Minimum of three (3) biochemical tests chosen that will work sequentially in identifying the organismThere is no maximum number of biochemical tests, but the tests must be relevant to the identification of the organismExplanation of the purpose of this test and why you chose it for your workupThe correct testing interpretationTwo points will be given for the correct answers to questions about the organism biochemical characteristics
Added by Janice R.
Step 1
- **Reasoning**: This initial test will help narrow down the possibilities to a few genera or species, making subsequent tests more targeted and efficient. - **Example Test**: Catalase Test - **Purpose**: This test identifies whether the organism can produce the Show more…
Show all steps
Your feedback will help us improve your experience
Sri K and 54 other Biology educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
Escherichia coli Pseudomonas mallei Bacillus megaterium Bacillus anthracis, Lactobacillus acidophilus, Pseudomonas aeruginosa, Serratia marcescens Staphylococcus caprae Streptococcus mutans Neisseria gonorrhoeae, Staphylococcus aureus, Streptococcus pyogenes, Proteus myxofaciens, Klebsiella pneumoniae subsp. pneumoniae Salmonella bongori Shigella sonnei Corynebacterium xerosis Enterobacter aerogenes Proteus vulgaris Escherichia vulneris Escherichia blattae Salmonella choleraesuis (subsp. diarizonae) Enterobacter hormaechei Enterobacter asburiae Citrobacter diversus Citrobacter freudii In order to receive full credit for this assignment, you must provide the following: 1. The correct identification of the unknown organism in this homework assignment. 2. The correct interpretation of the biochemical tests in the table below for this unknown organism. 3. Create a flow chart that demonstrates the tests that allowed you to separate the unknown organism from the list. 4. You do not need to isolate the entire list of organisms from each other, just your unknown from the list. 5. Using your biochemical and morphological results to identify the identity of your orphan organism by using the Bergey’s manual. 6. Create a flow chart and identify your orphan organism. UNKNOWN #3 The following biochemical tests were performed after an unknown bacterium was isolated into a pure culture. Each of the tests was incubated at 37°C for 24 hours, and when appropriate, the use of reagents was added in the correct volumes to each of the tests. The following table describes these results. Name of the Biochemical Test/Media | Appearance after addition of the reagent | POS/NEG | Interpret the Resulting Reactions of the test Catalase (example) | Bubbles | POS | POS for catalase: H2O2 → H2O + O2 Urea/Urea broth | Reddish/yellow | | Phenol red Lactose | Red | | Phenol red Mannitol | Yellow | | Simmons Citrate | Blue | | Methyl red (MR)/MRVP broth | Red | | Voges-Proskauer (VP)/MRVP broth | No change/copper color | | Indole production/SIM media | No red ring | | Phenol red Glucose | Yellow | | Gram Stain | Pink | | FTM tube/fluid thioglycollate media | Growth throughout the tube | | 0.4% Agar with Nutrient broth and 1% TTC. | Growth and red throughout the tube | | Starch Hydrolysis/Starch agar | Brown around the inoculation | | Gelatin Hydrolysis/Gelatin media | Solid | | Oxidase | No color change | | Nitrate reduction/Nitrate broth | Red after Nitrate A&B reagent is added | | Shape | ROD | | Fat hydrolysis/Spirit blue agar | White around the inoculation | | H2S production/SIM media | Black | |
Sri K.
Fill out the table to predict the characteristics of the eight-bacterial species (in bold) mentioned in the reading on pg. 1. Indicate the shape of each bacterium, as coccus, bacillus or spiral. Indicate the color of bacterium after the Gram stain, MSA test and blood test. Use (+) for a positive result and (-) for a negative result in the catalase, oxidase and coagulase tests. Names of "unknown" bacteria Shape Differential stain: Gram stain Isolation test: MSA test, Blood test Biochemical test: Catalase test, Oxidase test, Coagulase test 2. Based on the table, which test(s) (differential stain, isolation test, or biochemical test) is most helpful in distinguishing between the two Gram-negative rods? 3. An "unknown" bacterium was cultured on nutrient agar. The bacterium turned purple when Gram stained. The unknown presented as individual and clustered rods when observed under the compound microscope at 1000X magnification. Each rod was ~1.0 um broad and 2 to 4 um long. Biochemical testing showed the bacteria was able to hydrolyze hydrogen peroxide. Based on this summary and your table, what is the unknown bacteria?
Josee P.
Chapter 2 describes details of several biochemical tests that can be used to identify specific biomolecules, including amino acids, polypeptides, nucleic acids, carbohydrates, and lipids. Although these tests are qualitative, chapter 3 describes how one of these tests can be converted to a quantitative test: For each of the tests described in chapter 2, describe (this must be typed): What is the test used to identify? What is the reaction that occurs that is specific for that test and biochemical? How would you perform the test? What would you predict the results of the experiment would show (use a table)? Explain the results and why they might have occurred (i.e., why one is positive and another is negative). What conclusions can you make from the predicted results?
Recommended Textbooks
Biology for AP Courses
Objective Biology for NEET
Introduction to General, Organic and Biochemistry
Transcript
18,000,000+
Students on Numerade
Trusted by students at 8,000+ universities
Watch the video solution with this free unlock.
EMAIL
PASSWORD