Chapter 3.1 Flashcards
The Five I’s
-Inoculation
-Incubation
-Isolation
-Inspection
-Identification
Inoculation
Introduction of microbes into or upon a media
Culture
-(verb) Adding to and the growing of microbes in various media
-(Noun) Population of microbes in or on nutrient medium
Medium/Media (plural)
A nutrient-containing environment in which microbes can multiply
Incubation
Inoculated media placed in temp controlled chamber called incubators
Incubator temperatures and function
-Control temperature for culture growth.
-Temps ranging from 20-45 degrees C
-Also control atmospheric gasses ( oxygen, CO2)
Microbial growth in liquid medium is
Cloudy or has turbidity
Colonies
Visible masses of piled up cells
Media classified into 3 properties
1) Physical state 2) Chemical Composition 3) Functional type
Media Physical state
Liquid, semisolid, solid
Media Chemical composition
Chemically defined (synthetic) or Complex (not chemically defined)
Media Functional types (8)
-General purpose
-Enriched
-Selective
-Differential
-Anaerobic growth
-Specimen transport
-Assay
-Enumeration
Liquid Media
-Water based solutions that do not solidify above freezing temps
-Broths, milks, infusions
Semisolid media
-Clot like consistency at room temps
-Contains enough agar or gelatin to thicken but not solidify
-Used to determine motility of bacteria
-Also used to localize a reaction to specific site
Brain and heart infusion
- made by boiling cow or pig heart and brain. Very nutrient dense
semisolid- lower concentration of agar (0.5-1%)
Solid Media
-Provides a firm surface upon which cells can form discrete/separate colonies
-Used to isolate bacteria and fungi
Agar media
-Complex polysaccharide isolated from red alga
-Solid at room temp, liquefies at 100 C
-Begins to solidify at 42 C
-Any medium containing 1-5% agar usually has the word “agar” in its name
Defined (synthetic) Media
-Exact chemical compositions are known
-May contain pure organic and inorganic compounds that vary little from one source to another
Complex Media
-Contains at least one component that is not chemically definable.
-Provides rich mix of nutrients for microbes that have complex needs
examples: Blood, serum, meat extracts,milk, yeast extract, soybean