Bacterial Growth Curve

Bacterial growth is the division of one bacterium into two daughter cells in a process called binary fission. Providing no mutational event occurs the resulting daughter cells are genetically identical to the original cell. Hence, "local doubling" of the bacterial population occurs. Both daughter cells from the division do not necessarily survive. However, if the number surviving exceeds unity on average, the bacterial population undergoes exponential growth. The measurement of an exponential bacterial growth curve in batch culture is traditionally a part of the training of all microbiologists; the basic means requires methods for Measurement of cell mass: bacterial enumeration (cell counting) by direct and individual (microscopic, flow cytometry), direct and bulk (biomass), indirect and individual (colony counting), or indirect and bulk (most probable number, turbidity, nutrient uptake) methods. Models reconcile theory with the measurements.Cell numbers can also be counted through direct microscopic counts using special slides, electronic counting chambers, indirect viable cell counts(plate counts). Theoretically every cells can be counted but in reality cells form a colony and so problems are created.
Batch culture is the most common laboratory growth environment in which bacterial growth is studied, but it is only one of many. It is ideally spatially unstructured and temporally structured. The bacterial culture is incubated in a closed vessel with a single batch of medium. In some experimental regimes, some of the bacterial culture is periodically removed to a fresh sterile media is added. In the extreme case, this leads to the continual renewal of the nutrients. This is a chemostat also known as continuous culture. It is ideally spatially unstructured and temporally unstructured, in a steady-state defined by the nutrient supply rate and the reaction of the bacteria. In comparison to batch culture, bacteria are maintained in exponential growth phase and the