Digestion of seaweeds by the marine amoeba Trichosphaerium

Abstract

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 .

Utilization of Macroalgal Carbohydrates By The Marine Amoeba Trichosphaerium Sieboldi

“…On the other hand, Trichosphaerium maintained in 'axenic' cultures with autoclaved seaweed fragments grew rapidly regardless of the species of algae. In a previous study, Polne-Fuller et al (1990) induced digestive enzyme activity by feeding amoebae on a specific seaweed for one to three weeks, however, in the present study amoebae switched to alternate seaweed diets without noticeable delay in growth or consumption.…”

“…The present paper draws attention to a protist capable of digesting a wide range of macroalgal carbon and extends earlier work by Polne-Fuller et al (1990) who reported on an algal digesting strain of Trichosphaerium from California. Here, we partially characterize the nature of the digestive enzymes produced by T. sieboldi and present ultrastructural information on the cell wall which gives an insight into how the amoeba may be localizing the activity of extracellular enzymes.…”

“…Others have grown Trichosphaerium in 'axenic' culture with autoclaved fragments of macroalgae (Polne-Fuller, 1987;Polne-Fuller et al, 1990), however, the present study is the first to maintain pure cultures in the absence of any other organism. In serum supplemented medium, cells grew slowly but were maintained for over a year by subculturing monthly.…”

“…For example, populations have been isolated from sediments rich in microalgae or benthic thalloid algae (Sheehan & Banner, 1973, Rogerson et al, 1996 and from littoral seaweed surfaces (Polne-Fuller et al, 1990, Rogerson, 1991Crawford et al, 1994). Intact seaweed tissues and several phycocolloids have been shown to support growth of Trichosphaerium (Polne-Fuller, 1987) and crude enzyme preparations from a California strain have been shown to soften seaweed tissue and release intact protoplasts (Polne-Fuller et al, 1990). Trichosphaerium has also been shown to be capable of biodegrading the haloalkane 1-chlorooctadecate (Kaska et al, 1991).…”

Omics of an Enigmatic Marine Amoeba Uncovers Unprecedented Gene Trafficking from Giant Viruses and Provides Insights into Its Complex Life Cycle

“…Its members are primarily described from marine environments. They are among algae eating protists playing an important ecological role in the marine environment [ 15 , 16 ]. The taxonomy of Trichosphaerium is poorly understood mainly due to the dramatic morphological transformations it undergoes during its life cycle.…”