Production of Protoplast-like Structures from Various Species of Fungi

Abstract

IT has been shown that the juice of the gut of the snail Helix pomatia contains enzymes which attack the cell-walls of moulds, and has been used to prepare protoplast-like structures from strains of Neurospora crassa^1,2. These structures have been described as relatively stable, being able to grow and regenerate under appropriate conditions. However, it was found that some of these ‘protoplasts’ could be obtained only from particular strains, making them of somewhat limited value. Meinecke³ obtained structures resembling free protoplasts from Penicillium glaucum as a result of cultivation on thickened cellfree guinea pig serum. This communication describes an enzymatic method using the “suc digestif d'Helix pomatia” obtained from L'industrie Biologique Frariçaise², which has produced a high yield of protoplast-like structures from a number of species of fungi. However, during most of this work we used Fusarium culmorum and Aspergillus nidulans, which appear to be the most sensitive to snail enzyme among the organisms tested, giving rise to the formation of protoplasts in about 2-h incubation. These preparations resemble in many respects the protoplasts formed by digestion of the cell-wall of bacteria with lysozyme⁴ and yeasts, either with snail enzyme⁵ or Streptomycesenzyme^6–8. Observations were made using a phase-contrast microscope on living material either on wet-mount preparations or in moist chambers.