Culture medium for culturing yeast and method for culturing yeast

Abstract

The purpose of the present invention is to provide a culture medium for a lipid-producing yeast and a method for culturing a lipid-producing yeast. The medium and the method do not require as a nitrogen source the combined use of an ammonium salt and okara (soybean pulp) or an okara-derived liquid extract.　According to the present invention, an okara-derived liquid extract is concentrated through membrane filtration to a specific concentration and the concentrated liquid is added to a culture medium, thereby making it possible to culture a yeast (in particular, a yeast belonging to the genus Lipomyces) without using an ammonium salt. According to the present invention, the culture medium for culturing a yeast comprises a concentrated liquid that is obtained by concentrating a nitrogen component of an okara-derived liquid extract through membrane filtration. The okara-derived liquid extract is obtained by mixing okara with water in an amount of 15-40 times the dry weight of the okara, enzymatically treating the mixture with a protease, inactivating the protease, and subjecting the protease-inactivated mixture to solid-liquid separation. In the culture medium, the nitrogen concentration derived from the concentrated liquid is within the range of 0.1-0.4 wt%.

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