Linoleate 13-hydratase from Lactobacillus acidophilus LMG 11470 converted linoleic acid to hydroxyl fatty acid, which was identified as 13S-hydroxy-9(Z)-octadecenoic acid (13-HOD) by GC-MS and NMR. The expression of linoleate 13-hydratase gene in Escherichia coli was maximized by using pACYC plasmid and super optimal broth with catabolite repression (SOC) medium containing 40mM Mg2+. To optimize induction conditions, recombinant cells were cultivated at 37°C, 1mM isopropyl-β-d-thiogalactopyranoside was added at 2h, and the culture was further incubated at 16°C for 18h. Recombinant cells expressing linoleate 13-hydratase from L. acidophilus were obtained under the optimized expression conditions and used for 13-HOD production from linoleic acid. The optimal reaction conditions were pH 6.0, 40°C, 0.25% (v/v) Tween 40, 25gl-1 cells, and 100gl-1 linoleic acid, and under these conditions, whole recombinant cells produced 79gl-1 13-HOD for 3h with a conversion yield of 79% (w/w), a volumetric productivity of 26.3gl-1h-1, and a specific productivity of 1.05g g-cells-1h-1. To the best of our knowledge, the recombinant cells produced hydroxy fatty acid with the highest concentration and productivity reported so far.
- 13S-Hydroxy-9(Z)-octadecenoic acid
- Lactobacillus acidophilus
- Linoleate 13-hydratase
- Linoleic acid
- Whole cell conversion