Yeast having immunopotentiating capability and food or feed

摘要

A yeast including a cell wall having a low mannan content, wherein the yeast has an immunopotentiating capability, and is able to grow in a YPD liquid medium with an osmotic pressure of 300 mOsm, and wherein, when a part of a pre-culture of the yeast grown in a YPDS liquid medium is added to the YPD liquid medium so that OD660 is adjusted to 0.1, followed by incubating at 30° C. for 24 hours, the yeast grows to increase the OD660 of the YPD liquid medium to 1.0 or more.

主权项

1. Yeast comprising:
a cell wall including β-glucan and mannan at a low content of the mannan to an extent that the β-glucan is exposed on a surface of a cell of the yeast, wherein the yeast has an immunopotentiating capability, and is capable of growing in an uracil-containing YPD liquid medium having osmotic pressure of 300 mOsm, wherein, when a pre-culture of the yeast grown in an uracil-containing YPDS liquid medium is added to the uracil-containing YPD liquid medium so that OD660 is adjusted to 0.1, followed by incubating at 30° C. for 24 hours, the yeast grows to increase the OD660of the uracil-containing YPD liquid medium to 1.0 or more, the uracil-containing YPD liquid medium comprises 1% by mass of yeast extract, 2% by mass of peptone, 2% by mass of glucose, and 6×10−3% by mass of uracil, and the uracil-containing YPDS liquid medium comprises 1% by mass of yeast extract, 2% by mass of peptone, 2% by mass of glucose, 5.5% by mass (0.3 mol/L) of sorbitol, and 6×10−3% by mass of uracil, and wherein the yeast is in biologically pure culture, the yeast is not recombinantly modified, the yeast is mutated Saccharomyces cerevisiae and acquires the immunopotentiating capability through mutagenesis, which induces one or more mutations on chromosomes of Saccharomyces cerevisiae, the chromosomes of the yeast have one or more mutations compared with the chromosomes of the Saccharomyces cerevisiae not going through the mutagenesis, and the yeast is Saccharomyces cerevisiae FERM BP-11293 or Saccharomyces cerevisiae FERM BP-11294.