Evaluation of environmental parameters for production of 7, 10-dihydroxy-8(E)-octadecenoic acid from olive oil by Pseudomonas aeruginosa PR3

Research Highlights
• Optimization of environmental factors for production of dihydroxy fatty acid from olive oil.
• Production of dihydroxy fatty acid was highly dependant on kind and concentration of carbon source.
• Maximum conversion yield reached up to 85% of the substrate added.
• Magnesium ion was critically required for dihydroxy fatty acid production.

Microbial conversions of the free unsaturated fatty acids often generate novel hydroxy fatty acids (HFA), which are known to have special properties such as higher viscosity and reactivity. Among microbial strains known to produce HFAs, Pseudomonas aeruginosa PR3 has been well studied to produce 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) from the free oleic acid. Previously we reported that the strain PR3 could utilize olive oil instead of oleic acid as a substrate for production of DOD (Suh et al., 2011. Applied Microbiology and Biotechnology, 89, 1721–1727). In this study, we evaluated the environmental parameters for DOD production from olive oil by PR3. DOD production was closely related to the species and concentration of carbon source. Glucose and galactose showed optimal DOD production at 0.2% and 0.4%, respectively. Addition of 1.5% oil substrate to the culture 36 h after initiation of cultivation under 200 rpm represented a maximal 318 mg DOD production in 50 ml culture, corresponding to 85% conversion yield over the oleic acid content in olive oil.