title: Pyridine nucleotide levels and ratios in Aspergillus niger.
abstract: A reliable method for the extraction and assay of pyridine nucleotides (NAD, NADH, NADP, and NADPH) in filamentous fungi is presented. The method is applied to a study of the physiology of citric acid accumulation by Aspergillus niger. The measurement of "catabolic reduction change" (NADH/(NAD + NADH)) and "anabolic reduction charge" (NADPH/(NADP + NADPH)) as a means of characterizing the metabolic state is discussed.
mesh_terms: D001234:Aspergillus niger / Q000032:analysis*; D002951:Citrates / Q000378:metabolism; D005285:Fermentation; D008722:Methods; D009243:NAD / Q000032:analysis*; D009249:NADP / Q000032:analysis*; D013045:Species Specificity
chemical_list: D002951:Citrates; D009243:NAD; D009249:NADP