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Microbial modification of naturally occurring materials is one of the efficient ways to add new values to them. Hydroxylation of free unsaturated fatty acids by microorganism is a good example of those modifications. Among microbial strains studied for that purpose, a new bacterial isolate Pseudomonas aeruginosa PR3 has been well studied to produce several hydroxy fatty acids from different unsaturated fatty acids. Of those hydroxy fatty acids, 7,10-dihydroxy-8( E)-octadecenoic acid (DOD) was efficiently produced from oleic acid by strain PR3. However, it was highly plausible to use vegetable oil containing oleic acid rather than free oleic acid as a substrate for DOD production by strain PR3. In this study, we firstly tried to use olive oil containing high content of oleic acid as a substrate for DOD production. DOD production from olive oil was confirmed by structural determination with GC, TLC, and GC/MS analysis. DOD production yield from olive oil was 53.5%. Several important environmental factors were also tested. Galactose and glutamine were optimal carbon and nitrogen sources, and magnesium ion was critically required for DOD production from olive oil. Results from this study demonstrated that natural vegetable oils containing oleic acid could be used as efficient substrate for the production of DOD by strain PR3. [ABSTRACT FROM AUTHOR]

Hydroxy fatty acids are considered as important value-added product for industrial application because of their special properties such as higher viscosity and reactivity. Microbial production of the hydroxy fatty acids from various fatty acid substrates have been actively studied using several microorganisms. The new bacterial isolate Pseudomonas aeruginosa (PR3) had been reported to produce mono-, di-, and tri-hydroxy fatty acids from different unsaturated fatty acids. Of those, 7,10-dihydroxy-8( E)-octadecenoic acid (DOD) and 7,10,12-trihydroxy-8( E)-octadecenoic acid (TOD) were produced from oleic acid and ricinoleic acid, respectively. Based on the postulated common metabolic pathway involved in DOD and TOD formation by PR3, it was assumed that palmitoleic acid containing a singular 9- cis double bond, common structural property sharing with oleic acid and ricinoleic acid, could be utilized by PR3 to produce hydroxy fatty acid. In this study, we tried to use palmitoleic acid as substrate for production of hydroxy fatty acid by PR3 and firstly confirmed that PR3 could produce 7,10-dihydroxy-8( E)-hexadecenoic acid (DHD) with 23% yield from palmitoleic acid. DHD production was peaked at 72 h after the substrate was added to the 24-h-culture. [ABSTRACT FROM AUTHOR]

Hydroxy fatty acids (HFA) have gained importance because of their special properties such as higher viscosity and reactivity compared with other non-hydroxy fatty acids. The bacterial isolate Pseudomonas aeruginosa (PR3) was reported to produce mono-, di-, and trihydroxy fatty acids from different unsaturated fatty acids. Of those, 7,10-dihydroxy-8( E)-octadecenoic acid (DOD) was produced with high yield from oleic acid by PR3. Up to now, the substrates used for microbial HFA production were free fatty acids. However, it is possible to utilize triacylglycerides, specifically triolein containing three oleic groups, as a substrate by microbial enzyme system involved in HFA production from oleic acid. In this study we used triolein as a substrate and firstly report that triolein could be efficiently utilized by PR3 to produce DOD. Triolein was first hydrolyzed into oleic acid by the triolein-induced lipase and then the released oleic acid was converted to DOD by PR3. Results from this study demonstrated that natural vegetable oils, without being intentionally hydrolyzed, could be used as efficient substrates for the microbial production of value-added hydroxy fatty acids. [ABSTRACT FROM AUTHOR]

Paraquat-induced pulmonary fibrosis involves two factors, direct injury by oxygen free radicals and indirect injury by inflammatory cells and fibroblasts. Endothelin-1 (ET-1) has been shown to act as a mediator of pulmonary fibrosis, and its formation increases during oxidative stress. We investigated whether green tea extract (GTE), which has antioxidant properties, inhibits paraquat-induced pulmonary fibrosis and whether ET-1 is involved in this process. Paraquat (0.3 mg/kg) was instilled into the right lungs of rats, following which the rats were either not further treated (Group P, n = 7), or they were administered 1% GTE mixed with feed (Group PG; n = 7) or the ETA receptor antagonist ZD2574 (10 mg/kg through gavage; Group PZ; n = 7) for two weeks. As control, we used rats instilled with saline (Group N; n = 6). Two weeks after paraquat instillation, we assayed the degree of pulmonary fibrosis by light microscopic morphometry and hydroxyproline content; lipid peroxidation as a marker of oxidative stresses by measurement of malondialdehyde (MDA); ET-1 by immunohistochemistry; and prepro-ET-1 mRNA expression by reverse transcription-polymerase chain reaction. Compared with Group N, significant pulmonary fibrosis was observed in Group P, accompanied by increases in MDA, ET-1, and prepro-ET-1 mRNA expression. Compared with Group P, Group PG showed significant decreases in pulmonary fibrosis, along with decreases in MDA, ET-1, and prepro-ET-1 mRNA expression. We also observed significant decreases in pulmonary fibrosis in Group PZ compared with Group P. These findings suggest that GTE inhibits paraquat-induced pulmonary fibrosis by suppression of oxidative stress and ET-1 expression. [ABSTRACT FROM AUTHOR]