Abstract
Several guanineless mutants derived from Bacillus subtilis IAM 1145 were found to accumulate xanthosine in the culture broth. Further mutation of the guanineless mutants to adenine dependence led to remarkable increase in the accumulation of xanthosine. One of the guanine-adenine doubleless mutants, strain Gu-Ad-3-35, accumulated 8.9g of xanthosine per liter. Xanthosine was isolated in a crystalline form from the culture broth by a procedure involving charcoal treatment and ion-exchange chromatography.
