Sucrose非存在下でM-1酵素感受性の著しく異なるL. rhamnosusとL. plantarumのM-1酵素によるプロトプラスト形成過程の微細構造の電子顕微鏡観察を行った.両菌共にsucrose存在下でM-1酵素感受性を示し,プロトプラスト形成が観察された.両菌は,高浸透圧条件での原形質分離像およびM-1酵素による細胞壁の消化像に著しい差を示した. L. rhamnosusでは細胞壁消化が菌体先端部および隔壁部で進行するのに対して, L. plantarumでは菌体側壁部の消化のみが進行していた.しかしながら, sucrose非存在下における両菌のM-1酵素感受性を反映すると考えられる表層微細構造は全く観察されなかった.Lactobacillus rhamnosus and L. plantarum cells suspended in buffer solution showed the big differences in endo-N-acetylmuramidase (M-1 enzyme) susceptibility. Both strains had high susceptibility to M-1 enzyme in 0.75M sucrose solution and at this conditions the protoplast of these cells were formed. L. rhamnosus and L. plantarum were totally distinguished by the cell structures of plasmolysis and patterns of cell wall digestion with M-1 enzyme. However other specified fine structures responsible for M-1 enzyme susceptibility in buffer solution were not observed
