(1) The Sake'-yeast which was recently isolated and had the highest sporulation ability had been systemtically pursued as to its sporulation ability by culturing ten and more genrations at 40-41°C, 38°C, 33°C and 25°C by the Koji-agar plate cultures.
(2) The mean sporulation percentage amounted to the maximum in tne second generation when the yeast was cultured at 41°C and 38°C, and in fourth generation when it'was cultured at 33°C. As the generations went on over the maximum stages, the sporulation percentage decr eased rapidly. But when it was cultured below 25°C, there was no great difference in the sporulation percentage according to the generation.
(3) When the yeast cultured at 40-41°C, the asporogenous cells appeared more and more as the generation went on. They increased rapidly after the tenth generation.
(4) In the cultivation at 38°C and 33°C, when the yeast was transplanted at intervals of two or four days, asporogenous forms appeared on ty in two and one strain, respectively. But when the yeast was rapidly dried on plate cultures for ten and more days in the driest season of February, it had almost lost the sporulation ability.
(5) In the cultiavation at 25°C, asporogenous cells appeared only in one strain in the 8 th generation when examined up to 12th generation.
(6) In liquid cultures, when the yeast was precultured for short days such as 2 or 3 days, the sporulation ability was rather better in the cultivation at the higher temperature (38°C) than at the lower temperature (25°C). But as the days lapsed and the times of transplantation increased, the sporulation ability was gradually lowered at the higher temperature in comparison with the lower temperature.
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