Part 4: Diversity of Bacteria Flashcards
Cyanobacteria size
Larger than bacteria
Cyanobacteria forms
Unicellular, filamentous, or branching filamentous
What do some cyanobacteria form?
Heterocysts
Heterocysts are
Specialized nitrogen fixing cells
All cyanobacteria carry out
Oxygenic photosynthesis
Oxygenic photosynthesis
Harvest energy from light and produce oxygen
All cyanobacteria are
Autotrophs
Autotrophs
Fix CO2 to build cell material
Where do cyanobacteria carry out photosynthesis?
Thylakoids
What do cyanobacteria have that chloroplast don’t have?
Cell walls
What do cells of cyanobacteria contain?
Peptidoglycan
Gram negative cell wall type
Where do cyanobacteria reside in?
Terrestrial, freshwater, and marine habitats
What organism has the lowest nutritional requirement?
Cyanobacteria (primary producers)
Example of cyanobacteria
Prochlorococcus
What is one of the most abundant organisms on Earth?
Prochlorococcus
How much of prochlorococcus’s photosynthesis accounts for the world’s ocean?
Half
What group does most of the commonly encountered bacteria fall into?
Proteobacteria
Proteobacteria use what kind of metabolism?
Chemolithotrophs
Chemoorganotrophs
Phototrophs
Facultative organisms that can switch from one metabolic lifestyle to another
What are the well-studied groups of Proteobacteria?
Alpha, Beta, Gamma
What group of proteobacteria is the strange group?
Delta and Epsilon
What group of Proteobacteria only have one known species?
Zetaproteobacteria
Alphaproteobacteria include
Pathogens and non-pathogens
Alphaproteobacteria example of a non-pathogen
Rhizobium leguminosarum
What do Rhizobium leguminosarum form on legume plants?
Root nodules
What do Rhizobium leguminosarum do for legume plants?
Fix nitrogen into a bioavailable form
Alphaproteobacteria example of a pathogen
Rickettsia rickettsii
Rickettsia rickettsii is what kind of pathogen?
Obligate intracellular
How does Rickettsia ricketsii travel?
By insects through their bites
What do Rickettsia ricketsii cause?
Rocky mountain spotted fever
What is the closest relative to eukaryotic mitochondria?
Rickettsia
Betaproteobacteria example of non-pathogen
Neisseria mucosa
Where do Neisseria mucosa reside?
On mucous membranes
Betaproteobacteria example of pathogen
Neisseria gonorrhoeae
What group of bacterium grows well in lab?
Gammaproteobacteria
Example of Gammaproteobacteria
Escherichia coli
Pseudomonas aeruginosa
What kind of respiration does E. coli use?
Facultative aerobe
What kind of flagella does E. coli have?
Petrichous
What does E. coli ferment?
Lactose to a mixture of acids and alcohols
Where do E. coli reside?
Large intestine of warm-blooded animals
What kind of flagella does Pseudomonas aeruginosa have?
Polar flagella
Does P. aeruginosa ferment sugars?
No
What kind of pathogen is P. aeruginosa?
Opportunistic pathogen - causes infections in immunocompromised patients
What kind of infection does P. aeruginosa cause in cystic fibrosis patients?
Respiratory tract infections
Example of Deltaproteobacteria
Myxococcus xanthus
What kind of motility does M. xanthus have?
Gliding
How is M. xanthus a predator?
Releases exoenzymes to lyse other bacteria for nutrients
What happens when M. xanthus is starved?
Cells migrate together to form complex multicellular fruiting bodies?
Myxospores
M. xanthus individual cells that differentiate for dispersal
Firmicutes have what kind of cell walls
Gram positive
Firmicutes lack what nitrogenous bases?
Guanine and cytosine
Firmicutes include
Both lactic acid bacteria and non-lactic acid bacteria
Lactic acid bacteria fermentation produces
Lactic acid as an end product
Examples of lactic acid Firmicutes
Lactobacillus delbrueckii
Streptococcus pyogenes
Lactobacillus delbrueckii is used in
Yogurt production
Streptococcus pyogenes causes
Strep throat, scarlet fever, and the flesh-eating disease
Examples of non-lactic acid firmicutes
Staphylococcus aureus
What kind of respiration does S. aureus use?
Facultative aerobe
What kind of clusters does S. aureus form?
Grape-like
Where does S. aureus live?
On skin
What is special about S. aureus?
They are halotolerant - can be isolated using media with high NaCl like mannitol salt agar
What is a frequent cause of nosocomial infections?
