Bacteria
And
Biotechnology
By
Jodie Abel
University of Wisconsin River Falls
July 20, 2007
Activity Description
This curriculum activity project includes notes, assignments,
laboratory activities, instructional materials, and a variety of
evaluation methods. The project is designed to meet the needs of a
variety of learning styles and meets National standards. Teachers
can pick and choose any of the material that they feel meets his/her
classroom needs.
Class
This class is geared toward grade 10 biology. Depending upon your
curriculum it could also be used in environmental science or general
science classrooms.
Class Sections
This project would be appropriate for any sections pertaining to
bacteriology, soil, or waste management.
Length of Activity
This activity in full will take approximately 2-2 1/2 ninety minute
periods.
This activity would be incorporated with additional information in the
virus/bacteria unit. So the days which we observe our plate grow we
would be working on other activities that wouldn’t focus on just
bacteria or biotechnology. These activities would include things such
as a 3-D model or a comic book.
National Standards
A.1, C.1e, C.3e, C.5d, D.2, E.1, F.6
Activity Outline
Day 1
I.
Introduction to Bacteria
A. Objectives:
1. What are bacteria and why are they important?
2. Label the parts and describe the function of a typical
bacterial cell.
3. Distinguish between the three typical bacterial cell
shapes.
B. Notes:
1. Background information and terminology
C. Assignment:
1. Reviews the concepts covered in notes/lecture
D. Lab: Observing Bacteria
1. Students will observe three bacterial shapes
discussed in lecture using a compound microscope.
2. Once lab is completed students need to complete a
lab write up.
E. Review
1. Discuss and review newly learned items.
F. Read over lab: Identifying Limits to the Growth of Bacteria
Day 2
II.
Introduction to Biotechnology
A. Objectives:
1. Define biotechnology.
2. How can biotechnology be used to distinguish
between different types of bacteria.
3. Be aware of the importance of bacteria in
environmental processes.
B. Quiz
1. Assessing concepts covered in day 1 material.
C. Lab technique review
D. Lab: Identifying Limits to the Growth of Bacteria
1. Students will learn how to extract and grow bacteria.
2. Students will determine whether an environmental
factor such as temperature can control the growth
and reproduction of bacteria.
E. Assessment
1. Discussion and observation of the lab and lab
technique.
Day 3
I.
Introduction to biotechnology continued
A. Objectives
1. Students should understand that specific
decomposers can be isolated using a specific media.
2. Be aware of the existence of dormant microbes in
soil and water.
B. Lab: Identifying Limits to the Growth of Bacteria
(continued)
1. Students will observe the bacteria which they grew.
2. Students will make and observe bacteria under the
microscope.
C. Review and discuss what was learned and observed.
D. Assessment
1. Students will complete lab questions and discuss
what they observed and what they think may
happen.
Day 4
I.
Finish biotechnology and bacteria
A. Lab: Identifying Limits to the Growth of Bacteria
(continued)
1.
Students will perform a final observation of plates grown
and record their results.
Section 18.2 Archaebacteria and Eubacteria
I.
Diversity of Prokaryotes
A.
Two Types
1. Archaebacteria – 3 types
a. Lives in oxygen free environments and producers
methane gas
1)
Marshes, sediments, digestive tracts
b. Lives in water w/ high concentration of salt
c. Lives in hot, acidic water of sulfur springs
2. Eubacteria – 3 types
a. Heterotrophs
1)
Parasites – live off other living organisms
2)
Saprophyte – feed on dead organisms or
organic wastes.
b. Photosynthetic autotrophs
1)
Live in places w/ sunlight
2)
Composed of independent cells
c. Chemosynthetic autotrophs
1)
Make their own food by breaking down
inorganic material containing sulfur and
nitrogen through chemosynthesis.
2)
Converts atmospheric nitrogen into
compounds that plants can use.
II.
What is Bacterium?
A.
Structure
1. Cell Wall – supports and protects
2. Capsule – sticky jelly-like material that surrounds the cell
wall of some bacteria.
3. Plasma Membrane – surrounds the cell and regulates
what enters and leaves the cell.
4. Pili (Pilus) – extensions of the plasma membrane
a. Helps bacterium stick to a surface
b. Acts as a bridge between bacteria allowing them to
exchange DNA.
5. Plasmid – small circular chromosome containing few
genes.
6. Flagellum – whip like extension
a. Aids in locomotion
b. Found in most bacteria
7. Chromosome – single, not enclosed in a nucleus,
contains most of the genes.
B.
C.
D.
E.
1928 – Penicillin was discovered (mold). It interferes w/
bacteria’s ability to make cell walls.
