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Effects of mycelial extract and crude protein of the medicinal mushroom, <i>Ophiocordyceps sobolifera</i>, on the pathogenic fungus, <i>Candida albicans</i>


Aphidech Sangdee
Kusavadee Sangdee
Benjaporn Buranrat
Sutthiwan Thammawat

Abstract

Purpose: To investigate the antifungal effect of the mycelial extracts and crude proteins of the medicinal mushroom, Ophiocordyceps sobolifera on Candida albicans.

Methods: The antifungal activities of the mycelial extracts and crude proteins of seven strains of the entomopathogenic fungus, Ophiocordyceps sobolifera, were screened against Candida albicans strain NCYC854 using an agar well diffusion method. Minimum inhibitory concentrations (MIC) and minimum fungicidal concentration (MFC) were determined using broth microdilution method. The kinetics of fungal death was elucidated via time-kill assays, and while ultrastructural alteration changes to fungal cells were investigated by scanning electron microscopy (SEM).

Results: The antifungal activities of the mycelial extracts were superior to those of the crude proteins. Among the isolates, Cod-KK1643 exhibited the highest activity with the lowest MIC against the test strains. Therefore, it was chosen for further investigations. The isolate Cod-KK1643 exhibited concentration- and time-dependent fungistatic activity in the time kill assay. However, these activities were absent in the crude protein of the isolate. Moreover, Cod-KK1643 mycelial extract induced morphological alterations in fungal cells, such as decreased cell size, and crushed or cracked appearance. Slight alterations in cell morphology (decreased cell size or crushed appearance) were observed in the crude protein treatment.

Conclusion: The mycelial extracts of the fungus, O. sobolifera (especially isolate Cod-KK1643) exert potent antifungal activity against human pathogenic fungus, C. albicans.

Keywords: Anti-fungal activity, Candida albicans, Entomopathogenic fungus, Ophiocordyceps sobolifera

Journal Identifiers


eISSN: 1596-9827
print ISSN: 1596-5996