Identify/discuss a minimum of 5 experiments that were most helpful in the ID of your microbe Explain/Interpret what the results mean or indicate Discuss any variables or reasons why your results may have been contrary to book results

QUESTION

Paper Criteria (please see attached for more details)

• Must use paragraph format (write as narrative)
• MLA bibliography format
• Length of paper 4-5 pages (less than three, not including chart, will not be accepted)
• 1 ½ line spacing, 11 pt type font, proper grammar, punctuation, spelling, number pages
• Refrain from the use of personal pronouns and be specific (minimize fluff)
• Names of all genus (first word in microbe name) is capitalized and species (second name) is lower case (e.g., S. aureus)
• Names of all taxa must be printed in italics.The first use of the name should be written out with subsequent uses abbreviating the first name (e.g., Staphylococcus aureus andS. aureus)
• Chart size should not exceed 1/2 page
• Identify/discuss a minimum of 5 experiments that were most helpful in the ID of your microbe
• Explain/Interpret what the results mean or indicate
• Discuss any variables or reasons why your results may have been contrary to book results
• Must reference all quoted materials used
• Cannot use class handout materials or Wikipedia as a cited reference

Results!!

-Sugar Fermentation (Lactose, Dextrose, and Sucrose)- positive for both acid and gas production.(Hence “AG” via chart attached)

-Triple suagr iron (TSI)- positive for acid production

-Methyl Red Voges Proskauer (MVRP) Test- MR Reaction was (-) no glucose breakdown /no color change, VP Reaction was (+) glucose breakdown to acetylmethylcarbinol – red ring around top of broth

-Citrate Utilization Test- (+) citrate utilization giving alkaline PH- royal blue media

-Sulfide, Indole, & Motility (SIM Test)- Sulfide- (-) no H2S to FeS/ no color change,Indole (+) indole production cherry red at top of agar, Motility was (+) due to cloudiness throughout agar

-Gelatin (Protein) Hydrolysis- (-) gelatinase was produced medium remains liquid after refrigeration.

-Starch Hydrolysis – (-) no starch hydrolysis agar is blue/blackincluding around bacterial growth

-Casein (Milk) Hydrolysis- (+) casein hydrolyzed clear zone around bacterial growth.

-Lipid Hydrolysis- (-) no lipid , opaque agar

-Urea Hydrolysis- (-) no urea/color change

-Nitrate Reduction- (+) reduced nitrates to nitric oxide, nitrous oxide or nitrogen gas, no color change

-Oxidase Test- (-) no cytochrome oxidase activity/no color change

-Catalase Test- (+) catalase production, bubbles appear

ANSWER

Identification of a Microbe: Experimental Insights and Interpretation

Introduction

The identification of microorganisms is crucial in various scientific fields, including microbiology, medicine, and environmental science. This essay explores the experimental findings and their interpretations that aided in the identification of a particular microbe. Through a series of tests, including sugar fermentation, Triple Sugar Iron (TSI), Methyl Red Voges Proskauer (MRVP), citrate utilization, Sulfide, Indole, and Motility (SIM), gelatin hydrolysis, starch hydrolysis, casein hydrolysis, lipid hydrolysis, urea hydrolysis, nitrate reduction, oxidase test, and catalase test, the microbe’s characteristics were assessed and analyzed.

Sugar Fermentation

The microbe exhibited positive results for both acid and gas production when tested with lactose, dextrose, and sucrose. This observation indicates that the microbe possesses the ability to ferment these sugars, which is a significant characteristic for microbial identification.

Triple Sugar Iron (TSI) Test

Positive results for acid production in the TSI test suggest that the microbe can metabolize carbohydrates and produce acids. This finding is in line with the expected behavior of certain microorganisms, further supporting the identification process.

Methyl Red Voges Proskauer (MRVP) Test

The MR reaction yielded negative results, indicating the absence of glucose breakdown and no color change. However, the VP reaction was positive, signifying glucose breakdown to acetylmethylcarbinol (Melkonian, 2022). The presence of a red ring around the top of the broth confirms this interpretation (Chaudhry, 2022). These results provide valuable insights into the metabolic capabilities of the microbe.

Citrate Utilization Test

Observing a color change to royal blue in the media indicates that the microbe utilizes citrate as its sole source of carbon and energy. The ability to utilize citrate is a distinct characteristic of certain microbial species, contributing to the identification process.

Sulfide, Indole, and Motility (SIM) Test

Negative results for sulfide production suggest that the microbe does not produce hydrogen sulfide (H2S). However, the presence of a cherry red color at the top of the agar confirms indole production. Furthermore, the cloudiness observed throughout the agar indicates the motility of the microbe. These findings provide valuable clues to narrow down the potential identification possibilities.

Gelatin Hydrolysis, Starch Hydrolysis, Casein Hydrolysis, and Lipid Hydrolysis

The microbe displayed characteristics such as the absence of gelatin hydrolysis, no starch hydrolysis (as indicated by the blue/black agar), positive casein hydrolysis (clear zone around bacterial growth), and no lipid hydrolysis (opaque agar) (Aryal, 2022). These results aid in further narrowing down the potential identification of the microbe.

Urea Hydrolysis, Nitrate Reduction, Oxidase Test, and Catalase Test

The microbe demonstrated negative results for urea hydrolysis, indicating its inability to hydrolyze urea. However, it showed positive results for nitrate reduction, suggesting the microbe’s capability to reduce nitrates. The oxidase test yielded negative results for cytochrome oxidase activity. Conversely, the catalase test was positive, as bubbles appeared, indicating the production of catalase. These findings contribute additional insights into the metabolic and biochemical characteristics of the microbe.

Conclusion

Through a comprehensive series of experiments, including sugar fermentation, TSI, MRVP, citrate utilization, SIM, and various hydrolysis tests, as well as urea hydrolysis, nitrate reduction, oxidase test, and catalase test, valuable insights into the identification of the microbe were obtained. The observed results provide essential information regarding the microbe’s metabolic capabilities, substrate utilization, and enzymatic activities. This knowledge serves as a foundation for a more precise identification of the microbe, contributing to our understanding of its ecological role and potential impacts in various fields.

References

Aryal, S. (2022). Gelatin Hydrolysis Test – Principle, Procedure, Uses and Interpretation. Microbiology Info.com. https://microbiologyinfo.com/gelatin-hydrolysis-test/ 

Chaudhry, R. (2022, August 15). Biochemistry, Glycolysis. StatPearls – NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK482303/ 

Melkonian, E. A. (2022, August 8). Biochemistry, Anaerobic Glycolysis. StatPearls – NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK546695/