According to the differential centrifugation at 26,000g for 60 min., 57,000g 60 min. and 20,000g 123 min., the spherical particles about 50mμ diameter were purified from the suspension of lysed P. solanacearum B-19 strain under action of bacterial virus strain A (strain S1). After the investigations of viral activity and of one step growth experiment, the particles were defined as the virus particles. The electron microscope was applicated to the morphological studies of host bacteria and viral life cycle, and the results were as follows: Fig. 1. P. solanacearum from a young culture (8 hours). Well nourished cell, filled with homogeneous protoplasm. (Cr shadowing. ×16,000) Fig. 2. P. solanacearum from an old culture (4S hours). The protoplasm was granulated. (Cr shadowing. ×16,000) Fig. 3. The sections of bacterial cells from an old culture, showing dense parts within cells. (×18,000) Fig. 4. The sediment after centrifugation at 26,000g for 60 min. (Cr shadowing. ×18,000) Fig. 5. The sediment after centrifugation at 57,000g for 60 min. (Cr shadowing. ×22,000) Fig. 6. The purified P. solanacearum virus strain A (strain S1) particles. (Cr shadowing. ×28,000) Fig. 7. The virus particles adsorbed on the surface of bacteria. Fig. 8. The protoplasm of lysed bacteria by the virus. (Cr shadowing. x11,000) Fig. 9. Bacterial cells lysed by the virus and liberated virus particles. The flagella still attached to the lysed bacterial cells. (Cr shadowing. ×15,000) Fig. 10. The lysis of bacteria by the virus. (Cr shadowing. ×16,000)
1. Pseudomonas solanacearum E.F. Smith の電子顕微鏡像について若干の形態学的考察を行つた. 2. 分割遠心分離法により P. solanacearum のウイルスA株(S1株)の増強液より直径約50mμの活性球型粒子を精製分離し, そのウイルス学的活性及び生活環の検討により, この粒子が P. solanacearum のウイルス粒子であることを確認した.