metabolized instead, the solution will become alkaline and turn blue in color. If casein is digested, the milk will coagulate to form a curd (a solid). Casein may be metabolized all the way down to individual amino acids. This process, called peptonization, results in a clear (not milky) liquid that is usually brown in color. Finally, the litmus may be reduced and become colorless. The culture will then look milk white.
Materials:
1. Litmus Milk Broth 2. Bunsen Burner 3. Inoculation Loop 4. Nutrient slant 5. Goggles 6. Lab Coat 7. Incubator
Procedure:
1. Get an Inoculation loop and sterilize it using the Bunsen burner.
2. Take bacteria from your nutrient slant on inoculation loop
3. Inoculate a litmus milk tube with the bacteria.
4. Incubate for 72 hours; observe results every 24 hours for 3 days.
Lab safety: 1) Always have lab coat on 2) Always have hair tied back 3) Always have safety goggles on 4) No loose clothing 5) No loose jewelry
For our hypothesis we had based it of the chart. We had thought our unknown bacteria is E coli so we said that we wanted to get and acid, curd reduction. Thus, making our hypothesis correct.
Glossary:
1. Metabolized - the sum of the physical and chemical processes in an organism by which its material substance is produced, maintained, and destroyed, and by which energy is made available. 2. Lactose - milk sugar 3. Casein - milk protein 4. Litmus

You May Also Find These Documents Helpful

  • Good Essays

    Glucose exposure resulted in a yellow color change proving that Unknown #7 fermented glucose and produced an acid but when exposed to Sucrose Unknown #7 produced a red color change indicating that it was a non-fermented of sucrose which was reflected with an alkaline bi-product. The Enterotubes showed that Unknown #7 was an "enteric" bacterium with a score of "46141" Lysine, Adonitol, Lactose, Dulcitol/Phenylalanine, and Harnstoff/Uree were all negative, while Ornithine, Arabinose, and Sorbitol were proven to be positive. The IMViC test identifies members of Enterobacteriaceae and included Indole that tested negative, Methyl Red which produced a red color change showing that Unknown #7 could ferment glucose to acidic ends, Vogves Proskaer which tested negative because Unknown #7 failed to convert those acidic bi-products back to neutral ends, and Citrate which tested positive with a blue color change and growth on the medium because Unknown #7 was able utilize citrate. The Nitrate Reduction test displayed Incomplete Reduction with a red color change when Solution A and B were added meaning that it could only reduce NO3- to NO2-…

    • 553 Words
    • 3 Pages
    Good Essays
  • Powerful Essays

    The purpose of the unknown bacteria lab assignment was to select an unknown bacteria culture and, through a series of metabolic tests, identify which bacteria genus resided in the pure culture received. A nutrient broth inoculated with bacterial culture (numbered 45, henceforth referenced as U45) was selected and a streak plate was made to isolate a pure culture for use throughout the assignment.…

    • 1738 Words
    • 7 Pages
    Powerful Essays
  • Better Essays

    By doing these tests we will be able to see how the unknown bacteria reacts to certain conditions. If our results of these lab experiments are conclusive then we should be able to determine what our unknown bacteria is.…

    • 1370 Words
    • 6 Pages
    Better Essays
  • Better Essays

    Unknown Project

    • 2236 Words
    • 9 Pages

    This test is used to observe the difference between gram positive staphylococci bacteria and to differentiate for mannitol fermentation. If a yellow media change is observed then the bacteria has the presence of acid by-products of mannitol fermentation. For my bacteria no change in the color of the media is observed but growth is. Therefore we know that our bacteria has no mannitol fermentation.…

    • 2236 Words
    • 9 Pages
    Better Essays
  • Better Essays

    Unknown Lab Report

    • 2145 Words
    • 9 Pages

    The purpose of this lab was to identify two unknown bacteria cultures using various differential tests. The identification of these unknown cultures was accomplished by separating and differentiating possible bacteria based on specific biochemical characteristics. Whether the tests performed identified specific enzymatic reactions or metabolic pathways, each was used in a way to help recognize those specifics and identify the unknown cultures. The differential tests used to identify the unknown cultures were oxidase, catalase, lactose and sucrose fermentation, Kugler/iron agar, nitrate reduction, gelatin hydrolysis, starch hydrolysis, manitol salt, MR-VP, citrate, bile esculin, indole, urease, DNase, and coagulase.…

