Abstract
When Escherichia coli B was grown in the salts-glucose medium in the presence of 5×10^<-5>M of pyridazine-3-carboxylic acid (Pyd-3-CA), it was found that quinolinic acid (QA) was accumulated in the medium. QA was isolated by absorption on charcoal from the medium, by ion exchange column chromatography, and in some cases, by thin layer chromatography, and it was identified by paper chromatography, paper electrophoresis, ultraviolet absorption spectra at various pHs, and infrared absorption spectra. The mechanism of the accumulation of QA was discussed in view of the inhibition of the biosynthesis of nicotinic acid derivatives by Pyd-3-CA in E. coli B.
