solutions (1% (w/w) in 1% (w/w) acid) of
each substances were added to Muller Hinton agar (supplemented
with blood for anaerobic bacteria) for final chitin, chitosan, NAc-
COS or COS concentrations of 0.1%, 0.08%, 0.05%, 0.03%, 0.01%,
0.006% and 0.003% (w/v).