Preparation and Biological Regulation of Lactones by Microbial Transformation: A Review

Lactones are widely used in confectionery, beverages, dairy products, baking and other foods due to their typical creamy, floral and fruity aromas. In recent years, because consumers prefer the natural properties of products, the preparation and biological regulation of lactones by microbial transformation has attracted much attention. The microbial transformation mechanisms of γ- and δ-lactones are reviewed in this paper, including the way of fatty acids entering mitochondria, β-oxidation, cyclization and degradation metabolic pathways. The existing regulation methods of microbial transformation are also summarized, such as gene regulation based on genomics, dissolved oxygen, substrate batch culture, cell immobilization and strain mutagenesis. The research direction of regulation of lactones is prospected, which can provide reference for more economical and efficient microbial transformation of lactones.