Stable ionotropic gel for cell immobilization using high molecular weight pectic acid

Abstract

It is shown t h a t Ca-and 81-pectnte gel beads prepared by use of high moleculiir weight polygelacturonic acid (viz. polygalnctiironic acid having a high STAUDIXGER index) are well suited for cell immobilization. The pcctate beads are much more insensitive to those ions and chemical agents which destructively act on alginate beads (such as phosphate, citrate, gluconate, lactate as well as u high excess of sodium, potassium, and/or ammonium ions), even without addition of gelling cations to the liquid phase.

Ethanolic fermentation with saccharomyces cerevisiae cells immobilized in pectate gel

“…On the contrary we could show in previous papers [7,8] that Ca or A1 pectate beads prepared by use of high-molecular weight pectic acid (STAUDINGER index > 200 ml/g) having a low methoxy group content (< 3%) are well suited for the immobilization of yeasts and bacteria. The pectate gels showed a much higher tolerance against both complexing agents (phosphate, citrate, lactate, tartrate etc.)…”

Gel Entrapment and Micro-Encapsulation: Methods, Applications and Engineering Principles

“…Beads can be easily produced by dropping the polymer-cell solution into a cross-linking solution. Calcium (Navarro et al, 1983;Berger and Riihlemann, 1988;Gemeiner et al, 1989c;Tom et al, 1989) as well as aluminium (Berger and Riihlemann, 1989) have been used as counterions for the gellation of pectinate (Navarro et al, 1983;Berger and Rühlemann, 1988) and pectate (Berger and Rühlemann, 1988;Gemeiner et al, 1989;Toth et al, 1989) concentration is higher at the surface than in the centre of the gel (Skjäk-Braek et al, 1989). Calcium pectate as well as aluminium pectate beads ate much less sensitive to small monoand multivalent anions, i.e.…”

Properties of Hydrogel Materials Used for Entrapment of Microbial Cells in Production of Fermented Beverages

“…In contrast to the precedent papers [7,15,18 -20] (alginic acid, sodium salt of Fluka, Janssen Chimica, etc. [7,15,20] The following essential macromolecular properties of the respective precursors have to be checked at least when comparing suitability of both materials (CPG and CAG) for cell entrapment: average molecular weight (or, if necessary, limiting viscosity number, [15,20] Staudinger index, [18] calcium-linking uronate unit (D-galacturonate in pectate and L-guluronate in alginate) content [7,15,20] and, in the case of CPG, degree of esterification (d.e. Also further fundamental macromolecular characterictics data of this material are reported [21,22] and actualized continuously; [7,21] the Protanal grade preparations, recommended for immobilization and encapsulation of a large number of different cells including bacteria, yeasts, molds, algae, blue/green algae, plant and animal cells, are of high purity.…”

“…), the reference alginates described in this paper are represented by commercial preparation of sodium alginate (Protanal-produced by Protan Biopolymers, Drammen) with a known content of L-guluronic acid (Anonymous). [7,15,18] The necessary data either fully absented [24 -27] or were incomplete, [18,28,29] or the macromolecular properties of polyuronate gel precursors (pectate, alginate) were insufficiently compatible in papers [7,15,20] published so far. [23] This is also the reason why these commercial preparations are gaining dominant position as alginate carriers of immobilized biosystems.…”