抄録
Bud scar-rich preparation, which consisted mostly of crater-like bodies with some fragment of cell wall, was easily obtained from the isolated cell walls of baker's yeast by enzymic treatment under appropriate condition. In spite of low glucosamine content, which is due to the action of chitinase in the enzyme preparation, X-ray diffraction analysis showed that the structure of chitin was well preserved in this preparation. On the other hand, the preparation obtained by chemical treatment of intact yeast cells indicated high glucosamine content. Differing from the results of Bacon et al., the present preparation obtained after 2 cycles of chemical treatment still retained the original cellular shape with remnant cytoplasmic materials. After 5 cycles of the treatment, bud scar-rich fraction nearly equal to that obtained by enzymic treatmet was obtained. By the treatment of the bud scar-rich preparation with chitinase, the characteristic annular structure disappeared with concomitant decrease of glucosamine content, and at the same time, stainability with fluorescent dye, Brightener, of the annular structure disappeared. It was concluded that chitin is the intrinsic entity which constitutes the annular structure of the bud scar region and can be stained with Brightener. The appearance of stainable structures and buds together with the increase in cellular content of glucosamine was observed during culture of age 0 cells. The emergence of buds was preceded by the appearance of the stainable structures ; the increase of glucosamine content proceeded in accordance with the appearance of the annular structure. The morphological basis of the budding was discussed with special reference to the role of the annular structure.
