RT Journal Article
T1 High yield production of monomer-free chitosan oligosaccharides by pepsin catalyzed hydrolysis of a high deacetylation degree chitosan
A1 Roncal, Tomás
A1 Oviedo, Alberto
A1 de Armentia, Iratxe López
A1 Fernández, Laura
A1 Villarán, M. Carmen
AB The high molecular weight of chitosan, which results in a poor solubility at neutral pH values and high viscosity aqueous solutions, limits its potential uses in the fields of food, health and agriculture. However, most of these limitations are overcome by chitosan oligosaccharides obtained by enzymatic hydrolysis of the polymer. Several commercial enzymes with different original specificities were assayed for their ability to hydrolyze a 93% deacetylation degree chitosan and compared with a chitosanase. According to the patterns of viscosity decrease and reducing end formation, three enzymes-cellulase, pepsin and lipase A-were found to be particularly suitable for hydrolyzing chitosan at a level comparable to that achieved by chitosanase. Unlike the appreciable levels of both 2-amino-2-deoxy-d-glucose and 2-acetamido-2-deoxy-d-glucose monomers released from chitosan by the other enzymes after a 20 h-hydrolysis (4.6-9.1% of the total product weight), no monomer could be detected following pepsin cleavage. As a result, pepsin produced a higher yield of chitosan oligosaccharides than the other enzymes: 52% versus as much as 46%, respectively. Low molecular weight chitosans accounted for the remaining 48% of hydrolysis products. The calculated average polymerization degree of the products released by pepsin was around 16 units after 20 h of hydrolysis. This product pattern and yield are proposed to be related to the bond cleavage specificity of pepsin and the high deacetylation degree of chitosan used as substrate. The optimal reaction conditions for hydrolysis of chitosan by pepsin were 40 °C and pH 4.5, and an enzyme/substrate ratio of 1:100 (w/w) for reactions longer than 1 h.
SN 0008-6215
YR 2007
FD 2007-12-28
LA eng
NO Roncal , T , Oviedo , A , de Armentia , I L , Fernández , L & Villarán , M C 2007 , ' High yield production of monomer-free chitosan oligosaccharides by pepsin catalyzed hydrolysis of a high deacetylation degree chitosan ' , Carbohydrate Research , vol. 342 , no. 18 , pp. 2750-2756 . https://doi.org/10.1016/j.carres.2007.08.023
NO We thank the Spanish Ministry of Industry, Tourism and Trade for financial support of this project through the PROFIT program (FIT-060000-2005-362 and FIT-060000-2006-63). Funding to T.R. under the Torres Quevedo program of the Spanish Ministry of Education and Science and the European Social Fund is also acknowledged (PTQ2004-0945).
DS TECNALIA Publications
RD 31 jul 2024