Figure 5.

Adsorption isotherms of enzymatically tailored water-extracted mucilage from wild-type Col-0. Water-extracted mucilage was partially degraded with RGase (3 h) and then precipitated with ethanol. The ethanol precipitate was recovered as enzymatically tailored mucilage. The mass of bound material per mass of cellulose (q_e) and the concentration of free material remaining in solution at equilibrium concentration (C_e) were quantified. Values are means ± sd of two technical replicates. A, Binding isotherms show that, in contrast to the ethanol-soluble fraction (black squares), the ethanol precipitate (white squares) is able to bind to cellulose in vitro. B, Binding isotherms for each of the main individual sugars (Rha, GalA, and Xyl) in the ethanol precipitate show that Xyl strongly adsorbs onto the cellulose surface (black circles), with Rha (black triangles) and GalA (white triangles) binding more weakly. C, A linearized form of the Langmuir model was applied to the Xyl-binding isotherm experimental data shown in B. A maximum adsorption capacity of 37 µg Xyl mg⁻¹ cellulose and an adsorption constant of 0.0311 mL µg⁻¹ Xyl were determined, corresponding to a modest maximum adsorption capacity but a very high affinity of the polymer for cellulose.