Abstract

CALCIUM-ALGINATE BEADS AS CARRIERS FOR BIOCATALYST ENCAPSULATION

*Michele Vitolo

Abstract

Beads resulting from the gelation of sodium alginate (SG800® and S1100®) with calcium chloride were evaluated in function of reagent concentrations (CaCl2: 0.05M, 0.1M and 0.4M; sodium alginate: 5 g/L, 10 g/L and 20 g/L) and temperatures (30oC and 40oC). Temperature does not affect significantly the production of beads, differently from reagent concentrations. The beads presented a high resistance to mechanical attrition (agitation of 1,000 rpm for 1 h) and fermentation stress (represented by the joint action of carbon dioxide pressure and the increasing in cell number). A linear correlation between the number of beads obtained and the calcium and alginate consumed, as well as an encapsulation yield over 90% (for example, SG800: 20g/L; 0.4M CaCl2; 98% and S1100: 20g/L; 0.4M CaCl2; 97%), was also observed.

Keywords: Immobilization, encapsulation, calcium chloride, alginate, entrapment.