1. Important Bacterial Groups
In addition to being classified by Gram staining and shape, bacteria are also classified by biochemical properties and evolutionary relationships.

2. Proteobacteria Largest and most diverse group
Several subgroups w/ varying nutritional needs
Aerobic and anaerobic
Many live in symbiotic relationships with other organisms.

3. Proteobacteria cont.
Nitrogen-fixing bacteria live in nodules on the roots of legumes (beans, alfalfa, clover etc.)
Atmospheric nitrogen is not in a form usable to plants; without these bacteria plants could not make nitrogen

5. Proteobacteria cont. Agrobacterium- causes tumors in plants
Rocky Mountain Spotted Fever
Stomach ulcers
E. coli- live in digestive tract
Salmonella- food borne illnesses

6. Rocky Mountain Spotted Fever
…carried by ticks

7. Gram-Positive Bacteria
Very large group
Includes bacteria that cause strep throat
Botulism
Members of the genus Lactobacilli used to make yogurt
anthrax

8. Anthrax- a biological weapon

9. Gram-positive bacteria that grow in soil are used to make antibiotics
What color do they stain?
Why?

10. Cyanobacteria A.k.a blue-green algae Photosynthetic Very numerous
Contribute to oxygen-rich atmosphere
Food source to marine animals

11. Spirochetes Gram negative Spiral-shapted Aerobic or anaerobic
Corkscrew rotation
Pathogens or free living
Syphilis
Lyme Disease

12. Chlamydia Gram negative
Only live inside animal cells which supply them with nutrients and protection
no peptidoglycan
Can lead to inability to have children
Sometimes no symptoms are observed
Can be passed from mother to child