Biotransformation of the Proteogenic Amino Acids Phenylalanine, Tyrosine and Tryptophan by Yarrowia Species: An Application to the Preparative Synthesis of Natural Phenylacetic Acid

Abstract

The biotransformation of the aromatic amino acids phenylalanine, tyrosine and tryptophan originates a number of bioactive compounds. Yeasts are the most used microorganisms for the transformation of (L)-phenylalanine into the flavour phenylethanol. Here, we reported a study on the biotransformation of the proteogenic aminoacids phenylalanine, tyrosine and tryptophan by yeast strains belonging to Yarrowia genus. We found that the latter microorganisms, in high aerobic conditions, metabolise the aromatic amino acids (L)-phenylalanine and (L)-tyrosine with the almost exclusive formation of phenylacetic acid and 4-hydroxyphenylacetic acid, respectively. Differently, the biotransformation of (L)-tryptophan with Y. lipolytica, gave anthranilic acid as the main product. As stated by the European and USA legislations concerning natural flavour production, phenylacetic acid obtained by microbial conversion of phenylalanine of natural origin can be commercialised as a natural flavour. Accordingly, our findings were exploited in a new process, based on the Yarrowia strains-mediated biotransformation of natural (L)-phenylalanine, that allows the large-scale preparation of the high-value, natural flavour, phenylacetic acid.

Yarrowia lipolytica Yeast: A Treasure Trove of Enzymes for Biocatalytic Applications—A Review

“…Since this review article concerns the biosynthesis of valuable compounds for use in various industries, the authors' attention is more focused on the metabolism of other groups of compounds, such as proteinogenic amino acids. In the research of Serra et al [36], the strain Y. lipolytica DSM 8218 conducted a biotransformation of L-phenylalanine to 2-phenylethanol and phenylacetic acid (Figure 3). Under low aeration conditions, the yield of the latter two was 16.1%, while the concentration of phenylacetic acid was 0.47 g/L.…”

“…Moreover, the authors also took into account two other aromatic amino acids, i.e., L-tyrosine and L-tryptophan. The biotransformation of the former amino acid led to obtaining of an analogous derivative and thus 4-hydroxyphenylacetic acid, while the application of L-tryptophan in the concentration of 5 g/L resulted in the biosynthesis of 2-aminobenzoic acid (anthranilic acid, 33.6%), indole-3-lactic acid (16%), and indolacetic acid (1.3%) [36].…”