Antifungal Activity of Radicicol against Mucor flavus IFO 9560

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Author(s)

Abstract

The antifungal activity of radicicol against Mucor flavus IFO 9560 was investigated. Radicicol induced bursting of spores during germination and morphological changes of the mycelial tip such as overbranching and swelling during exponential growth. In addition, radicicol showed a dose-dependent inhibitory effect on spore germination. Radicicol also inhibited the incorporation of radioactive precursors into DNA, RNA, protein, and chitin fractions by 20-30%, but not into the lipid fraction. There were no inhibitory effects on either endogenous or exogenous cellular respiration. Moreover, leakage of UV-absorbing, phenol sulfate-positive, or folin reagent-positive materials from the mycelia was not observed at an early stage of growth inhibition. On the other hand, kinetic studies of chitin synthase in the untreated mycelia revealed that radicicol noncompetitively inhibited the enzyme at K_i of 87 μM. Furthermore, upon incubation of the normal mycelia with radicicol in 50 mM KH_2PO_4-NaOH buffer (pH 6.5) containing 10 mM MgCl_2, chitin synthase from the mycelia was inactivated gradually at first, and completely after 24-h incubation. These results suggested that radicicol exhibits the antifungal activity by disturbing cell wall biosynthesis through the inactivation of chitin synthase. However, at an early stage of growth inhibition, radicicol was thought to affect cellular function including nucleic acid and protein syntheses, in addition to the reversible noncompetitive inhibition of chitin synthase.

Journal

  • Journal of Bioscience and Bioengineering

    Journal of Bioscience and Bioengineering 88(4), 380-386, 1999-10-25

    The Society for Biotechnology, Japan

References:  30

Codes

  • NII Article ID (NAID)
    110002684427
  • NII NACSIS-CAT ID (NCID)
    AA11307678
  • Text Lang
    ENG
  • Article Type
    ART
  • ISSN
    13891723
  • NDL Article ID
    4978375
  • NDL Source Classification
    ZP15(科学技術--化学・化学工業--醗酵・微生物工学)
  • NDL Call No.
    Z53-S65
  • Data Source
    CJP  NDL  NII-ELS  Crossref 
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