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brookie > MBIO 1010 final- lecture 7a > Flashcards

MBIO 1010 final- lecture 7a Flashcards

lectures 7-11

1
Q

what are the two ways to categorize microbial diversity?

A
  1. phylogenetic diversity
  2. functional diversity
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2
Q

what are archaea more similar to: eukarya or bacteria?

A

eukarya

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2
Q

how many known bacterial phyla are there?
archaea phyla?
eukaryotic super groups?

A

bacterial phyla: 92
archaea phyla: 26
eukaryotic super groups: 5

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3
Q

phylogenetic diversity

A

microbes are grouped into phyla based on evolutionary relationships
-often based on 16s (small ribosomal subunit) rRNA gene sequences

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4
Q

functional diversity

A

groups microbes based on the activities they carry out
-ex: anoxygenic phototrophs (seen in multiple phyla)
-ex: oxygenic phototrophy: only seen in one phylum

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5
Q

what group is in the phylum Tenericutes?

A

mycoplasmas

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6
Q

mycoplasmas, example ( 4)

A

-bacteria in the phylum Tenericutes
-phylogenetically related to gram positives, but lack a cell wall (NOT considered gram +)
-often pleomorphic (shapeless or changes shape); because of lack of cell wall
-ex: Mycoplasma genitalium

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7
Q

how do mycoplasmas stain in the gram stain

A

gram stain negative
-no peptidoglycan to trap crystal violet

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8
Q

Mycoplasma genitalium (3)

A

example of a Mycoplasma
-common cause of urethritis and pelvic inflammatory disease
-first free living bacteria to have its genome sequenced (very small genome)
-one of the smallest genomes known (500 kbp)

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9
Q

phylum Actinobacteria , groups (3)

A

-phylum of gram positive bacteria
-high GC (cytosine + guanine) gram +’s
-groups: coryneform bacteria, propionic acid bacteria, mycobacteria

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10
Q

coryneform bacteria, example (2)

A

-in the phlum Actinobacteria
-club shaped morphology
-example: Corynebacterium diptheriae

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11
Q

Corynebacterium diptheriae (3)

A

-produces an endotoxin that inhibits protein synthesis
-causes tissue death in the respiratory tract (diptheria)
-can lead to death by suffocation

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12
Q

propionic acid bacteria

A

group in the phylum Actinobacteria
-found in swiss cheese

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13
Q

mycobacteria , ex (3)

A

group in the phylum Actinobacteria
-have a modified gram positive cell wall (layer of mycolic acids outside of the peptidoglycan layer)
-makes them acid fast (gram stain does not work; appears blue)
-ex: Mycobacterium tuberculosis

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14
Q

Mycobacterium tuberculosis (3)

A

-very slow growing (24 hr/gen)
-colonies can take weeks to grow on agar medium
-cause of tuberculosis (slow and fatal respiratory disease)

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15
Q

Phylum filamentous Actinobacteria , example (7)

A

-filamentous gram positives
-form branching hyphae and mycelia (often mistaken for fungi)
-hyphae produce reproductive spores for dispersal (conidia)
-most are obligate aerobes
-live in well aerated soils (gives soil earthy smell; geosmins)
-produce antibiotics
-ex: Streptomyces griseus

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16
Q

Streptomyces griseus (2)

A

-produces Streptomycin
-broad spectrum antibiotic, inhibits protein synthesis of gram negative bacteria

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17
Q

how do filamentous Actinobacteria reproduce? (5)

A
  1. growth phase
  2. tip curls
  3. partitioning of tip
  4. cell wall thickens + constricts
  5. spores mature
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18
Q

geosmins

A

gives soil its earthy smell
-produced by Filamentous Actinobacteria

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19
Q

Phylum Bacterioidetes , example (4)

A

-large, heterogeneous (diverse) phylum of GRAM NEGATIVE bacteria
-aerobes and anaerobes
-few unifying characteristics (very diverse)
-ex: Bacteriodes thetaiotamoicron

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20
Q

Bacteriodes thetaiotamoicron (3)

A

in the phylum Bacterioidetes
-strict anaerobe
-numerically dominant in the human large intestine
-produces enzymes that degrade polysaccharides (increases the variety of plant polymers humans are able to digest)

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21
Q

Phylum Acidobacteria (5)

A

-makes up 20-50% of soil microbial community
-very little is known about them
-only recognized within the last 20 years
-difficult to cultivate
-first sequenced its genome in 2009

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22
Q

phylum Chlamydiae, example (4)

A

-gram negative cell wall type, but lack peptidoglycan
-obligate intracellular parasites
-unique lifecycle with two types of cells (elementary body + reticulate body)
-ex: Chlamydia trachomatis

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23
Q

lifecycle of Chlamydiae

A

unique lifecycle with two types of cells:

  1. elementary body: small, dense, dormant cells that resist drying up
    -allows for the infection of new host cells
  2. Reticulate body: larger vegetative cels, multiply inside an existing host
    -not infective (only elementary body is)
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24
Q

Chlamydia trachomatis (2)

A

-causes trachoma (infection of the eye)
-causes scarring and blindness

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25
Q

phylum Planctomycetes, example (5)

