Combination of Soaking in Sodium Hydroxide and Chitin Deacetylase Appltcution on Shrimp Chitin in Producing Low Molecular Weight Chitosan

Abstract

Thermostable chitin deacetylase produced by Bacillus K29-14 was used to produce chitosan from shrimp chitin. Chemical treatment before the enzyme application on chitin was conducted by soaking it in 60 % NaOH solution, which led chitin to swell and change the crystalline structure in order to allow the enzyme to penetrate and deacetylate it. The enzyme had performed high deacetylation degree (72-99 %) following soaking at 60-75 °C for 60-180 min. and then incubating with the enzyme at 55 0C for 24 hours Deacetylation degree increased when soaking temperature in NaOH was increased or soaking time in NaOH was lenght, as well as by addition of enzyme. The chitosan had low molecular weight and viscosity, indicated that depolymerization was occured, so that resulied oligomer chitosan.