Elucidation of degradation pattern and immobilization of a novel alginate lyase for preparation of alginate oligosaccharides

Alginate lyases are important enzymes to prepare alginate oligosaccharides for industrial applications and elucidating the degradation pattern of alginate lyases is essential for expanding their applications. Herein, we cloned and expressed AlyPL6, a novel member of polysaccharide lyase family-6 (PL6) with high activity from Pedobacter hainanensis NJ-02. It was found that AlyPL6 could recognize tetrasaccharide as the minimal substrate to release oligosaccharides with low degrees of polymerization (DPs). As a result, it could be speculated that the cleavage site of substrate is located between −1 and +1 subsites. For further application, AlyPL6 was then immobilized onto mesoporous titanium oxide particles (MTOPs) with >55.4% of maximal activity retained at 45 °C after it was reused for 10 times. The research provided extended insights into the substrate recognition and degradation pattern of PL 6 alginate lyases, which may benefit the further application of alginate lyases a lot.