bacterial diversity and growth

Question 1

taxonomy

Answer 1

the science of classification. Identifies the relationships between groups of organisms. Can be used to identify novel species.

Question 2

taxa

Answer 2

categories of organisms

Question 3

relatedness is a result of

Answer 3

evolutionary history or phylogeny

Question 4

the three domain theory of classfication

Answer 4

originally based on physical difference by microscopy. Now done by genetics

Question 5

prokaryotes

Answer 5

no membrane bound nucleus of organs

Question 6

gram positive

Answer 6

purple and thick peptidoglycan retains the crystal violet

Question 7

gram negative

Answer 7

thinner peptidoglycan doesn’t retain the stained is counterstains with safranin

Question 8

operating into two groups is not enough

Answer 8

can be gram variable or indeterminate

Question 9

how can we study non cultural bacteria

Answer 9

culture independent analyses: fluorescent oligonucleotide that binds specific DNA
–> hard: you have to know what you are looking for to design oligonucleotides

Question 10

gram positive bacteria is further subdivided into

Answer 10

low G+C and High G+C based not he % of GC in genome

Question 11

low G+C known as

Answer 11

Firmicutes

Question 12

low GC content

Answer 12

30%- firmicutes

Question 13

hight GC content known as

Answer 13

actinobacteria

Question 14

high GC content

Answer 14

60-70% actinobacteria

Question 15

firmicutes

Answer 15

lactobacillus, streptococcus, staphylococcus, bacillus, clostridium

Question 16

lactobacillus and streptococcus are members of the lactic acid bacteria (LAB)

Answer 16

produce lactic acid during metabolism and tolerant to low pH

Question 17

staphylococcus, bacillus and clostridium produce other acidic by products e.g.

Answer 17

butyric acid, propionic acid, acetic acid

Question 18

lactobaccillus

Answer 18

• bacillus-rod shaped.
• variable in size
• imporntnat part of human gut flora

Question 19

staphylococcus

Answer 19

• coccus-round
• medically important
• s.aureus- boils proidec toxins
• MRSA
• commensal- S.epidermidis

found in the nose and harmless skin bacteria

Question 20

clostridium

Answer 20

• rod shaped
• forms endospores
• medically important
• C.tetani- tetnus
• C. botulinum
• C.difficile- hospita associated

Question 21

streptococcus

Answer 21

• ‘twisted chain’
• coccus
• Divide on a single axis therefore the rrogenitorcells grow in pairs or chains

Question 22

examples of high GC gram positives

Answer 22

actinomcyes
frank
streptomyces

Question 23

actinmycetales the order of:actinomcyes
frank
streptomycin… have a similar appearance to

Answer 23

fungus–> originally thought to be fungi before DNA technology

Question 24

frankia

Answer 24

filamentous, carry out nitrogen fixation in soils. Atmospheric N to ammonia

Question 25

streptomyces

Answer 25

- from mycelium - produce spores called conidia not same as endospores - important producers of antibiotics

Question 26

when do streptomycin produce antibiotics

Answer 26

during nutrient depletion therefore a survival mechanism for competition --> active against gram +ve and -ve bacteria and fungal infections

Question 27

actinmyces

Answer 27

facultative anaerobes. Looks like fungal hyphae under microscope. Important for soil ecology

Question 28

proteobacteria

Answer 28

gram negative bacteria

Question 29

proteobacteria- gram negative bacteria is subdivided into

Answer 29

alpha, beta, gama, delta, epsilon

Question 30

alpha

Answer 30

rhizobiales

Question 31

rhizobiales: Bradyrhizobium/ Rhizobium

Answer 31

Bform symbiosis with plants and fix nitrogen to ammonia

Question 32

beta

Answer 32

Neisseriales

Question 33

Neisseriales: Neisseria

Answer 33

diplococci. medically important - meningitis- carried by 95% of pop - -> gonorrhea

Question 34

gamma

Answer 34

Enterobacteriales

Question 35

enterobacteriales

Answer 35

shigella escherichia salmonella

Question 36

enterobacteriales: shigella and salmonella

Answer 36

responsible for serious good poisoning

Question 37

enterobacteriales escherichia

Answer 37

common inhabitant of intestinal tract but uncommon pathogen

Question 38

epsilon

Answer 38

Campylobacterales

Question 39

campylobacterales

Answer 39

campylobacter and helicobacter

Question 40

campylobacterales: campypylobacter

Answer 40

highly motile bacillus, curve- food born disease e.g. C.jejuni

Question 41

campylobacterales: helicobacter

Answer 41

has multiple flagella. causes stomach ulcers e.g. H pylori

Question 42

which is the most common proteobacteria (gram negative)

Answer 42

Y-proteobacteria- contains many human pathogens

Question 43

why is so much known about the gram negative proteobacteria and gram positive firmicutes?

Answer 43

they are easily cultured and grown in labs

Question 44

what needs to be studied to classify bacteria

Answer 44

the study of 16S rRNA. FISH- fluorescent in situ hybridisation. Different coloured oligonucleotides match diff 16s rRNA sequences. can identify the complexity of a bacterial group

Question 45

16s rRNA gene is

Answer 45

common in all bacteria, but varies slightly in its sequence between related species

Question 46

binary fission

Answer 46

a kind of asexual reproduction- fly grown parent cell splits into two halves- producing two new cells

Question 47

process of binary fission

Answer 47

- cell elongation - septum formation - completion of septum; formation of walls and cell separation

Question 48

B.subtilis

Answer 48

no cell wall constriction in binary fission

Question 49

Caulobacter

Answer 49

no septum formation in binary fission

Question 50

obligate aerobes

Answer 50

bacteria can only grow in oxic zones (oxygen rich)

Question 51

anaerobes

Answer 51

can only grow in anoxic zones

Question 52

facultative aerobes

Answer 52

can grow in both oxic and anoxic conditions--> however higher conc of bacteria in oxygen rich areas

Question 53

microaerophiles

Answer 53

prefer to grow in more oxic zones

Question 54

aerotolerant

Answer 54

has no preference to oxic or anoxic environments

Question 55

segregation of genomes

Answer 55

facilitated by proteins MinC, D and E. | -MinE pushes C and D to the poles and acts as a signal for FtsZ

Question 56

what protein is essential in cell morphology

Answer 56

MreB--> thought to give rod shape and give bacterial cytoskeleton. Coccoid cells do not have MreB suggesting that this the default shape for a bacterium

Question 57

both mass and cell number increases as

Answer 57

generation time increases- exponential growth

Question 58

what is the most important factor affecting growth

Answer 58

temperature e. g. as temp increases so does growth rate, until maximal rate and then protein denaturation; collapse of cytoplasmic membrane and thermal lysis - -> due to ENZYMES having an optimum temo

Question 59

diff bacteria have different optimal temps

Answer 59

e.g. some grow best at temps below zero and others temps above 100

Question 60

psychrophiles

Answer 60

grow best at 4 degrees, but can grow at temps below 0. e.g. Polaromonas vacoulata

Question 61

mesophile

Answer 61

39 degrees e.g. E.coli

Question 62

Hyperthermophiles

Answer 62

106 degrees e.g. Pyrolobus fumarii