Microbial conversion of beta-ionone by immobilized Aspergillus niger in the presence of an organic solvent.

Aspergillus niger JTS191 was capable of the conversion of beta-ionone to a mixture of its derivatives that is utilized to an essential oil of tobacco. The authors attempted this microbial conversion in the presence of an organic solvent to improve its reaction rate. The addition of isooctane accelerated the microbial conversion of beta-ionone. It took three days to complete the reaction whereas without isooctane it took more than six days. The addition of isooctane also improved the resistance of A. niger to the antifungal property of beta-ionone. A. niger pellets were immobilized in hydrophobic polymer, PU-3, and applied for the microbial conversion of beta-ionone. Further improvement of the resistance to the antifungal property of beta-ionone was achieved by immobilization. PU-3 immobilized A. niger was repeatedly used for microbial conversion of beta-ionone in the presence of isooctane for more than 480 hours.