Download - 3. Phylum Proteobacteria
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria
GRAM NEGATIVE BACTERIAWide morphological and metabolic diversity.
Clinical, environmental, and industrial relevancePhylum with highest number of cultured representatives
5 groups (based on 16S rRNA): a, b, g, d, and e
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
2. Phylum Proteobacteria
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.1. a-Proteobacteria: Rhizobium
N2 fixing organisms:
Some cyanobacteria (Bacteria)Some anoxygenic phototrophs (Bacteria)Some chemolithotrophs (Bacteria/Archaea)Some chemoorganotrophs (Bacteria/Archaea)
Some chemoorganotrophs (Bacteria)
FREE LIVING
SYMBIONTS
E.g. symbionts of leguminous
plants
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.1. a-Proteobacteria: Rhizobium
RECOGNITION
NOD FACTORS
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.1. a-Proteobacteria: Rhizobium
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.1. a-Proteobacteria. Agrobacterium
pTi
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.1. a-Proteobacteria: “acetic acid bacteria”
They oxidize sugars and alcoholsAcidophilic
Acetobacter
Gluconobacter
H20 O2
ETHANOL
ETHANAL
ACETIC ACID
e- e-
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.1. a-Proteobacteria: Caulobacter
Prosthecae: cytoplasmic extrusions (stalks, hyphae, or appendages)Budding division (mother cells retain their original identity)Attachment, increased surface-to-volume ratio, reduced cell sinking Aquatic bacteria (either planctonic or benthonic)
PROSTHECAE
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.2. b-Proteobacteria. Neisseria
Aerobic diplococcusPenicillin sensitivePathogens and normal microbiotaCarrier state
N. meningitidis (“meningococcus”)
Aerosols
Nasopharynx
Blood stream:Meningitis
(sudden onset of headheache, vomiting and stiff neck)
Intravascular coagulation shock
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.2. b-Proteobacteria: Neisseria
N. gonorrhoeae (“gonococcus”)
- Very sensitive to environmentalstress (drying, sunlight, UV light…)- High incidence (STD, ETS) - Mild symptoms* in women(asymptomatic carriers). PID- Complications if untreated
Sexual contact
Mucous membranes of the genitourinary tract
Reasons?
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.2. b-Proteobacteria. Acidithiobacillus
Thiobacillus ferrooxidans
Chemolithotroph: donor: Fe2+ / acceptor: O2
They use large amounts of substrate (they fix CO2)
pH acidic (acidiphilic)
Acid mine drainage (formation of H2SO4 and Fe3+) (O2, water and bacteria)
Biolixiviation
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.2. b-Proteobacterias. Zooglea
WASTEWATER TREATMENT
BOD:Biological Oxygen Demand
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.3. g-Proteobacteria: Legionella
RodsComplex nutritional requirements (Fe)Resistent to b-lactamicTerrestrial and aquatic habitatsWaterborne, aerosols (no person-to-person)
Cases per 100.000 inhabitants. Spain
Emerging disease (1976)
L. pneumophilaLEGIONELLOSIS
Pontiac feverPneumonia
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.3. g-Proteobacteria: Legionella
Legionella inside an alveolar macrophage
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.3. g-Proteobacteria: Haemophilus
Haemophilus influenzae
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.3. g-Proteobacteria: Pseudomonas
More than 100 speciesSome species utilize over 100 different compoundsAerobic chemoorganotrophic rods• Some chemolitotroph (H2, CO)
• Some anaerobic (NO3- / fermentation)
Sugar oxidation: Entner-Doudoroff pathwayFluorescent pigments
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.3. g-Proteobacteria: Pseudomonas
Opportunistic pathogen; intrahospitalary infections Resistence plasmids (plasmids R)
Respiratory tract infectionsSkin infectionsBacteremiaEndocarditisJoint infectionsFastrointestinalinfectionsUTIEye infectionsCNS infectionsUpper respiratory tract infections
Cystic fibrosis complications
Pseudomonas aeruginosa
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.3. g-Proteobacteria: Pseudomonas DEGRADATIVE
MEGAPLASMIDS
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.3. g-Proteobacteria: Family Enterobacteriaceae
Enteric bacteria
Facultatively aerobic, gram negative rods• Fermentation of sugars to organic acids
• Some respire NO3- to NO2
- (never to N2)
