Microbiology lab 2

Answer the questions as requested

2420-Lab 7- Microbial Growth: Temperature, Oxygen and Osmotic Balance

Directions:

Answer following questions after reading the information and watching the video from the link below. Use color RED or BLUE for your answers. Submit the completed document on eCampus for grading. Refer to

· the textbook chapter 4 (sections 4.1, 4.3 and 4.4) (Nester- McGraw Hill)

· Lab Manual by Dr. Su, pages (optional)

· Link:

Environmental Influences of Bacterial Growth

, Virtual Edge Experiment-

5A-B

·

pH Requirement of bacteria

Bacterial Growth:

Read the information from textbook from chapter 4 review

sections 4.1, 4.3 and 4.4
to answer the following questions.

Watch the following video:

· For background:

Bacterial Growth

1. Label the phases of growth on the following curve:

2. What happens to bacteria in the phases labeled as A, B, C and D in the above figure?

A:

B:

C:

D:

3. If we add more nutrients and space at the end of the exponential phase for a growing bacterial culture, what will happen?

Oxygen Requirement of bacteria

Read the information from textbook from chapter 4 review

sections 4.3-4.4 to answer the following questions.

Watch the following videos:

· For background:
Oxygen Requirement of bacteria

· For experiment:

Oxygen requirement of bacteria using soft agar

Results of the bacterial oxygen requirement of bacteria:

4. Why can only some organisms tolerate oxygen?

5. Describe the kind of bacteria shown in the figure above in terms of oxygen (concentration) requirement and special enzymes.

6. Which oxygen related enzymes are present or absent in the bacteria from tubes A-E?

Temperature Requirements of Bacteria:

Read the information from textbook from chapter 4 review
sections 4.3-4.4 to answer the following questions.
Watch the following videos:

· For background:

Temperature Requirement of bacteria

· For experiment:

Temperature Influence on bacterial growth

Temperature tolerance of bacteria

Write the correct term for bacteria growing under the following conditions

7. Most medically important bacteria

8. Bacteria growing on or inside your body

9. Bacteria growing in your refrigerator

10. Bacteria growing in the arctic ocean in winter

11. Bacteria growing in hot springs in Arkansas

12. Bacteria growing in geysers

13. Why are bacteria not able to grow at temperature higher than the maximum tolerance limit?

14. Do bacteria grow at the temperatures lower than the minimum tolerance limit? Why or why not? Explain

Osmotic Balance Requirements of Bacteria:

Read the information from textbook from chapter 4 review
sections 4.3-4.4 to answer the following questions.

Read the following:

· For experiment: Osmotic Influences

Osmotic tolerance of bacteria

Halophiles
: On human body, Staphylococcus aureus is known to tolerate sweat. These bacteria may cause skin infections if athletic gear is shared among athletes without proper sanitization. In nature we will find bacteria, algae and fungi in water bodies or soil with higher salt concentrations. These organisms come under a group called “halophiles”.

Habitat
: Halophiles are usually found in salt lakes, salt marshes, subterranean salt deposits, dry soil, salted meat and hypersaline seas.

3 groups based on the salt concentration tolerance
:

· Halophiles-2-5% salt required for growth

· Moderate halophiles-5-20% salt required for growth

· Extreme halophiles-20-30% salt required for growth

Write the correct term for bacteria growing under the following conditions

15. Based in your knowledge about tonicity, for cells to survive they have to be surrounded by ______tonic environment.

16. Why would cells not survive in hypotonic or hypertonic environment?

2420-Lab 8- Control of Microbes: Susceptibility to Antimicrobials

Directions:

Answer questions after reading the information and watching the video from the links below. Use color RED or BLUE for your answers. Submit the completed document on eCampus for grading. Refer to

· the textbook chapter 5 (sections 5.1-5.6), Chapter 8 (8.3) and chapter 20 (20.3-20.4) (Nester- McGraw Hill)

· Lab Manual by Dr. Su, (optional)

· Link: Control of Microbes-

I (

13-A

, B,)

(Virtual Edge Experiment-13- A, B)

I. Lethal Effects of UV radiation:

Read the information from textbook from chapters 5 and 8 review

sections 5.4 and 8.3
to answer the following questions.

Watch the following video:

13- A, B, C

1. What wavelength in “nm” is considered ultra-violet radiation?

2. What is the correlation of energy and wavelength in the electromagnetic spectrum showed above?

3. Would you consider mutations occurring after exposure to UV light spontaneous or induced?

4. What are the effects of UV light exposure on DNA?

5. Can the damage caused by UV light repaired? How?

6. In the experiment 13-A, why is the cover of petri-dish removed when exposing the bacteria to UV?

7. What will happen if the person doing experiments with UV light does not protect eyes while actively using UV light?

II. Kirby-Bauer Disc Diffusion Method

Read the information from textbook from
chapter 20

review

section 20.2, 20.4 to answer the following questions.

For background:

13-B

Define the following terms

8. Bacteriostatic

9. Bactericidal

10. Antimicrobial

11. Antibiotic

12. Susceptibility

13. Zone of Inhibition

14. Selective Toxicity

15. Therapeutic index

16. Broad-spectrum antibiotic

17. Narrow-spectrum antibiotic

18. Dysbiosis

For experiment:
13-B

Kirby-Bauer disc diffusion test procedure:

Finding out susceptibility: by measuring the diameter of the zone of inhibition

19. What information would you get after performing the Kirby-Bauer experiment?

20. Why is the zone of inhibition circular?

21. If the disc used was a square or a triangle, what shape would be the zone of inhibition?

22. Which antibiotic is the most effective and the least effective against E.coli based on the following picture of the results of a Kirby-Bauer disc diffusion test?

