Regulation of pyrimidine biosynthesis in Acidovorax delafieldii

The regulation of de novo pyrimidine biosynthesis in the nutritionally versatile bacterium Acidovorax delafieldii ATCC 17505T was influenced by carbon source and pyrimidine supplementation. Uracil supplementation of succinate-grown A. delafieldii ATCC 17505T cells produced a greater decrease in the de novo pyrimidine biosynthetic pathway enzyme activities than did orotic acid supplementation. The presence of orotic acid or uracil in the medium of the glucose-grown wild type cells generally increased the pyrimidine biosynthetic enzyme activities. After the pyrimidine limitation of an A. delafieldii orotate phosphoribosyltransferase mutant strain, the pyrimidine biosynthetic pathway enzyme activities in the glucose-grown mutant cells were more highly derepressed than in the succinate-grown mutant cells.