Student of Biotechnology,

Abstract: Lipoxygenase (linolenate: oxygen oxidoreductase (E.C.1.13.1.13) is found in a wide variety of plants, particularly the legumes. It is present in groundnut, soyabeans, peas, potato and wheat. Under appropriate conditions, this enzyme leads to the deterioration of fat-soluble vitamins and essential fatty acids of oils and fats. Since little is known about this enzyme in rice bran (which is a good source for edible grade oil), work on this aspect is undertaken. This enzyme when reacted with substrate (rice bran oil) yields oxylipins. Oxylipins are saturated and unsaturated oxidized fatty acids. These compounds include the eicosanoids (e.g. prostaglandins, thromboxanes, leukotrienes, lipoxygenase products), many of which are pharmacologically important compounds with biological activities. These compounds are highly toxic towards bacteria and fungi. This study aims at isolating lipoxygenase from rice bran and using the oxylipin produced by the enzyme reaction which is used to inhibit Pseudomonas aeruginosa, an opportunistic human pathogen. Results of partially purified enzyme activity are found to be 0.65/ml/min. Whereas inhibition zone of 2.2 cm is observed with the produced oxylipins which are lower than that of the used standard antibiotic Streptomycin i.e., 2.6 cm. In conclusion partially purified enzyme has provided an oxylipin showing low inhibition compared with standard which is not surprising as it is a pure antibiotic. Further the study is suggestive to use the pure compound as antibiotic