Chitin and chitosan exhibited similar inhibitory
growth activity against the two S. aureus strains throughout the
5e6 h incubation period (Figs. 3and 4). In contrast, the amount of
bacteria increased rapidly in the control group (S. aureus). The late
exponential phase was reached after 2 h with an OD of 0.38.
Bacteria growth was at slower rate in the experimental groups
containing 0.1% chitin and 0.1% chitosan with the late exponential
phase being reached after 4 h. The maximum OD (i.e. absorbance at
640 nm) in the control groupwas 0.4 (i.e.1.2 108 cell/mL), butwas
only 0.25 (i.e. 0.75 108 cell/mL) for the experiments with chitin
and chitosan.