title: Isolation and initial characterization of a uracil auxotroph of the blue-green alga Anacystis nidulans.
abstract: A uracil-requiring auxotroph of Anacystis nidulans was isolated after treatment with N-methyl-N'-nitrosoguanidine. Neither precursors in the de novo pyrimidine pathway nor compounds of "salvage" or degradative pathways could replace the uracil requirement. The reversion frequency for mutation to a nonuracil requirement for growth was 2.0 times 10(-8). The calculated average rate of uracil utilization was 1.1 times 10(-17) mol of uracil per unit cell mass/h. The amount of uracil required for the synthesis of a unit cell mass was 3.8 times 10(-17) mol of uracil.
mesh_terms: D000458:Cyanobacteria / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D008769:Methylnitronitrosoguanidine; D009153:Mutagens; D009154:Mutation; D014498:Uracil / Q000378:metabolism*
chemical_list: D009153:Mutagens; D008769:Methylnitronitrosoguanidine; D014498:Uracil