Production of a novel compound, 10,12-dihydroxystearic acid from ricinoleic acid by an oleate hydratase from Lysinibacillus fusiformis
文摘
A recombinant oleate hydratase from Lysinibacillus fusiformis converted ricinoleic acid to a product, whose chemical structure was identified as the novel compound 10,12-dihydroxystearic acid by gas chromatograph/mass spectrometry, Fourier transform infrared, and nuclear magnetic resonance analysis. The reaction conditions for the production of 10,12-dihydroxystearic acid were optimized as follows: pH-.5, 30?°C, 15?g?l? ricinoleic acid, 9?mg?ml? of enzyme, and 4?% (v/v) methanol. Under the optimized conditions, the enzyme produced 13.5?g?l? 10,12-dihydroxystearic acid without detectable byproducts in 3?h, with a conversion of substrate to product of 90?% (w/w) and a productivity of 4.5?g?l??h?. The emulsifying activity of 10,12-dihydroxystearic acid was higher than that of oleic acid, ricinoleic acid, stearic acid, and 10-hydroxystearic acid, indicating that 10,12-dihydroxystearic acid can be used as a biosurfactant.