Overexpression of the NADP+-specific isocitrate dehydrogenase gene (icdA) in citric acid-producing Aspergillus niger WU-2223L

Keiichi Kobayashi, Takasumi Hattori, Rie Hayashi, Kotaro Kirimura

    Research output: Contribution to journalArticle

    9 Citations (Scopus)

    Abstract

    In the tricarboxylic acid (TCA) cycle, NADP(+)-specific isocitrate dehydrogenase (NADP(+)-ICDH) catalyzes oxidative decarboxylation of isocitric acid to form α-ketoglutaric acid with NADP(+) as a cofactor. We constructed an NADP(+)-ICDH gene (icdA)-overexpressing strain (OPI-1) using Aspergillus niger WU-2223L as a host and examined the effects of increase in NADP(+)-ICDH activity on citric acid production. Under citric acid-producing conditions with glucose as the carbon source, the amounts of citric acid produced and glucose consumed by OPI-1 for the 12-d cultivation period decreased by 18.7 and 10.5%, respectively, compared with those by WU-2223L. These results indicate that the amount of citric acid produced by A. niger can be altered with the NADP(+)-ICDH activity. Therefore, NADP(+)-ICDH is an important regulator of citric acid production in the TCA cycle of A. niger. Thus, we propose that the icdA gene is a potentially valuable tool for modulating citric acid production by metabolic engineering.

    Original languageEnglish
    Pages (from-to)1246-1253
    Number of pages8
    JournalBioscience, Biotechnology, and Biochemistry
    Volume78
    Issue number7
    DOIs
    Publication statusPublished - 2014

    Keywords

    • Aspergillus niger
    • citric acid production
    • metabolic engineering
    • NADP+-isocitrate dehydrogenase

    ASJC Scopus subject areas

    • Medicine(all)

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