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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). [3]
Bactericidals kill bacteria directly, whereas bacteriostatics prevent them from dividing. However, these classifications are based on laboratory behavior. The development of antibiotics has had a profound effect on the health of people for many years. Also, both people and animals have used antibiotics to treat infections and diseases.
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).
Glycopeptide antibiotics are a class of drugs of microbial origin that are composed of glycosylated cyclic or polycyclic nonribosomal peptides.Significant glycopeptide antibiotics include the anti-infective antibiotics vancomycin, teicoplanin, telavancin, ramoplanin, avoparcin and decaplanin, corbomycin, complestatin and the antitumor antibiotic bleomycin.
μ is the growth rate of a considered microorganism, μ max is the maximum growth rate of this microorganism, [S] is the concentration of the limiting substrate S for growth, K s is the "half-velocity constant"—the value of [S] when μ/μ max = 0.5. μ max and K s are empirical (experimental) coefficients to the Monod equation. They will ...
Once a bacterium has been identified following microbiological culture, antibiotics are selected for susceptibility testing. [5] Susceptibility testing methods are based on exposing bacteria to antibiotics and observing the effect on the growth of the bacteria (phenotypic testing), or identifying specific genetic markers (genetic testing). [6]
In the absence of antibiotics or other stressors, filamentation occurs at a low frequency in bacterial populations (4–8% short filaments and 0–5% long filaments in 1- to 8-hour cultures). [3] The increased cell length can protect bacteria from protozoan predation and neutrophil phagocytosis by making ingestion of cells more difficult.
A diauxic growth curve refers to the growth curve generated by an organism which has two growth peaks. The theory behind the diauxic growth curve stems from Jacques Monod's Ph.D. research in 1940. A simple example involves the bacterium Escherichia coli ( E. coli ), the best understood bacterium.