Partial purification and characterization of lipoxygenase‐like enzyme from Pseudomonas aeruginosa 2HSP

Abstract

Naturally occurring renewable fatty acids in vegetable oil and their chemical derivatives are industrial useful compounds. Castor oil contains greater than 85% of its fatty acid component as ricinoleic acid and is an industrial useful compound. About 100 million pounds of soapstock is produced in the United States annually. Soapstock is a plentiful and relatively inexpensive byproduct of edible oil refining. The acidulated soapstock contains about 15% of free fatty acids (primarily as oleic acid and linoleic acid). We are interested in promoting the cash value of soapstock by converting fatty acids in soapstock to value-added hydroxy fatty acid derivatives. We recently isolated a microbe, Pseudomonas aeruginosa 2HSP, which is capable of transforming oleic acid to 10-hydroxy-8 (E)-octadecenoic (HOD) and 7,10-dihydroxy-8 (E)-octadecenoic (DOD). The transformation of oleic acid to HOD and then DOD has been proposed to include lipoxygenase and hydroxylase. However, the enzyme(s) has (have) never been fully explored yet. Our interest in lipoxygenase-like enzyme stems partly from the fact that HOD is a ricinoleic acid-like compound with potential industrial applications. We have partially purified lipoxygenase-like enzyme using ammonium sulfate fractionation and ion exchange chromatography. The enzyme activity was monitored by TLC analysis of the biotransformation products. This work is supported in part from by the grants from USDA CSREES 2004-35504-14712 and the University Research Council from Western Illinois University.