Precursor direct biosynthesis of odd-chain polyunsaturated fatty acids by oomycete Pythium

The growing demand for improving the nutritional value of food has driven efforts to enhance the production of polyunsaturated fatty acids (PUFAs) through microbial cultivation, mainly using low-cost substrates in closed-loop systems. One promising approach is precursor-driven biosynthesis, which enables the controlled production of odd-chain PUFAs. In this study, we cultivated two oomycetes from the genus Pythium (ATCC 38472 M1 and X42) under 20 different conditions in the presence of propionic acid and TWEEN 80 to stimulate the production of odd-chain PUFAs. This approach led to an increased yield of specific odd-chain PUFAs, including C17:2ω6, C17:3ω3, C17:4ω3, C19:2ω5, C19:3ω5, C19:4ω5, and C19:5ω2. The microorganisms were grown in two different media: potato dextrose broth (PDB) and waste brewery yeast, either alone or supplemented with propionic acid and/or TWEEN 80. The addition of propionic acid facilitated the biosynthesis of odd-chain PUFAs without the need for genetically modified strains, yielding quantities suitable for fermenter-scale production.