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Bacterial growth curve\Kinetic Curve. In autecological studies, the growth of bacteria (or other microorganisms, as protozoa, microalgae or yeasts) in batch culture can be modeled with four different phases: lag phase (A), log phase or exponential phase (B), stationary phase (C), and death phase (D).
This picture depicts the initial appearance of three different Winogradsky columns. They are soil and water samples from a river, the later two columns have been modified with phosphate, nitrate, sulfur and oxygen additives. These additions promote the growth of various bacteria specific to the anaerobic and aerobic regions of the column.
The first phase is the fast growth phase, since the bacterium is consuming (in the case of the above example) exclusively glucose, and is capable of rapid growth. The second phase is a lag phase while the genes used in lactose metabolism are expressed and observable cell growth stops. This is followed by another growth phase which is slower ...
Figure 1: A bi-phasic bacterial growth curve.. A growth curve is an empirical model of the evolution of a quantity over time. Growth curves are widely used in biology for quantities such as population size or biomass (in population ecology and demography, for population growth analysis), individual body height or biomass (in physiology, for growth analysis of individuals).
Bacterial growth curve. Bacterial growth follows four phases. When a population of bacteria first enter a high-nutrient environment that allows growth, the cells need to adapt to their new environment. The first phase of growth is the lag phase, a period of slow growth when the cells are adapting to the high-nutrient environment and preparing ...
Schematic diagram of cellular growth (elongation) and binary fission of bacilli. Blue and red lines indicate old and newly generated bacterial cell wall, respectively. (1) growth at the centre of the bacterial body. e.g. Bacillus subtilis, E. coli, and others. (2) apical growth. e.g. Corynebacterium diphtheriae. This is bacterial proliferation.
Once the growth medium in the petri dish is inoculated with the desired bacteria, the plates are incubated at the optimal temperature for the growing of the selected bacteria (for example, usually at 37 degrees Celsius, or the human body temperature, for cultures from humans or animals, or lower for environmental cultures). After the desired ...
Cells in different growth stages have different physical properties. Cells in a culture can thus be physically separated based on their density or size, for instance. This can be achieved using centrifugation (for density) or filtration (for size). In the Helmstetter-Cummings technique, a bacterial culture is filtered through a membrane.