
Full text loading...
In strains of Bacillus subtilis able to synthesize purines de novo, massive sporulation is suppressed by the combination of excess ammonia, glucose and phosphate. Purine auxo-trophs, blocked in the general or the guanine-specific portion of the branched purine pathway, sporulated in such a medium when the purine required for normal growth was removed from the medium. The resulting spore titre and the sporulation frequency increased with the residual growth rate in the purine-free medium, i.e. with the leakiness of the purine mutation. Sporulation was further increased by allowing residual growth in growth-limiting amounts of guanosine. Non-leaky purine mutants blocked before 5′-phosphoribosyl-5-amino-4-imidazole carboxamide also sporulated well when supplied with 5-amino-4-imidazole carboxamide at concentrations (2 mm) that supported growth at a suboptimal rate.
Article metrics loading...
Full text loading...
References
Data & Media loading...