In situ detoxification of the fermentation medium during gamma-decalactoneproduction with the yeast Sporidiobolus salmonicolor

gamma-Decalactone (gamma-C-10) is known to be highly toxic for the microorg anims used for its production. In this work, three techniques were studied in order to overcome this toxicity during a bioconversion process using ric inoleic acid as precursor of the lactone: in situ trapping in oily phases, in porous hydrophobic sorbents and in beta-cyclodextrins. Oily phases added to the media (olive, Miglyol, tributyrin, and paraffin) had a protective e ffect on Sp. salmonicolor, and they improved the lactone production. beta-c yclodextrins, which have a hydrophobic cavity that can trap molecules such as gamma-C-10, have been used to protect the yeasts. The results showed ins ufficient preservation of cell viability. Some sorbents (activated carbon a nd polystyrene-based sorbents) were successfully tested during bioconversio n. In all cases viability exceeded the reference one. Nevertheless the arom a production was 30% lower than the reference. All of these solutions led t o some enhancement of the cell viability during bioconversion of methyl ric inoleate to gamma-C-10. For improvement of the lactone production, the oil trapping method seemed to be the best with the experimental conditions test ed.