5,8-Dihydroxy-9,12,15(Z,Z,Z)-Octadecatrienoic Acid Production by Recombinant Cells Expressing Aspergillus nidulans Diol Synthase

Whole cells of recombinant Escherichia coli expressing diol synthase from Aspergillus nidulans produced 5,8-dihydroxy-9,12,15(Z,Z,Z)-octadecatrienoic acid from α-linolenic acid via 8-hydroperoxy-9,12,15(Z,Z,Z)-octadecatrienoic acid as an intermediate. The optimal conditions for 5,8-dihydroxy-9,12,15(Z,Z,Z)-octadecatrienoic acid production using whole recombinant cells were exhibited at pH 7.0, 40 °C, and 250 rpm with 40 g/L cells, 12 g/L, α-linolenic acid, and 5 % (v/v) dimethyl sulfoxide in a 250-mL baffled flask containing 50 mL reaction solution. Under these conditions, whole recombinant cells produced 9.1 g/L 5,8-dihydroxy-9,12,15(Z,Z,Z)-octadecatrienoic acid for 100 min, with a conversion yield of 75 % (w/w), a volumetric productivity of 5.5 g/L/h, and specific productivity of 137 mg/g-cells/h. As an intermediate, 8-hydroperoxy-9,12,15(Z,Z,Z)-octadecatrienoic acid was observed at approximately 1.4 g/L after 100 min. With regard to dihydroxy fatty acid production, this is the highest reported volumetric and specific productivities thus far. This is the first report on the biotechnological production of 5,8-dihydroxy-9,12,15(Z,Z,Z)-octadecatrienoic acid.