Chitosan from Syncephalastrum racemosum used as a film support for lipase immobilization R.V.S. Amorim a,b, * , E.S. Melo a , M.G. Carneiro-da-Cunha a , W.M. Ledingham a , G.M. Campos-Takaki c a Laborat orio de Imunopatologia Keizo Asami––LIKA and Departamento de Bioqu  ımica, Universidade Federal de Pernambuco-UFPE, Av. Professor Moraes Rego s/n, Cidade Universit  aria, 50670-901 Recife, PE, Brazil b Departamento de Biologia Molecular, Universidade Federal da Para  ıba––UFPB, Campus I––Cidade Universit  aria, 58051-900, Jo~ ao Pessoa, PB, Brazil c N ucleo de Pesquisas em Ci^ encias Ambientais––NPCIAMB and Departamento de Qu  ımica, Universidade Cat olica de Pernambuco––UNICAP, Recife, PE, Brazil Received 2 April 2001; received in revised form 12 September 2002; accepted 11 January 2003 Abstract Chitosan from a native Mucoralean strain, Syncephalastrum racemosum, isolated from herbivorous dung (Northeast-Brazil), was used as a film support for lipase immobilization. S. racemosum showedhighestchitosanyield(152mggdrymyceliaweight 1 ;15.2% of dry mycelia weight) among the nine strains screened, which presented 89% D-glucosamine. A chitosan film was used for lipase (EC 3.1.1.3) immobilization using glutaraldehyde as a bifunctional agent. The immobilized lipase retained 47% (12.6 lmols 1 m 2 ) of its initial catalytic activity after four cycles of reaction. This result is comparable (same order of magnitude) to that of the enzyme immobilized on film made from commercially available crustacean chitosan. Ó 2003 Elsevier Science Ltd. All rights reserved. Keywords: Chitosan; Mucoralean; Film; Immobilization; Lipase 1. Introduction Chitosan, a cationic biopolymer consisting of (1,4)- linked 2-amino-deoxy-b-D-glucan, is a deacetylated derivative from chitin, the second most abundant poly- saccharide in nature. It has been described as occurring in the cell wall of some fungi, particularly in the Zygo- mycetes (Miyoshi et al., 1992; Tan et al., 1996). Commercially available chitosan is obtained from crustacea and has been used in a wide variety of appli- cations. Its membrane has several uses including food processing, protein purification, and skin replacement technology (Muzzarelli, 1983). It has also been used as a support for enzyme immobilization, since it offers con- siderable advantages such as form versatility (powder, gel beads, flocks, fibres, capsules and membranes), low biodegradability and cost, high affinity towards proteins and absence of toxicity (No and Meyers, 1995). En- zymes such as catalase (C ß etinus and € Oztop, 2000), tyro- sinase (Carvalho et al., 2000), dextranase (Abdel-Naby et al., 1999), and beta-galactosidase (Shin et al., 1998) have been immobilized on commercial crustacean chitosan. Commercial lipases are expensive and methods to extend their active life have been intensively investi- gated and developed. Numerous methods of lipase im- mobilization are available, but adsorption is the most frequently reported methodology in the literature (Gunnlaugsdottir et al., 1998). However, adsorption is stabilised by weak forces and surfactants can often sol- ubilise most of the lipolytic activity. The aim of this work was to screen the production of chitosan from nativeandculturecollectionMucoraleanstrainslooking for its utilization as a support for lipase covalent immobilization. * Corresponding author. Address: Laborat orio de Imunopatologia Keizo Asami––LIKA, Universidade Federal de Pernambuco-UFPE, Av. Professor Moraes Rego s/n, Cidade Universit aria, 50670-901 Recife, PE, Brazil. Fax: +55-81-3271-8485. E-mail address: ramorim@dbm.ufpb.br (R.V.S. Amorim). 0960-8524/03/$ - see front matter Ó 2003 Elsevier Science Ltd. All rights reserved. doi:10.1016/S0960-8524(03)00035-X Bioresource Technology 89 (2003) 35–39