MICROBIO LAB EXAM 1

started from midterm review, bottom up

What is lichen

relationship between fungus and green algae/cyanobacteria grown on branches

What is relationship with lichen

Relationship +/+

Fungus provides shelter

Green Algae/Cyanobacteria provides food

Commensalism

an association between 2 organisms in which one benefits and the other is not harmed nor benefited

Relationship +/0

what kind of test is this

Colisure Test

Which is negative, positive for coliform and positive for E.Coli

Negative: yellow

Positive: red, coliform

Positive: fluoresce, E.coli

What test is this and what does it do

E. C test in a compact dry, meant to find E.coli count

Which color is E.coli, which is Coliform

E.coli is blue Coliform is purple

what test is this

Eosine Methylene Blue

what is present in the top left, top right, then bottom quadrant

coliform, e. coli, non-coliform

what test is this called

Catalase Test

which is positive and which is negative

bubbles is positive negative has no bubbles

which will show positively enterococcus faecium or staphylococcus spp

staphylococcus spp

What tests use the media Mueller Hinton Agar

Kirby Bauer Test, E-Test

What test is this called

Kirby Bauer

what is the area around the patches called in a Kirby Bauer Test

Zone of inhibition

What does alcohol do as a degerming agent

1. 1. dissolves lipids

2. 2. denature proteins

Which one is halotolerant and which one is halophile

which is hypertonic, isotonic, hypotonic

left is hypertonic, middle is isotonic, right is hypotonic

examples of a culture is the osmolarity

1 S. saprophyticus

2 Escherichia coli

3 halobacterium

do slide 15 of 23 plxzplzpzlpzl

Acidophiles (mostly fungi)

optimum pH 0-5.5

Basophiles (Thiobacillus, archaea)

optimum pH 8.5-11.5

Neutrophiles (most bacteria)

optimum pH 6.5-7.5

What culture is in this vile

S. epidermidis

What culture is in this vile, pH=4.5

S. cerevisiae

Obligate aerobes

need O2 to grow

Obligate anaerobes

can’t grow with O2

Facultative Anaerobes

can grow without O2, but grows better with O2

Aerotolerant anaerobes

don’t require O2, same growth with or without O2

Microaerophiles

requires low O2 to grow

Classifications of effects of temperature on growth

Psychrophiles, Mesophiles, Thermophiles

Psychrophiles

organisms can grow at low temperature (5’C or below)

Mesophiles

organisms can grow at mid-range temperature (30’C-37’C)

Thermophiles

organisms can grow at high temperature (above 50’C)

Hyperthermophiles

grow at higher than 70’C

Spread Plating Steps

1. 1. Sample (0.1mL) poured onto solid medium

2. 2. Dipping cell spreader in alcohol

3. 3. Burning off excess alcohol

4. 4. Cool the cell spreader down

5. 5. Spread sample evenly over the surface

6. 6. plate incubated until bacterial colonies grow on the surface of the medium

#what dis

Fungi: Rhizopus

#whatdis

Fungi: Zygomycota Rhizopus

#whatdis

Fungi: Coprinus

#whatdis

Fungi Peziza

#whatdis

Fungi: Ascus

Which group of fungi reproduces sexually

Rhizopus, Coprinus, Peziza, Ascus, Zygomycota

Which group of fungi reproduces asexually

Penicillium spp., Mold, Yeast, Aspergillus, Condiophore

#whatdid

Fungi: Penicillium spp.

#whatdis

Fungi: Aspergillus

#whatdis

Fungi: Mold

#whatdis

Fungi: Yeast

#whatdis

Condiophore

what kinda stain is this

Endospore Staining

what kinda stain is this

acid fast

what kinda stain is this

Negative staining

Gram Positive is

purple!

Gram Negative is

Pink!

Gram positive will show on

staphylococcus spp. bacillus megaterium

Gram Negative

Escherichia coli, Pseudomonas fluorescens/P. putida

#whatdis

Gram negative bacilli

#whatdis

Gram negative cocci

#whatdis

Gram positive cocci

#whatdis

gram positive bacillus

KNOW THE STEPS AND PROCESSES FOR GRAM STAIN

slide 9/23 or a lecture, don’t forget about which stains are what

Gram positive cell wall characteristics

presence of thick peptidoglycan layer and one inner membrane

Gram negative cell wall characteristics

presence of thin peptidoglycan layer, one inner membrane and one outer layer

Gram Stains → Stains

Crystal violet, Iodine, Alcohol 95% (decolorizer), Safranin

Crystal violet stain

is the primary stain

Iodine stain is

the mordant/enhancer

Alcohol in a stain context is

the decolorizer, rinse for 2-3 seconds

Safranin is the

secondary or counter stain

Smear Prep steps

slide 7/23

Cell shapes and associations

cocci: staphylococcus spp. rods: bacillus megaterium, e. coli, pseudomonas spp.

clusters, chains

do slide 6/23

Columbia CNA Agar OIIR

organisms: selective for G+, inhibitory for G-

inhibitor: colistin, nalidixic acid

indicator: none

results: growth of G+ organisms

MacConkey Agar

organisms: selective for G-, inhibitory for G+

inhibitor: Bile salts

indicator: Neutral red (pH drop around colony = color change)

results:

• lactose fermenters → red/pink colonies w/w/o zone of precipitation

• lactose non-fermenters → clear colonies

Mannitol Salt Agar

organisms: growth of staphylococcus species

inhibitor: sodium chloride 7.5%

indicator: Phenol Red

results:

• S. saprophyticus: yellow colonies and yellow media (ferments mannitol)

• S. epidermidis: grows, but does not ferment mannitol (media not yellow)

Blood agar plates

organisms: enrich for fastidious organisms, G+ and G-

inhibitor: none

indicator: blood (of hemolytic patterns)

results: Beta, Alpha, Gamma

Autoclave machine uses Temp, Pressure and Time

Temperature: 121’C

Pressure: 15psi

Time: 15min

Why use a nutrient agar plae

isolation of colonies

Why use a nutrient agar slant

temporary storage of culture

Why use nutrient broth

propagation of culture

know slide one