Bacterial Diversity

8/4/2019 Bacterial Diversity

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Purvi kakrani

Dr. Harish kakrani

Dr. Bhanu Kakrani

BACTERIA MORPHOLOGY

CHARACTERISTICS

TO STUDY BACTERIAL DIVERSITY.

4/13/2012 1Purvi kakrani, Dr. Harish Kakrani & Dr. Bhanu Kakrani


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Bacteria?

Bacteria are often viewed as the cause of diseases in humans and animals.

Some bacteria are useful, for example certain bacteria aids in digestion.

Bacteria make up the base of the food web in many environments.

Bacteria are of such immense importance because of their extreme

flexibility, capacity for rapid growth and reproduction, and great age.

They can be photosynthetic, using light, or chemosynthetic, using inorganicchemicals as the source of energy, but most are heterotrophic, absorbing

nutrients from the environment.

Leptospira, causes serious disease in livestock



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Background InformationProkaryotes

Prokaryotes represent two domains, bacteria

and archaea.

Archaea live in Earths extreme environments.

Bacteria are the most abundant and diversifiedorganisms on Earth.



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Bacterial Structure

Biochemical processes that

normally occur in a chloroplast

or mitochondrian of eukaryotes

will take place in the inner

membrane of prokaryotes.

Bacterial DNA is circular and

arrayed in a region of the cell

known as the nucleotide .

Scattered within bacteriasinner membrane are numerous

small loops of DNA known as

plasmids .



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Structure

Some bacteria haveflagella with a differentmicrotubule structure thanthe flagella of eukaryotes..

Ribosomes are thestructures in cells whereproteins are assembled.

Bacterial ribosomes have

different sized ribosomalsubunits than doeukaryotes.



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Bacteria Have One of Three

Cellular Shapes

Rods (bacilli)

Coccoid-Shaped

Spirilla



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Reproduction

Prokaryotic cell division is

binary fission.

Single DNA molecule that first

replicates.

Attaches each copy to adifferent part of the cell

membrane.

Cell begins to pull apart.

Following cytokinesis, there

are then two cells of identical

genetic composition.



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NowOn to our experiment...

Purpose: Identify varieties of bacterial colonies and investigatebacterial species diversity, by isolating, culturing, and analyzingbacterial colonies, or species, that inhabit:

Air

Pond Water

Raw Chicken Washed/Unwashed hands

Keyboard

Soil Sample

Hypothesis: Knowing that bacteria can thrive in almost anywhereon our planet, we reason that all of the environments tested willgrow bacterial species. We further hypothesize that the thumbprint of the washed hand with the anti-bacterial soap, shouldhouse less species than any others tested, because the anti-bacterialsoap should kill off all bacteria.



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Methods

For chicken, soil, pond water,and keyboard samples, streakthe plate using the streak platemethod to isolate bacterialcolonies.

Leave agar plate open for airsample.

For the unwashed hand gentlypress thumb against agar.

Take washed hand and gentlypress thumb against agar.

Wrap in Parafilm and incubatethe cultures for about one weekat 22 C.

Observe and Interpret Data

Figure 1. Streak Plate Method. (a) Streak theplate back and forth across top half of plate. (b)Rotate plate a quarter turn counter clockwise andstreak top right quarter of plate. (c) Rotate plate aquarter turn counter clockwise and streak top rightquarter of plate again.

C.

B.

A

.



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Results: Soil

12

3

SIZE SHAPE MARGIN SURFACE COLOR

4 mm Irregular Lobate Wavy Yellow/white

3 mm Irregular Lobate Wrinkled Brown/yellow

5 mm Filamentous Filamentous Wrinkled Green/white



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Results: Pond Water

#Size Shape Margin Surface Color

1 2 mm round smooth Smooth grey

2 2 mm round lobate contoured beige

3 1 mm round Smooth Smooth clear

1.

2.

3.



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Results: Raw Chicken

# Size Shape Margin Surface Color1 2mm Irregular lobate contoured yellow/green

2 3mm irregular lobate wrinkled clear/white

3 1mm round Smooth Smooth Yellow/green

4 2mm Irregular wavy contoured brown

1.

2.

3.

4.



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Results: Air

# Size Shape Margin Surface Color1 5 mm Irregular Smooth Smooth Yellow/orange

2 5 mm Round smooth contoured Yellow/orange

3 1 mm Irregular Wavy contoured Yellow/white

4 3 mm Irregular Lobate wrinkled Yellow/brown

5 3mm Irregular Lobate smooth White

6 5 mm round Smooth Smooth White/yellow7 8 mm irregular lobate contoured White/yellow

12

3

4

5

6

1

7

5



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Results: Washed Hand


1 4 mm Irr egular lobate Smooth yellow

2 1 mm filamentous filamentous smooth white

1.

