Production of 13S-hydroxy-9(Z)-octadecenoic acid from linoleic acid by whole recombinant cells expressing linoleate 13-hydratase from Lactobacillus acidophilus

Abstract

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 40 mM Mg2+. To optimize induction conditions, recombinant cells were cultivated at 37 degrees C, 1 mM isopropyl-beta-D-thiogalactopyranoside was added at 2 h, and the culture was further incubated at 16 degrees C for 18 h. 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 degrees C, 0.25% (v/v) Tween 40, 25 gl(-1) cells, and 100 gl(-1) linoleic acid, and under these conditions, whole recombinant cells produced 79 gl(-1) 13-HOD for 3 h with a conversion yield of 79% (w/w), a volumetric productivity of 26.3 gl(-1) h(-1), and a specific productivity of 1.05 g g-cells(-1) h(-1). To the best of our knowledge, the recombinant cells produced hydroxy fatty acid with the highest concentration and productivity reported so far. Crown Copyright (C) 2015 Published by Elsevier B.V. All rights reserved.