Biochemical Studies on Myo-inositol in Microbes

Part I. Dependency of the Yeasts on Myo-inositol and the Abnormalities of Inositol Exacting Yeasts Cultured in Inositol Deficiency

Abstract

Physiological roles of myo-inositol, which had not yet been elucidated, was investigated by using inositol requiring strains of yeast. The results of fundamental investigation are described in this paper. Yeasts were classified into five types according to the level of inositol requirement. Some strains accumulated a fairly large amount of inositol in the medium. These inositol producing strains include certain film-forming yeasts. At least two types of inositol exacting yeasts existed, those which died due to inositol deficiency and those which did not die. Cell death was presumed to be due to unbalanced growth, because death was not observed under condition where the biosynthesis of protein or nucleic acid was inhibited.
A method was developed to enrich auxotrophic mutants using Saccharomyces cerevisiae inositol-less mutant A-21-20 at the parental strain.