2.



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Results: Unwashed Hand

#

Size Shape Margin Surface Color

1 2 mm Irregular lobate smooth yellow

2 2 mm round Smooth smooth yellow

3 1 mm round Smooth Smooth white 1

2 3



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Results: Keyboard

# Size Shape Margin Surface Color

1 2 mm Irregular lobate wrinkled yellow

2 1 mm roun d smooth smooth greenish


1 4 mm Irregular lobate Smooth yellow

2 1 mm filamentous filamentous smooth white

1.

2.



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Control

An unopened agar

nutrient plate, which

ruled out agar

contamination, had nobacteria species

present.



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Species vs. Environments

0

2

4

6

8

# of Species

Environments

Number of Bacterial Species on Agar Plate

Series1 7 2 2 3 3 4 3

Air Keyb Unw Was Pond Chic Soil



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Conclusions/Observations

The results supported our hypothesis since

bacteria grew in all of our samples.

The results did not support our hypothesis

concerning the hand washed with anti-bacterial

soap since it did not house less species than the

other environments tested.

We were surprised to learn that the air not onlyhousedthe most bacteria, but housed the most

bacterial diversity of species as well.



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Further Investigations

Further studies can be conducted by using TEMmicroscopy, SEM microscopy, and gram staining,to specifically identify what type of bacterial

species were present in each environment. Research can also be conducted to figure out as to

why the unwashed hand contained more bacteriathan the washed hand.

Further research can be done to determine if anyof the bacteria found in our samples are harmful tohumans.



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Questions to Ponder

Do all bacteria grow at the same rate, and

what factors in the environment contribute

to determining their carrying capacity? What research can be done to determine

whether bacterial species and fungus

compete with each other for nutrients and

space in selected environments?



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References

Coccoid-shaped Bacterium (causes skin infections),Enterococcus faecium

(SEM x33,370). This image is copyright Dennis Kunkel at

www.davidkunkel.com, used with permission.

Morgan, I.G. and Brown Carter, M. E.,Investigating Biology: A

Laboratory Manual for Biology. California: Benjamin/Cummings Publishing

Co., Inc. 1993.

Rod-Shaped Bacterium, hemorrhagicE. coli, strain 0157:H7 (division)

(SEM x22,810). This image is copyright Dennis Kunkel at

www.davidkunkel.com, used with permission.

Spirilla- shaped Bacterium (SEM x33,370). This image is copyright Dennis

Kunkel at www.davidkunkel.com , used with permission.



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Gram stain Negative.Motility Motile.Habitat Occurs naturally in soil and water as well as the

intestine.Pathogenicity: Associated with urinary and respiratory tract infections,

endocarditis, wound infections, and eye infections.

Serratia marcescens



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Gram-positive and gram-negative bacteria



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Difference Between Gram-Negative

and Gram-Positive Bacteria

Gram-Negative Bacteria Gram-Positive Bacteria

More complex cell wall. Simple cell wall.

Thin peptidoglycan celll wall layer. Thick peptidoglycan celll wall layer.

Outer lipopolysaccharide wall layer. No outer lipopolysaccharide wall layer.

Retain safranin. Retain crystal violet/iodine.

Appear pink/red. Appear blue/purple.



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Antibiotic Sensitivity Test



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P10

C30

NA30

NB30S10

K30

E15

TE30

20

8

14

14

10

Antibiotic Sensitivity Test



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Hypothesis:

Kanamycin is one of the most sensitiveantibiotics because infections treatedinclude respiratory tract, urinary tract, skin,

soft- tissue and abdominal infections.Prediction:The size of the zone of inhibition is the

largest.Results:The size of the zone of inhibition is the 2ndlargest



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Antibiotic Resistance

Some bacteria have developed resistance to antibiotics naturally. Bacteria can become resistant to drugs in a number of ways.

- Mutation.- Exchange genes with other bacteria.- Resistant traits spread to future generations quickly because

of rapid reproducing.



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Limitations Reason unknown why S. marcescens is sensitive to certain

medications.

Further research needed.

Future Work

Develop new drugs to confront bacteria resistance.

Mechanism Antibiotics kill or stop the growth of harmful bacteria.


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