Biosynthesis of short-chain fatty acids in lactating mammary supernatant

Abstract

1. 1. Acetate, acetoacetate, β-hydroxybutyrate and butyrate are effective precursors for the synthesis of butyric, hexanoic, octanoic, decanoic and longer-chain acids by the mammary supernatant obtained from lactating goats and rabbits. 2. 2. The distribution of 14C in the acids synthesized from specifically labeled substrates indicates that prior cleavage of acetoacetate and β-hydroxybutyrate is not necessary for the synthesis of butyric acid. 3. 3. Avidin had little effect on the synthesis of butyrate. The synthesis of hexanoic and longer-chain acids, however, was inhibited indicating the involvement of malonyl-CoA only in the stepwise elongation of the butyryl chain. 4. 4. Citrate was seen to enhance the synthesis of butyrate as well as the longerchain acids. It was also found to be helpful in preserving the enzyme system during storage.