Homework SourseList the phases of the bacterial growth curve and describe i
Solution
The growth of bacteria is affected by both physical and nutritional factors. The physical factors include the pH, temperature, osmotic pressure, hydrostatic pressure, toxin concentrations and moisture content of the growing medium. The nutritional factors include the nutrient availability of carbon, nitrogen, sulphur, phosphorous, and other trace elements in the growth medium. The distinct phases of bacterial growth are: lag phase, log phase, stationary phase and the death phase.
The lag phase is characterized by few to no bacterial growth at all. At this phase, the bacteria get acquainted to the environment and grow in size synthesizing biochemicals and assimilating nutrients.
The second phase is the log phase, in which the bacterial cells divide at a constant, exponential rate. The pathogenic species inflict disease symptoms during this phase.
At the third phase, the stationary phase, the population growth stagnates as the rate of cell death becomes equal to the rate of cell division. The rapid cell division results in utilization of nutrients and release of toxic byproducts.
The fourth phase is the death phase. The population number declines steadily due to starvation and/or high toxin concentrations.
Strep throat is caused by the bacteria , Streptococcus pyogenes, which is known as group A streptococcus. These bacteria are highly contagious and spread by airborne droplets through coughs or sneezes, shared food, contacted common surfaces like doorknob, hand rails etc.The infection results in inflammation, pain, and swelling of the mucous membranes lining the back of the throat and the tonsils.
Though strep throat by bacteria is the most common cause of sore throat, it can also be due to viral infection. A viral sore throat is typically non-responding to antibiotics and improves on its own.
