Microbial growth and growth control Flashcards
Why do microbial populations grow?
Cell and population growth are essential for microbial survival
How can we control microbial growth?
Control bacterial growth, understand and measure growth
How do bacterial cells grow?
Synthesising new cellular components
Binary fission
Explain FtsZ ring in bacterial cell division
Directed by FtsZ protein
Assembles into ring-like structure at center
How does the DNA copy itself?
Septal ring positioned so division splits cytoplasm
Explain bacterial cell multiplication
Structural components of cell and chromosome duplicated
Exponential growth
What are the phases of microbial growth curve?
Lag
Log(exponential)
Stationary
Death
How do you measure population growth?
Plating sample onto agar
Spectrophotometer
Microbial mass
What is the lag phase?
No increase
What is the log phase?
Growth at max rate
Optimal cell growth
What is the stationary phase?
Nutrients become depleted and waste
Growth ceases
What is the death phase?
Severe nutrient deprivation
How to control of microbial growth?
Temperature
pH
Water availability
Radiation
