Unit 4 Flashcards
5 phyla in Bacteria
- Proteobacteria
- Firmicutes, Tenericutes, Actinobacteria
- Bacteroidetes
- Chlamydiae, Planctomycetes, Verrucomicrobia
- Hyperthermophilic bacteria
- other
Proteobacteria
- largest metabolic diversity
- highest significance in medicine, agriculture, industry
- metabolic: aerobic, anaerobic, microaerophilic, chemolithotrophs, chemoorganotrophs, phototrophs
- based on 16S r RNA
5 classes of Proteobacteria
- alphaproteobacteria
- betaproteobacteria
- gammaproteobacteria
- deltaproteobacteria
- epsilonproteobacteria
- zetaproteobacteria
alphaproteobacteria
- rhizobia- plants symbionts
- Rhizobium
- Rickettsia
- Caulobacter
rhodopseudomonas
nitrobacter - genes enable them to form nodules acquired through HGT
- Agrobacterium tumefaciens associated with plants (cannot form root nodules)
- genes involved in gall disease nonrelated to nodule formation genes
Rickettsia rickettsii
Rocky Mountain spotted fever
- obligate, intracellular parasite
- metabolically specialized to use glutamate or glutamine as energy source
Wolbachia pipientis
colonize insect eggs
- obligate, intracellular parasite
- metabolically specialized to use glutamate or glutamine as energy source
betaproteobacteria
Burkholderia
Neisseria
Nitrosomonas
- Burkholderia cepacia
- soil organism
- opportunistic pathogen
- disease protection (promote plant growth)
- form biofilms (problem in hospitals)
Neisseriales
- Neisseria meningitidis
- Neisseria gonorrhoeae
Neisseria meningitidis
fatal inflammation of membranes of lining the brain
Neisseria gonorrhoeae
causative agent of gonorrhea
Methylophilales
Methylophilus methylotrophus
Nitrosomonadales
Nitrosomonase europea
Nitrosopira sp.
gammaproteobacteria
largest and most diverse
well-known pathogens
Enterobacteriales
“enteric bacteria”
fermentation - SLP
E. coli
gammaproteobacteria
- nutritional role in intestinal tract (K)
- helps O2 consumption in gut (anoxic)
- pathogenic strains (uti, diarrhea)
- enterohemorrhagic E coli strain (enterotoxin- foodborne disease)
Enterobacter aerogenes
gammaproteobacteria
- water and sewage
- intestional tract
- urinary tract
Klebsiella pneumoniae
gammaproteobacteria
- soils and water
- humans
- fixes N2 - unique in enteric bacteria
Salmonella
gammaproteobacteria
- always pathogenic
- typhoid fever and gastroenteristis
Proteus
gammaproteobacteria
- highly motile
- urease
- causes UTI
Shigella dysenteriae
gammaproteobacteria
- endotoxin
- invades epithelial cells
- excretes neurotoxin
- acute GIT distress
Pseudomonas aeruginosa
gammaproteobacteria
- burn victims, cystic fibrosis
- resistant to antibiotics bc of R plasmid
Vibrio cholerae
- gammaproteobacteria
causes cholera in humans
deltaproteobacteria
- sulfate reducers
- sulfur-reducers
- iron-reducers
- predator bacteria
famous deltaproteobacteria
bdellovibrio
myxococcus
desulfovibrio
geobacter
epsilonproteobacteria
helicobacter
campylobacter
- gram neg
- motile
- pathogenic
campylobacter
acute gastroenteritis
helicobacter pylori
pH adaptation in gut
- pathogen causes chronic/acute gastritis leading to peptic ulcers
- low pH triggers bacterial adaptation- urease enzyme (expressed)
- urease degrades urea to ammonia and CO2
- ammonia consumes H+ in cytoplasm- protect from acidification
zetaproteobacteria
Mariprofundus ferrooxydans
- microaerophilic
- Fe2+ = energy source
- O2 acceptor
- CO2 fixation
Firmicutes
lactic acid bacteria (LAB)
- gram pos known as main safe industrial-scale producers of lactic acid
Lactobacillus
lactobacillus delbrueckii
- prepare yogurt
streptococcus thermophilus
firmicutes
- acidification in cheese
- symbiotically grows in actobacillus delbrueckii
streptococcus pyogenes
strep
streptococcus viridans
mutants causing dental caries
streptococcus
- complete b-hemolysis (pyrogenes group)
- round shaped colonies with smooth surface - incomplete b-hemolysis (viridans group)
- greening agar under colonies
famous genera of non sporulating bacteria
listeria
staphylococcus
listeria
listeria monocytogenes
- vector for cancer immunotherapy
staphylococcus epidermidis
nonpathogenic organism
on skin or mucous membranes
staphylococcus aureus
pathological conditions like pneumonia, osteomyelitis, meningitis, arthritis
famous sporulating bacteria
bacillus
clostridium
only in Firmicutes
what is the advantage to being in soil?
