1967 Volume 13 Issue 1 Pages 1-14
A mutant strain No. 6, devoid of 5′-nucleotide-degrading ability, was derived from adenine auxotrophic strain No. 93 originating from Bacillus subtilis 209-4, and the accumulation of 5′-IMP under various conditions was examined.
In No. 6, the early stage of growth was inhibited in the presence of more than 500μg/ml of adenine, whereas the duration of the maximum growth was maintained only shortly followed by a marked lysis in the presence of less than 180μg/ml of adenine. On the other hand, such phenomenon was not observed at all in the case of the adenineless mutant No. 93. Such a characteristic response to adenine in the mutant devoid of 5′-nucleotide-degrading ability seems to be related with activity of phosphatase (5′-nucleotidase or alkaline phosphatase) in cells.
The mechanism of the accumulation of the purine and pyrimidine derivatives by No. 6 was also influenced by the adenine content in the medium. When 100μg/ml of adenine was added to the culture, nucleotides accumulated as the result of the degradation of cellular RNA. On the other hand, when more than 180μg/ml of the adenine was present, mostly inosine was accumulated in medium; this was considered to be synthesized de novo by viable cells.
