2023 Volume 60 Pages 34-41
About four strains of wild type yeast that were obtained from some fruits and a flower in Asahikawa-city and Asahikawa neighbor areas, and in North Tohoku area, we observed their cell length, quantity of propagation at 5-35°C and performance of alcohol fermentation (the gas yield) at 15-35°C. The results obtained were as follows:
(1) The cell length of ANCT-06051 isolated from a mountain ash fruit was 4.7 μm, which was the longest in the four wild type yeasts. The quantity of propagation of ANCT-06051 was the most in the four strains at 5-35°C. The gas yield of ANCT 06051 became the maximum at 25°C, and decreased at 15°C and 35°C.
(2) The cell length of ANCT-07017 isolated from an azalea petal was 3.7 μm. The quantity of propagation of ANCT-07017 was a lot next to ANCT-06051 at 5-25°C. The gas yield of ANCT-07017 which was incubated for seven days at 15-35°C was the highest in the four strains.
(3) The cell length of ANCT-07018 isolated from an apple peel was 3.5 μm, which was the smallest in the four strains. The quantity of propagation of ANCT-07018 increased with temperature at 5-35°C. There was a little quantity of gas yield at 25°C and 35°C, but the yield was not confirmed at 15°C.
(4) The cell length of ANCT-07023 isolated from a cherry fruit was 3.7 μm. The quantity of propagation of ANCT-07023 was less than that of ANCT-07018 at 5-25°C. The gas yield of ANCT-07023 was approximately similar to ANCT-07018 at 15-35°C.
(5) The cell lengths of NBRC 0308 (a sake yeast) and ANCT-07009 (a commercial dry yeast) were longer than the four wild type yeasts, and were superior in the quantity of propagation to the four yeasts at 10-25°C. Although the gas yields of NBRC 0308 and ANCT-07009 at 15°C showed a tendency to decrease, the gas yields of them at 15-35°C for 7 days were higher than that of the three wild type yeasts (ANCT-06051, ANCT-07018, ANCT-07023) .
(6) In ANCT-06051 and NBRC 0308, there was not the significant difference to the quantity of propagation and the gas yield on YM-media of pH=4.2-7.8 at 25°C.