Glucuronoyl esterases – production, characterization and their role in hydrolysis of lignin-carbohydrate ester bonds

In a materials biorefinery, the goal is to extract the polymers cellulose, hemicellulose and lignin in their native and polymeric form. In such concepts enzymatic treatment that targets specific linkages, could serve as important processing steps. The chemical linkage proposed to connect lignin with hemicellulose, the so-called lignin-carbohydrate complexes (LCCs), is an obstacle for an intact and efficient extraction of wood polymers. Furthermore, enzymes that act on LCC bonds may boost enzymatic hydrolysis of lignocellulose-derived streams.

GEs have been suggested to target the ester bond between aliphatic alcohols on lignin and the glucuronic acid residues present as side chains on wood xylans. In the present work, we produced and characterized GEs from fungal sources. Variants with and without CBM were also produced. The ability of the produced GEs to hydrolyse syntethic model compounds, lignin-carbohydrate model compounds and natural LCC fragments will be discussed.