A

-budding and appendaged bacteria
-protein stalk is used for attachment
-lack peptidoglycan in cell wall
-some have membrane bound components in the cell wall (very uncommon in prokaryotes)
-ex: Gemmata obscuriglobus

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26
Q

Gemmata obscuriglobus

A

in the phylum Planctomycetes
-nucleoid is surrounded by a true-unit membrane (NOT a true membrane)

27
Q

Phylum Cyanobacteria, example (11)

A

-impressive morphological diversity, generally larger than other bacteria
-unicellular, filamentous, or branching filamentous
-some form heterocysts (specialized nitrogen-fixing cells)
-all carry out oxygenic photosynthesis
-all are autotrophs (fix CO2 to build cell material through the calvin cycle)
-carry out photosynthesis in thylakoids (specialized membranes)
-gram negative cell wall type; CONTAINS peptidoglycan
-widely distributed in terrestrial, freshwater, and marine habitats
-lowest nutritional requirements of any organisms (primary producers)
-can produce toxic blooms (effects nervous system, liver, skin, etc)
-ex: prochlorococcus

28
Q

what did cyanobacteria used to be called and why?

A

used to be called blue-green algae
-because they preform oxygenic photosynthesis
-commonly found in freshwater and marine habitats
-form toxic blooms

29
Q

Prochlorococcus (2)

A

in the phylum Cyanobacteria
-one of the most abundant organisms on earth
-accounts for roughly 1/2 of photosynthesis in ALL oceans

30
Q

Phylum Proteobacteria (3)

A

-includes many of the most commonly encountered bacteria
-most metabolically diverse phylum (includes chemolithotrophs, chemoorganotrophs, phototrophs, and facultative organisms)
-divided into six classes (beta, alpha, gamma, delta, epsilon, zeta proteobacteria)

30
Q

classes of Proteobacteria

A

-Alpha, Beta, Gamma: well studied with many important species
-Delta, Epsilon: smaller classes, broad range of phenotypes
-Zeta: has barely been studied, only one known species (marioprofundus ferrooxydans)

31
Q

Rhizobium leguminosarum (3)

A

in the class Alphaproteobacteria
-forms root nodules on legume plants; symbiotic relationship
-bacterium fixes nitrogen into a bioavailable form
-plant provides nutrients + a home for the bacterium

31
Q

Alphaproteobacteria , examples (3)

A

includes pathogens and non pathogens
-non pathogen example: Rhizobium leguminosarum
-pathogen example: Rickettsia rickettsii

32
Q

Rickettsia rickettsii (3)

A

in the class Alphaproteobacteria
-obligate intracellular pathogen, carried by insects and transmitted through insect bites
-causes rocky mountain spotted fever
-closest known relative to mitochondria (phylogenetically)

33
Q

what is the closest known relative to mitochondria

A

Rickettsia rickettsii (in the class Alphaproteobacteria)

34
Q

Betaproteobacteria, examples (4)

A

-includes pathogens and non pathogens
-metabolically diverse
-non pathogen example: Neisseria mucosa
-pathogen example: Neisseria gonorrhea

34
Q

Neisseria mucosa (2)

A

in the class Betaproteobacteria
-non pathogenic
-lives in mucous membranes in the human body

35
Q

Neisseria gonorrhea (2)

A

in the class Betaproteobacteria
-pathogenic
-causes gonorrhea

35
Q

Gammaproteobacteria, examples (4)

A

-metabolically and ecologically diverse
-many are important research models
-ex: Escherichia coli
-ex: Pseudomonas aeruginosa

36
Q

Escherichia coli (4)

A

in the class Gammaproteobacteria
-gram negative, rod shapes, facultative aerobes
-motile by peritrichous flagella
-ferments lactose to a mixture of acids and alcohols
-resident of the large intestine in warm blooded animals (indicator of fecal contamination)

37
Q

Pseudomonas aeruginosa (5)

A

in the class Gammaproteobacteria
-gram negative, rod shapes, polar flagella
-does not ferment sugars
-naturally resistant to many antibiotics and disinfectants
-opportunic pathogen (causes illness in immunocompromised patients)
-ex: respiratory tract of cystic fibrosis patients (cannot clear fluids/phlegm as efficiently)

38
Q

Deltaproteobacteria, examples (4)

A

-contains many species with strange behaviours
-example Myxococcus xanthus
-example Bdellovibrio bacteriovorous
-example Delsulovibrio

39
Q

Myxococcus xanthus (5)

A

in the class Deltaproteobacteria
-gliding motility (no flagella)
-PREDATORY: releases exoenzymes to lyse other bacteria for nutrients
-when starved, cells migrate together to form complex multicellular fruiting bodies
-individual cells differentiate into myxospores for dispersal
-two forms of motility: Adventurous (A), and Social (S)

40
Q

two forms of motility in Myxococcus xanthus

A
  1. “A” motility (adventurous): single cells can distribute
  2. “S” motility (social): single cells cannot move
    -work together and appear to travel in “waves”
41
Q

Delsulfobibrio (3)

