[NAD-metabolizing capacity of Saccharomyces cerevisiae mutants].

The activity of the key enzymes of the salvage synthesis and degradation of NAD (nicotinic acid mononucleotide pyrophosphorylase and NAD glycohydrolase) was studied in Saccharomyces cerevisiae mutants selected earlier as potential producers of NAD. An enhanced NAD-producing ability of the mutants was shown to be related to their reduced NAD-degrading activity: thus, NAD glycohydrolase in mutants 110, 118, and 206 was inactive in all growth phases regardless of the level of NAD biosynthesis.