Chapter 11 Flashcards
Tell me 5 things you know about Proteobacteria
- Name is from the mythological Greek God Proteus, who could assume many chapes
- Proteobacteria are gram-negative. (What does this mean?)
- Chemoheterotrophic (organisms that use organic molecules as a source of carbon and energy)
- Largest taxonomic group of bacteria
- Five Classes
- Alphaproteobacteria
- Betaproteobacteria
- Gammaproteobacteria
- Deltaproteobacteria
- Epsilonproteobacteria
Name 1 characteristic of the Alphaproteobacteria and then the bacteria that fall under this category (7 total)
- Found in low-nutrient aquatic environments
- Caulobacter
- Hyphomicrobium
- Rhizobium and Bradyrhizobium
- Argobacterium
- Nitrobacter and Nitrosomonas
Describe the characteristics of Caulobacter.
What class does it belong under?
- Produces two types of cells: swarmer and stalked
- Reproduce via budding rather than binary fission
- Belongs under Proteobacteria: Alphaproteobacteria
Which class of Proteobacteria are found in low-nutrient aquatic environments?
Alphaproteobacteria
Describe the characteristics of Hyphomicrobium and indicate which class it belongs in.
- Reproduction by budding
- Hypha or prothesca grows out of one end and bud grows at the tip of prostheca
- Belongs to the Alphaproteobacteria class
Describe the characteristics of Rhizobium and Bradyrhizobium and indicate which class they belong in.
- Fix nitrogen in the roots of leguminous plants
- Known by the common name of rhizobia
- Part of the Alphaproteobacteria class
Describe the characteristics of Nitrobacter and Nitrosomonas and indicate which class they belong to.
- Chemoautotrophic (uses inorganic chemicals as energy source (instead of light); CO2 as carbon source
- Plays important role in Nitrogen Cycle
- Nitrosomonas: NH4+ ► NO2-
- Nitrobacter: NO2- ►NO3-
Describe the characteristics of Agrobacterium and indicate which class they belong to.
- Plant pathogen; causes crown gall (think of those tumors on stalks of plants)
- Inserts a plasmid into plant cells, inducing a tumor
- Belongs to Alphaproteobacteria
Name the 3 bacteria under the class of Betaproteobacteria.
- Spirillum
- Sphaerotilus
- Bordetella
Describe the characteristics of Spirillum and indicate which class it belongs to.
- Found in freshwater
- Move via flagella
- A part of the Betaproteobacteria class
Describe the characteristics of Sphaerotilus and indicate which class it belongs to.
- Found in freshwater and sewage
- Form sheaths to aid in protection and nutrient gathering
- A part of the Betaproteobacteria class
Describe the characteristics of Bordetella and indicate which class it belongs to.
- Non-motile rods
- B. pertussis: causes whooping cough
- Part of the Betaproteobacteria class
Name the three main orders under Gammaproteobacteria
- Pseudomonadales
- Enterobacteriales
- Pasteurellales
Describe the characteristics of Pseudomonadales and indicate which class they belong to.
- Pseudomonas (genus of Gammaproteobacteria)
- Opportunistic pathogens; nosocomial infections
- Metabolically diverse
- Polar flagella; common in soil
- P. Aeruginosa: wound and urinary track infections
What can you tell me about Enterobacteriales?
- Commonly called enterics - they inhabit the intestinal tract; ferment carbohydrates
Can you name all 10 enterobacteriales discussed in the powerpoint for Chapter 11?
- Shigella
- Klebsiella
- Serratia
- Escherichia
- Salmonella
- Proteus
- Yersinia
- Erwinia
- Enterobacteria
- Cronobacter
Which Enterobacteriales causes bacillary dysentery?
Shigella
Which Enterobacteriales causes pneumonia?
Klebsiella - K. pneumoniae
What are nosocomial infections?
Which Enterobacteriales is the most common cause of nosocomial infects?
Nosocomial infections: is an infection that is acquired in a hospital or other health care facility.
Part of the Serratia Genus. Produces red pigment and is the common cause of nosocomial infections.
