Bacterial Reproduction and Growth

Abstract

Bacteria growing in a suitable medium increase in number by having each cell increase in size, and then each cell divides to produce two daughter cells. The increase in cell number in a culture is, therefore, a result of the activity of the cell during the division cycle, between the period of birth by division and the subsequent division. There is a close relation between the composition of the growth medium and the bacterial growth rate and Deoxyribonucleic acid (DNA) replication. The exponential growth of bacteria can be understood from the increase of cellular material, such as ribonucleic acid and protein, which, in turn, generate more cellular components. Recent studies have revealed a relation between the cell cycle and the control of initiation of DNA replication, cell division and cell surface synthesis.

Key Concepts:

• Bacterial growth rate is a function of the growth conditions.

• Fast-growing rod-shaped bacterial cells are larger than slow-growing cells.

• A key regulatory event in the bacterial cell cycle is the initiation of DNA replication.

• Bacterial cells age over time.

• Multiple rounds of chromosome replication can be accommodated within one bacterial cell cycle.

• Bacteria use their nutritional state as a cue for the start of cell division.