Process for producing yeast cells

DETAILED DESCRIPTION What we claim is: 1.
A process for producing yeast cells which comprises culturing aerobically a yeast belonging to Pichia aganobii in a culture liquor containing methanol and/or ethanol as a carbon source, nitrogen sources, inorganic salts and other nutrient sources, and recovering yeast cells therefrom.
2.
A process according to claim 1 in which the yeast is Pichia aganobii Y-16, Y-145, Y-410 or Y-1023.
3.
A process according to claim 1 in which the culture liquor contains up to 6 wt.
% of methanol and/or ethanol, and the culturing is effected at 10.
degree.
to 37.
degree.
C.
at a pH of 7.
5 or less.
4.
A process according to claim 1 in which the initial concentration of methanol and/or ethanol is controlled at 0.
5 wt.
% or less and the concentration of methanol and/or ethanol throughout the cultivation is maintained at a constant level by compensating as much methanol and/or ethanol as is consumed during cultivation.
5.
A process according to claim 1 in which ammonia is added from time to time to the culture liquor, when ammonium salts are used as a nitrogen source.
6.
A process according to claim 1 in which an assimilable carbohydrate is added to the culture liquor.




Description:
This invention relates to a process for producing yeast cells by use of a novel yeast.
More particularly, the invention pertains to a process for producing yeast cells by culturing in a culture liquor containing methanol and/or ethanol as main carbon sources a novel yeast belonging to Pichia, and separating the cells of said yeast from the culture liquor.
Heretofore, waste molasses, sulfite pulp waste liquors and n-paraffins have been used as carbon sources in culture media for the production of yeast cells.
Recently, however, there are many literature references concerning processes for producing yeast cells by culturing yeasts with inexpensive carbon sources.
In recent years, methanol and ethanol have come to be produced in large quantities with the progress of organic synthetic chemical industries, so that the said alcohols have come to be obtainable at low costs