Identifying bacteria
1. Gram Staining – distinguishes 2 types of bacteria (cell
wall)
a. Gram: positive = purple
b. Gram: negative = pink
***Each affected differently by antibiotics
3 types of shapes
Reproduction
1. Binary Fission – asexual
a. Copies chromosome
b. Cell grows larger
c. 2 chromosomes separate and move to opposite ends
of the cell.
d. A partition separates the cell into 2 similar cells.
2. Conjugation – sexual reproduction
a. 1 bacterium transfers all or part of its chromosome to
another cell
b. Transferred through or on a pilus that connects the 2
cells.
III.
A.
B.
IV.
Adaptations in Bacteria
Diversity of Metabolism
1. Cellular Respiration – breaking down food to release
energy.
a. Two types
1)
Obligate aerobes – require oxygen
2)
Obligate anaerobes – killed by O2
Survival Mechanism
1. Endospore – forms when there are unfavorable
conditions.
a. Its structure contains a bacterium’s DNA and some
cytoplasm encased by a tough covering
b. Resists drying out, extremes in temperature, and
harsh chemicals.
c. When conditions are favorable, they will germinate.
Importance of Bacteria
A.
4 Main Jobs
1. Nitrogen Fixation – converting nitrogen (N2) into
ammonia (NH3) or vice versa.
2. Recycling of Nutrients – break down materials so
others can use it.
3. Food and Medicine –
a. Food: yogurt, cheese
b. Medicine: antibiotics for diseases such as
1)
Strep throat
2)
TB
3)
Lyme disease
4)
Cavities
4. Bacteria Cause Disease
a. Carried in air, food, water, and can invade wounds.
b. They don’t affect the human population because of
improved water and sewage plants, nutrition, and
medical care.
Name____________________________ Date _________ Block ____
Archaebacteria and Eubacteria Worksheet
Determine if the following statements are binary fission (BF) or
conjugation (C).
____ 1. Bacterium w/ a new genetic makeup is produced.
____ 2. Circular chromosome is copied.
____ 3. Genetic material is transferred through a pilus.
____ 4. Two identical cells are produced.
____ 5. Sexual reproduction occurs.
Multiple choice.
____ 1. Bacteria that are obligate anaerobes release energy from food by
a. cellular respiration
b. using oxygen
c. using nitrogen
d. fermentation
____ 2. As an Endospore, a bacterium
a. produces toxins
c. causes diseases
b. dries out
d. is protected.
____ 3. Botulism is caused by endospores of C. botulinum that have
a. been killed.
b. produced toxins
c. germinated.
d. reproduced.
____ 4. Nitrogen is important because all organisms need it to make
a. proteins
b. ATP
c. DNA
d. all of these
____ 5. The process by which bacteria use enzymes to convert nitrogen gas into
ammonia is called
a. nitrogenation
b. atmospheric separation
c. nitrogen fixation
d. eutrophication
____ 6. Bacteria return nutrient to the environment by breaking down
a. dead organic material
c. enzymes and sugar
____ 7. Bacteria are not used to make
a. vinegar
b. jams
b. inorganic materials
d. nitrogen in legumes
c. cheese
d. yogurt
____ 8. Bacteria are responsible for the following diseases
a. Strep throat and tetanus
b. gonorrhea and syphilis
c. tuberculosis and diphtheria
d. all of these
Short Answer.
1. Name three types of environments in which Archaebacteria are found.
a.
b.
c.
2. What structure do some bacteria use to move?
3. What are three different shapes of bacteria?
a.
b.
c.
4. Describe the difference between gram-positive bacteria and gram-negative
bacteria.
5. In what three ways do Eubacteria obtain nutrients?
a.
b.
c.
Name _____________________________ Date ________ Block ___
Bacteria Lab
Introduction: Bacteria come in three shapes: spherical (coccus), rod-like
(bacillus), and spiral (spirillum) shaped. They may appear singly or in pairs,
chains, or clusters. Each species has a typical shape and reaction to Gram stain.
Objective: To observe three different types of bacteria using a microscope.
Procedure:
2.
3.
4.
5.
Observe one of the three types of bacteria located on the slide.
Observe this bacterium on low power and draw what you see in the
first circle located in the data portion of the lab.
Next observe the same bacterium under high power. Draw what
you see in the second circle.
Repeat steps 1-3 observing the remaining two types of bacteria.
Data:
Low Power
Low Power
Low Power
High Power
High Power
High Power
Conclusions:
1. Explain how all three types of bacteria are similar.
2. Distinguish between each type of bacteria.
3. How do sizes of the three bacteria compare?
4. What adaptive advantages might there be for bacteria to form groups of
cells?
