Difference between Fimbriae and Pili The fimbriae differ fr | Gaurav Gupta sir

Difference between Fimbriae and Pili

The fimbriae differ from the pili in the following ways:

Pili are fine hair like microfibers having pilin – a thick tubular structure while the fimbriae are tiny bristle-like fibers emerging from the surface of the bacterial cells

Pili are longer than fimbriae
Occurrence of the fimbriae in each cell is about 200-400 while the occurrence of pili are lesser than one to ten every cell

Fimbriae are found in the both the gram negative and positive bacteria both, pili are present in the gram negative bacteria only

The fimbriae are composed of fibrillin protein while the pilin protein makes up the pili

The fimbriae are less rigid compared to the pili

The formation of fimbriae is administered by the bacterial genes in the nucleoid area while the pili is administered by the plasmid genes

Fimbriae plays a role in attaching cells to the surface while pili are critical in bacterial conjugation