5. Classify each of the media used according to its functional type (i.e. define
ID: 272383 • Letter: 5
Question
5. Classify each of the media used according to its functional type (i.e. defined, undefined, selective, differential). a. MSA: b. Blood Agar: c. TSA: d. M9 minimal media 6. How does MSA allow Staphylococci to grow and inhibits the growth of other microbes, and how do pathogenic forms of Staphylococci differ from non-pathogenic forms when grown on MSA? Blood agar is used to determine if a species has the ability to do what? What does a positive result for this ability look like on blood agar? 7. Why might a microbiologist grow a bacterial species on a medium that contains the minimal nutrients necessary for its growth, such as M9 minimal media? 8. 9. How can you improve your aseptic technique?Explanation / Answer
Hi Answer:
5. Classify each of the media used according to its functional type (i.e. defined undefined, selective, differential)
A. MSA: Mannitol salt agar media is commonly used as a selective and differential medium. It has high salt percentage up to 7.5 % which is used to select some organisms which are capable to grow in such high salt concentration.
B. Blood Agar: It is a selective enrichment media used to culture those organisms which are not growing easily on normal growth media. The bacteria which are grown on such special media are called fastidious as they need special, enriched nutritional environment as compared to normal bacteria. Haemophilus influenzae, Streptococcus pneumoniae, and Neisseria species are grown on blood agar media.
C. TSA: Tryptic Soy Agar is undefined medium it is recommended for use as a general growth medium for the isolation and cultivation of microorganisms. This medium is also recommended for use in the cultivation, storage, maintenance and transportation of pure cultures of microorganisms.
D. M9 minimal media: defined growth media is used to grow the recombinant strains. M9 is comprised of an M9 minimal salts base formulation that can be supplemented with various amino acids and carbon sources.
6. How does MSA allow Staphylococci to grow and inhibits the growth of other microbes, and how do pathogenic forms of Staphylococci differ from nonpathogenic forms when grown on MSA.
Answer: MSA is commonly used as a selective and differential medium. It is used for the selective growth of halophile and can differentiate pathogenic and nonpathogenic Staphylococcus. It has high salt concentration about 7.5% at this salt concentration most of the organisms are not grown but Staphylococci grow easily on this media.
On MSA pathogenic forms of Staphylococci can be differentiate from non pathogenic forms as when a pathogenic Staphylococci grew on the MSA it changes its red colour to yellow due to the generation of organic acid which changes the pH and the red colour changes to bright yellow, but in case of non pathogenic strain the organics acids are not generated so the color change of MSA didn’t take place.
7. Blood agar is used to determine if species have the ability to do what? What does a positive result for this ability look like on blood agar?
Answer: Some species have the ability to lyse red blood cells. The Blood agar media is used to determine the hemolysis activity of the specific microbial species. If an organism gives the positive result of hemolysis then the hemolysin radially diffuses outwards to the colony (or colonies) causing the complete or partial destruction of the red cells (RBC) in the medium and complete denaturation of hemoglobin within the cells to colorless products.
8. Why might a microbiologist grow a bacterial species on a medium that contains the minimal nutrients necessary for growth, such as M9 minimal media?
Answer: M9 is a minimal, defined growth medium used for cultivating recombinant strains of Escherichia coli. M9 Medium is useful for maintaining positive selective pressure on recombinant strains of E. coli with plasmids coding for the ability to produce essential substances such as amino acids or vitamins.
It is inexpensive, low auto-fluorescence and low absorbance. M9 can be supplemented with specific amino acids or other metabolites to allow for selection of specific auxotrophs the components of M9 make it very convenient media to grow the microbial system because its composition fully sports the growth of microbial systems.
9. How can you improve your aseptic technique?
Answer: In microbiology, the aseptic environment plays a major role and to maintain a pure culture of microorganisms we have to focus on the aseptic techniques so that any kind of contamination can be avoided. The aseptic environment can be maintained by following practices:
1.Proper sterilization of media and media components.
2. Working place sterilization.
3. Pure culture maintenance.
4. Avoid the open use of any microbial culture always uses under the laminar hood.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.