Bacterial Diversity Flashcards
(87 cards)
1
Q
What are the three domains?
A
- Bacteria
- Archaea
- Eukarya
2
Q
What revolutionised classification?
A
16S rRNA phylogenetic
3
Q
Where is the prokaryotic taxonomy catalogues?
A
Bergey’s Manual of Systematic Bacteriology
4
Q
How are bacteria distinguished?
A
By Gram stain
5
Q
What are the types of Gram stain?
A
- Gram-positive
- Gram-negative
6
Q
What is a Gram-positive?
A
- Very simple cell wall structure
- Does not involve outer phospholipid bilayer
- Thick outer layer of peptidoglycan
- Stain purples
7
Q
What is a Gram-negative?
A
- Phospholipid bilayer
- Thinner layer of peptidoglycan
- Thicker phospholipid bilayer (asymmetric)
- Stains pink
8
Q
Which Gram stains pink?
A
Gram-negative
9
Q
Which Gram stains purple?
A
Gram-positive
10
Q
How do you have a greater speciation in some genera?
A
Using multigene analysis
11
Q
How is there better speciation in some genre by using multigene analysis?
A
16S rRNA is further divided by multi locus sequences typing picking genes around the genome
12
Q
What type of Gram is proteobacteria?
A
Gram-negative
13
Q
How is proteobacteria divide?
A
- Alpha - α
- Beta-β
- Gamma - γ
- Delta - δ
- Epsilon - ε
14
Q
Describe proteobacteria:
A
- Metabolically diverse
- Many environmental habitats (symbiont/nitrogen-fixers/aquatic environment)
- Major human pathogens exhibit chemotrophy under aerobic conditions
15
Q
What is an alpha proteobacteria?
A
Rhizobiales
16
Q
What are the genus of Rhizobiales?
A
Agrobacterium
Bradyrhizobium
Nitrobacter
Rhizobium
17
Q
What feature does Agrobacterium have?
A
Plant pathogen
18
Q
What feature does Bradyrhizobium have?
A
Symbiotic nitrogen fixer
19
Q
What feature does Nitrobacter have?
A
Nitrifying
20
Q
What feature does Rhizobium have?
A
Symbiotic nitrogen fixer
21
Q
What do Bradyrhizobium/Rhizobium do?
A
- Form symbiosis with plants
- Fix nitrogen to ammonia
22
Q
What is a beta proteobacteria?
A
Neisseriales
23
Q
What are the genus of Neisseriales?
A
Neisseria
24
Q
What are the features of neisseria?
A
- Human pathogen
- Characteristic diplococci
- Medically important species (Meningitis/gonorrhoea)
25
What is a gamma proteobacteria?
Enterobacteriales
26
What are the genus of Enterobacteriales?
Shigella
Escherichia
Salmonella
27
What are the features of Shigella/Salmonella?
- Human pathogen
| - Responsible for serious food poisoning
28
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)
29
What are Enterobacteriales?
- Largest sub-group of the proteobacteria
| - Most pathogenic species in this group
30
What is a delta proteobacteria?
Spirilla
31
What are the genus of Spirilla?
Bdellovibrio
32
What are the features of Bdellovibrio?
- Uses other bacteria as a host
- Curved bacteria
- Potential antimicrobial (wide spread in soils and aquatic environments)
33
What is an epsilon proteobacteria?
Campylobacterales
34
What are the genus of Campylobacterales?
Campylobacter
| Helicobacter
35
What are the features of Campylobacter?
- Human pathogen
- Highly motile bacillus, curved
- Medically important species (foodborne disease)
36
What are the features of Helicobacter?
- Human pathogen
- Has multiple flagella
- Causes stomach ulcers
37
What Gram is bacteriodetes an example of?
Gram-negative
38
What are the four major orders of Bacteroidetes?
- Sphingobacteriales
- Cytophagales
- Flavobacteriales
- Bacteroidales
39
What are the types of Gram-positive bacteria divided?
- Low G+C
| - High G+C
40
On what bases are Gram-positives divided?
Based on the %GC content in the genome
41
Is this a high or low G+C?
| atagagctaa ttattggaaa agataaaaag gggataagaa taaataaagt tcctttacaa
Low G+C
42
Is this a high or low G+C?
| acaatgggcg caagcctgat gcagcaacgc cgcgtgaggg acgacggcct tcgggttgta
High G+C
43
What are low G+C known as?