S. aureus
Endospore forming Firmicutes include
Bacillus and Clostridium
Bacillus are what kind of endospore formers?
Aerobic
Clostridum are what kind of endospore formers?
Anaerobic
Where are endospore formers usually found?
In soil
What are most endospore formers?
Non-phagocytic saprophytic soil organisms
Bacillus subtilis are used as a model for
Gram positive cell structure and genetics
Cell division and differentiation (into endospores)
Where does C. botulinum live?
Tiny anoxic pockets in soil
What does C. botulinum secrete?
A variety of exoenzymes to degrade plant material
What does C. botulinum produce?
Deadly neurotoxin which causes botulism
Proper canning procedures must either
Reach temp above 120C to destroy endospores
Include enough acid or sugar to prevent germination
Tenericutes are known as
The Mycoplasmas
Mycoplasmas are related to
Gram positives
Mycoplasmas stain
Gram negative because they don’t have a cell wall
What shape are Mycoplasmas?
Pleomorphic - variety
Mycoplasma genitalium is the common cause of
Urethritis and pelvic inflammatory disease
M. genitalium was the first
Free-living bacterium to have its genome sequenced
Size of M. genitalium
Very small - 500 kbp
Actinobacteria are gram
Positive
Actinobacterium have high amount of what nitrogenous baases?
Guanine and Cytosine
Actinobacterium include
Coryneform bacteria
Mycobacteria
Corynebacterium produce
An exotoxin that inhibits protein synthesis that cause tissue death in the respiratory tract - diptheria
Mycobacteria cell wall
Modified gram positive cell wall - layer of mycolic acids outside the peptidoglycan layer - makes them acid fast
Mycobacterium tuberculosis growth
~24 hr/gen
M. tuberculosis take how long to grow on agar medium?
Weeks
Filamentous Actinobacteria
Streptomyces
Streptomyces form
Branching hyphae and mycelia
Hyphae produce
Reproductive spores for dispersal - conidia
Streptomyces use what kind of respiration
Obligate aerobes
Streptomyces live in
Well aerated soils
What gives soil its earthy smell?
Geosmins produced by Streptomyces
What do Streptomyces produce?
Substances that kill or inhibit the growth of other microbes - antibiotics
Streptomyces griseus produces
Streptomycin - a broad spectrum protein synthesis inhibitor active against Gram negative bacteria
Bacteroidetes
Large, heterogenus phylum of Gram negative bacteria
Bacterioidetes have what in common?
Not much at all
Bacteroides thetaiotaomicron uses what kind of respiration?
Strict anaerobe
B. thetaiotaomicron lives where?
Large intestine of humans
B. thetaiotaomicron produces
Enzymes to degrade polysaccharides - greatly increasing the variety of plant polymers that can be digested by the human gut
Chlamydiae have what kind of cell wall type?
Gram negative that lacks peptidoglycan
What kind of parasite is Chlamydiae?
Obligate intracellular
Life-cycle forms of Chlamydiae
Elementary and reticulate body
Elementary body
Small dense cell, resists drying
Allows infection of new host cells
Reticulate body
Larger vegetative cells
Multiply inside an existing host but are not infective
Chlamydia trachomatis causes what
Trachoma - infection of eye that can cause scarring and blindness
Planctomycetes are what kind of bacteria?
Budding and appendaged
What does Planctomycetes use their stalk for?
Attachment
Cell wall of Planctomyces lack
Peptidoglycan
What is unique about Planctomycetes cell?
Some have membrane-bound compartments
Gemmata obscuriglobus nucleoid
Surrounded by a true-unit membrane
What suggest that the last LUCA may have been a hyperthermophiles?
Several deeply branching phyla
Deinococcus-thermus species
Thermus aquaticus
Deinococcus radiodurans
Thermus aquaticus metabolism
Chemoorganoheterotroph
Thermus aquaticus source of temperature stable enzymes
Taq DNA polymerase
Taq DNA polymerase allows
DNA synthesis reactions in the lab to be carried out quickly at high temperatures
Taq DNA polymerase is an essential tool for
PCR (polymerase chain reaction)
Deinococcus radiodurans is extremely resistant to?
Radiation
Deinococcus radiodurans have highly effective
DNA repair mechanisms
Deinococcus radians form
Pairs or tetrads in response to massive DNA damage
Can fuse nucleoids from two cells to facilitate repair
Deinococcus radians cell wall type
Gram negative but stain gram positive because of thick peptidoglycan