© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 871 Biotechnol. J. 2008, 3, 871–877 DOI 10.1002/biot.200700197 www.biotechnology-journal.com 1 Introduction In the last several years, fundamental studies have examined a new field of research concerned with the exploitation of novel environmental and eco- logical materials derived from marine wastes. Im- mense quantities of marine processing byproducts including fish bone, fish muscle protein and inter- nal organs, fish skin collagen and gelatin, fish oils such as omega-3 fatty acids, shellfish and crus- tacean shell wastes are of both environmental and economic concern for seafood processing plants [1]. At present, current discards from the world’s fisheries exceed 20 million tons, which equates to almost 25% of the total production of marine cap- ture fisheries [2]. Moreover, European legislation (EU Council Directive 1999/31/EC, 1999) has set specific targets for the amount of biodegradable municipal waste (BMW) for disposal at landfills [3]. In Ireland, figures from An Bord Iascaigh Mhara (The Irish Sea Fisheries Board), estimate that 63,786 tonnes of marine processing waste were produced nationally in 2002, 45% of which arose from the northwest region [4]. Traditionally, the greater part of fisheries wastes are utilized in the production of low-economic value products such as fertilizers, fish silage or pet foods [5]. However, with advances in bioprocess engineering technologies coupled with novel enzymatic and microbial hy- drolysis methods, processing wastes may serve as cheap raw materials for the generation of high-val- ue bioactive compounds with a variety of applica- tions [1, 6, and 7]. Various applications of chitin, Review Mining marine shellfish wastes for bioactive molecules: Chitin and chitosan – Part A: extraction methods Maria Hayes 1 , Brian Carney 1 , John Slater 1 and Wolfram Brück 1 1 Centre of Applied Marine Biotechnology (CAMBio), Letterkenny Institute of Technology, Port Road, Letterkenny, Co. Donegal, Ireland. Legal restrictions, high costs and environmental problems regarding the disposal of marine pro- cessing wastes have led to amplified interest in biotechnology research concerning the identifica- tion and extraction of additional high grade, low-volume by-products produced from shellfish waste treatments. Shellfish waste consisting of crustacean exoskeletons is currently the main source of biomass for chitin production. Chitin is a polysaccharide composed of N-acetyl-D-glu- cosamine units and the multidimensional utilization of chitin derivatives including chitosan, a deacetylated derivative of chitin, is due to a number of characteristics including: their polyelec- trolyte and cationic nature, the presence of reactive groups, high adsorption capacities, bacterio- static and fungistatic influences, making them very versatile biomolecules. Part A of this review aims to consolidate useful information concerning the methods used to extract and characterize chitin, chitosan and glucosamine obtained through industrial, microbial and enzymatic hydrolysis of shellfish waste. Keywords: Chitin · chitosan · oligosaccharides · bioactive molecules Correspondence: Dr. Brian Carney, Centre of Applied Marine Biotechnolo- gy CAMBio, Letterkenny Institute of Technology, Port Road, Letterkenny, Co. Donegal, Ireland. E-mail: Brian.Carney@Lyit.ie Telephone: +353 (0) 74 9186565 Fax: +353-749186300 Abbreviations: COS, chitosan oligosaccharides, DCE, cis-1,2-dichloro- ethene, DD, degree of deacetylation, DP, degrees of polymerisation, ECM, extracellular matrix, FITC-chitin, Fluorescein isothiocyanate chitin, GlcNAc, N-acetylglucosamine, LMMC, low molecular mass chitosans, NOCC, N-O- Carboxymethyl chitosan, PVC, polyvinyl chloride, SCSP, shrimp and crab Received 22 August 2007 Revised 24 January 2008 Accepted 31 January 2008