Pfizer, a pharmaceutical company chemically synthesized an antibiotic, Granegin, against E. coli. Observe the initial results of this novel antibiotic in the table below and answer questions 23-25:

Picture	Effective concentration and the effect of the antibiotic of humans
Sample 1- 5 g- No effect on human body Sample 2- 20 g- No effect on human body Sample 3- 30g- Severe diarrhea in humans Sample 4- 40g- Lethal effect on human body Sample 5- 35 g- Severe diarrhea and headache in humans Sample 6- 10g- Effect-none Sample 7- 10g- Effect-none Sample 8- 10g- Effect-none

23. At what concentration the novel antibiotic is the most effective against E. coli?

24. At what concentration the novel antibiotic is the least effective against E. coli?

25.

If you were a health professional, which of the above antibiotic concentrations would you choose for treatment against E. coli infections and why?

2420-Lab 9- Immunology- Agglutination

Directions:

Answer questions after reading the information and watching the video from the links below. Use color RED or BLUE for your answers. Submit the completed document on eCampus for grading. Refer to

· the textbook chapters 15, 18 (sections 15.4, 18.3, 18.4), (Nester- McGraw Hill)

· Link: Agglutination- (Antigen-Antibody reaction) –

I (6-A, B,)

(Virtual Edge Experiment-6- Introduction, A –skip B)

I. Introduction:

Read from

· the textbook chapters 15, 18 (sections 15.4, 18.3, 18.4), (Nester- McGraw Hill)

· Link: Agglutination- (Antigen-Antibody reaction) –

I (6-A)

(Virtual Edge Experiment-6- Introduction, A)

Define the following terms:

1. Antigen

2. Antibody

3. Epitope

4. Immunoassay

5. Polyclonal antibodies

6. Monoclonal antibodies

7. Agglutination

8. Precipitation

II. Hemagglutination (Blood typing)

For background:

6-A

9. Complete the following table.

	Blood type	Antigens present On the erythrocyte	Antibodies present in plasma	Can donate blood to	Can receive blood from
	A+
	A-
	B+
	B-
	AB+
	AB-
	O+
O-s

10. Draw the results of different blood types in the following trays

Blood type

A+

A-

B+

B-

AB+

AB-

O+

Hemagglutination results Well A-with anti-A antibodies	Hemagglutination results Well B- with anti-B antibodies	Hemagglutination results Well Rh- with anti-Rh antibodies
O-

2420-Lab 10- Food Microbiology and Unknown Bacteria Identification

Directions:

Answer questions after reading the information and watching the video from the links below. Use color RED or BLUE for your answers. Submit the completed document on eCampus for grading. Refer to

·

the textbook chapters 10, 30 (sections 10.4, 18.3, 18.4), (Nester- McGraw Hill)

· Link: Agglutination- (Antigen-Antibody reaction) –

I (6-A, B,)

(Virtual Edge Experiment-6- Introduction, A –skip B)

·

The questions on the quiz will be related to chapters 10 and 30.

I. Introduction to Food Microbiology

Read from

·

10 easy homemade fermented products

: choose a product that requires bacteria for fermentation

· Don’t be limited to the above website. You can perform your own literature search and choose a legal fermented product.

Define the following terms:

1. Fermentation

2. Cellular aerobic respiration

3. Cellular anaerobic respiration

4. What are the differences between anaerobic respiration and fermentation?

5. What are the similarities between anaerobic respiration and fermentation?

II. Make ONE fermented product at home of your choice.

NOTE:

· If you are not 21 or older, DO NOT brew alcohol beverage.

· Choose any product that fits your budget

· If you cannot perform this experiment due to any reason, choose a fermented product, complete a literature search and answer the following questions

· Keep track of money spent for this experiment. DO NOT SPEND TOO MUCH MONEY

6. Which fermented product did you choose and why?

7. What was the procedure?

8. How did you ensure there was no contamination?

9. What will happen if the fermentation process of the product you chose goes wrong?

10. Would you call fermentation food spoilage or preservation? Explain your answer.

11. Share your experience on the Discussion Board.

III. Identifying the unknown bacteria

In this section, we will explore how to identify bacteria from a sample. The sample could be medical (blood, urine, stool etc), food, water, soil or other.

For identification of bacteria one has to follow certain steps:

1. Isolate the bacterial species

2. Grow the bacterial species in a laboratory successfully

3. Identify the species using staining techniques, biochemical tests, serological typing, molecular biology

4. Confirm identification by confirmatory tests- biochemical tests, molecular tests (DNA sequence analyses)

Conduct a literature search on steps you would take to identify the bacterial species in the fermented product you chose.

Some helpful links:

·

Biochemical Tests of Bacteria

·

Summary of Biochemical Tests

·

Using Biochemical Testing for Bacterial Identification

Write up a report in the following format:

Fermented product chosen:

Bacteria involved:

Steps taken to identify the bacterial strain: (Explain each technique in your own words)

· Isolation

· Staining

List Biochemical Tests that would be performed to identify and confirm