PRODUCTION OF ADENOSINE BY A GROWTH-IMPRO VED MUTANT OF BACILLUS-SUBTILIS - (INDUSTRIAL-PRODUCTION OF ADENOSINE .3.)

In the course of adenosine production by Bacillus subtilis No.43-35, x anthine non-requiring revertants appeared frequently in the late phase of main culture. Adenosine productivities of the isolated revertants were extremely decreased. The appearence of the revertants was not aff ected by the times of cell duplication, but by the change of medium co nditions accompanying cell growth. The growth of Bacillus subtilis No. 43-35 in a minimal medium was inhibited by the addition of L-leucine a nd L-serine. A mutant in which growth was not inhibited by L-leucine a nd L-serine was isolated from No.43-35. The mutant, No.11-7, thus obta ined, showed higher adenosine productivity than the parent strain, No. 43-35. In addition, the xanthine non-reqiring revertants did not appea r through the fermentation by No.11-7. Strain No.11-7 produced 30 g/l adenosine from 130 g/l glucose in a glass jar fermenter with a working volume of 300 ml under the best cultural conditions found.