What is Fimbriae or Pili?

Explanation

1. Pili or Fimbriae are hair like appendages found on surface of cell wall of gram-negative bacteria Eg: Enterobacterium.
2. The pili are 0.2 to 20 `mu`m long with a diameter of about 0.025`mu`m.
3. In addition to normal pili there are special type of pili which help in conjugation called sex pili are also found.