What are the 4 phases of bacterial growth curve?
For this reason, graphs that show the growth of bacterial cultures are plotted as the logarithm of the number of cells. Bacterial colonies progress through four phases of growth: the lag phase, the log phase, the stationary phase, and the death phase.
How long is stationary phase in bacterial growth?
As the cells remain in stationary phase then there is continued development for the bacteria to become dormant. So a cell after 12 hours of growth might be in stationary phase but it will be somewhat physiologically different than at 24 hours and certainly different than at 4 days, yet all are stationary phase.
What is a typical bacterial growth curve?
It has been determined that in a closed system or batch culture (no food added, no wastes removed) bacteria will grow in a predictable pattern, resulting in a growth curve composed of four distinct phases of growth: the lag phase, the exponential or log phase, the stationary phase, and the death or decline phase.
In which phase of the bacterial growth curve is the generation time the shortest?
log phase
Generation time is shortest during log phase and is strongly dependent upon growth factors present in the medium. This phase lasts for several hour depending on the type of organism, conditions of growth and density of organism.
What is the difference between stationary phase and death phase?
growth is followed by the stationary phase, in which the size of a population of bacteria remains constant, even though some cells continue to divide and others begin to die. The stationary phase is followed by the death phase, in which the death of cells in the population exceeds the…
What causes a bacterial culture to enter the stationary phase?
Why would a bacterial culture enter the stationary phase? Overcrowding – accumulation of metabolic waste products, depletion of nutrients, and pH changes.
What is the OD of bacteria stationary phase?
The stationary-phase cells were diluted to an OD600 of 0.6 with fresh medium, and then crystal violet was added to each bacterial cell culture (final concentration, 50 or 200 mg/liter).
Why do organisms go into stationary phase?
The entry of bacteria to the stationary phase can be caused by different factors, including limitation of a specific essential nutrient, accumulation of toxic by-products, presence of stress factors such as changes in pH, temperature, osmolarity, etc.
Which choice best illustrates what occurs in the stationary phase of bacterial growth?
Which choice illustrates best what occurs in the stationary phase of bacterial growth? lag phase. The duration of logarithmic growth would increase if bacterial cells divided into three equal daughter cells rather than two. The lag phase does NOT occur if all the cells in the culture are viable.
Why do bacteria enter stationary phase?
The stationary phase is often due to a growth-limiting factor such as the depletion of an essential nutrient, and/or the formation of an inhibitory product such as an organic acid. Stationary phase results from a situation in which growth rate and death rate are equal.
Why are antibiotics produced in stationary phase?
During the stationary phase, cells switch to a survival mode of metabolism. As growth slows, so too does the synthesis of peptidoglycans, proteins, and nucleic-acids; thus, stationary cultures are less susceptible to antibiotics that disrupt these processes.