Cloning of the Bacillus Subtilis IMP Dehydrogenase Gene and its Application to Increased Production of Guanosine

The gene encoding inosine 5′–monophosphate dehydrogenase (IMP dehydrogenase) of Bacillus subtilis was cloned in pBR322 in Escherichia coli and subsequently subcloned into the B. subtilis plasmid, pC194. The introduction of the recombinant plasmid encoding IMP dehydrogenase to B. subtilis NA6128, an inosine overproducer, elevated its level of IMP dehydrogenase activity and remarkably increased the productivity of guanosine, accompanied by a decreased accumulation of inosine.