what is a pili
A pilus (Latin for 'hair'; plural: pili) is a hairlike appendage found on the surface of many bacteria. The terms pilus and fimbria (Latin for 'fringe'; plural: fimbriae) can be used interchangeably, although some researchers reserve the term pilus for the appendage required for bacterial conjugation.ovement produced by type IV pili is typically jerky, and so it is called twitching motility, as distinct from other forms of bacterial motility, such as motility produced by flagella. However, some bacteria, for example Myxococcus xanthus, exhibit gliding motility.