Stable carbon isotope fractionation of fatty acid in sea cucumber (Apostichopus japonicus): insights from an experimental study

ABSTRACT

Isotope fractionation of fatty acids can reflect the metabolic pathway of fatty acids in organisms, but few studies have been conducted. In this study, stable carbon isotope fractionation of fatty acids in sea cucumber (Apostichopus japonicus) was conducted by feeding experiments of comparing the fatty acid profile and δ¹³C of fatty acids in body wall to diet. The results showed that the fractionation of δ¹³C of fatty acids in A. japonicus was −1.588–7.403‰. The fractionation of δ¹³C of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs) was 1.098–7.403‰, −1.588–2.778‰, and −1.559–5.614‰, respectively. The degree of fractionation of δ¹³C of SFAs was greater than that of unsaturated fatty acids (UFAs). We simulated the possible metabolic process of fatty acids in A. japonicus based on fatty acid profile and δ¹³C of fatty acids, indicating that the combination of these two methods could be potentially used in the study of fatty acid metabolism in marine benthic animal of A. japonicus. Our finding provides a new technique for the metabolic pathways of biomolecules in organisms.

KEYWORDS:

• Fatty acid profile
• δ¹³C value
• isotope fractionation
• compound-specific isotope analysis (CSIA)
• metabolic pathway

Acknowledgments

We thank professor Yang of College of Fisheries and Life Science, Dalian Ocean University for his guidance in laboratory culture of A. japonicus.

Disclosure statement

No potential conflict of interest was reported by the author(s).