EFFECT OF THE CARBON SOURCE SUCCINATE ON PYRIMIDINE SYNTHESIS IN BURKHOLDERIA-CEPACIA

The effect of the carbon source succinate on pyrimidine synthesis in t he pathogen Burkholderia cepacia ATCC 25416 was investigated. The five de novo pathway enzyme activities of pyrimidine biosynthesis in B. ce pacia were shown to be affected when ATCC 25416 cells were grown in th e presence of uracil. Pyrimidine limitation of a uracil auxotrophic B. cepacia strain lacking orotidine 5'-monophosphate decarboxylase activ ity increased aspartate transcarbamoylase, dihydroorotase, dihydroorot ate dehydrogenase and orotate phosphoribosyltransferase activities by at least 1.5-fold which indicated that these pathway enzymes may be re gulated by a uracil-related compound. The levels of the de novo pyrimi dine biosynthetic enzyme activities in B. cepacia ATCC 25416 cells app eared to be influenced to a greater degree in cells grown on succinate than on glucose as a carbon source.