Oxidation of medium-chain acyl-CoA esters by extracts of Aspergillus niger: enzymology and characterization of intermediates by HPLC

Summary: The activities of β-oxidation enzymes were measured in extracts of glucose-and triolein-grown cells of Aspergillus niger. Growth on triolein stimulated increased enzyme activity, especially for acyl-CoA dehydrogenase. No acyl-CoA oxidase activity was detected. HPLC analysis after incubation of triolein-grown cell extracts with decanoyl-CoA showed that β-oxidation was limited to one cycle. Octanoyl-CoA accumulated as the decanoyl-CoA was oxidized. β-Oxidation enzymes in isolated mitochondrial fractions were also studied. The results are discussed in the context of methyl ketone production by fungi.