Chitin and chitosan have been investigated as an
antimicrobial material against a wide range of target
organisms like algae, bacteria, yeasts and fungi in
experiments involving in vivo and in vitro interactions
with chitosan in different forms (solutions, films and
composites). Early research describing the antimicrobial
potential of chitin, chitosan, and their derivatives dated from
the 1980-1990s[9-14]. Generally, in these studies the chitosan
is considered to be a bacteriocidal (kills the live bacteria or
some fraction therein) or bacteriostatic (hinders the growth
of bacteria but does not imply whether or not bacteria are
killed), often with no distinction between activities. Recent
data in literature has the tendency to characterize chitosan
as bacteriostatic rather than bactericidal[15], although the
exact mechanism is not fully understood and several other
factors may contribute to the antibacterial action[16].