| abstract |
Riboflavin is obtained directly from the culture in a high yield by cultivating a riboflavin-producing microorganism in a medium using a lower (C, to C 4 ) aliphatic compound, separating riboflavin contained in the culture in the form of heated aqueous solution from solid matters, and crystallizing riboflavin from the heated aqueous solution. n Riboflavin is also prepared in a high yield by cultivating a riboflavin-producing yeast belonging to the genus Saccharomyces which has purine requirements and/or resistance to 3-amino-1,2,4-triazole in a medium and collecting riboflavin formed and accumulated in the medium. n Moreover, riboflavin is prepared in a high yield even in the presence of iron ions by preliminarily cultivating in liquid a riboflavin-producing yeast belonging to the genus Saccharomyces and then cultivating it in a riboflavin-producing medium containing zinc ions. |