Biotransformation of ricinoleic acid into g-decalactone by yeast cells: recent progress and current questions

Lactone aroma compounds production can be achieved biotechnologically by microbial fermentation and notably using yeasts. Many studies have been carried out to understand the mechanisms implicated in such bioreactions, and a pathway involving peroxisomal β-oxidation was established but some unelucidated points remain. In the recent years, new developments appeared proposing biotechnological ways to overcome and understand lactone toxicity or its commonly observed reconsumption and trying to explain some confused points like fatty acid emulsification, entry and storage into the cell. The importance of acyl-CoA oxidases in the metabolic pathway implicated and thus in the lactone production as well as on its reconsumption was also focused. Simultaneously with a presentation of the biotransformation pathways, these points are discussed in the light of new data including not yet published data obtained mainly with the yeast Yarrowia lipolytica.