ABSTRACT
Different encapsulation matrices were tested for immobilized cells of Candida guillermondii UFMG-Y65 used for acetonitrile degradation. Acetonitrile degradation by free cells and cells immobilized in Ba-alginate, k-carrageenan and citric pectin was studied. The rate of acetonitrile degradation was monitored for 120h by measuring yeast growth and ammonia concentration. Different alginate concentrations did not affect cell viability, but the period of incubation in BaCl(2) solution reduced the number of viable cells. Likewise, the gel nature and the matrix structure of the support resulting from the cell immobilization conditions were of fundamental importance for biocatalyst activity and performance, affecting substantially the patterns of microbial growth and enzymatic activity. Alginate-immobilized cells degraded acetonitrile more efficiently than k-carrageenan or citric pectin-immobilized cells.