Continuous production of chitooligosaccharides by an immobilized enzyme in a dual-reactor system

Abstract

A chitosanolytic activity found in a commercial α-amylase from Bacillus amylolyquefaciens (BAN) was covalently immobilized onto glyoxal agarose beads (25% recovery of activity) and assessed for the continuous production of chitooligosaccharides (COS). The immobilization did not change the reaction profile (with chitotriose and chitobiose as major products, using chitosans of different polymerization and deacetylation degrees), but significantly increased the enzyme thermostability. A two-step process was proposed, in which chitosan was first hydrolyzed in a batch reactor to a viscosity that could flow through a packed-bead reactor (PBR), thus avoiding clogging of the column. The relationship between hydrolysis degree of chitosan (1% w/v) and viscosity of the solution was assessed in a batch reactor. A 50% hydrolyzed chitosan did not cause any clogging of the PBR. Under these conditions, the productivity of the PBR at the lowest dilution rate was 37 gCOS L-1 h-1 , with a conversion yield of 73%. In contrast, at the highest dilution rate, the productivity was nearly 200 gCOS L-1 h-1 , but the conversion yield dropped to around 40%.

Enzymatic production of fully deacetylated chitooligosaccharides and their neuroprotective and anti-inflammatory properties

“…In a previous work, we demonstrated that a Carbo-Pack PA-200 column was appropriate for the separation of complex mixtures of COS in less than 30 min employing a diluted NaOH solution (4 mM) as mobile phase (Santos-Moriano et al 2016b). This method represented a significant improvement compared with previous chromatographic protocols to separate deacetylated or partially acetylated COS (Xiong et al 2009, Horsch et al 1996, Lü et al 2009.…”

Continuous Packed Bed Reactor with Immobilized β-Galactosidase for Production of Galactooligosaccharides (GOS)

“…The binding chemistry between the amino groups of the protein and the glyoxyl moieties of the support is rather simple and gives rise to robust linkages between the enzyme and the carrier [25][26][27]. However, the immobilization must be performed at alkaline pH in order to deprotonate amino groups and thus enhance their nucleophilicity [28].…”

Immobilization of the β-fructofuranosidase from Xanthophyllomyces dendrorhous by Entrapment in Polyvinyl Alcohol and Its Application to Neo-Fructooligosaccharides Production

“…The strategies for enzyme immobilization are commonly classified into three groups [18]: support binding (by adsorption or covalent linkages), entrapment and cross-linking. For reactions involving the transformation of carbohydrates, covalent binding is preferred over adsorption to avoid enzyme leakage [19], but most of the commercial activated carriers are expensive [20][21][22]. Cross-linking gives rise to biocatalysts with highly concentrated enzyme activity, significant stability and low production costs due to the absence of carrier, although the recovery of activity is commonly low [14,15].…”