Biotransformation of Poly R-478 by continuous cultures of PVAL-encapsulated Trametes versicolor under non-sterile conditions

Mycelia of Trametes versicolor were aseptically encapsulated in PVAL hydrogel beads of 1-2 mm diameter. The encapsulated mycelia were grown continuously in an aerated reactor under non-sterile conditions. After 65 days contamination of the PVAL hydrogel beads by bacteria was found only in the outer layer to a depth of 50 mu m The encapsulated fungi still expressed ligninolytic enzymes, as confirmed by the biotransformation of Poly R478. Elimination of Poly R-478 by encapsulated Trametes versicolor reached an efficiency of up to 89%, which was due partially to biotransformation (65%) and partially to adsorption onto biomass (24%). PVAL-encapsulated mycelia of Trametes versicolor were viable for at least 6 months without nutrient supplementation, if stored at 7 degrees C in a refrigerator. By encapsulation Trametes versicolor was apparently protected against microbial contaminants and against mechanical stress, which is known to inactivate ligninolytic enzymes. Encapsulated Trametes versicolor might thus be applicable for bioremediation to serve as an inoculum for reactor systems or for field-side applications.