3.2.1.162 Endohydrolysis of (1->4)-beta-linkages in the backbone of lambda-carrageenan, resulting in the tetrasaccharide alpha-D-Gal-p2,6S2-(1->3)-beta-D-Gal-p2S-(1->4)-alpha-D-Gal-p2,6S2-(1->3)-D-Gal-p2-S