Inmovilización de lactobacillus helveticus en soportes vítreos obtenidos por tecnología Sol-Gel

Abstract

The immobilization of bio catalyst agents like cells and enzymes, is a tool used to improve and simplify biotechnical continued industrial processes, given that it allows to work with higher concentrations of the bio catalyst agent, retain it inside the bioreactor to avoid their loss in the outside current, decreases the number of separation operations, and therefore, the cost of purification of the product. For such an end, we studied the technical feasibility of immobilizing cells of lactobacillus helveticus encapsulating it in supports elaborated by means of Sol-Gel process using as precursor tetraetil-orto-silicate (TEOS) and later, with immobilized cells, we studied the viability of the cells through its capacity of conversion of the lactose coming from the serum of milk in lactic acid. These results were compared with those obtained using free cells under the same operation conditions, and it was observed that the immobilized cells didn't only conserve their metabolic activity, but rather, in some cases, the conversion of lactose to lactic acid was improved. Obtained particles had size distribution among 1-3 mm, good mechanical resistance, stability in the support, and a pore size that it was not highly restrictive to the transfer of molecules between support and product. Finally, the immobilized cells showed good behaviour during at least five successive fermentations of 40 hours each one.