5. Which of the bacteria was Gram negative?
Name ______________________________ Date ______ Block ____
Lab: Identifying Limits to the Growth of Bacteria
Problem: Does temperature limit the growth and reproduction of bacteria?
Materials:
Glass-marking pencil
3 sterile agar plates
Sterile cotton swabs
Bacterial culture
Transparent tape
Hand lens
Gram’s iodine
Procedure:
1. Put on plastic gloves. Using a glass-marking pencil or marker to label the
edges of the agar plates 3˚C, 20˚C, and 37˚C. Also, write your name on
each plate.
2. Dip a sterile swab in the bacterial culture and wipe it back and forth in a
zigzag pattern over the entire surface of the agar on one plate. Cover the
plate and seal it with transparent tape.
3. Repeat step 4 with each plate, using a new sterile swab for each plate.
4. Place the plate labeled 3˚C in a refrigerator. Leave the plate labeled 20˚C
in a place designated by your teacher. Place the plate labeled 37˚C in an
incubator. Be sure to store each plate upside down.
5. After 24 hours examine the plates with a hand lens. Bacterial colonies
look like small white or colored dots on the agar surface. In data table,
record the number of bacterial colonies on each agar plate. Return each
plate to its location.
6. After a second 24 hours, record in data table 1 the number of bacterial
colonies on each agar plate. Return your agar plates to your teacher for
safe disposal.
7. Make a line graph of the results in data table one using Microsoft Excel.
Data:
Data Table 1
Temperature (˚C) # colonies (24 hours) # colonies (48 hours)
3
20
37
Analyze and Conclude:
1. At what temperature were the most bacterial colonies visible after 24
hours? At what temperature were the fewest bacterial colonies visible
after 24 hours? Include drawing of your plates.
2. Did the same plate have the most bacteria after 48 hours? The fewest?
3. Describe the effect of temperature on the growth of bacteria.
4. Do you consider your data reliable? Explain.
5. Did the results of your experiment confirm your prediction?
6. How did your results compare to others in your class?
Teacher preparation:
1. Provide a diluted liquid culture of noninfectious bacteria such as E. coli
obtained from a biological supply store.
2. Make Starch Agar
a. Add 2 grams of soluble starch to 400 ml of distilled water.
b. Add 9.2 grams of nutrient agar and autoclave for 15 minutes at
121˚C for 15 minutes or use a pressure cooker at 15 psi of steam
pressure. Makes approximately 20 plates.
c. Sterilize water and glassware using same procedure. Foil wrapped
glassware can also be sterilized in the oven at 400˚F for 2 hours.
3. Make Gram’s Iodine
a. Add 1 gram of iodine and 2 grams KI to 100 ml distilled water.
Bacteria Slide Preparation:
1. Put sterile swab of distilled water on slide.
2. Touch swab to colon and smear in distilled water on slide.
3. Let dry then pass through flame 3x quickly to fix.
4. Add one drop crystal violet, let sit 10 seconds.
5. Rinse slide with distilled water until it runs clear.
Name _______________________________ Date _____ Block ____
Archaebacteria and Eubacteria Quiz
Match the following terms with the correct definition.
a.
d.
g.
j.
chemosynthesis
cell wall
conjugation
endospore
b.
e.
h.
k.
parasites
pili
gram staining
obligate aerobes
c.
f.
i.
l.
saprophytes
flagella
binary fission
nitrogen fixation
____ 1. Live off other living organisms.
____ 2. Feed on dead organisms and organic waste.
____ 3. Supports and protects the bacteria.
____ 4. Extensions of the plasma membrane.
____ 5. Whip like extensions.
____ 6. Distinguishes 2 types of bacteria.
____ 7. Asexual reproduction
____ 8. Sexual reproduction
____ 9. Forms when there are unfavorable conditions.
____ 10. Bacteria that require oxygen.
____11. Converting nitrogen into ammonia
____ 12. A process of breaking down inorganic material containing sulfur and
nitrogen.
References:
Books and Periodicals
Biggs, Alton. (2002). Biology; The Dynamics of Life. Glencoe/McGraw-Hill,
Westerville, OH.
Brinson, Leslie. Selecting Soil Organisms, Monsanto/St. Louis Manual.
Miller, Levine. (2005). Biology. Pearson Prentice Hall, Boston, MA. Pg. 471-477.
Miller, Levine. (2005). Biology. Pearson Prentice Hall, Boston, MA. Pg. 491.
Lab Material Ordering Information
Carolina Biologicaal Supply Company
2700 York Road
Burlington, NC 27215
1-800-334-5551
Nasco-Fort Atkinson
901 Janesville Ave.
Fort Atkinson, WI 53538
1-800-558-9595
www.enasco.com