Abstract
Enzymatic production of N-acetyl-D-glucosamine (GlcNAc) from chitin was investigated using crude enzyme from the liver of Japanese common squid Todarodes pacificus and cuttlefish Sepia esculenta. The ratio for the activities of endo- and exo-type chitinolytic enzyme, chitinase and β-N-acetylhexosaminidase, in the crude enzyme prepared from the liver of Japanese common squid was 1:19 and those of cuttlefish was 1:20. Both enzyme activities from cuttlefish were about 1.5 time higher than those of Japanese common squid. Crude enzyme of Japanese common squid, corresponding to 2 g of liver weight, produced 26.8 mg of reducing sugar from 50 mg of colloidal chitin during 5 days of incubation at 37°C. In the crude enzyme from cuttlefish, 44.4 mg of reducing sugar was obtained under the same reaction conditions. The main product of the produced reducing sugar, analyzed by HPLC, was GlcNAc. These results suggest that squid liver could be a source of chitinolytic enzyme for the enzymatic production of GlcNAc.
