Nature of deoxyribonucleic acid synthesis and its relationship to protein synthesis during outgrowth of Bacillus cereus T.

Deoxyribonucleic acid (DNA) synthesis during early outgrowth of spores of Bacillus cereus T (thy(-)) has been examined. (14)C-thymidine incorporated begins 2 to 5 min after germination and continues at a slow rate up to 30 min, after which the rate of (14)C-thymidine incorporation increases considerably. Early DNA synthesis up to 30 min after germination is dependent upon simultaneous protein synthesis. The examination of the stability of proteins synthesized soon after germination shows that they are susceptible to intracellular degradation. The evidence provided here indicates that protein degradation is the cause of observed dependence of DNA synthesis on simultaneous protein synthesis. The DNA synthesis occurring soon after germination is primarily a repair type synthesis which is followed by the onset of normal replication approximately 30 min after germination.