Definition Of Growth Curve In Microbiology

Requirements of macro and micro elements for growth 11.

Definition of growth curve in microbiology. A growth curve is an empirical model of the evolution of a quantity over time. 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. The initial phase is the lag phase where bacteria are metabolically active but not dividing. The spectrophotometer measures the turbidity or optical density which is the measure of the amount of light absorbed by a bacterial suspension.

The growth of bacteria and other organisms is simply referred to as the increase in cell number cell size and cell mass. There are four distinct phases of the growth curve. Samples are removed at intervals and the number of viable bacteria is counted. The increase in the cell mass of the organism is measured by using the spectrophotometer.

Multiplication of unicellular bacteria 4. 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 values for the measured property can be plotted on a graph as a. Physical factors influencing growth. The bacterial growth curve represents the number of live cells in a bacterial population over a period of time.

The bacteria are cultured in sterile nutrient medium and incubated at the optimum temperature for growth. The curve thus obtained is a sigmoid curve and is known as a standard growth curve. Growth curve of bacteria is a standard curve which consists of four distinct phases like log lag stationary and death phase which shows a sigmoid growth. Measurement of bacterial growth 3.

Batch culture the typical growth curve for population of cells can be divided into several distinct phases called the lag phase log phase stationary phase and death phase. When plotted on a graph a distinct curve is obtained referred to as the bacterial growth curve. Lag phase a log phase or exponential phase b stationary phase c and death phase d. A logarithmic growth curve is plotted which shows various phases see graph.

Method of obtaining bacterial growth curve. Bacterial growth curve and its significance. Definition of growth 2. Bacterial growth curve a curve on a graph that shows the changes in size of a bacterial population over time in a culture.

In this article we will discuss about 1. They are used to track the rise and fall of populations of plants animals and other multicellular organisms over time. When a broth culture is inoculated with a small bacterial inoculum the population size of the bacteria increases showing a classical pattern. Determination of generation time 5.

Growth curves are also common tools in ecological studies. Bacterial growth curve kinetic curve. Lag exponential log stationary and death.