Virulence factors and pathogenicity
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.3. g-Proteobacteria: Family Enterobacteriaceae
Escherichia
Warm blooded animalsGut microbiota (comensals)Pathogenic strains: E. coli enterotoxigenic (ECET) E. coli enteropathogenic (ECEP) E. coli enterohemorrhagic (ECEH) (STEC)
E. coli O157:H7 E. coli O104:H14
GastroenteritisHemolytic uremic syndrom (HUS)
Urinary tract infections (UTI)
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
vitamin K
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.3. g-Proteobacterias. Familia Enterobacteriaceae
Salmonella
Habitat: gastrointestinal tract of wild and domestic animals, birds, pets, and insects. Zoonosis.Main pathogenic serovars: S. typhimurium: salmonellosis (enterocolitis) S. typhi: typhoid fever
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.3. g-Proteobacteria: Family Enterobacteriaceae
Shigella
Reservoir: infected gutS. dysenteriae: - Shigellosis or bacillary dysentery (“disentería bacilar”) - HUS
Shigella cells invading intestinal epithelium
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.3. g-Proteobacteria: Family Enterobacteriaceae
Buboes (“bubones”)
Gangrene and black spots (“black death”)
Bacteria in lung tissue
Yersinia: Y. pestis PLAGUE (bubonic, pneumonic and speticemic). Zoonotic disease.
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.3. g-Proteobacterias: Vibrio
Curved and straight rodsAquatic mediaMany species, some pathogenic: V. cholerae: cholera
CHOLERA TOXIN
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.3. g-Proteobacteria: Photobacterium
FMNH2 + O2 + RCHO FMN + RCOOH + H2O + luzNADH
NAD+
FMN
luciferase
Autoinduction: “quorum sensing”
Inducer molecule: acyl homoserine lactone (AHL)
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.4. d-Proteobacteria: Bdellovibrio
“Predator” of other bacteria
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.4. d-Proteobacteria: SULFATE (AND SULFUR) REDUCING BACTERIA (SRB)*
Desulfo- (generally) or Desulfuro-They reduce sulfate/sulfur(acceptors)Final products: H2S
Strict anaerobes (anoxic environments)Group I:
Acetate cannot be used as donor
Sulfate reducing bacteria
Group II:
H2 and acetate can be used as donors
Sulfate reducing bacteria
Fixation of CO2 (acetil-CoA pathway)
Group III:
H2 or organic matter as donors
S and sulfite reducing bacteria (NEVER sulfate)
DonorsH2 O. M.
*Some sulfate-reducing bacteria are not delta-proteobacteria
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.4. d-Proteobacteria: SULFUR AND SULFATE REDUCING BACTERIA
m.o.
NO3-
Mn+4
Fe+3
SO4-2
CO2
E’ (V
)
+0.8
-0.2
0
Stratification of electronic acceptorsLimited organic matterMost important metabolism: sulfate reductionCompetence (or not---) with methanogenic Archaea
Marine sediments
Consortia of SRB/methane oxidizing Archaea
O2
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.4. d-Proteobacteria: MYXOBACTERIA
Vegetative cells: long rods without flagella (names: Myxo…). Gliding.Fruiting bodies: cell-to-cell communication and differentiation
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.5. e-Proteobacteria: Campylobacter and Helicobacter (both microaerophilic)
Campylobacter: acute gastroenteritis, food borne disease (chicken meat…)
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
Helicobacter: gastritis and ulcers
http://www.nobelprize.org/nobel_prizes/medicine/laureates/2005/marshall-lecture.pdf
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.6. OTHER PROTEOBACTERIA: NITRIFYING BACTERIA
a, b, g , and d ProteobacteriaElectron donors: NH4
+ and NO2- / Acceptor: O2 (Nitroso…/ Nitro…)
They consume large amounts of substrate: chemolithoautotrops/ chemolithoheterotrophs Soils and waters; ammonia-rich sites; leaching of NO3
-
NH4+ NO2
- NO3-
Nitrosomonas Nitrobacter
AMO: ammonia monooxygenase
NOR: nitrite oxidoreductase
Nitrification
Nitrospira (independent phylum)Nitrifying Archaea
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.6. OTHER PROTEOBACTERIA: SULFUR OXIDIZING BACTERIA
a, b, g, e Proteobacteria
Donors: H2S, S0, S2O32-, metallic suflides, H2 / Acceptor: O2 (sometimes NO3
- )
S0 accumulation inside or outside the cell
Acidithiobacillus: acidiphilic (A. ferrooxidans FeS2, Fe2+); autotrophs
Thiomargarita: anaerobic oxidation (acceptor: NO3-)
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014Hydrothermal vents: H2S, H2, CO2, O2, N2...
