Chitosan as one of the natural biopolymers with antimicrobial activities could be a good choice to be
applied in many areas including pharmaceuticals, foods, cosmetics, chemicals, agricultural crops, etc.
There have been many studies in the literature which show this superb polymer is dependent on many
factors to display its antimicrobial properties including the environmental conditions such as pH, type of
microorganism, and neighbouring components; and its structural conditions such as molecular weight,
degree of deacetylation, derivative form, its concentration, and original source. In this review, after a brief
explanation of antimicrobial activity of chitosan and its importance, we will discuss the factors affecting
the antimicrobial properties of this biopolymer based on recent studies