An unknown sample #18 was obtained on November 6, 2017. The sample came in a glass test tube with a cotton swab that contain the unknown sample. To find the identity of the unknown sample, we had to conduct several biochemical tests to eliminate and narrow down possible organisms that fit the biochemical description to accurately identify our unknown organism of interest. These biochemical tests provided insight on the physical color retention of our unknown sample, and through’s the unknown organism’s ability to break down tested compounds to determine if it had the corresponding enzyme that would allow it to do so. The testing of unknown organisms to accurately discover its identity is crucial in the field of health science. For in a life
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Using aseptic technique and using the streaking plate method. We also inoculated the unknown sample with the cotton swab onto a TSA slant, in which we transfer the unknown organism to the bottom of the slant and through a zigzag motion to make sure the TSA slant was completely covered with our unknown organism. Once the TSA plate and slant was inoculated with our unknown organism it was allowed to be incubated at 35 degrees Celsius for 24 hours. After the plates had undergone incubation for the full 24 hour duration, color and morphology was observed and noted for our unknown organism. Gram staining was than conducted after, in which we determine if the unknown organisms was either positive or negative based on the thickness of its peptidoglycan wall that was able to retain the crystal violet color or not. This determination lead to the test of gelatin hydrolysis test, followed by a urease test, and lastly a lactose fermentation test. To narrow down our possible potential organisms that match our unknown, that would lead to accurately identifying our …show more content…
This was allowed to be incubated for 24 hours at 35 degrees Celsius. The observation of color change and gas formation is what ultimately led to the identification of our unknown organism.
Results:
Dichotomous key
Gram Stain: After performing the gram stain, our unknown organism appeared to be pink indicating that it is gram negative and that the morphology is rod shape or bacillus. This indicate that this peptidoglycan cell wall is much thinner compared to the control we observed from bacillus cereus.
Gelatin Hydrolysis test: The purpose of the gelatin hydrolysis test was to determine if our organism had the enzyme gelatinase, to hydrolyze gelatin in the gelatin agar plate that it was initially inoculated into. After incubation and applying TCA it appears that it did not in fact have that partially enzyme. And so it result observed was a opaque cloudy dime sized center, with no visible clearing.
Urease
Using aseptic technique and using the streaking plate method. We also inoculated the unknown sample with the cotton swab onto a TSA slant, in which we transfer the unknown organism to the bottom of the slant and through a zigzag motion to make sure the TSA slant was completely covered with our unknown organism. Once the TSA plate and slant was inoculated with our unknown organism it was allowed to be incubated at 35 degrees Celsius for 24 hours. After the plates had undergone incubation for the full 24 hour duration, color and morphology was observed and noted for our unknown organism. Gram staining was than conducted after, in which we determine if the unknown organisms was either positive or negative based on the thickness of its peptidoglycan wall that was able to retain the crystal violet color or not. This determination lead to the test of gelatin hydrolysis test, followed by a urease test, and lastly a lactose fermentation test. To narrow down our possible potential organisms that match our unknown, that would lead to accurately identifying our …show more content…
This was allowed to be incubated for 24 hours at 35 degrees Celsius. The observation of color change and gas formation is what ultimately led to the identification of our unknown organism.
Results:
Dichotomous key
Gram Stain: After performing the gram stain, our unknown organism appeared to be pink indicating that it is gram negative and that the morphology is rod shape or bacillus. This indicate that this peptidoglycan cell wall is much thinner compared to the control we observed from bacillus cereus.
Gelatin Hydrolysis test: The purpose of the gelatin hydrolysis test was to determine if our organism had the enzyme gelatinase, to hydrolyze gelatin in the gelatin agar plate that it was initially inoculated into. After incubation and applying TCA it appears that it did not in fact have that partially enzyme. And so it result observed was a opaque cloudy dime sized center, with no visible clearing.
Urease