An alginate-like polysaccharide produced by the fermentation of Azotobacter vinelandii or Pseudomonas mendocina. The chemical structure consists of blocks of (1,4) linked-β-D-polymannuronic acid (poly M), (1,4) linked-α-L-polyguluronic acid (poly G) and alternating blocks of the two uronic acids (poly MG) . Unlike the alginate from seaweed this polysaccharide is partially acetylated.