Submitted to: Current Microbiology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/27/2006
Publication Date: 11/15/2008
Citation: Kuo, T., Huang, J., Labeda, D.P., Wen, L., Knothe, G.H. 2008. Production of 10-Hydroxy-8(E)-Octadecenoic Acid from Oleic Acid Conversion by Strains of Pseudomonas aeruginosa. Current Microbiology. 57(5):437-441. Interpretive Summary: Surplus vegetable oils represent attractive renewable resources for the production of useful chemicals. Previously, we found a special bacterial strain able to convert common fatty acids of vegetable oils to produce novel new bioproducts useful as surface-active substances and antifungal agents. In this study, we further examined other strains of this microorganism available in the Agriculture Research Service (ARS) Culture Collection (NRRL) for producing a compound structurally similar to ricinoleic acid, an important industrial hydroxy fatty acid, from oleic acid, an abundant fatty acid of soybean oil. The results showed that different strains varied for producing the desired compound and that a new strain was identified and further characterized for enhanced activity. The impact of this study provides new information and opportunity for researchers to develop a bioprocess for producing the new bioproduct alternative to ricinoleic acid, which is only available from import.
Technical Abstract: Eighteen Pseudomonas aeruginosa strains, including patent strain NRRL B-18602, three strains isolated from composted materials amended with ricinoleic acid and two isolated from sheep manure, as well as 12 randomly selected from the holdings of the Agricultural Research Service ARS) Culture Collection (NRRL), were examined for their ability to produce 10-hydroxy-8(E)-octadecenoic acid (HOD) from oleic acid conversion. The chemical structure of HOD was confirmed by gas chromatography-mass spectrometry, nuclear magnetic resonance and Fourier transform infrared spectroscopies. There were no substantial amounts of other new compounds found in the fermentation broths besides HOD and 7,10-dihydroxy-8(E)-octadecenoic acid. The results demonstrated that P. aeruginosa strains possessed varying levels of activity for producing HOD from oleic acid conversion. Using strain NRRL B-14938 as a model system for further characterization, optimal conditions for producing HOD were found to be at 26 deg C, pH 7.0 and after 60 h of reaction time in shake flasks using a medium containing EDTA as a chelating agent. This study has identified a high-yielding P. aeruginosa strain and provided the reaction characteristics for a scale-up production process of HOD that will be needed for testing its properties and potential new uses.