week 9 microbial diversity Flashcards
What are the three broad categories of bacteria?
- gram positives
- proteobacteria (gram-negative) and nonporteobacteria
- gram negative
What are the subcategories of gram-negative?
- cyanobacteria
- planctomycetes
- bacterodies
- thermotoga
- aquifex
Which bacteria are similar to archaea?
low hanging bacteria on the phylogentic tree
How are bacteria categorized? (like the system)
phylum
class
order
family - 16S RNA sequencing
genus - 16S
species - 16S
strain - shotgun metagenomic sequencing
gram stain
- (pink) or + (purple) is a classical staining technique
electron microscopy
- shown more nuance and complexity
- see physical strcuture of cell and its cell wall
What is a “better” way to classify bacteria?
The amount of plasma membranes a bacteria can have
monoderm
- Have only one plasma membrane and gram +
- gains a outermembrane
diderm
- has two membranes -plasma membrane and outer membrane
What is the difference between proteobacteria and non-proteobacteria?
- non-proteobacteria does photosynthesis
What are the characteristics of non-proteobacteria?
- a group of bacteria that contains photosynthetic bacteria
- Gram-positive and negative bacteria
- photoautotrophs and chemoheterotrophs-
What are the characteristics of proteobacteria
- a domain of bacteria that includes medical and scientifically important species
- gram-negative bacteria only
- facultative or obligatory anaerobe, chemolithotroph, and heterotrophic
What are microbial hyperthermophiles?
- extremophiles (survive in extreme conditions) and not archea
- chemoautotrophs but is gram-negative and non-proteobacteria
What are the two types of microbial hyperthermophiles?
- aquifex pyrophilus
- thermotga
what is aquifex pyrophilus?
- microaerophilic (requiring very little free oxygen) rod and growth optimum 85C
What is a thermotoga?
- a rod with an expansive stage, outer-sheath-like envelope - the toga (looser fitting sheath made up of proteins to hep it survive)
- The outer membrane is enriched in protein
- can grow on methanol and acetate
What is a class of phylum deinococcota?
- deinococci - isolated in soil around nuclear plants which will have a thick wall that makes it highly resistant to radiation
- spherical or rod-shaped
- often seen in pairs of tetrads
- resistant to desiccation (extremely dry) and radiation
is deinococci gram positive or negative?
- it is classified as negative because it is a diderm but because it has a thick cell wall it will retain the stain and will strain gram-positive
How do photosynthetic bacteria differ?
- pigment, morphology electron donors, metabolic types, and motility
How are photosynthetic bacteria differentiated?
if they carry out oxygenic or anoxygenic photosynthesis
What types of photosynthesis do cyanobacteria do? Characteristics?
- Oxygenic
- two photosystems
- water as an electron donor and generates oxygen
- largest and most diverse group of photosynthetic bacteria
What bacteria perform anoxygenic photosynthesis? Characteristics?
- purple, green bacteria and aerobic anoxygenic phototropic bacteria (AAnPs)
- one photosystem
- alternate electron donor to water (like H2S or H2)
Where are Bacteroidota and Fusobacteira found? What are the characteristics of fusobacteira?
- includes photoautotrophs and chemoheterotrophs found in the gut and oral cavity
- genus bacteroids found in poop
– fusobacteira - characteristic spindle-shaped, and can cause opptrunistic infections in huma
What are the morphology characteristics of chlamydiae? type of?
- gram-negative, coccoid, non-motile
- obligate intracellular parasites - rely on a host for metabolites small genome, so they can not make carbs or synthesize ATP or NAD+
what is the type of bacteria of phylum spirochaetota? functions?
- chemoorganotrophic bacteria with a periplasmic flagella
What are the 5 sub-classes of proteobacteria?
Alphaproteobacteria
Betaproteobacteria
gammaproteobacteria
deltaproteobacteria
eplisonproteobacteria
zeta proteobacteria - only one member so not really counted
How are alphaproteobacteria characterized?
- nitrogen-fixing, agrobacterium, marine
- most are oligotrophic - low nutrient environments
- metabolically diverse- methylotrophs, chemolithotrophs, and nitrogen fixers
What is an example of a class of alphaproteobacteria?
- Rhodobacterales is polar flagella - purple non-sulfur bacteria (uses light energy and has a relationship with nitrogen)
- rhodospiralles
What are the characteristics of betaproteobacteria?
- occupy the diverse environment - from obligate pathogens to oligotrophic groundwater
- burkholderiales, ammonia-oxidizing, arsenic resistant soil bacteria
What are the three genus of betaproteobacteria?
- thiobacilus
- neisseria
- bordetella
What is a thiobaclius?
- habitat?
- type of troph?
- soil freshwater and marine habitats
- chemolithotrophs - oxidize sulfur compunds
what is a Neisseria?