    • 2145 Words
    • 9 Pages
    Better Essays
  • Good Essays

    Unknown Microorganism

    • 1335 Words
    • 6 Pages

    The streak for isolation was chosen to see the formation of the different colonies and to see if the bacteria would cause growth on the plate. After observing the plate, it could be seen that the unknown had growth and formation of colonies. The Gram stain was chosen next to determine if the unknown was gram-negative or gram-positive. After looking at the gram stain under the microscope with the oil immersion it could be determined that the unknown was gram-negative due to the fact that the bacteria was pink in color and rod shaped. After determining the unknown was gram-negative, other bacteria’s were able to be eliminated from the options. The Triple Sugar Iron Test was chosen next because the unknown could be tested for glucose fermentation, lactose fermentation, sucrose fermentation and sulfur reduction. If the organism is able to ferment glucose and lactose and/or sucrose it will turn the medium yellow throughout (Leboffe & Burton 329). When the Triple Sugar Iron Test was complete, it showed a yellow butt, yellow slant and gas production. This determined that the unknown ferments glucose and one or both of the other sugars. The gas was produced by fermentation. The color change in the agar brought the unknown down to two options of unknowns, Escherichia coli or Hafnia alvei. The SIM medium test was chosen next to see sulfur reduction, indole production from tryptophan…

    • 1335 Words
    • 6 Pages
    Good Essays
  • Good Essays

    Biology Aqa Notes

    • 3967 Words
    • 16 Pages

    Metabolism is the sum total of all the biochemical reactions taking place in the cells of an organism.…

    • 3967 Words
    • 16 Pages
    Good Essays
  • Satisfactory Essays

    * Pasteurization: heat liquid to temp. that kills the most heat resistant pathogen but NOT all (milk)…

    • 709 Words
    • 3 Pages
    Satisfactory Essays
  • Powerful Essays

    hs201 intro to nutrition

    • 8247 Words
    • 33 Pages

    Metabolism: the numerous reactions that occur within the cell. The calories in foods are converted to energy in the cells of the body.…

    • 8247 Words
    • 33 Pages
    Powerful Essays
  • Satisfactory Essays

    Metabolism is the term used to describe the chemical reactions that take place inside a cell. Metabolic pathways are a series of these reactions catalysed by enzymes, and are carried out in small steps so that the product of one step can be the substrate of the next. The synthesis of larger molecules from this is called anabolism (e.g. constructing tissue) and the breaking down of these larger molecules is called catabolism (Dow et al., 1995, pp185-186).…

    • 333 Words
    • 2 Pages
    Satisfactory Essays
  • Powerful Essays

    Ws Ch04 E

    • 1491 Words
    • 9 Pages

    Metabolism (新陳代謝) refers to the (1) _______________ of the chemical reactions that take place in an organism to keep it alive.…

    • 1491 Words
    • 9 Pages
    Powerful Essays
  • Better Essays

    The embryos will be incubated in an air-conditioned room at 26ºC as an alternative to the unavailability of an incubator (OECD, 2013). During the test, the embryos will be exposed to white light in a 12h: 12h light/dark cycle (Villamizar, Vera, Foulkes, & Sánchez-Vázquez, 2014) to ensure the greatest survival…

    • 1095 Words
    • 5 Pages
    Better Essays
  • Satisfactory Essays

    Preserving Fish Specimen

    • 303 Words
    • 2 Pages

    4. Lay the fish on white Styrofoam board and spread-out all the fins using pin.…

    • 303 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    1. Make sure to have safety garments and gear on, goggles and aprons, before starting the…

    • 1531 Words
    • 8 Pages
    Good Essays
  • Good Essays

    Caesin is a major protein constituent in milk & is a mixed phosphor-protein. Casein has isoelectric pH of about 4.7 and can be easily separated around this isoelectric pH. It readily dissolves in dilute acids and alkalies. Casein is present in milk as calcium caseinate in the form of micelles. These micelles have negative charge and on adding acid to milk the negative charges are neutralized.…

    • 585 Words
    • 3 Pages
    Good Essays