Unknown Microorganism

There are many differents ways to identify a bacterial unknown and many different situations where identification would be beneficial. One way to identify bacterial unknowns is to perform biochemical tests. In this experiment multiple biochemical tests were done, by performing these tests on the bacterial unknown received the two different bacteria were then identified. The citrate test is done to test the ability of organisms to use citrate as a carbon source. This test uses Simmons citrate agar, the agar contains sodium citrate as the only carbon source and has bromothymol blue as the pH indicator. The organisms that use citrate as a carbon source use the enzyme to transport the citrate into the cell. The cells converts ammonium dihydrogen

The Unknown Bacteria 36/Bacteria # 2 on a TSA plate was examined by the naked eye and under a dissecting microscope. Bacteria # 2 was approximately 3 - 4 mm in diameter. They were circular in form with an entire margin and a flat elevation. The colonies were rough (granular), translucent, and white brownish color with black granules. The Gram stain resulted in a Gram negative rod. After the Gram stain was completed, the bacteria were streaked on an Eosin -Methylene Blue Agar plate and an Enterotube II was inoculated.

The purpose of this study project was to carefully isolate and identify two unknown bacteria from a mixed culture. The ability to properly evaluate biochemical test results is also necessary for the identification to be successful. The goal was to apply all of the methods and techniques that have been learned in the microbiology laboratory course for the proper identification of unknown bacteria. A certain amount of bacteria that were used throughout the course were possible bacteria that could be found in a mixed culture. The bacteria that were identified in the mixed culture were Staphylococcus Aureus and Kocuria Rhizophila.

The first result of importance was the result of the Gram stain. The observations of the unknown bacteria from the slant culture after Gram staining showed that the unknown bacteria were Gram negative bacilli (Image 1). After determining the unknown bacteria was Gram negative, an oxidase test was conducted on a sample from the slant culture. The cotton swap with the sample of bacteria did not change color when the oxidase reagent was applied, thus providing a negative result. With a negative oxidase test, further tests were conducted to determine various characteristics of the unknown bacteria. A MR-VP broth was inoculated with a sample from a slant culture of unknown bacteria. After incubation, the methyl red reagent was added to the broth, and the broth turned red, providing a positive result (Image 2). An EMB agar streak plate was inoculated with a sample from a slant culture of the unknown bacteria, and after incubation, growth was found on the plate, providing a positive result (Image 3). A Citrate agar slant was inoculated, and after incubation, growth was found on the media, providing a positive result (Image 4). A Urea agar slant was inoculated, and after incubation, the agar had changed from a peach color to a bright pink color, providing a positive result (Image 5). Using the flowchart (Figure 1) developed from the Table of Expected Results, the lab partners started at the oxidase test. Given the negative result of the oxidase test, the flowchart is

In a laboratory setting, it often becomes necessary to identify an unknown organism. In this experiment, researchers classified an unidentified bacterium based on its physical structure, colony morphology, optimal conditions and metabolic properties. A Gram stain using crystal violet, iodine, and safranin and a simple stain using methylene blue characterized the organism’s cell wall. Cultural behavior was classified by inoculating the organism onto nutrient agar and incubating it at 37° C for 48 hours, and observing its behavior, as well as using SIM medium to test for motility. Optimal growth temperature was

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

The first step toward identifying this unknown organism was to perform a Gram Stain to differentiate between gram positive and gram negative bacteria. This is an important step because it directs what the next tests will be. My Gram Stain on sample #12 showed that the bacteria was gram negative, however, after receiving the results of the OF glucose, H2S, Citrate, Urease and Motility tests, it was apparent that my Gram Stain was contaminated. I then performed a catalase test which came back negative, so I ordered a Bacitracin disc, Optochin disc and a CAMP test which had to be incubated overnight. After receipt of those test results,

The main idea of this experiment was to correctly identify the unknown bacteria, #3. Identification of unknown bacteria yields multiple benefits in many different areas in the research of microorganisms. In this experiment I performed many different test dealing with things such as the presence of enzymes, fermentation abilities and different chemical reactions. Observations made from the tests were then compared to a gram negative unknown chart in order to identify the bacteria. Based off of my results and the chart, I concluded the bacteria #3 was the bacteria Escherichia coli. E. coli is most commonly found in the intestines of warm blooded organisms. Most E. coli strands are non pathogenic however, there are strands

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,

The purpose of this study was to identify the unknown bacterium using biochemical tests and various methods that had been learned from previous the microbiology laboratory class. Identifying the unknown bacterium was determined by separating and differentiating possible

This report discusses the procedures and equipment needed to determine a bacterium knowing and having nothing but the sample bacteria given by the instructor. The importance of this lab is to test your ability to think clearly about what each test will tell you about your unknown organism and selecting tests that will save time and give you the most information. The objective of this lab is to determine what species level and genus level your bacterium is categorized as. The first step taken to determine the bacteria was to do a sub-culture of my stock broth to have a backup of my bacteria just in case my broth became contaminated. Doing a T-streak on a TSA plate is when the plate is divided into three sections and using an inoculating loop, grab some

Prokaryotes are ubiquitous, successfully adapting to diverse environments as well as developing symbiotic relationships with host organisms (Lengeler, Drews, & Schlegel, 1999). Prokaryotes may have both autotrophic and heterotrophic characteristics. A cyanobacteria is photosynthetic, commonly called blue-green algae, and may produce toxins (Crayton, 1993). Bacteria are most commonly associated in the general

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 the past, and even in modern times like today, it has been vital to distinguish and determine the identities of microorganisms in the world. These identities are not only important in knowing what agent causes various diseases and the treatment to be used, but also in understanding how microbes can be beneficial and valuable to the human body and life as a whole. With that being said, upon beginning this lab, the purpose of this study was to identity and investigate an unknown microorganism by applying the methods that were previously learned and practiced in the microbiology laboratory portion of class.

Each mixed culture that was tested had one gram positive and one gram negative bacterial species. The possible species of bacteria that could have been isolated from the mixtures included the following: Bacillus subtilis, Corynebacterium glutamicum, Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, Enterobacter aerogenes, Salmonella enterica, and Pseudomonas aeruginosa. The identities of the unknown species were determined through comparing the experimental data against data acquired from earlier experimentation.