Growth of bacteria

Growth of bacteria

When a bacterial cell reaches maturity  divides by binary fission into two identical organisms  these will in turn divide  colony.

Growth is dependent on:
• temperature (each organism has an optimum temperature at which it grows best)
• pH
• moisture content
• availability of nutrients
• presence of other organisms

Population growth curve:
When bacteria are introduced into a nutrient rich growth media  growth and division occur until nutrients exhausted, or oxygen depleted or pH decreases or waste products accumulate.

3 phases in growth curve:
Lag phase
• cells do not immediately start dividing – only grow in size

Exponential/logarithmic growth phase:
• cells multiple at maximal rate
• pathogenic bacteria are most virulent at this stage

Stationary growth phase:
• only small amount of multiplication at this stage
• number in population remains stable