A

in the class Deltaproteobacteria
-sulfate reducers
-obligate anaerobes
-some play a role in “oil well scouring” (creates toxin hydrogen sulfate; makes oil go bad)

41
Q

Bdellovibrio bacteriovorous (3)

A

in the class Deltaproteobacteria
-curved, highly motile predator of other proteobacteria and gram negative bacteria
-PARASITIC (uses macromolecules from its host)
-penetrates the cell wall and multiplies in the periplasm (between inner + outer membrane)

42
Q

Epsilonproteobacteria, example (3)

A

-small class
-famous for a new microaerophilic, spirillium shaped pathogens
-ex: Campylobacter jejuni

43
Q

Campylobacter jejuni (3)

A

in the class Epsilonproteobacteria
-transmitted in undercooked chicken
-one of the most common causes of food borne illness
-causes gastroenteritis and bloody bacteria

44
Q

Lactic acid bacteria, examples (3)

A

in the phylum Firmicutes
-aerotolerant anaerobes that produce lactic acid from fermentation
examples:
-Lactobacillus delbrueckii (yogurt)
-Streptococcus pyogenes (strep)

44
Q

Phylum Firmicutes, groups

A

second phyla of gram positives
-low GC gram positives
includes:
-includes lactic acid bacteria
-non lactic acid bacteria
-endospore forming firmicutes

45
Q

Lactobacillus delbrueckii

A

lactic acid bacteria in the phylum Firmicutes
-used in yogurt production

46
Q

Streptococcus pyogenes

A

lactic acid bacteria in the phylum Firmicutes
-causes strep throat, scarlet fever, and flesh eating disease
-different strains cause different illnesses

47
Q

Non-lactic acid bacteria, examples

A

in the phylum Firmicutes
examples:
-streptococcus aureus
-staphylococcus epidermidis

48
Q

Streptococcus aureus (5)

A

non-lactic acid bacteria in the phylum Firmicutes
-lives on human skin
-facultative aerobe
-forms characteristic grape-like clusters
-Halotolerant (can be isolated using mannitol salt agar; produces acids to turn plate yellow)
-frequent cause of nosocomial infections (infections acquired from a hospital)

49
Q

Staphylococcus epidermidis (2)

A

non-lactic acid bacteria in the phylum Firmicutes
-normal commensal on skin
-halotolerant (can be isolated on mannitol salt agar, but does not ferment mannitol; therefore plate remains pink)

50
Q

Endospore-forming firmicutes, examples (6)

A

-two best studies generas: Bacillis and Clostridium
-found primarily in soil
-most are non-pathogenic, Saprophytic (decomposer) soil organisms
-some can be dangerous pathogens
-ex: Bacillus subtilis
-ex: Clostridium botulinum

51
Q

Bacillus subtilis (4)

A

in the phylum Firmicutes (group endospore forming firmicutes)
-non pathogenic
-important lab bacterium, used to study:
1. Gram positive cel structure and genetics
2. Cell division and differentiation into endospores

52
Q

Clostridium botulinum (5)

A

in the phylum Firmicutes (group endospore forming firmicutes)
-strict anaerobe with fermentative metabolism
-lives in tiny, anoxic pockets in the soil
-secretes a variety of exoenzymes to degrade plant material
-can also grow in anaerobic canned foods (if not packaged properly)
-produces a deadly neurotoxin (causes botulism when consumed)

53
Q

Saprophytic

A

decomposing organisms

54
Q

two best studies genres of endospore forming firmicutes

A
  1. Bacillis (aerobic endospore formers)
  2. Clostridium (strictly anaerobic endospore formers)
55
Q

what is proper canning procedures to prevent botulism

A

must either:
1. Reach temps above 120C (to destroy endospores)
2. Include enough acid or sugar to prevent germination

56
Q

Phylum Hyperthermophilic bacteria, examples (5)

A

-deeply branching phyla
-all hyperthermophilic; thrive in very hot temps
-suggests that LUCA may have been a hyperthermophile (because of deep branches)
two famous species:
1. Thermus aquaticus
2. Deinococcus radiodurans

57
Q

Thermus aquaticus (4)

A

In the phylum Hyperthermophilic bacteria
-thermophilic chemo-organo-hetero-troph
-source of temperature stable enzymes (Taq DNA polymerase)
-allows for DNA synthesis reactions in the lab to be carried out quickly at high temperatures
-essential tool for PCR (polymerase chain reaction)

58
Q

Deinococcus radiodurans (5)

A

In the phylum Hyperthermophilic bacteria
-extremely resistant to radiation
-highly effective DNA repair mechanisms
-forms pairs or tetrads
-nucleoids from two cells can fuse to facilitate repair in response to massive DNA damage
-has gram negative cell wall type (but stains gram positive; thick peptidoglycan layer)

59
Q

what are the 11 bacteria phylas to know

A
  1. Tenericutes
  2. Actinobacteria
  3. Filamentous Actinobacteria
  4. Bacterioidetes
  5. Acidobacteria
  6. Chlamydiae
  7. Planctomycetes
  8. Cyanobacteria
  9. Proteobacteria
  10. Firmicutes
  11. Hyperthermophilic bacteria

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