Three novel rhamnogalacturonan I- pectins degrading enzymes from Aspergillus aculeatinus: Biochemical characterization and application potential

作者：Adrien Lemaire, Catalina Garzón, Aurore Perrin, Olivier Habrylo, Pauline Trezel, Solène Bassard, Valérie Lefebvre, Olivier Van Wuytswinkel, Anaïs Guillaume, Corinne Pau‐Roblot, Jérôme Pelloux · 发表于：Carbohydrate Polymers · 年份：2020 · DOI：10.1016/j.carbpol.2020.116752 · 被引用次数：35 · 研究领域：Polysaccharides and Plant Cell Walls、Biofuel production and bioconversion、Microbial Metabolites in Food Biotechnology

Rhamnogalaturonans I (RGI) pectins, which are a major component of the plant primary cell wall, can be recalcitrant to digestion by commercial enzymatic cocktails, in particular during fruit juice clarification process. To overcome these problems and get better insights into RGI degradation, three RGI degrading enzymes (RHG: Endo-rhamnogalacturonase; ABF: α-Arabinofuranosidases; GAN: Endo-β-1,4-galactanase) from Aspergillus aculeatinus were expressed in Pichia pastoris, purified and fully biochemically characterized. All three enzymes showed acidic pH optimum, and temperature optima between 40–50 °C. The Km values were 0.5 mg.ml−1, 1.64 mg.ml−1 and 3.72 mg.ml-1 for RHG, ABF, GAN, respectively. NMR analysis confirmed an endo-acting mode of action for RHG and GAN, and exo-acting mode for ABF. The application potential of these enzymes was assessed by measuring changes in viscosity of RGI-rich camelina mucilage, showing that RHG-GAN enzymes induced a decrease in viscosity by altering the structures of the RGI backbone and sidechains.