STUDIES ON INOSINE FERMENTATION-PRODUCTION OF INOSINE BY MUTANTS OF BACILLUS SUBTILIS

II. COMPOSITION OF MEDIUM FOR THE PRODUCTION OF INOSINE

Abstract

Using three typical inosine-producing mutants of Bacillus subtilis, the effect of medium composition on the inosine productivity was investigated.
1. To allow the bacteria grow and accumulate inosine, the synthetic medium should contain, besides suitable carbon and nitrogen sources, certain amounts of adenine and some amino acids. A considerable increase of inosine production was brought about by the addition of yeast extract or dry yeast to the medium. Excess amount of adenine was found to repress the inosine formation.
2. As the bulk carbon source, various kinds of carbon compounds belonging to hexose, pentose and polyalcohol were utilized. Glucose and starch hydrolysate were the most suitable.
3. Ammonium salts, urea and nitrates were all usable as bulk nitrogen sources. For the maximum production of inosine, greater amounts of nitrogen were necessary than that required for the full growth of the bacteria.