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The current comparative analysis identifies options to control the position of acetyl group release at initial stages of reaction, and enzyme combinations likely to accelerate deacetylation of major hemicellulose sources.

Colorimetric detection of reaction products is typically preferred for initial surveys of acetyl xylan esterase (AcXE) activity. This chapter will describe common colorimetric methods, and variations thereof, for measuring AcXE activities on commercial, synthesized, and natural substrates. Whereas assays using pNP-acetate, α-naphthyl acetate, and 4-methylumbelliferyl acetate (4MUA) are emphasized, common methods used to measure AcXE activity towards carbohydrate analogs (e.g., acetylated p-nitrophenyl β-D-xylopyranosides) and various acetylated xylans are also described. Strengths and limitations of the colorimetric assays are highlighted.

Wheat arabinoxylan was treated with two α-arabinofuranosidases exhibiting different mode of action to create three different polymeric substrates. These three substrate preparations were characterized by xylopyranose backbone sugars that are (1) singly substituted by arabinose at C2 or C3, (2) doubly substituted by arabinose at C2 and C3, and (3) largely unsubstituted. All xylan preparations were grafted with glycidyl methacrylate using cerium ammonium nitrate and then evaluated in terms of graft yield and adsorption to cellulose surfaces. The highest graft yield was observed for the xylan preparation characterized by a largely unsubstituted xylopyranose backbone. Furthermore, QCM-D analyses revealed that grafted xylans exhibited a two-stage desorption pattern, which was not seen with the ungrafted xylans and was consistent with increased water sorption. Accordingly, this study demonstrates the potential of arabinofuranosidases to increase the yield and influence the viscoelastic properties of grafted xylans used as biobased cellulose coatings.