Wat is the significance of understanding microbial growth
200 words
Answers
Bacteria divide and reproduce asexually. Binary Fission and everything is equally divided between the two daughter cells.
Time it takes for a single cell to go from one division to the next: generation time or doubling time. This is also the time it takes for a population to double. For many "typical" bacteria under "ideal" conditions this doubling time may be as fast as 20 minutes.
Bacterial population increases exponentially or logarithmically. That is:
(x)(2)n , where x=initial number of bacterial cells and n=the number of generations.
[Remember that if 2n=y, then n=log2y].
This is also a geometric progression: 2, 2x2, 2x2x2, 2x2x2x2, etc.
Bacterial Growth Curve:
When an organism is inoculated into a nutrient solution 4 distinct growth phases are noted:
1.) Lag Phase - where the organisms are "getting used to the medium and physical conditions" - that is they are inducing the necessary enzymes for growth.
2.) Logarithmic (Log) Growth Phase - This is the phase where the generation time is measured. The more ideal the conditions, the faster the growth - up to the maximum growth rate for the species.
3.) Stationary Phase - during this phase the number of new cells equals the number of dead cells so that there is no net increase in viable cells. Nutrient are becoming depleted, the pH is changing, toxic wastes are building up, oxygen levels are becoming depleted.
4.) Death Phase - Rate of cell death is faster than regeneration. Death may accelerate and become exponential.