The exact mechanism of antibacterial activity of
chitosan still needs to be elucidated. Different
mechanisms have been described. It may be due
to staking of chitosan molecules on the microbial
cell surface creating a polymer membrane, which
blocks the transport of nutrients towards the cell
(Kumar et al., 2004b). Zheng and Zhu (2003) demostrated that chitosan weakened or even broke
the cell membrane of S. aureus, impairing the physiological
activities of the bacteria, and killed them.
This study demostrates that the antibacterial activity
of chitosan is effective. The product obtained
by acid hydrolysis exhibits a similar behaviour as
the compound obtained by enzymatic hydrolysis
(Wang et al., 2007). Additionally, our results demonstrate
that the antibacterial activity could be
correlated to the molecular weight, a result similar
to that reported by Zheng and Zhu (2003).