Prokaryotes

The Prokaryotes
Bacteria
I Proteobacteria: most of the gram-negative, chemoheterotrophic bacteria
A. alphaproteobacteria
1. includes most of the proteobacteria that are capable of growth at very low levels of nutrients.
2. some have unusual morphology
a. prosthecae: protusions like stalks or buds
3. include agriculturally important bacteria capable of inducing nitrogen fixation in symbiosis with plants
a. Azospirillum
4. Orders
a. Caulobacterales
i. Caulobacter
b. Rickettsiales
i. Ehrlichia
ii. Rickettsia
iii. Wolbachia: symbionts of insects
c. Rhizobiales
d. Rhodospirillales
B. betaproteobacteria
1. Thiobacillus
2. Spirillum
3. Sphaerotilus: sheathed bacteria
4. Burkholderia
5. Bordetella
6. Neisseria
7. Zoogloea
C. gammaproteobacteria
1. constitute the largest subgroup of proteobacteria.
2. Beggiatoa
3. Francisella
4. Pseudomonadales
5. Azotobacter and Azomonoas
6. Legionellales
7. Enterobacteriales
a. salmonella
b. Escherichia
c. shigella
d. klebsiella
e. serratia
8. Pasteurellales
D. deltaproteobacteria
1. Distinct because they contain bacteria that prey on other bacteria.
2. important contributors to the sulfur cycle
E. epsilonproteobacteria
1. slender gram negative rods that are helical or vibrioid.
a. Campylobacter
b. Helicobacter

II Nonproteobacteria gram negative bacteria
A. Cyanobacteria
B. Purple and green Photosynthetic bacteria
III Gram-postitive bacteria
1. low G+C (firmicutes
a. Clostridiales
b. Bacillales
i. stapylococcus
c. Lactobacillales
i. streptococcus
d. Mycoplasmatales
2. High G+C
a. Mycobacterium
b. Nocardia
IV Chlamydiae
V Spirochaetes
A. have axial filaments
VI Bacteriodetes
VII Fusobacteria

Various notes on prokaryots:
Cell size of prokaryots are limited because nutrients must enter by simple diffusion.

Azo: prefix frequently encountered in nitrogen-fixing genera of bacteria