🧪Micro lab #2

Why do we use media for bacteria?

it provides all the nutrients required for them to grow

What kind of nutrients does media provide?

carbon, energy, nitrogen

What are the 2 types of media based on chemical constituents? describe them

Chemically defined: know what chemicals are in it
Complex medium: don’t know what chemicals are in it

What are the 2 different types of media based on selection and screening? describe them

Selective medium: only lets 2 grow while killing the rest
differential medium: lets all grow but can be chosen based on characteristics

When should we use min (defined) medium and when should we used complex?

min (defined): when you want more control over the medium
Complex: when you want bacteria to grow faster

What are pros/cons of defined (min) media and complex?

pros: have control over what you add/remove
cons: inhibits grow of other bacteria
pro: faster
cons: less control

What are the 2 types of culture we can have?

liquid, solid

Why do we use agar on media?

make the media solid

why do we use agar instead of gelatine?

not many microbes can metabolize it (digest it)
agar holds better in temperature

What is gelatine and agar made out of ?

collagen, algae

Describe broth. Can you tell what kind of bacteria is on it?

high concentration of bacteria,
no

Describe plate

Flat media that we can use to count and grow bacteria/colonies

What media can use to calculate CFU ?

plate

Describe Slat

help save space, bacteria can grow better bc theres more space

Describe deep

used to view motility and oxygen levels

Which medium is the best for determining if a culture is pure?

Agar bc when you swap it and see 2 colonies who look identical then it mean they are pure
2 different colonies: different bacterias

How can you check if there is grow in deep?

center → outside= motability
center → no movement= no matability

Do the number of colonies equal the # of cells ?

no

t/f 1 colony came from a cell

true

What is aseptic technique?

avoid contamination of culture media

Use of aseptic (sterile) technique avoid ______

contamination

Preventing unwanted microbes in things is ____

contaminant

What is inoculation?

adding microbes into a sterile place

Difference between Inoculate vs. Inoculum

add microbes
microbes being added

Which one shows motility (turbidity) ?

#2

what is a pure culture ?

a culture that has only 1 type of microorganism