Lecture 4A Flashcards
(30 cards)
largest and most metabolically diverse phylum of Bacteria, and constitute the majority of known bacteria of medical, industrial, and agricultural significance
Proteobacteria
what are the diff. generating mechanisms of Proteobacteria
- chemolithotrophic,
- chemoorganotrophic
- phototrophic
Six classess of Proteobacteria
Alpha-
- Beta-
- Gamma-
- Delta-
- Epsilon-
- Zetaproteobacteria
The single known species in Zetaproteobateria
Mariprofundus ferrooxydans (Italicized)
- a marine oxidizing bacterium
2nd largest class of Proteocbacteria
mostly obligate aerobes or facultative anaerobes
Alphaproteobacteria
Orders under Alphaproteobacteria
RRRRCS
-Rhizobiales
-Rickettsiales
-Rhodobacterales
-Rhodospirillales
-Caulobacterales
-Sphingomonadales
Largest and most metabolically diverse order of Alphaproteobacteria and contain phototrophs. chemolithotrophs, symbionts, free-living nitrogen-fixing bacteria.
Rhizobiales
Key genera under Rhizobiales
- Bartonella
- Methylobacterium
- Pelagibacter
- Rhizobium
- Agrobacterium
Metabolism of Rhizobiales order?
mostly obligate aerobes and facultative aerobes
Genera that has the ability to form root nodules
- Bradyrhizobium
- Ochrobactrum
- Azorhizobium
- Devosia
- Methylobacterium
- Mesorhizobium
- Phyllobacterium
- Sinorhizobium
- Rhizobium.
Key general of Rickettsiales
Rickettsia, Wolbachia
all obligate intracellular parasites or mutualists of animals.
Not yet cultivated in the absence of host cells
Rickettsiales
are transmitted by
arthropod bites
Rickettsia and Ehrlichia
are obligate parasites or mutualists of insects and other arthropods.
Wolbachia and other genera
Diseases caused by Rickettsia
Typhus (Rickettsia prowazekii)
Rocky mountain fever (Rickettsia rickettsii)
What are the key metabolic limitations of Rickettsias?
- Can oxidize only glutamate and glutamine
- Unable to synthesize essential metabolites
Why is Rickettsias obligate intracellular parasites?
- Metabolic fragility
- Short survival outside hosts
Key genera of Other groups of Alphaproteobacteria
- Rhodobacter,
- Acetobacter
- Caulobacter
- Sphingomonas
orders that contain metabolically diverse organisms
Rhodobacterales and Rhodospirillales
- are typically oligotrophic and strictly aerobic chemoorganotrophs.
- Species typically form prosthecae or stalks , and many species display asymmetric forms of cell division.
Caulobacterales
- include diverse aerobic and facultatively aerobic chemoorganotrophs as well as species of aerobic anoxygenic phototrophs
Sphingomonadales
about 500 described species
- third largest class of proteobacteria
Betaproteobacteria
Six orders of Betaproteobacteria
- Burkholderiales
- Hydrogenophilales
- Methylophilales
- Neisseriales
- Nitrosomonadales
- Rhodocyclales
is the type genus for the Burkholderiales
Burkholderia
