Mineralization of Chitin in an estuarine sediment: the importance of the Chitosan pathway

In order to study the mineralization of chitinous material, pieces of squid pen chitin-protein in litter bags were exposed to a range of aquatic environments. Scanning electron microscopy showed that they were rapidly colonized by a wide variety of microbes. Populations within microhabitats, however, had a low species diversity, suggesting that cells colonizing initially could rapidly establish colonies. The squid pen was digested in all environments studied, but at rates that varied with season and habitat. Analyses of estuarine sediments of the River Ythan, Aberdeenshire showed appreciable levels of chitin and chitosan, and appreciable activities of chitinase and chitin deacetylase. These results suggest that two pathways are important in the mineralization of chitin in these sediments: one involving chitinases and N-acetylglucosamine, and another involving chitin deacetylase and chitosanase.