The conversion of ricinoleic acid from renewable sources to long-chain α,ω-dicarboxylic acids or w-hydroxyl carboxylic acids by microbial processes is constrained by toxicity issues. Here, we demonstrate the possible role of Corynebacterium glutamicum as a new microbial strategy for the biotransformation of fatty acids. The established strain Escherichia coli failed to grow at 5 mM n-heptanoic acid, while the specific growth rate of C. glutamicum declined by 28%. We partially constructed a previously designed multistep biocatalytic pathway in C. glutamicum, and confirmed that the C. glutamicum biocatalyst successfully converted ricinoleic acid to undec-9-enoic acid, heptyl ester via 12-keto-oleic acid. We investigated the effects of cultivation and reaction temperatures, and the type and concentration of non-ionic detergent on recombinant C. glutamicum whole-cell bioconversion. At a cultivation temperature of 30 °C and a reaction temperature of 35 °C, and in the presence of 0.09 g/L Triton X-100, the whole-cell C. glutamicum biocatalyst produced 0.8 mM undec-9-enoic acid, heptyl ester from 1.9 mM 12-ketooleic acid. It also generated 0.7 mM undec-9-enoic acid, heptyl ester from 5.5 mM ricinoleic acid. This is the first report of undec-9-enoic acid, heptyl ester production using a recombinant C. glutamicum-based biocatalyst.
Bibliographical noteFunding Information:
This research was supported by the MOTIE/KEIT R&D Program (No. 10044604, Bioproduction of long-chain dicarboxylic acids from fatty acids and lipids) and C1 Gas Refinery Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (2015M3D3A1A01064929).
© 2017 Elsevier Ltd
- Corynebacterium glutamicum
- Heptyl ester
- Renewable fatty acid
- Undec-9-enoic acid