Both NADH-and NADPH-dependent activities of nitrate reductase (NR) were considerably reduced, compared to the wild type. Xanthine dehydrogenase (XDH) activities and molybdenum cofactor biosynthesis abilities (Moco activities) were deficient. NADH-NR activity was recovered by adding 0.5 mM molybdate to the growth medium. However, nitrate reductase activities increased, compared to the wild type.