Expression of a Recombinant Cholesterol Esterase from Mustela putorius furo in Pichia pastoris and Its Applicability for γ-Oryzanol Hydrolysis.

Ferulic acid (FA) exhibits antioxidant and anti-inflammatory properties, making it valuable for numerous industrial applications. Traditionally, FA is produced by the alkaline hydrolysis of γ -oryzanol, which is typically associated with wastewater generation. Recently, an increasing demand of natural FA necessitates its green production via enzymatic hydrolysis of γ -oryzanol, a mixture comprising triterpene alcohol ferulates and phytosteryl ferulates. Thus far, γ -oryzanol can be hydrolyzed by only four commercial cholesterol esterases with low yields. Herein, we report a recombinant cholesterol esterase from Mustela putorius furo (MPFCE) for the enzymatic hydrolysis of γ -oryzanol. The enzyme yielded 25.5% FA, which is the highest reported through enzymatic means thus far. The hydrolysis profile revealed that the enhanced yield primarily resulted from the near-complete hydrolysis of phytosteryl ferulates, together with slight hydrolysis of triterpene alcohol ferulates. MPFCE serves as a potential candidate for the enzymatic production of FA through targeted hydrolysis of γ -oryzanol.