- non-motile, aerobic, cocci
- many form pairs with side flattened
- gonerherra and menigenitis
What is bordetella?
- aerobic, motile, coccibacili
- chemoogranotrophs
- mammalian parasites that multiply in respiratory epithelial cells
- whopping cough and kennel cough
what is the major definer of delta proteobacteria?
- anerobic (desulfovibrio- deep into soil )
- aerobic - predator or gliding
How are deltaproteobacteria characterized?
- ferric iron-reducing, sulfur-reducing
- categorized by if aerobe or anearobe
- strictly anaerobic branch contains most of the known sulfate/sulfur reducing bacteria
What are the two types of anaerobic delta proteobacteria?
- Bdellovibrio - a predator that invades another cell, colonizes it, consumes resources, eats away, replicates, and dips
- myococcus - gliding - which produces digestive enzymes and uses gliding mechanisms to go through the wreckage of E. coli and consume it
What are the characteristics of gammaproteobacteria?
- defined based on metabolism and ecological niechc
- the largest bacteria class
- photolithotrophs, enterics and pathogens
- Pseudomonas, Xanthomonas, acidithiobacilus
What are gammaproteobacteria best known for?
- Enterobacteriaceae
- facultative anaerobes
- chemoorganotrophs
- family includes E. Coli
What are family vibronacea? (gammaproteobacteria)
- aquatic biolumanitic bacteria and pathogens
- luminescent bacteria - quorum signaling
- vibro parahaemolyticus - gasteroenteris in humans from contaminated seafood
- vibrio cholera; causes cholera
what are the two orders of gammaproteobacteria?
- psudomonadales (pseudomonas)
- legionellaes
what are the characteristics of pseudomonas?
- motile by polar flagella
- aerobic chemoorganotrophs
- can degrade a wide variety of organic molecules
- 2nd causal factor of UTI
what is legionellaes?
- intracellular pathogens (natural host for amoeba)
- dimorphic lifestyle - protozoa
- genus L. pneumophila causative agent - legionnaires disease
What are the characteristics of epsilionbacteria?
- inhabits the digestive tract of animals and serves as symbionts or pathogens
- microbes that are specific in their growth pattern
What are the two categories of epsilonproteobacteria? examples of each?
- polar flagella - campylobacter
- peritrichous flagella - helicobacter
what is campylobacter?
- C. fetus - reproductive disease in cattle and sheep
- use molecular mimicry to turn the immune system against the host
what is helicobacter?
- cause gastritis, peptic ulcer disease, and gastric cancer
- microaerophile - cannot grow under ph 4.5
- BURROWS INTO GASTRIC mucosa, secretes urea (converts urea to CO2 + NH3), which drives up the local pH
What is a feature of proteobacteria?
- magnetotatic
- intracellular magnets align themselves with the earth’s magnetic field
- occupy freshwater or marine sediments
- highly motile to orient themselves on the magnetic field
- identified in alpha, gamma and delta
what are the three morphologies gram positives differentiated by?
- bacilli
- cocci - streptococcus
- branching filaments
what is the order of branching filaments?
- Actinomycetota
- chemoorganohetrotrophs
- facultative or strict anaerobes (requires co2)
- makes hyphae
what is an example of Actinomycetota?
Bifidobacterium
- non-motile, non-sporing and anaerobic
- important in human gut microflora
what is a family of Actinomycetota?
- Mycobacteriaceae
- straight or slightly curved rods that branch or form filaments
- diderm cell envelope (stains positive)
what is mycomembrane?
- external to peptidoglycan
- constructed of packed mycolic acids, complex fatty acids
- hydrophobic and impenetrable to antibiotics
- requires porins for entry into cell wall
two diseases caused by Mycobacteriaceae?
TB and leprosy
what are the Firmicutes genus?
- bacillus
- clostridiales
What is bacillus?
- endospore-forming, chemohetrototrophic rods
- produce various antibiotics
- motile with peritrichous flagella
examples of bacillus
- B. subtilis - mosy well studied gram postive
- B. cererus - food poisoning
- B. anthracis - anthrax
- B. thuringiensis - insecticide
what are clostridiales?
- forms heat-resistant endospores
- responsible for many cases of food spoilage
Examples of clostridiales?
- C. Botulism
- C. tetani - tetanus
- C. difficle - gastrointestinal tract disease
Two families of streptococcus?
- staphylococcus
- streptomycetes
What is staphylococcus?
- faculative anerobeic, nonmotile cocci
- normally associated with warm-blooded animals in skin and mucous membranes
- cause many human disease (MRSA)
streptomycetales?
- example of true multicellularity
- among the largest bacterial genomes - complex life cycle
- can hemolyse - enter blood and kill
what is the trait that Enter and streptococcaceae share?
- strictly fermantive
enterococci
- enterococcus faecalis - normal resident of intestinal tracts of humans and many animals, opportunistic pathogen
