General Phylogeny

Domain Comparison

Archaea

Halophiles

Halophiles

Halophiles

ArchaeaThermophiles

ArchaeaMethanogens

Bacterial Morphology

Coccus

Bacillus

Spiral

Bacterial MorphologyCoccus

Diplococcus

Streptococcus

Staphylococcus

Gram Staining

+ -

Crystal VioletIodine

EthanolSafranin

A B C

D

H I J

GFE

EndosporesDNA, ribosomes, and some

cytoplasm encasedBacterial defense against

temperature, pH, chemicals, and aridity

F+

Genetic Recombination: Conjugation

F+

F-Pilus (Conjugation Bridge)

Host DNA

Genetic Recombination: Transduction

Nutrition

Chemoautotrophs Chemoheterotrophs

Photoautotrophs Photoheterotrophs

CyanobacteriaPhotoautotrophic Heterocysts

N2 Fixation

When Bacteria AttackExotoxins

Poisons released to weaken hostClostridium botulinumClostridium tetaniVibrio cholerae

When Bacteria Attack

EndotoxinsPoisons located in outer membraneEscherichia coli, Salmonella

Review Questions1. Bacteria cannot grow in temperatures above

100oC, so why is pressure cooking at 120oC and 15-20psi necessary for sterilization?

2. Contrast chemoautotrophism and chemoheterotrophism.

3. Carbon fixation : mesophyll cells : nitrogen fixation :: _________

4. Would you rather be infected by a Gram+ or a Gram- bacterium?

Review Answers1. Some Gram+ bacteria can form endospores and resist boiling.

The combination of heat and high pressure can kill them, though.

2. Chemoautotrophism – Chemical energy source and CO2 carbon source. Chemoheterotrophism – Chemical energy source and organic carbon source.

3. Carbon fixation : mesophyll cells : nitrogen fixation :: heterocysts4. Gram+ because they are more likely to be susceptible to

antibiotics, and Gram- can contain endotoxins. ORGram- because some Gram+ can form endospores.