Biotransformation of linalool to furanoid and pyranoid linalool oxides by Aspergillus niger

Biotransformation of (+/-)-linalool with submerged shaking cultures of Aspergillus niger, particularly A. niger ATCC 9142, yielded a mixture of cis- and trans-furanoid linalool oxide (yield 15-24%) and cis- and trans-pyranoid linalool oxide (yield 5-9%). Biotransformation of (R)-(-)-linalool with the same strain yielded almost pure trans-furanoid and trans-pyranoid linalool oxide (ee > 95). These conversions were purely biocatalytic, since in acidified water (pH < 3.5) almost 50% linalool was recovered unchanged, the rest was lost by evaporation. The biotransformation was also carried out with growing surface cultures.