The colonies were smooth, translucent, and had a white brownish color. The Gram stain resulted in Gram positive cocci. After the Gram stain was completed, the bacteria were streaked on a Mannitol-Salt Agar plate and a Catalase test was performed. After these test were completed a Phenol Red Dextrose Fermentation tube was inoculated, and a SIM Tube inoculated.
Record the results of your investigations of each unknown in Table 1 by completing the following steps:
Preliminary studies help identify Genus species of bacteria. Two different preliminary study pathways must be used since two different pathogens were found in the sample. A dilution and a quadrant streak are the ideal methods to separate pure cultures of bacteria. MacConkey Agar and CAN (MAC) is a selective media that is used for the cultivation of gram negative bacteria. (PEA) is a selective media that is used
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,
In this experiment, an unknown bacterium was given to each individual student. The main purpose of this lab was to identify the given unknown bacteria going through a series of biochemical tests as one of the gram negative bacteria among six different Gram negative bacteria Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa and Salmonella typhimurium. At the very beginning, streaking method; T-streak technique was used to isolate the pure colonies. For the morphological identification of unknown bacteria, Gram Stain Method was done. Biochemical tests that were conducted for the experiment
(Harley, 2011, pp. 102-103) Sucrose and lactose serve as a fermentable carbohydrate sources which promote its growth of fecal forms and provide color change differentiation. (Harley, 2011, p. 104) Therefore, if E. coli is being platted on the EMB, after plate’s incubation period, it should produce a green metallic sheen on the agar due to the bacteria being a strong fermenter. My unknown bacteria tested positive for growth, and agar was fermented reddish burgundy in color. Subsequently, the unknown bacteria was later inoculated with a sterilized loop into the liquid tryptic soy broth and incubated at an appropriate temperature. Its results were used for proper identification of turbidity, spots and flocculation. (BD™ Tryptic Soy Broth (TSB), 2008) The results of the unknown were cloudiness and some settlement on the bottom of the tryptic soy liquid. The next step was conducted to find out if all the bacteria, as well as the unknown culture, required oxygen for growth, varying from an aerobic environment, where bacteria needs oxygen to grow, to facultative anaerobic environment, where bacteria will grow either with or without oxygen but better in its presence. All the bacteria, along with the unknown, were separately inoculated and tested. My unknown culture results tested positive for growth in facultative anaerobic environment. In the next sequence of lab experiments, the results of unknown bacteria were determined by glucose fermentation,
The bases of this experiment was to discover the identify of the unknown from three possible specimens: Klebsiella pneumonia, Escherichia coli, and Enterobacter aerogenes. Utilizaing the T streak technique, the bacteria was isolated into pure colonies for further study. The Gram Stain method was used to identity the morhphology of the bacteria such as the shape and whether the bacteria was Gram positive or Gram negative. Biochemical test were also used to help identify the unknown bacteria. The biochemical test used was the Triple Sugar Iron Agar, Sulfur Indole Motility test, Methyl Red test, Voges-Proskauer test, Citrate test, Urease test, and the Gelatin test. After observing the morphology of the bacteria using the Gram Stain method and utilizing all the possible biochemical test, the bacteria was identified to be Enterobacter aerogenes.
In class, we were given the task of identifying an unknown bacterium broth culture. After receiving number 69, I went through several tests to figure out what bacterium I received. First, I created a slide from my broth by putting a small amount of the unknown broth on to a clean slide and letting it dry for ten minutes. After this, I stained the slide by applying four reagents in order; crystal violet, grams iodine, decolorizer and safranin. From the stained slide, I discovered that this bacterium was gram-negative, which would determine the next couple of tests I would do to identify my unknown bacterium. I began by streaking for confluent growth from my broth culture onto a TSA plate. From the TSA plate, I aseptically transferred a loop
Description of the Microorganism: Write a paragraph describing your organism. Please be sure to include the type of organism (bacterial, viral, fungal, protozoa, helminth, etc), morphology (shape, arrangement, colony morphology if applicable), description of structure (gram result, type of nucleic acid or virion structure, spore type, etc if applicable) and also the type of microscope and/or stain you would use to view the organism.
The proposed identity of the unknown organism is Staphylococcus hyicus subspecies chromogenes though, due to variability of results for the specie strains, the unknown organism may also be Staphylococcus haemolyticus. All test results were consistent with my partner’s and other groups who had the same unknown organism. No test results contradicted the physiological concept of another test.
The identification of the unknown organism was first tested using a Gram’s staining procedure. This test uses a series of dyes and liquid solutions that give a bacterial smear a color contrast and aid in its identification. This method differentiates bacteria based on the thickness of their peptidoglycan composed cell walls. This Gram’s staining test was initiated by first donning gloves and obtaining a clean microscopic slide which was cleaned with alcohol. The slide was then marked with a culture number, and a circle was made in the center with a marker. A drop of water was placed in the center and the excess was absorbed. A wire loop was
The TSA+G trial had two plates with readable bacterial growth. One plate from the treadmill group had significant bacterial growth and measurable ZI created by the cleaning solution and cinnamon oil discs. One plate from the dumbbell group also showed significant bacterial growth and measurable ZI created by the cleaning solution and cinnamon oil discs. The remaining two plates in both groups had observable colony formations, but did not produce measurable ZI. No colonies were observed on any of the exercise mat or cable machine plates.
On the first day of testing, a gram stain test, a KOH test, a catalase test, and an oxidase test were completed. The gram stain test indicated that the unknown species is a gram positive rod, and the bacteria showed no strings during the KOH test confirming that the species is gram positive. From these two tests, the unknown was concluded to be in the family Bacillicae. The bacteria remained yellow on the cotton swab even after the oxidase reagent was dropped onto the swab showing that the bacteria is oxidase negative. For the second day of testing, the bacteria were inoculated on an SBA plate, and the analysis of this plate was difficult. The result of the SBA plate was difficult to discern, and it was unclear if the bacteria completed beta hemolysis or alpha hemolysis. Therefore, an additional SBA test needed to be completed, and with this second test it was more obvious that the SBA plate underwent alpha hemolysis. The SBA result showing negative beta hemolysis, along with the negative result from the oxidase test, indicated that Bacillus cereus was not the identity of the unknown. At the same time that the SBA hemolysis test was undergone, the inoculation of an MSA plate at 37 degrees for 24 hours was also completed. There was yellow growth on the MSA plate indicating that it could grow at 7.5% NaCl and ferment mannitol.
The Gram-Stain was performed as the basis for testing and identification, as Gram-Stains are a primary test for identifying bacteria. Based on the result of the Gram-Stain, several more tests may be carried out to identify the bacteria. In this experiment, the initial Gram-Stain had no result, as there were no bacteria that could be seen in the microscope. This could be due to not collecting enough of the organism on the slide before beginning the Gram-Stain. The T-Streak was conducted in order to both be able to observe and conclude morphology of the organism as well as have an incubated culture to conduct other tests from. The results of the T-Streak showed that the organism was round, smooth, and flat. After the T-Streak was done another Gram-Stain was conducted in order to identify status of the bacteria. Using the T-Streak culture give more culture to work with and guarantees that an adequate amount of culture is put on the Gram-Stain slide. The Gram-Stain showed that the bacteria was Gram-Positive eliminating Groups VI-X on the flow chart. The positive result indicated that the bacteria have a thick cell wall composed primarily of peptidoglycan. When viewed under the microscope, the bacteria had a purple ring around them, but were slightly pink mostly likely due to over decolorization, and were thus able to be classified as Gram-Positive. They were in the form of irregular