Microbial Growth Flashcards
How fast does S. aureus grow?
27-30 mins.
What happens in binary fission?
Cell duplication, unilateral growth
Most bacteria divides cell through?
Binary fission
True or false. Growth is unequal in budding.
True.
Steps in binary fission
Single cells -> DNA replication -> septum formation moves down & divides cell
What does a closed culture system do?
Provide nutrients
True or false. A single cell that divides into two is considered as two generations.
False. One generation only.
3 kinds of cell division
Binary fission, budding, and biofilms
Organisms in death phase undergo?
Involution to conserve energy (limit nutrient use)
There is an overwhelming amount of toxic waste in this phase
Death phase
Describe the toxic environment in stationary phase
Highly acidic pH, decrease in oxygen (overall increase in microbial waste)
In budding, (blank) develops from (blank).
Daughter, mother
How fast does E.Coli grow?
15-18 mins.
Increase in population
Exponential
What is produced in biofilms?
Polysaccharide matrix
You can determine the generation time of organisms during this phase
Exponential phase
What forms during death phase in some organisms?
Endospores
Duration of lag phase depends on?
Nutrients available, species
No growth but increase in metabolic activity
Lag phase
Biofilms are?
A community of microorganisms that are trapped in slimy material
How long does Mycobacterium tuberculosis grow?
18-24 hrs.
Open system (chemostat) works by?
Taking samples at several intervals (usually every hr)
Exponential phase may be maintained through?
Chemostat
How fast does Bacillus subtilis grow?
26 mins.
True or false. A single cell that divides into two are two generations.
False. One generation only.
How long does Leptospira sp. grow?
6-8 hrs.
Factors that govern cell division
Dilution rate, concentration of limited nutrients
Stages in bacterial growth curve
Lag, exponential, stationary, death phase
Also called the adjustment d
Lag phase
Why do we want to maintain exponential phase?
Due to increase rate
Equal rate of replication and death
Stationary
Budding allows organisms to?
Keep growing and survive environmental conditions
