Production of 10R-hydroxy unsaturated fatty acids from hempseed oil hydrolyzate by recombinant Escherichia coli cells expressing PpoC from Aspergillus nidulans

Abstract

The first and second preferred substrates of recombinant Escherichia coli cells expressing 10R-dioxygenase (PpoC) from Aspergillus nidulans and the purified enzyme were linoleic acid and α-linolenic acid, respectively. PpoC in cells showed higher thermal and reaction stabilities compared to purified PpoC. Thus, 10R-hydroxy unsaturated fatty acids were produced from linoleic acid, α-linolenic acid, and hempseed oil hydrolyzate containing linoleic acid and α-linolenic acid as substrates by whole recombinant cells expressing PpoC. The optimal reaction conditions for the production of 10R-hydroxy-8E,12Z-octadecadienoic acid (10R-HODE) were pH 8.0, 30 °C, 250 rpm, 5 % (v/v) dimethyl sulfoxide, 5 g l⁻¹ linoleic acid, and 60 g l⁻¹ cells in 100-ml baffled flask. Under these conditions, whole recombinant cells expressing PpoC produced 2.7 g l⁻¹ 10R-HODE from 5 g l⁻¹ linoleic acid for 40 min, with a conversion yield of 54 % (w/w) and a productivity of 4.0 g l⁻¹ h⁻¹; produced 2.2 g l⁻¹ 10R-hydroxy-8E,12Z,15Z-octadecatrienoic acid (10R-HOTrE) from 3 g l⁻¹ α-linolenic acid for 30 min, with a conversion yield of 72 % (w/w) and a productivity of 4.3 g l⁻¹ h⁻¹; and produced 1.8 g l⁻¹ 10R-HODE and 0.5 g l⁻¹ 10R-HOTrE from 5 g l⁻¹ hempseed oil hydrolyzate containing 2.5 g l⁻¹ linoleic acid and 1.0 g l⁻¹ α-linolenic acid for 30 min, with a conversion yield of 74 and 51 % (w/w), respectively, and a productivity of 3.6 and 1.0 g l⁻¹ h⁻¹, respectively. To the best of our knowledge, this is the first report on the biotechnological production of 10R-hydroxy unsaturated fatty acids.