In this article we will discuss the structure and functions of pili and fimbriae. Structure of Pili and Fimbriae: Both fimbriae and pili are like flagella as both are the appendages on bacterial cell wall. They originate from cytoplasm that protrudes outside after penetrating the peptidoglycan layer of cell wall. Fimbriae are made up of 100% protein called fimbrilin or [...]
In this article we will discuss about the classification of pili. Mainly pili are of two types: (a) Common pili which act to adhere the cell to surfaces, and (b) Sex pili which join the other bacterial cell for transfer of genome. Ottow (1975) has classified the pili into the following six groups: Group 1: Fimbriae of this group act [...]
In this article we will discuss about the meaning and functions of capsule. Meaning of Capsule: Some of the bacterial cells are surrounded by the extracellular polymeric substances (EPS) which are commonly called capsule or glycocalyx. It forms an envelope around the cell wall and can be observed under light microscope after special staining technique (Fig.4.2). The presence of capsule [...]