produce endospores
bacillus thuringiensis
fatal in insects
- genes for crystal protein introduced to genetically modified crops to create GMO plants resistant to insects
Clostridium
SLP
degrade cellulose
cellulolytic species have cellulosomes
- cellulosomes: complex multienzyme structure on outer surface of cell, binds insoluble cellulose and degrades into soluble products
clostridium butyricum
ferment sugar
produces butyrate
clostridium aceticum
ferments sugar
produces acetic acid
clostridium botulinum
causes botulism
clostridium tetani
tetanus
clostridium perfringens
gangrene
actinobacteria
soil and plant bacteria
harmless commensals except Mycobacterium tuberculosis
streptomyces
antibiotic producing species
- spores created from hyphae allowing for survivla
- spores called CONIDIA
- different than spores from Bacillus and Clostridium
propionic acid bacteria
dairy industry
- in Swiss cheese
- fermenting to produce CO2
- homofermentative streptococci and lactobacilli makes lactic acid
- PAB uses lactic acid as substrate
mycobacteria
Mycobacterium tuberculosis
- T7SS: landmark, characteristic cell wall
- complex branch-chain hydroxylated lipids- mycolic acids
Bioprospecting in Graveyard
- healing soil tested by QUinn
- looking for new antibiotics to treat growing problem of drug-resistant bacteria
- found streptomyces bacteria
- contain new antibodies
- three dangerous pathogens could be killed by antibodies
Tenericutes
- no cell walls
- one of smallest
- mycoplasmas bc most notable genus is Mycoplasma
- doesnt stain gram pos bc lack cell wall
mycoplasma
- cell membrane more stable
- stability due to sterols
- lipoglycans in cell membrane are specific polysaccharides in membrane that stabilizes
Bacteroidetes
normal commensals in intestinal tract
- dominant bacteria in large intestine
- bacterial enzymes increases diversity of plant polymers that can be degraded in digestive tract
- Sphingolipids - no lipid backbone- sphingosine
fibre vs non-fibre diet response
- low fibre = more Bacteroidetes = changes gut chemical enviro which affects cellular signaling and cause cancer
- microbes eat intestinal mucosa = ulcerative colitis
- increase Firmicutes with high fiber
Chlamydia
Chlamydiae
- shared common ancestor
- based on 16S r RNA
- obligatory intracellular parasites and human pathogens
- small genome - characteristics for parasite
life cycle of chlamydiae
type 1: elementary body
type 2: reticulated body
type 1
dense
dry-resistant
- transmission
type 2
less dense
non-infectious
- multiplying (binary fission)
Chlamydia trachomatis
trachoma and genital infections
some gene eukaryotic (HGT)
- no peptidoglycan
- Chlamydia anomaly
what is Chlamydia susceptible to?
penicillin antibiotics
produces PBP
Planctomycetes
extensive cellular compartmentalization
- gemmata
- stalked and budding bacteria
what do ICT compartments resemble?
organelles
what is the key difference between prokaryotic and eukaryotic cells?
compartmentalization of cellular space through organelles
Gemmata
contains pirellulosomes
nucleoid with circular DNA
nucleoid and ribosomes in pirellulosomes
what kind of DNA is in prokaryotes?
covalently closed, circular and supercoiled
what kind of DNA is in eukaryotes?
highly condensed
partitioned from remaining cytoplasm by true unit membrane
Planctomycetes sp.
budding bacterium
2 poles of cell
swarmer cell w flagellum
stalked bacterium
cell wall and cytoplasmic filled stalk
Caulobacter crescentus
alphaproteobacteria
- budding bacterium
- 2 poles of cell
- swarmer cell with flagellum
- stalked bacterium
- proteinogenic stalk
Brocadia anammoxidans
anaerobic oxidation of ammonia within anammoxosome structure
- anammoxosome membrane made of ladderane lipids
- anammoxosomes protect cytoplasmic components from toxic intermediates
Verrucomicrobia
- symmetric cell division, prosthecae
Prosthecobacter
2 genes with significant homology to genes that encode tubulin in eukaryotic cells
-share more homology
tubulin homolog
FtsZ
- key protein making up cytoskeleton of eukaryotic cells
Hyperthermophilic bacteria
aquifex
thermotoga
thermodesulfobacterium
- evolutionary old
aquifex
most thermophilic of all known
H2 or S^0 as e donor
O2 or nitrate as e acceptor
- obligately chemolithotrophic and autotrophic
- cannot oxidize organic compounds
thermotoga
anaerobic metabolism (H2 as donor Fe3+ as acceptor)
hot springs
hydrothermal vents
over 20% of genes originated from Archaea by HGT
- fermentation
thermodesulfobacterium
strict anerobe
orgnaics as e donor
sulfate as acceptor
ether-linked lipids
- C17 hydrocarbon with fatty acids
Phylum Deinococcota
Deinococcus radiodurans
Thermus aquaticus
Deincoccus radiodurans
most radiation-resistant
survives 5000 Gy
mechanism of resistance is v active DNA repair system
Thermus aquaticus
source of heat-resistant enzyme Taq DNA polymerase
best = 65-70
survives = 50-80
many heat-stable enzyme isolated
- source of key enzyme in automated PCR
