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.