Effects of fatty acid synthase-inhibitors on polyunsaturated fatty acid production in marine diatom Fistulifera solaris JPCC DA0580

Abstract

Omega-3 polyunsaturated fatty acids (PUFAs) such as eicosapentaenoic acid (EPA, C20:5ω-3) are essential for human health and fish growth especially in aquaculture sector. However, with the growing of aquaculture, the demand of PUFA supply also has been increasing. Fistulifera solaris, a marine diatom, is known for its ability to accumulate 65% of lipid content per dry cell weight, and can produce the high content of EPA. Thus, this diatom shows a great potential to be a feedstock of omega-3 PUFAs for fish feeds. In this study, in order to further understand and enhance the metabolism of PUFA biosynthesis in the diatom, the impacts of ketoacyl-ACP synthase (KAS) and ketoacyl-CoA synthase (KCS) inhibition on the PUFA production were analyzed by adding the specific inhibitors. KAS and KCS enzymes both play a role in the fatty acid elongation. As a result, the inhibition of KAS showed an increase in EPA content without arresting the cell growth. On the other hand, inhibition of KCS did not show a significant impact on the PUFA content in F. solaris. Our finding suggests that the specific suppression of KAS function can be a promising way to enhance the omega-3 PUFA production in F. solaris.

Keywords: Alachlor; Cafenstrole; Cerulenin; Diatom; Eicosapentaenoic acid; Ketoacyl-ACP synthase; Ketoacyl-CoA synthase; Omega-3 polyunsaturated fatty acids.