Heterologous Production of Calendic Acid Naturally Found in Calendula officinalis by Recombinant Fission Yeast

Calendic acid (CA) is a conjugated fatty acid with anti-cancer properties that is widely present in seed oil of Calendula officinalis. Using the co-expression of C. officinalis fatty acid conjugases (CoFADX-1 or CoFADX-2) and Punica granatum fatty acid desaturase (PgFAD2), we metabolically engineered the synthesis of CA in the yeast Schizosaccharomyces pombe without the need for linoleic acid (LA) supplementation. The highest CA titer and achieved accumulation were 4.4 mg/L and 3.7 mg/g of DCW in PgFAD2 + CoFADX-2 recombinant strain cultivated at 16 degrees C for 72 h, respectively. Further analyses revealed the accumulation of CA in free fatty acids (FFA) and downregulation of the lcf1 gene encoding long-chain fatty acyl-CoA synthetase. The developed recombinant yeast system represents an important tool for the future identification of the essential components of the channeling machinery to produce CA as a high-value conjugated fatty acid at an industrial level.

Automated summary

By co-expressing C. officinalis fatty acid conjugases (CoFADX-1 or CoFADX-2) and Punica granatum fatty acid desaturase (PgFAD2), we successfully engineered the synthesis of calendic acid (CA) in the yeast Schizosaccharomyces pombe without the need for linoleic acid (LA) supplementation. The highest CA titer achieved was 4.4 mg/L, with an accumulation of 3.7 mg/g of DCW in the PgFAD2 + CoFADX-2 recombinant strain cultivated at 16 degrees C for 72 h. This study provides a valuable tool for identifying the essential components needed to produce CA as a high-value conjugated fatty acid at an industrial scale.