isolation and growth of microbes Flashcards
how much of the cell does water make up?
80%
what are chemotrophs?
break chemical bonds to derive energy
what are phototrophs?
energy derived from sunlight via photosynthetic pigments
are all cells carbon based?
yes
what are heterotrophs?
Obtain organic carbon (carbohydrates, protein, fats, DNA, Amino acids)
what are autotrophs?
Obtain carbon by fixing CO2
what are the essential elements?
DNA/RNA, Amino acids, peptidoglycan
what metals are needed for metabolism?
zinc, copper, iron, sulfur
what are the coenzymes for metabolism?
NAD and Flavins
what are the three sates of media?
liquid, solid, semi-solid
what is liquid media?
“broth” inside of a test tube
what is solid media?
in a Petri dish
* This requires an agent to solidify
* Agar ~[1.5%]
what is semi-solid media?
- Similar to Solid (0.4%-1.0% of agar)
– Example: Nutrient agar 0.4% ( Motile
organism vs. non-motile) - This media will jiggle like Jell-O ®
- Some may contain a Redox indictor
such as TCC (Triphenyl Tetrazolium
Chloride)
characteristics of an autoclave
- Heat 121°C (HEAT)
- 15 psi (Pressure)
- 15 minutes, more volume will increase time (TIME)
always use_____when preparing sterilized media
aseptic technique
characteristics of complex media
- Exact chemical constitution of
the medium is not known - Wide range of growth
characteristics of defined media
- Exact chemical constitution of
the medium is known - Are usually composed of pure
chemicals off the shelf - Narrow range of growth
characteristics of selective medium
s one which has a component(s) added to it which will inhibit or prevent the growth of certain types or species of bacteria and/or promote the growth of desired species.
characteristics of differential media
a component(s) is added that allows a researcher to distinguish between different types of bacteria based on some observable trait (color) in their pattern of growth on the medium.
what are the four culture techniques?
aseptic technique, pure culture, quadrant streak, isolated colony
what is aseptic technique?
– Is a set of specific practices and procedures performed under carefully controlled conditions with the goal of a pure culture.
– Work area
– Loops and needles
– Test Tubes
what is a pure culture?
A culture of a single species, without
contaminants.
what is a quadrant streak?
Is a technique, in order to obtain isolated colonies.
what is an isolated colony?
– Is the idea, that one bacterial cell will divide, 2,4,8,16,32,64,
, into a visible colony ~10 million cells.
– Each of these cells are the same “clonal”
