Group Unknown Essay

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 purpose of this lab was to identify two unknown bacteria from a mixed culture. The reason for identification of unknown bacteria was to help students recognize different bacteria through different biochemical tests and characteristics. This is important in the medical field because identification of unknown bacteria can help treat a patient by knowing the contributing source of a disease. Also knowledge of different bacteria helped others make antibiotics used today. This lab was completed by using the methods learned thus far in identification of bacteria.

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 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

A broth in test tube labeled #2 was used to identify the unknown organisms. A T-soy agar plate was the first media I inoculated. I used the streak isolation technique to isolate a pure strain from colonies, so that organisms can be identified. I inoculated a MacConckey to help me identify my Gram negative organism and observed that the organism was a non-lactose fermenter, then I performed a Citrase test which was negative. The last test I performed was a TSI, the butt was positive for hydrogen sulfide production and fermentation of glucose. All 3 results helped me conclude that my Gram negative organism was Proteus vulgaris. P vulgaris inhabits the human intestinal tract of human and animals. It is also found in soil, polluted water and fecal matter. This bacterium is

An unknown microorganism from three potential microbes—Bacillus megaterium, Escherichia coli, and Enterococcus faecalis—was determined by performing eight biochemical tests. Biochemical tests that were used to differentiate these possible microorganisms from each other were gram staining, motility with a semi-solid agar tube, oxygen requirements, catalase test, phenylalanine deaminase test, eosin methylene blue agar (EMB) and mannitol salt agar (MSA). The unknown microorganism was further clarified through a polymerase chain reaction (PCR) test and basic local alignment search tool (BLAST) database. Based on all the observations of the tests, the unknown bacterium was identified as B. megaterium.

A highly conserved gene will be used to identify a prokaryotic species isolated from the body. Fundamental lab techniques will be also explored and utilized, such as amplifying using PCR, cloning, and transforming the gene into a host cell. DNA electrophoresis and specific substrate plating will serve as analysis check points. The final product will be sequenced and compared to similar species to observe phylogenetic relationships.

The unknown bacteria B22 contained an opaque white, circular colony, along with an irregular margin on the initial inoculated agar plate. The broth characteristics included growth with the presence of a flocculent and all around cloudiness; however, the slant characteristics included just a spreading edge. After the bacterium identified to be gram positive, a blood agar plate identified the bacteria to have gamma hemolysis capabilities; additionally, the mannitol salt agar identified the bacterium to indeed ferment the mannitol and the urease enzyme was as well identified from the urea agar. Subsequently, the phenol red mannitol broth showed no mannitol fermentation and the phenol red glucose broth showed fermentation with acid and no gas

The Gram negative stain and rod shape eliminated six of the possibilities. The SIM (Sulfur Motility and Indole) testing proved that the organism was motile, was a gas producer, did not produce indole, and Triple Sugar Iron-Agar Slant produced a black butt and red slant indicating glucose fermentation and confirmed sulfur gas production, leaving only Proteus vulgaris as another possible outcome. Casein, gelatin, and urease testing were needed to conclude my results, as only P. vulgaris would be found to possess the enzymes casease, gelatinase, and urease, which, none of those were found in my unknown organism. Both of the two organisms were negative to hydrolyze starch, and neither can metabolize oxygen.

Proteus mirabilis is a gram negative that is a member of the Enterobacteriaceae family. Under the microscope, it appears as a small gram negative bacillus. The characteristics’ of Proteus mirabilis are that they show a swarming motility, they are enable to ferment lactose, they ferment maltose, they ferment glucose, they ferment xylose, and they produce H2S. This organism is part of the normal flora and they are ubiquitous in the environment. There are a variety of tests that can be used to identify Proteus mirabilis such as the Oxidase test, the Methyl Red/Voges-Proskauer (MR/VP), Kliger’s Iron Agar (KIA), Nitrate Broth, Motility Agar, MacConkey Agar, etc.

In this research, five formulated preliminary questions were answered. Finding the answers to these questions was vital as it would reveal the distinguishing features of each unknown sample which, in turn, would bring me closer to identifying my microorganisms ' species more accurately. As one will notice, these questions gradually focus from general aspects into specific aspects of the microorganisms. The questions are as follows:

After observation of the slide, the capsule stain of the unknown culture appeared unstained with a blackish background and the cells were reddish brown and they were large and arranged in pairs, which indicates that there is presence of some bacterial