Chitosan glutamate was obtained from
Pronova (Drammen, Norway). It contained
42% glutamate and had a deacetylation
range of 75^85% (manufacturer’s data).
Chitosan solutions were prepared in deionized
water and autoclaved at 1211C for
20 min. The antimicrobial activity of chitosan
was not a¡ected by autoclaving in laboratory
media for up to 30 min (Roller and Covill
1999). All microbiological media and diluents
were from Oxoid (Basingstoke, UK). All
other chemicals were from Sigma Chemical
Co (Poole, Dorset, UK), unless otherwise
indicated.