Fig. 1.

Bacterial biofilm development produces a classic structure. The formation of biofilms consists of five stages: reversible attachment, irreversible attachment, maturation stage I, maturation stage II and dispersion. In the reversible attachment stage, bacteria attach to the matrix through the swing of flagella. In the irreversible attachment stage, the expression of the flagella gene is lost. Then, several cell clusters mature, and thick cell clusters embedded in the biofilm matrix enter mature stage I. In mature stage II, the bacterial clusters reach the maximum thickness, and microcolonies can be seen. When the biofilm is dispersed, the biofilm cycle will cycle again