On the merits of viable-cell immobilisation.

Aims: To evaluate the efficacy of a novel microencapsulation procedure using whey protein and pectin to improve the survival rate of Lactobacillus rhamnosus CRL 1505 to low pH and bile.



Methods and Results: Lactobacillus rhamnosus CRL 1505 was encapsulated by ionotropic gelation using pectin (PE) and pectin–whey protein (PE–WP). Both types of beads (MCPE/WP and MCPE–WP/WP) were covered with a layer of whey protein by complex coacervation. The noncapsulated lactobacilli were not sensitive to bile salts but to acid. Both microparticles protected Lact. rhamnosus CRL 1505 at pH 2·0, but only MCPE/WP was effective at pH 1·2.



Conclusions:  The combination of ionotropic gelation and complex coacervation techniques is efficient to obtain microcapsules of pectin covered with whey proteins. The MCPE/WP beads were more stable than the MCPE–WP/WP beads in simulated gastric conditions, thus offering better protection to Lact. rhamnosus CRL 1505 at low pH.



Significance and Impact of the Study:  Pectin beads with a whey protein layer (MCPE/WP) could be used as probiotic carrier in functional foods of low pH (e.g. apple juice), thus protecting Lact. rhamnosus CRL 1505 against the stressful conditions of the gastric tract.

Whey protein coating bead improves the survival of the probiotic Lactobacillus rhamnosus CRL 1505 to low pH.

Comparison of alginate and pectin based beads for production of poultry probiotic cells

Cells are generally found in an immobilized state in natural environments. In biotechnology, immobilization provides protection to the cell from unfavorable conditions, washout, shear, and immunological rejection. Moreover, immobilization provides for an organization of the cells, enabling synergistic interactions between adjacent cells. Multicellular organisms result from higher levels of cell organization and structure that result from a form of cell immobilization. It is therefore not surprising that scientists and engineers seriously consider cell immobilization as a means of solving technological problems involving the handling and processing of cellular materials.

Encapsulation and Immobilization Techniques

The first immobilization of a biological catalyst by sorption of invertase on the activated charcoal goes back to the 1916 However, the first impulse has soon been forgotten A new push came in the mid-1950s starting a real immobilization rush In the following years appeared thousands of papers and patents and many reviews and monographs (eg Zaborsky, 1973; Sundaram & Pye, 1974; Mosbach, 1976; Chibata, 1978; Wiseman, 1985)

Natural and Synthetic Carriers Suitable for Immobilization of Viable Cells, Active Organelles, and Molecules

It is shown that Ca- and Al-pectate gel beads prepared by use of high molecular weight polygalacturonic acid (viz. polygalacturonic acid having a high STAUDINGER index) are well suited for cell immobilization. The pectate 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 a high excess of sodium, potassium, and/or ammonium ions), even without addition of gelling cations to the liquid phase.

I. Rühlemann

Papers

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