Which genus of Enterobacteriales causes E.coli?
Escherichia: E. Coli: indicator of fecal contamination; causes foodborne disease and urinary tract infections
Which genus of Enterobacteriales has a species that causes thyphoid fever? What is the species name?
Salmonella
- 2400 serovars
- Common form of foodborne illness
- Salmonella typhi (S. typhi) causes typhoid fever
Remember Typhoid Mary?
Which genus of Enterobacteriales forms colonies of concentric rings?
Proteus
- Swarming motility; colonies form concentric rings
Which genus and species of Enterobacteriales caused the plague?
How was the plague transmitted?
Yersinia
- Y. pestis causes plague
- Transmitted via fleas
What are plant pathogens?
Which genus of Enterobacteriales has plant pathogens?
Plant pathogen: a disease-causing organism which attacks plants.
Genus: Erwinia
Crown Rot is a good example
Which specie(s) and genus of Enterobacteriales cause urinary tract infections and nosocomial infections?
Enterobacter
- E. Cloacae and E. aerogenes cause urinary tract infections and nosocomial infections
Which genus and species of Enterobacteriales causes meningitis?
Cronobacter
- Discovered in 2007
- C. sakazakii causes meningitis; found in a variety of environments and foods
What do you know about Pasteurellales?
- Part of the Enterobacteriales class
- Species: Pasteurella
- Pathogen of domestic animals
- P. multocida is transmitted to humans via animal bites
- Haemophilus
- Require X factor (heme) and V factor (NAD+ NDAP+) in media
- H. influenzae causes meningitis, earaches, and epiglottitis
- Species: Pasteurella
Which genus of Deltaproteobacteria attacks other gram-negative bacteria?
Bdellovibrio
Which class does the genus Myxococcales belong to? What does myxo mean? What are the characteristics of this genus?
- Belongs to Deltaproteobacteria class
- Myxo = mucus
- Characteristics:
- Move by gliding and leaving a slime trail
- Cells aggregate and form a fruiting body containing myxospores
Can you explain the 6 steps of the Myxobacteria fruiting body?
- Myxospores
- Mysxospores are resistant resting cells released from sporangioles upon favorable conditions
- Germination
- Myxospores germinate and form gram-negative vegetative cells, which divide to reproduce
- Vegetative Growth Cycle
- Vegetative myxobacteria are motile by gliding, forming visible slime trails
- Aggregation
- Underfavorable conditions, the vegetative cells swarm to central locations, forming an aggregation
- Mounding
- Aggregations of cells heap up into a mound, an early fruiting body
- Mounds of myxobactreia differentiate into a mature fruiting body, which produces myxospores packed within sprangioles
Describe the physical characteristics and oxygen needs of Epsilonproteobacteria. Name two genus.
helical or curved; microaerophilic (some oxygen, but not too much!)
- Campylobacter (pictured)
- One polar flagellum
- C. jejuni causes foodborne intestinal disease
- Helicobacter
- Multiple flagella
- Causes peptic ulcers and stomach cancer
Which class and genus/species of Proteobacteria causes peptic ulcers and cancer?
Epsiloproteobacteria
- Campylobacter
- C. jejuni
What are heterocysts?
Specialized nitrogen-fixing cells formed during nitrogen starvation by some filamentous cyanobacteria
What can you tell me about Cyanobacteria?
- It’s the Oxygen Photosynthetic Bacteria!
- Carry out oxygenic photosynthesis
- Many contain heterocysts that can fix nitrogen
- Gas vesicles that provide buoyancy
- Unicellular or filamentous
What are gloeoclapsa?
A genus of cyanobacteria. Groups of these cells, which divide by binary fission, are held together by the surrounding glycocalyx.
What are the anoxygenic photosynthetic bacter classes?
What do you know about them?
The Phyla Chlorobi and Chloroflexi
- Carry out anoxygenic photosynthesis
- Green sulfur: phylum Chlorobi
- Green nonsulfur: Phylum Chloroflexi
- Purple sulfur and purple nonsulfur photosynthetic bacteria are proteobacteria