Production of oleamide, a functional lipid, by Streptomyces sp. KK90378

Oleamide (cis-9-octadecenamide) is an endogenous primary amide of fatty acid that is produced in small amounts in animal brains. It is known to induce sleep and to lower temperature by destroying the lipid plasma membrane structure of cells, thereby disclosing gap junction channels. To develop a new biological production method for oleamide, a screening program was conducted to isolate a microorganism producing oleamide. Among 1,500 soil microorganisms tested, KK90378 exhibited a potent positive reaction with Dragendorff's reagent, used to detect the primary amide of oleamide. KK90378 was identified as a Streptomyces species based on cultural and morphological characteristics, the presence of diaminopimelic acid in the cell wall, and the sugar patterns for the whole-cell extract. Streptomyces sp. KK90378 produced oleamide 3 days after culture at 28°C, pH 7.2. A series of purification steps, including hexane extraction, silica gel column, and preparative thin layer chromatographies, were performed for the purification of oleamide. A spectrophotometric analysis using ¹H, ¹³C-NMR, and GC-MS confirmed that the chemical structure of the purified oleamide was identical to that of authentic oleamide.