Journal of Chemical Technology and Biotechnology J Chem Technol Biotechnol 83:1664–1669 (2008) Combined use of waste materials – recovery of chitin from shrimp shells by lactic acid fermentation supplemented with date juice waste or glucose Lydia Adour, a Wassila Arbia, b Abdeltif Amrane c∗ and Nabil Mameri b a D´ epartement de Chimie, Facult ´ e des Sciences, Universit ´ e Mouloud Mammeri, Tizi-Ouzou, Alg ´ erie b Laboratoire des Biotechnologies Environnementales et G ´ enie des Proc ´ ed ´ es (BIOGEP), Ecole Nationale Polytechnique, El Harrach, Alg ´ erie c UMR 6226 ‘Sciences Chimiques de Rennes’ Universit ´ e de Rennes 1/ENSCR/CNRS Equipe Chimie et Ing ´ enierie des Proc ´ ed ´ es de l’Environnement, ENSCR, Avenue du G ´ en ´ eral Leclerc, 35700 Rennes, France Abstract BACKGROUND: Chitin, a source of chitosan, was extracted from the teguments of white shrimp Parapenaeus longirostris, by means of Lactobacillus helveticus growing on date juice waste or glucose for comparison. A fermentor containing 10% (w/v) of shrimp shells was inoculated with a suspension of L. helveticus strain milano (10% v/v). RESULTS: For an initial pH of 8.5–9.0 and a temperature of 30 ◦ C, maximum deproteinization and demineralization were 76 and 53%, achieved for 80 and 300 g L −1 glucose, respectively. The level of demineralization increased to 60% for an increase in in temperature from 30 to 35 ◦ C. The use of date juice, as an alternative to the use of a primary carbon source such as glucose, led at best to 44% demineralization, for 208 g L −1 of total sugar at 35 ◦ C, and 91% deproteinization, for 80 g L −1 total sugar content at 30 ◦ C. CONCLUSION: Demineralization was not improved by the use of date juice, most likely due to its calcium content, which, during acidification, prevents the diffusion of calcium from the shells to the surrounding medium. Contrarily, the proteolytic activity of LAB appeared to be improved by the mineral content of date juice, leading to almost complete deproteinization of shrimp shells.  2008 Society of Chemical Industry Keywords: chitin extraction; date juice waste; demineralization; deproteinization; lactic acid bacteria; shell invertebrates INTRODUCTION Chitin is synthesized by several living organisms. It is a structural component of the arthropods exoskeleton and of the cell walls of fungi and yeast, 1 the natural sources for chitin extraction; it can also be found in plants and animals. However, the principal commercial source of chitin remains the shells of invertebrates, marine or fresh water invertebrates, such as shrimps, crabs, lobsters and krill, 2–4 which are provided in great quantities by the food processing industry. 5 Valorization of the teguments, the main waste of these industries, can therefore be considered as an important environmental and economic challenge. 6 Chitin is the source of chitosan, 7 a polysaccharide that has numerous applications, such as in food and nutrition, in agriculture and environmental protection, medical, dietetic and cosmetic products. 7,8 Chitin extraction by fermentative processes has received considerable interest in recent years. Studies involved various genera of lactic acid bacteria, 9 proteolytic bacteria, 10 fungi, 3,11,12 a new chlorella (single-cell green algae)–virus system, 13 or two-step fermentation involving a lactic acid bacterium and a protease producing bacterium. 14 It was clearly shown that demineralization and deproteinization of the chitinous matter depend primarily on the fermentation conditions. Shrimp shell demineralization constitutes the first step of the process and requires an acidic pH, achieved during the fermentative process by the production of lactic acid resulting from the breakdown of a carbon substrate. Glucose is usually considered for this purpose; 9,14,15 however, the possible use of low-cost by-products, as was the case for whey, 6,16 can provide an opportunity for the valorization of high carbon content wastes. 16 For this, date juice was considered in this work. The management of waste has become, during recent decades, a major environmental problem, ∗ Correspondence to: Abdeltif Amrane, UMR 6226 ‘Sciences Chimiques de Rennes’ Universit ´ e de Rennes 1/ENSCR/CNRS, Equipe Chimie et Ing ´ enierie des Proc ´ ed ´ es de l’Environnement, ENSCR, Avenue du G ´ en ´ eral Leclerc, 35700 Rennes, France E-mail: abdeltif.amrane@univ-rennes1.fr (Received 24 February 2008; revised version received 18 April 2008; accepted 20 April 2008) Published online 28 May 2008; DOI: 10.1002/jctb.1980  2008 Society of Chemical Industry. J Chem Technol Biotechnol 0268–2575/2008/$30.00