Expression and Characterization of a Novel λ-Carrageenase Cgl150A_Wa from Wenyingzhuangia aestuarii

λ-Carrageenan is a highly sulfated polysaccharide alternating of 1,4-O-α-D-galactopyranose-2,6-sulfate (D2S,6S) and 1,3-O-β-D-galactopyranose-2-sulfate (G2S). λ-Carrageenases are desirable tools for λ-carrageenan degradation. Based on the genome mining, a novel λ-carrageenase Cgl150A_Wa was cloned from the bacterium Wenyingzhuangia aestuarii and expressed in Escherichia coli. Cgl150A_Wa was an endo-acting enzyme and exhibited its maximum activity at 30°C and pH 8.0. By employing a glycomics strategy that combined ultra-performance liquid chromatography-mass spectrometry analysis and glycoinformatics, Cgl150A_Wa was proven to degrade λ-carrageenan octaose and hexaose, and the major hydrolysis product of Cgl150A_Wa was λ-carrageenan tetrose. In addition to the typical λ-carrageenan motifs, the active center of Cgl150A_Wa might tolerate desulfated λ-carrageenan motifs. Cgl150A_Wa is a potential biotechnological tool for preparing λ-carrageenan oligosaccharides and structural investigation.