BACTERIAL MORPHOLOGY CONTD...
2). Pili or Fimbriae : They are thin,soft, hair like appendages that extends from cytoplasmic membrane of Gram negative bacteria . They are shorter, straighter & numerous than flagella. They are composed of pilin protein, but don't function as motility.
- Helps in attachment ie allows pathogenic bacteria to attach epithelial cells, linings of respiratory tract, intestinal tract etc. So, Pili helps in colonization & prevents bacteria from being washed away by the flow of mucus or body fluid.
- .F-Pilis: It acts as port of entry of genetic material during bacterial matting(conjugation).
Glycocalyx in Bacteria and Nature
- Provides protection against temporary dryness by binding with water molecules.
- Blocks attachment by Bacteriophages.
- It acts as antiphagocytic & thus contributes for virulence of bacteria,
- Promotes attachment of bacteria to surface. May promotes stability of bacteria ie prevents aggregation.
- Slime layers causes binding of non pathogenic bacteria to solid forming a thick layer of cells called Biofilms.
- It acts as antigen & helps in identification of disease.