Batch culture, Continuous culture & Synchronous culture - Definition & Brief Description

Batch culture

It is a technique used to grow microorganism or cells. In this, microorganisms are grown in a closed system where a limited supply of nutrients are provided at the beginning. The temperature, pressure and pH are maintained accordingly. In the beginning, microorganisms will grow utilizing the provided nutrients. Over the time, nutrients become limited and waste products begins to accumulate. Hence, microbes begin to die, following the four stages of microbial growth curve i.e. lag phase, log phase, stationary phase and death phase. The major advantage of this technique is that it runs for a certain period of time and under limited nutrients. This technique is widely used for the purification of antibiotics, pigments etc.

Continuous culture

It is another technique used to grow microorganisms. In this technique, fresh nutrients are supplied and waste products are removed continuously at the same rate and other conditions like temperature, pressure and pH are kept optimum. This technique maintains the continuously growing microbial culture at exponential phase of growth curve. The chamber used to grow organisms is known as chemostat in which sterile medium is added from one end and medium containing microorganism is removed from the other end thereby keeping the volume of culture at constant level. This technique is useful in extracting primary metabolites like amino acids, organic acids etc.

Synchronous culture

Synchronous culture is a microbiological culture that contains population of the cells that are in the same growth stage. The entire population of culture is kept constant with respect to growth and division. This technique is used to study cell cycle, growth and effect of various factors on microbial cell cycle and growth. Synchronous culture can be obtained by various ways. By the use of certain chemical growth inhibitor like nocodazole, cell growth can be arrested. Once the growth has been completely stopped, inhibitor is removed and cells will begin to grow synchronously. In other method, instead of growth inhibitor, external conditions are changed which will arrest the cell growth. Then the external condition is changed again to resume the growth and all the cells will grow synchronously.