Degradation of phenol by Trichosporon sp. LE3 cells immobilized in alginate

The degradation of phenol by freely suspended cells of Trichosporon sp. LE3 and alginate-immobilized cells was studied in batch culture. The alginate concentration (2 or 4%) and the cross-linking salt used (BaCl2 or CaCl2) affected the rate and percentage of phenol degradation. The highest values were obtained for immobilized cells at 2% calcium alginate, although complete degradation of 15 and 18 mM phenol was not observed. When the cell concentrations in the assays were doubled, the 2% calcium alginate-immobilized cells were able to degrade up to 30 mM phenol in less than 120 hours, although the free cells did not completely degrade phenol at concentrations above 20 mM. The maximum phenol degradation rate was a strong function of initial phenol concentrations, being the highest values being observed for 20 mM phenol.