Diversity of Bacteria

Diversity of Bacteria

Bacteria

• Very diverse
• Thousands of species in one gram of soil!
• Five major caldes

Proteobacteria

• Large and diverse group
• Photo and chemo trophs
• Gram negative: form of classification, thinner peptidoglycogen layer
• Rhizobium
• Latin "Rhino" = root
• Mutualistic with many plants Example: Legumes
• Fix atmospheric N2 into usable organic nitrogen (NH3)

• E. coli
• Harmless in human intestine (commensal)
• Helps with digestion
• Produces necessary vitamins
• Can produce antibiotics which only hurt other bacteria, reducing competition Example: Probiotics in yogurt
• Some strains can be toxic
• Bad to have E. coli anywhere but the intestines

Chlamydias

• Pathogenic: can infect and harm humans
• Only live within animal cells
• No peptidoglycogen
• Often not recognized as foreign by cells defense Example: Chlamydia trachomatis is an STD

Spirochetes

• Pathogenic
• Helical structure
• Swim by spiraling Examples: Syphilus and Lyme disease

Cyanobacteria

• Photoautotrophs
• Produce atmospheric oxygen
• Likely gave rise to chloroplasts in eukaryotes

Gram-positive Bacteria

• Some pathogenic Examples: Botulism, tuberculosis, leprosy, anthrax

Importance of Bacteria

• Used to make cheese and yogurt
• Use their metabolic and chemical attributes
• Treat sewage
• Bioremdiation
• Antibiotics
• N fixation
• Extremophile eubacteria
• Taq (Thermos aquaticus)
• Enzymes maintain function at high temperatures
• Use these enzymes in PCR where temperatures must fluctuate