Alginate Degradation: Insights Obtained through Characterization of a Thermophilic Exolytic Alginate Lyase
Magnus Ø. Arntzen, Bjørn Pedersen, Leesa J. Klau, Runar Stokke, Maren Oftebro, Simen Antonsen, Lasse Fredriksen, Håvard Sletta, Olav A. Aarstad, Finn L. Aachmann, Svein Jarle Horn, Vincent G. H. Eijsink
Abstract
The potential markets for seaweed-derived products and seaweed processing technologies are growing, yet commercial enzyme cocktails for complete conversion of seaweed to fermentable sugars are not available. Such an enzyme cocktail would require the catalytic properties of a variety of different enzymes, where fucoidanases, laminarinases, and cellulases together with endo- and exo-acting alginate lyases would be the key enzymes. Here, we present an exo-acting alginate lyase that efficiently produces monomeric sugars from alginate. Since it is only the second characterized exo-acting alginate lyase capable of degrading alginate at a high industrially relevant temperature (≥60°C), this enzyme may be of great biotechnological and industrial interest. In addition, in-depth NMR-based structural elucidation revealed previously undescribed rearrangement products of the unsaturated monomeric sugars generated from exo-acting lyases. The insight provided by the NMR assignment of these products facilitates future assessment of product formation by alginate lyases.