GROWTH OF BACTERIA
It is an orderly increase in all of an organism's components. It represents an increase in biomass.
Phases of Bacterial Growth
1. The lag phase
2. Logarithmic (exponential) phase
3. The most stationary phase
4. Phase of decline
It occurs at the same time as bacterial cell reproduction.
It is the amount of time it takes for a bacterial population to double in size. Bacteria multiply by absorbing nutrients and incorporating them into cellular components. Bacteria then divide into two equal daughter cells and multiply by two.
The pattern of cell numbers displayed by a bacterial population after it has been inoculated into a new culture medium.
The normal bacterial growth curve is divided into four stages.
The period of adaptation during which active macromolecular synthesis such as DNA, RNA, various enzymes, and other structural components are produced.
It is the period of preparation for reproduction; there is no increase in cell number.
The period during which cells are actively multiplying.
Cell division occurs at a logarithmic rate, which is determined by the medium and culture conditions.
When the bacteria have reached their maximum cell density or yield.
There is no further increase in the number of viable bacterial cells. The rate of growth is exactly equal to the rate of death.
When one of the following conditions occurs, a bacterial population may reach stationary growth:
1. The required nutrients have been depleted.
2. The accumulation of inhibitory end products
3. Physical constraints prevent a further increase in population size.
The time when the rate of bacterial cell death exceeds the rate of new cell formation.
The number of viable cells is rapidly decreasing.
Few organisms can survive for this long at the expense of nutrients released by dying microorganisms.
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