Microencapsulation of Baker’s Yeast in Gellan Gum Beads Used in Repeated Cycles of Glucose Fermentation

Abstract

The purpose of this work is to prepare ionically cross-linked (with CaCl 2 ) gellan particles with immobilized yeast cells for their use in repeated fermentation cycles of glucose. The study investigates the influence of ionic cross-linker concentration on the stability and physical properties of the particles obtained before extrusion and during time in the coagulation bath (the cross-linker solution with different CaCl 2 concentrations). It was found that by increasing the amount of the cross-linker the degree of cross-linking in the spherical gellan matrix increases, having a direct influence on the particle morphology and swelling degree in water. These characteristics were found to be very important for diffusion of substrate, that is, the glucose, into the yeast immobilized cells and for the biocatalytic activity of the yeast immobilized cells in gellan particles. These results highlight the potential of these bioreactors to be used in repeated fermentation cycles (minimum 10) without reducing their biocatalytic activity and maintaining their productivity at similar parameters to those obtained in the free yeast fermentation. Encapsulation of Saccharomyces cerevisiae into the gellan gum beads plays a role in the effective application of immobilized yeast for the fermentation process.

Microencapsulation of Saccharomyces cerevisiae into Alginate Beads: A Focus on Functional Properties of Released Cells

“…Delayed kinetic of cell release could be exploited in alcoholic fermentation processes, since the cell growth in the beads contribute to increase the final ethanol concentration. Moreover, microencapsulated yeasts could be used in a continuous fermentation process due to several advantages such as the ease of cell separation from the medium, a cost reduction due to the reuse of cells in subsequent reaction cycles and a reduced possibility of contamination, as reported by different authors [42,43]. After assessing the optimization of method, the effect of microencapsulation was studied on some selected functional properties of yeasts (hydrophobicity, auto-aggregation, biofilm formation, survival).…”

An Accessible Method to Improve the Stability and Reusability of Porcine Pancreatic α-Amylase via Immobilization in Gellan-Based Hydrogel Particles Obtained by Ionic Cross-Linking with Mg2+ Ions

“…In previous research, we obtained gellan-based hydrogel particles ionically cross-linked with magnesium acetate, zinc acetate, or calcium chloride using immobilized yeast cells that can be used in multiple fermentation cycles for ethanol production. Thus, it was demonstrated that the gellan matrices obtained by ionic cross-linking are stable, maintain the cellular viability of yeast cells, and can be used in several different fermentation cycles; the maximum number was 40 for the gellan particles cross-linked with magnesium acetate [ 82 , 83 , 84 ].…”

“…The originality of our work lies in the immobilization of α-amylase in hydrogel particles ionically cross-linked with magnesium acetate. Mg 2+ ions were used for cross-linking the gellan-based particles because an increase in the activity of the bioactive component immobilized in this type of particles was observed [ 82 ] compared to the studies carried out with gellan particles cross-linked with Ca 2+ [ 83 ] or Zn 2+ ions [ 84 ].…”

Modeling the Physical Properties of Gamma Alumina Catalyst Carrier Based on an Artificial Neural Network

“…Numerous studies have been conducted on neural networks as prediction alternatives for metal-based properties; however, for ceramic-based carriers, the implementation of ANNs is not yet ordinarily used. In the present work, an ANN numerical model is used to predict the physical properties of a porous alumina ceramic carrier [11,14]. This involves the concentration of yeast, the temperature of sintering, and soaking times as input parameters with three diverse readings taken to enhance the accuracy of the results and reduce the estimation error.…”