BACTERIA GROWTH
Bacterial growth is the division of one bacterium into two daughter cells in a process called binary fission. Providing no mutational event occurs the resulting daughter cells are genetically identical to the original cell. Hence, "local doubling" of the bacterial population occurs. Both daughter cells from the division do not necessarily survive. However, if the number surviving exceeds unity on average, the bacterial population undergoes exponential growth. The measurement of an exponential bacterial growth curve in batch culture was traditionally a part of the training of all microbiologists; the basic means requires bacterial enumeration (cell counting) by direct and individual (microscopic, flow cytometry ), direct and bulk (biomass), indirect and individual (colony counting), or indirect and bulk (most probable number, turbidity, nutrient uptake) methods. Models reconcile theory with the measurements.
THE NORMAL REPRODUCTIVE METHOD
Lag Phase:
Bacteria are becoming "acclimated" to the new environmental conditions to which they have been introduced (pH, temperature, nutrients, etc.). There is no significant increase in numbers with time.
Exponential Growth Phase:
The living bacteria population increases rapidly with time at an exponential growth in numbers, and the growth rate increasing with time. Conditions are optimal for growth.
Stationary Phase:
With the exhaustion of nutrients and build-up of waste and secondary metabolic products, the growth rate has slowed to the point where the growth rate equals the death rate. Effectively, there is no net growth in the bacteria population.
Death Phase:
The living bacteria population decreases with time, due to a lack of nutrients and toxic metabolic by-products.
TYPE OF BACTERIA
these are type of bacteria:
shiga toxin-producing escherichia coli
campylobacter jejuni
salmonella spp
bacillus cereus
FROM: DHM B
1) NUR ATIKAH BINTI JAMAL
2) NURUL AIFAIZA BINTI AMAN
3) NORUL FATIYAH BINTI YAAKUB