Firmicutes
44
What are high G+C known as?
Actinobacteria
45
What are the different orders of low G+C?
- Lactobacillales
- Bacillales
- Clostridiales
46
What are the genus of Lactobacillales?
Lactobacillus
| Streptococcus
47
What are the genus of Bacillales?
Straphylococcus
| Bacillus
48
What are the genus of Clostridium?
Clostridium
49
What are Lactoballius and Streptococcus members of?
Lactic acid bacteria
50
What are lactic acid bacteria?
- Produce lactic acid during metabolism
| - Tolerant to low pH
51
What acidic by-products are produce from Straphylococcus, Bacillus and Clostridium?
- Butyric acid
- Propionic acid
- Acetic acid
52
What are the features of Lactobacillus?
- Lactic acid produces
- Human commensal (fermented products - yogurts)
- Variable size
53
What does lacto mean?
Milk
54
What does bacillus mean?
Rod shaped
55
What are the features of Streptococcus?
- Many human pathogens
- Human commensals
- Medically relevant (subdivide by haemolytic)
56
What does strepto mean?
Twisted chain
57
What does coccus mean?
Spherical/round
58
What are the features of Staphylococcus?
- Some human pathogens
| - Medically important pathogens (boils, produces toxin/MRSA)
59
What does Staphyl mean?
Grape
60
What are the features of Bacillus?
- Rod shape
- Endospores (enables survival during extremes of environments)
- Human pathogens
- Medically important
61
What are the features of Clostridium?
- Anaerobes
- Endospores
- Human pathogen
- Location of spores help to identify the species
- Medically important
62
What an order of high G+C?
Actinomycetales
63
What are the genus of Actinomycetales?
Actinmyces
Frankia
Streptomyces
64
What are the features of Actinmyces?
- Filamentous
- Branching
- Human pathogen
- Facultative anaerobe
- Look like fungal hyphae under microscope
- Important fro soil ecology
65
What are the features of Frankia?
- Symbiotic nitrogen fixers
- Filamentous
- Carry out nitrogen fixation in soil
- Atmospheric N to ammonia
66
What are the features of Streptomyces?
- Filamentous
- Produce antibiotics
- Form mucelium
- Produce sports called conidia
- Occurs during nutrient depletion
67
Are conidia the same as endospores?
NO
68
What is must commons sub-division containing many human pathogens?
γ- proteobacteria
69
Why do we know so much about the Gram negative Proteobacteria, Bacteroidetes and Gram positive Firmicutes?
They are easily cultural and grown in the lab
70
How can we study non-culturable bacteria?
- Culture independent analyses
- Assess phylogeny into species group
- FISH (Fluorescent in situ hybridisation)
71
What is culture independent analysis to identifying non-culturable bacteria?
fluorescent oligonucleotides bind specific DNA
72
What are examples of fluorescent oligonucleotides?
- DAPI
- Acridine orange
- SYBR Green 1
73
What is assess phylogeny/classify bacteria into species group to identifying non-culturable bacteria?
Phylogenetically classify non-culturable bacteria you need to study the 16S rRNA gene of the bacteria
74
What is FISH in relation to identifying non-culturable bacteria?
Different coloured oligonucleotides match different 16S rRNA sequences
75
What is an ecosystem?
Sum of all organisms and abiotic factors in a particular environment
76
What is symbiosis?
Mutualism and commensalism
77
How is mutualism symbiosis?
Both species benefit
78
How is commensalism symbiosis?
One species benefits, the other neither harmed nor benefited
79
What is syntrophy?
Two or more organisms catabolising a nutrient that can not be catabolised by one on its own
80
What is an example of commensalism to mutualism?
Bacteria living in our large intestine supply us with vitamin K
81
What is species richness?
The total number of species present in an ecosystem
82
What is species abundance?
The proportion of each species in an ecosystem
83
What are Archaea more suited to?
Extreme conditions below the photic zone
84
What is microbial ecology interaction with plants?
- Legume-root nodule symbiosis
| - Essential in fixing nitrogen and suppling to plants
85
What is microbial ecology interaction with mammals?
- Human microbiome project
| - Gut microbiome
86
What is facultative anaerobe?
Makes ATP via aerobic respirations if oxygen is present BUT can also do anaerobic respiration
87
What is obligate aerobe?
Cannot make ATP in absence of oxygen
