CH 11: the Prokaryotes: Domains, Bacteria, and Archaea

Highlight the bacteria and then tell why they fit into one of the categories such as phylum, class, etc. highleighed term memsn she said to know it.

the Prokaryotes: Domains, Bacteria, and Archaea

•One circular chromosome, not in a membrane

•No histones

•Lack organelles

•Peptidoglycan cell walls

•Binary fission

Phylum- Proteobacteria

Class -a (alpha) Proteobacteria

•Human pathogens:

•Bartonella- human pathogen

•B. hensela  Cat-scratch disease

•Brucella (obligate paracites) Brucellosis- by contact with animals

The a (alpha) Proteobacteria

Obligate intracellular parasites:(produce only in a mamalian cell)

• Ehrlichia. Tick-borne, ehrlichiosis

•Rickettsia. Arthropod-borne, spotted fevers, by insect bites

• R. prowazekii   Epidemic typhus (transmitted by lice)

• R. typhi         Endemic murine typhus (by rat fleas)

• R. rickettsii       Rocky Mountain Spotted Fever(by ticks)

The a (alpha) Proteobacteria

•Wolbachia. Live in insects and other animals

most popular in the bacteria world since it effects insects- spread fast

The a (alpha) Proteobacteria

•Caulobacter. Stalked bacteria found in lakes

•Hyphomicrobium. Budding bacteria found in lakes

budding releases genetic material to other cell and the cell that receives it is not similar to the parent cell

The a (alpha) Proteobacteria

•Nitrobacter and Nitrosomonas

•Chemoautotrophic:

• Oxidize nitrogen for energy

• Fix CO₂

  • Nitrobacter. NH₄⁺ to NO₂^–

  • Nitrosomonas. NO₂^– to NO₃

The a (alpha) Proteobacteria

•Nitrogen-fixing bacteria:

• Azospirillum

  • Grow in soil, using nutrients excreted by plants

  • Fix nitrogen

• Rhizobium

  • Fix nitrogen in the roots of plants

nitrogen in the soil- crop rotation

The b (beta) Proteobacteria

•Thiobacillus

• Chemoautotrophic, oxidize sulfur: H₂S  to SO₄^2–

The b (beta) Proteobacteria

•Neisseria

• Chemoheterotrophic, diplococci

• Inhabit mucous membranes of mammals

• N. meningitidis

• N. gonorrhoeae

•Spirillum

• Chemoheterotrophic, helical spirochetes

• In fresh water

The b (beta) Proteobacteria

•Bordetella

• Chemoheterotrophic, rods, whooping cough

• B. pertussis

•Burkholderia. Nosocomial infections, grow in disinfectants, contaminate drugs equipment and durgs in hospitals

•Zoogloea. Slimy masses in aerobic sewage-treatment processes

The g (gamma) Proteobacteria

•Pseudomonas

• Opportunistic pathogens

• Metabolically diverse

• Polar flagella

•Azotobacter and Azomonas- Nitrogen fixing

•Moraxella -Conjunctivitis-inflammation of membrane the covers the eye and lines the eyelids

•The g (gamma) Proteobacteria

•Order-Enterobacteriales (enterics):

• Peritrichous flagella, facultatively anaerobic

  • Enterobacter\

  • Erwinia

  • Escherichia

  • Klebsiella

  • Proteus

  • Salmonella

  • Serratia- on catheters

  • Shigella

  • Yersinia

The g (gamma) Proteobacteria

•Pasteurella

• Cause pneumonia and septicemia, transmitted by dog and cat bites

•Haemophilus- in mucous

• Require X (heme) and V (NAD⁺, NADP⁺) factors

The e (epsilon) Proteobacteria

•Campylobacter

• One polar flagellum

• Gastroenteritis

The e (epsilon) Proteobacteria

•Helicobacter pylori

• Multiple flagella

• Peptic ulcers

• may be associated with some stomach cancers

cyanobacteria

•Nonproteobacteria, gram-negative

•Oxygenic photosynthesis

•Gliding motility

•Fix nitrogen

Purple and Green Photosynthetic Bacteria

•Anoxygenic (not producing oxygen) photosynthesis

•Purple and green sulfur bacteria

Phylum- Chlamydia

•Transmit to human by interpersonal contact or by respiratory routes

•C. trachomatis

• Trachoma-blindness in human

• STD, urethritis

•C. pneumoniae

•C. psittaci

• Causes respiratory disease psittacosis (ornithosis)

Phylum-Spirochaetes

•Coiled morphology, endoflagella (axial filamets)

•Borrelia (Lyme disease-transmitted by ticks or lice

•Leptospira (from water – urine of dogs, rats and swine)

•Treponema (Treponema pallidum- cause of syphilis)

Phylum- Fusobacteria

•Fusobacterium

• Found in mouth and intestine

• May be involved in dental diseases

Phylum Firmicutes order Clostridiales

•Low G + C Gram positive bacteria

•Clostridium

• Endospore-producing

• Obligate anaerobes

Order-Bacillales

Bacillus

• Endospore-producing rods

  Staphylococcus

• Clusters of Cocci

Order-Lactobacillales

•Generally aerotolerant anaerobes, lack an electron-transport chain

• Lactobacillus

• Streptococcus

• Enterococcus

• Listeria

Order-Mycoplasmatales

•Wall-less, pleomorphic

•Lack a cell wall

•0.1 - 0.25 µm

M. pneumoniae

Domain Archaea

•Hyperthermophiles

• Pyrodictium

• Sulfolobus

•Methanogens

• Methanobacterium

•Extreme halophiles

• 2000 m deep in the ocean

• Halobacterium

Microbial Diversity

•PCR indicates up to 10,000 bacteria/gm of soil. Many bacteria have not been identified or characterized because they:

• Haven't been cultured

• Need special nutrients

• Are part of complex food chains requiring the products of other bacteria

• Need to be cultured to understand their metabolism and ecological role