Identification of molecular species of polyol oils produced from soybean oil by Pseudomonas aeruginosa e03-12 nrrl b-59991

Authors: Hou, Ching; Lin, Jiann; Ray, Karen

Submitted to: Biocatalysis and Agricultural Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/7/2015
Publication Date: 9/25/2015
Citation: Hou, C.T., Lin, J.T., Ray, K. 2015. Identification of molecular species of polyol oils produced from soybean oil by Pseudomonas aeruginosa E03-12 NRRL B-59991. Biocatalysis and Agricultural Biotechnology. 4(4):500-505. doi: 10.1016/j.bcab.2015.08.017.

Interpretive Summary: Soy-polyol oils (oxygenated triacylglycerols) are important starting materials for the manufacture of polymers such as polyurethane. Currently, they are produced by a two step chemical process involving epoxidation and then the subsequent opening of the oxirane ring. The objective of this study is to develop a new bioprocess to produce polyol oils directly from soybean oil. We succeeded in establishing a new method for microbial screening and products separation by using High Performance Liquid Chromatography (HPLC) and Thin Layer Chromatography (TLC). With our new screening method, we screened 650 cultures from soil and water samples. The top 11 polyol oil producers are bacteria belonging to either Acinetobacter or Pseudomonas. The polyol oil produced by Acinetobacter haemolyticus A01-35 were a mixture of many DAG containing hydroxy FA and normal FA. In this study, we examined another strain Pseudomonas aeruginosa E03-12 and found that it produced both polyols of TAGs and DAGs. Strain E03-12 produced more polyol oils than stain A01-35. Our findings accelerate the establishment of a new bioprocess for the production of polyol oils from soybean oil and will benefit the U.S. farmers.

Technical Abstract: The objective of this study is to develop a bioprocess for the production of polyol oils directly from soybean oil. We reported earlier methods for microbial screening and production of polyol oils from soybean oil (Hou and Lin, 2013). The polyol oil produced by Acinetobacter haemolyticus A01-35 (NRRL B-59985) were a mixture of 57 molecular species of DAG containing tri-, di-, mono-hydroxy FA and normal FA. The top 11 positive cultures out of the 650 cultures screened were identified (Hou et al., 2014) as bacteria belonging to either Pseudomonades or Acinetobacters. In our continuous studies, we found that strain A01-35 produced more DAGs containing normal fatty acids than polyol oils. In this study, we examined another producers Pseudomonas aeruginosa E03-12 NRRL B-59991 for its polyol oils production. Tricaprylin was selected as internal standard for HPLC quantitative estimation of products. A CombiFlash chromatographic method using hexane and acetone on a normal phase silica column was established for separation of the polyol oil products. The molecular species of the polyol oils produced from soybean oil by strain E03-12 were identified with HPLC/MS. We identified 41 molecular species of DAG, among them 32 molecular species containing one hydroxy FA and one normal FA, 8 molecular species containing two hydroxy FA without normal FA, and one molecular species containing two normal FA without hydroxy FA. The hydroxy FA included mono-, di- and tri-hydroxy FA. Eight molecular species of DAG containing one trihydroxy FA and 14 molecular species of DAG containing one dihydroxy FA. We have also identified 64 molecular species of TAG, among them 13 molecular species containing two hydroxy FA, 42 molecular species containing one hydroxy FA and 9 molecular species containing no hydroxy FA. This is different from our previous findings with Acinetobacter haemolyticus A01-35 which produced only DAG polyol oils. Apparently Pseudomonas aeruginosa E03-12 NRRL B-59991 has very active hydroxylase for the production of hydroxy acylglycerols.