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.6. OTHER PROTEOBACTERIA: PURPLE BACTERIA
Anoxygenic phototrophs
Reaction centre: bacteriochlorophyllsAntenna pigments: BChl + carotenoids
Photosynthetic systems: invaginations of the cytoplasmatic membrane
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
e-
BChl EXCITED
BChl
BASAL
Eo (-)
Eo (+)
LIGHT NO external electron donors for ATP
ATP: Cyclic photophosphorilation
H+H+
cte-
e-
BChl EXCITED
BChl BASAL
External electron donors for NAD(P)H
NAD(P)H: Reverse electronic flow
H+H+
cte-
H2SS0
Fe2+
S0
SO42-
Fe3+
NAD(P)+
NAD(P)He-
3. Phylum Proteobacteria3.6. OTHER PROTEOBACTERIA: PURPLE BACTERIA
Images property of Fernando Santos
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
g-Proteobacteria (“purple sulfur bacteria”): highly sensitive to O2; highly tolerant to [H2S]
S compounds as electron donors. Photoautotrophs (Calvin cycle) Photoheterotrophs
N2 fixers
a/b-Proteobacteria (“purple nonsulfur bacteria”): more tolerance to O2; very sensitive to high [H2S]
Chenoorganotrophs, Photoheterotrophs, photoautotrophs
N2 fixers
Anoxic areas blooms
Sulfide-rich waters(SRB)
3. Phylum Proteobacteria3.6. OTHER PROTEOBACTERIA: PURPLE BACTERIA
Meromictic lakes, microbial mats
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
Metabolic diversity of nonsulfur purple bacteria
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
Microbial mats: stratification of microbial populations driven by environmental gradients
Images property of Fernando Santos
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.6. OTHER PROTEOBACTERIA: METHANOTROPHS
Methylotrophs vs. methanotrophs
Biotic and abiotic methane
Methanotrophs vs. methanogens
Where does the methane come from?
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
Type I Type II
3. Phylum Proteobacteria3.6. OTHER PROTEOBACTERIA: METHANOTROPHS (Methylo…)
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
Methane as energy source
Methane monooxygenase
Methano Methanol Formalhehyde CO2
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
Ribulose monophosphate pathway
Serine pathway
Type IIType I
Methane as carbon source
Methane Methanol Formalhehyde biomass
L. 6: Bacteria Domain (II). 2nd Biology ARA 2013-2014
3. Phylum Proteobacteria3.6. OTHER PROTEOBACTERIA: RICKETTSIAS
a/g ProteobacteriaObligate intracellular parasites*Induce phagocytosis, do not survive outside hostsHighly specific energy metabolism*, synthesize few compoundsTransmitted by arthropod vectorsDamage to blood vessels
Epidemic tifus (Rickettsia prowazekii) Vector: human louse
Rocky Mountains spotty fever (Rickettsia rickettsii) Vector: tick
*Q Fever (Coxiella) Vectors: tick, aerosols, dairy productsOne bacteria is enough!! (Biological weapon)
Fever, headheach, weaknessRash
Organ infectionsHigh mortality untreated
*Exception