Growth of Bacterial Popualtions Flashcards
What does the viable count method use to count cells?
The plating method
what does the direct total cell count use to count bacteria?
microscope and hemocytometer
what are the advantages of using the direct count method?
-easier to count
-individual bacteria counts
-can count alive or dead cells
faster
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what are the disadvantages of using direct cell count method?
requires culturing, only 1% of bacteria can be cultured
what is needed when using indirect measurments of growth (turbitity)
spectrophotometer, standard curve to compare numbers
what is the indirect measurments of growth (turbitity) method used for?
identify bacteria concentrations
what does the flow cytometer allow for?
allows for cell counting
The flow cytometer uses what to count one cell at a time?
hydrodynamic focusing
what does the forward light scatter measure in the flow cytometer?
cell size
what does the side light scatter measure in the flow cytometer?
cell regularity
what is another name for the continuous culture system?
open culture open system
is the continous culture system a controlled system?
yes
in the continuous culture system, what is the specific growth rate controlled by?
dilution rate
in the continuous culture system, what is the cell density controlled by?
the concentration of limiting nutrient
what does the chemostat allow for?
it allows for you control your sample
in the chemostat method, what does it mean by controlled dilution rate?
rate a which new media is added and old media is removed
in the stationary phase of bacterial growth culture curve, what is the name of the cells that are more dormant
persister cells
what do the persister cells do in the stationary phase?
go into starvation mode
what happens when the persister cells go into starvation mode?
-there is an increase in crosslinking within peptidogycan
- chaperone proteins begin to protect DNA and bind enxymes to prevent denaturing
