Abstract
To explore the biocatalytic hydroxylation of vitamin D3 catalyzed by Bacillus cereus HDZJU1-11 in ionic liquid biphasic systems, a comparison was conducted of the substrate solubility and biocompatibility in 5 ionic liquids ([PrMIm][PF6], [BMIm][PF6], [BMIm][NTf2], [HMIm][PF6], and [OMIm][NTf2]) and the optimization of phase ratio, pH, and substrate concentration in ionic liquid biphasic systems was performed. [BMIm][PF6], [BMIm][NTf2], and[OMIm][NTf2] were chosen to construct biphasic systems. In [BMIm][PF6]/water biphasic system, the optimal conversion condition is as follows: 0.5 mg/mL vitamin D3 and [BMIm][PF6] (Vwater∶VIL=4∶1) are added after 12 h fermentation of Bacillus cereus, and the pH of water phase is 7.5. The concentration of 25-hydroxyvitamin D3 is increased to 0.38 mg/mL at 24 h fermentation. The optimal conversion conditions in ionic liquid biphasic systems are determined, which lays a foundation for expanding experiment and industrial applications.
Abstract
To explore the biocatalytic hydroxylation of vitamin D3 catalyzed by Bacillus cereus HDZJU1-11 in ionic liquid biphasic systems, a comparison was conducted of the substrate solubility and biocompatibility in 5 ionic liquids ([PrMIm][PF6], [BMIm][PF6], [BMIm][NTf2], [HMIm][PF6], and [OMIm][NTf2]) and the optimization of phase ratio, pH, and substrate concentration in ionic liquid biphasic systems was performed. [BMIm][PF6], [BMIm][NTf2], and[OMIm][NTf2] were chosen to construct biphasic systems. In [BMIm][PF6]/water biphasic system, the optimal conversion condition is as follows: 0.5 mg/mL vitamin D3 and [BMIm][PF6] (Vwater∶VIL=4∶1) are added after 12 h fermentation of Bacillus cereus, and the pH of water phase is 7.5. The concentration of 25-hydroxyvitamin D3 is increased to 0.38 mg/mL at 24 h fermentation. The optimal conversion conditions in ionic liquid biphasic systems are determined, which lays a foundation for expanding experiment and industrial applications.