Digestion of seaweeds by the marine amoeba Trichosphaerium

A crude enzyme preparation from the marine amoeba Trichosphaerium was used to produce protoplasts from Sargassum muticum, Macrocystis pyrifera Porphyra perforata, and other red and brown marcroalgae. Cortical and medullary protoplasts of Sargassum, which were impossible to obtain using mixtures of previously available enzymes have now been prepared. Intact inner cortical and medullary protoplasts of Macrocystis, which were not observed in past isolations were obtained. Improved protoplast yields of as much as 500 fold resulted from feeding the amoebae on specific seaweeds. Cuticles of live Sargassum and Macrocystis were digested easily by the amoebae. However cuticles of autoclaved Macrocystis and those of Porphyra (fresh or autoclaved) were eaten last. In spite of the absence of identifiable extracellular enzymatic activity in the medium the amoebae were able to cut and consume live fronds and blocks of gelled agars carrageenans, and alginates.