Microbiology and Cell BiologyThe basis of biotechnology

Prokaryotic vs. Eukaryotic CellsCells are the basic unit of life.

Prokaryotes Eukaryotes

•Single-celled•No nucleus•No membrane-

bound organelles•Smaller (0.001 to

0.75 mm)

•Single or multi-celled

•Have a nucleus•Have membrane-

bound organelles•Larger

Domains of LifeEukarya

-Eukaryotes

Archaea -prokaryotes- often extremophiles

Bacteria-prokaryotes- largest group

Three Domains

Man’s Use of Microorganisms

Microbiology – study of microorganisms (microbes) and their effects on living organisms.

•Antibiotics•Model systems•Biological weapons•Biofuels•Food additives•Pharmaceutical and protein production

Koch’s Postulates1. The microorganism must be found in abundance in all

organisms suffering from the disease but should not be found in healthy animals.

2. The microorganism must be isolated from a diseased organism and grown in pure culture.

3. The cultured microorganism should cause disease when introduced into a healthy organism.

4. The microorganism must be re-isolated from the inoculated, diseased experimental host and identified as being identical to the original specific causative agent.

Importance of Antibiotics

•A medicine that inhibits the growth of or destroys a microorganism

•Main line of defense against bacterial disease

•First discovered in 1928 by Alexander Flemming (penicillin)

•1940s – large scale use began in the military during WWII

•Antimicrobial resistance continues to increase.

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Identifying Bacteria - Gram staining

• Invented by Hans Christian Gram in 1882

• Two purposes:▫Determine the cell wall

composition▫Make the shape of the cells

visible (400x to 1000x magnification)

Identifying BacteriaBased on the thickness of the peptidoglycan cell wall

Gram-positive Gram-negative

• Cell walls are thick so they take up the stain.

• Tend to turn purple or blue w/ Gram stain

• Cell walls are thin so they do not take up the stain.

• Tend to turn red w/ Gram stain.

Figure

3.6

Identifying Bacteria - Assays•Tests the activity of

a drug or biomolecule in an organism or sample

•Ex: Starch hydrolysis test – determines if bacteria produce amylase

Bacteria ClassificationCoccus Bacillus Spirillum

Spherical shape Oval or rod shaped Spiral shaped

Three types based upon their shapes…

“strepto” from Greek streptos meaning ‘twisted chain’

“staphylo” from Greek staphule meaning ‘bunch of grapes’

In the guts (digestive tracts) of animals

Where do Bacteria Live?

•Use photos

Morning Glory Pool (hot spring), Yellowstone National Park

Sulfur-consuming bacteria form “cave snot”

Bacteria in glaciers has been estimated at 8 million years old

salt marsh bacteria

Anatomy of a Eukaryotic Cell

Uses of Eukaryotic Cells in Biotechnology

•Fermentation – yeast •Protein production•Therapeutic drugs – i.e. antibodies•Stem cells

▫Embryonic▫Adult/ Induced pluripotent

Resources

•http://cleanairsystems.biz/images/bac02.jpg

•http://textbookofbacteriology.net/Anthrax.html

•http://mortada8.maktoobblog.com/category/microbiology-immunology/bacteria/