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Bacteria - Microbial diversity (Week 11) - Coggle Diagram
Bacteria - Microbial diversity (Week 11)
Background
There are 55 bacterial phyla
More with candidatus status
Process of recognition
Identified based on 16S rRNA sequencing
Heterogenous samples
~90% from 4 Phyla
Proteobacteria
Pseudomonadota
Actinobacteria
Actinomycetota
Firmicutes
Bacillota
Bacteroides
Bacteroidota
Deep-branching bacteria (Diverged early on)
Aquificae / Aquificota
Flagella
Motile
Non-spore
Gram negative
Conditions
Hyperthermophile
80 - 120°C
Extremophile
Chemolithoautotrophs
Inorganic
Oxygenic requirements
Microaerophilic
Requires only little concentrations of oxygen
High concentrations of oxygen is poisonous
Anaerobic
Thermotogae / Thermotogota
Gram negative
Loose protein sheath
Protection against harsh conditions
Conditions
Hyperthermophile
Gained from horizontal gene transfer (From archaea)
Extremophile
Chemo-organotrophic
Anaerobic
Deinococcota / Deincoccus-Thermus
Unusual cell wall
Two membranes
Thick
Conditions
Aerobic
Heterotrophic
Two varying conditions for spp. (Subspecies)
Thermus spp. - Thermophiles
Deinococcus spp. - Resistance
UV
Ionising Radiation
Both extremophiles
Chloroflexi / Chloroflexota
Green non-sulfur
Does not require sulfur for it's metabolic processes
Key feature
No outer membrane
Therefore, mainly gram negative
Morphology
Long filamentous
Conditions
Moderate thermophiles
Aerobic
Photoheterotrophic
Unable to use Carbon dioxide as a source of carbon
Requires organic compounds (aside from CO2)
Anoxygenic
Cyanobacteria
Metabolism
CO2 fixation
Nitrogen fixation
Absorption spectrum (Pigments or Morphology)
Blue - Green
Brown - Green
Red
Habitat / Medium
Aquatic
Terrestrial
Proteobacteria / Pseudomonadata (Phyla)
α (Alpha)
Consisting of 10 orders
Mainly anaerobes
Prefers low nutrient habitats / mediums
Examples
Rhizobiales
Largest / Most common
Diverse
Conditions
Phototrophic
Chemolithotrophic
Methlyotrophic
Metabolism
Nitrogen fixation
e.g. Batonella spp.
Human pathogen
Rickettsiales
Parasite
Obligate
Intracellular
e.g. Rickettsia spp.
β (Beta)
Containing 6 orders
Examples
Burkholderieales
Highly diverse
Burkholderia spp.
Agriculture beneficial
Pathogenic
Others
Neiserriales
Nitrosomonadales
Hydrogenophiles
Rhodocylales
Methylophilales
γ (Gamma)
Diverse in metabolism
Phototrophic
Purple sulfur
Chemolithotrophic
Used in
Medical
Scientific
Example: Enterobacteriales (Enteric bacteria)
Habitat
Intestines
Soil
Water
Metabolism / Nutrition
Facultative anaerobe
Chemoorganotrophs
Pathogenic
Includes / Examples
Salmonella
E. coli
Shigella
Proteus
Enterobacter
Klebsiella
Serratia
Yersinia
δ (Delta)
Sulphate / Sulfur-reducing
Bacteriovore
Myxococcales
Bdellovibrionales
Metabolic cooporation
Syntrophobacterales
H2 production
Consumed by others
ε (Epsilon)
Examples
Campylobacterales
Campylobacter
Food-bourne pathogen
Helicobacter
Stomach ulcers
Usually sulphur oxidisers
Mainly known by rRNA sequencing
No identifiable phenotypic features
ζ (Zeta)
More metabolically specialised
Conditions
Obligate Fe(II)-oxidisers
Microaerobic
Habitats
Estuarine
Border between freshwater and seawater
Brackish water
Marine
Spirochaetota (Phyla)
Morphology
Helical / Spiral shape
Spirilla
Endo-flagella
Corkscrew-like motion
Movement
Gram-negative
Conditions
Facultative/ Anaerobic
Examples
Treponema pallidum
Responsible for disease
Yaws
Syphilis
Bejel
Borrelia burgdorferi
Lyme disease
Leptospira
Leptospirosis
Transmission
Contaminated water
Animal urine
Chlamydiota (Phyla)
Metabolism
Parasitic
Obligate
Intracellular
Pathogenic
Conditions
Aerobic
Morphology
Small genome
Gram-negative
Causes / Effects
Eye disease
STI
Firmicutes / Bacillota (Phyla)
Morphology
Majority are gram-positive
Low G-C content in the genome
Shape
Cocci
Bacilli
Conditions
Facultative anaerobe mostly
"Lactic acid bacteria"
Produces Lactic acid
e.g. Milk spoilage
Specialisation in fermentation
Genera - Bacillales and Clostridium
Produces endospores, to survive in harsh conditions
Includes the genera
Bacillales
Releases endospores, grows in diverse habitats
Lactobacillales
Lactic acid bacteria
Used in
Fermentation
Probiotics
Clostridiales
Obligate anaerobe
Pathogenic
Actinobacteria / Actinomycetota (Phyla)
Morphology
Gram-positive
High G-C content
Genome
Conditions
Habitats
Soil-dwelling
Aquatic
Facultative anaerobe
Heterotrophic
Cellulose
Lignin
Chitin
Spore-forming
Includes / Examples
Streptomyces
Used in
Antibiotics
Industrial enzymes
Morphology
Filamentous
Hyphae
Mycobacterium
Waxy cell wall
Slow growing
Pathogenic
Propionibacterium
Causes
Acne
Used in
Cheese production
Bacteroides / Bacteroidetes (Phyla)
Morphology
Gram-negative
Diet / Nutrients
Complex polysaccharides
Includes / Examples
Bacteroidales
Obligate anaerobe
Lives in the intestines
Flavobacteriales
Conditions
Aerobe
Aquatic
Psychro
-philes
-tolerants
Degrades organic matter