Bacterial Diversity Flashcards
What are the three domains?
- Bacteria
- Archaea
- Eukarya
What revolutionised classification?
16S rRNA phylogenetic
Where is the prokaryotic taxonomy catalogues?
Bergey’s Manual of Systematic Bacteriology
How are bacteria distinguished?
By Gram stain
What are the types of Gram stain?
- Gram-positive
- Gram-negative
What is a Gram-positive?
- Very simple cell wall structure
- Does not involve outer phospholipid bilayer
- Thick outer layer of peptidoglycan
- Stain purples
What is a Gram-negative?
- Phospholipid bilayer
- Thinner layer of peptidoglycan
- Thicker phospholipid bilayer (asymmetric)
- Stains pink
Which Gram stains pink?
Gram-negative
Which Gram stains purple?
Gram-positive
How do you have a greater speciation in some genera?
Using multigene analysis
How is there better speciation in some genre by using multigene analysis?
16S rRNA is further divided by multi locus sequences typing picking genes around the genome
What type of Gram is proteobacteria?
Gram-negative
How is proteobacteria divide?
- Alpha - α
- Beta-β
- Gamma - γ
- Delta - δ
- Epsilon - ε
Describe proteobacteria:
- Metabolically diverse
- Many environmental habitats (symbiont/nitrogen-fixers/aquatic environment)
- Major human pathogens exhibit chemotrophy under aerobic conditions
What is an alpha proteobacteria?
Rhizobiales
What are the genus of Rhizobiales?
Agrobacterium
Bradyrhizobium
Nitrobacter
Rhizobium
What feature does Agrobacterium have?
Plant pathogen
What feature does Bradyrhizobium have?
Symbiotic nitrogen fixer
What feature does Nitrobacter have?
Nitrifying
What feature does Rhizobium have?
Symbiotic nitrogen fixer
What do Bradyrhizobium/Rhizobium do?
- Form symbiosis with plants
- Fix nitrogen to ammonia
What is a beta proteobacteria?
Neisseriales
What are the genus of Neisseriales?
Neisseria
What are the features of neisseria?
- Human pathogen
- Characteristic diplococci
- Medically important species (Meningitis/gonorrhoea)
What is a gamma proteobacteria?
Enterobacteriales
What are the genus of Enterobacteriales?
Shigella
Escherichia
Salmonella
What are the features of Shigella/Salmonella?
- Human pathogen
- Responsible for serious food poisoning
What are the features of Escherichia?
- Human commensal, some pathogens
- Common inhabitant of intestinal tract but uncommon pathogen
- Very important research tool (e.g E.coli)
What are Enterobacteriales?
- Largest sub-group of the proteobacteria
- Most pathogenic species in this group
What is a delta proteobacteria?
Spirilla
What are the genus of Spirilla?
Bdellovibrio
What are the features of Bdellovibrio?
- Uses other bacteria as a host
- Curved bacteria
- Potential antimicrobial (wide spread in soils and aquatic environments)
What is an epsilon proteobacteria?
Campylobacterales
What are the genus of Campylobacterales?
Campylobacter
Helicobacter