Metabolisms of Nucleosides in Bacteria

The bacterial enzymes which catalyze the nucleoside-N-ribosyl group transfer reaction between pyrimidine and purine nucleoside were studied.It was found that some bacteria had the intracellular enzyme system which catalyzes the nucleoside-N-ribosyl group transfer and could produce purine nucleosides from purine bases and pyrimidine nucleosides.Using the cell-free extract of Erwinia carotovora, inosine was isolated in fine crystals from uridine and hypoxanthine through the nucleoside-N-ribosyl transfer reaction.It seemed that the bacteria which can transfer the N-ribosyl group may be divided into two groups, based on the pH dependency of this reaction.This reaction was stimu lated by inorganic phosphate.Reactions were carried out at 37°C and pH 7.0 (Erwinia carotovora) and 9.0 (Corynebacterium sependonicum).