Anti-yeast activity
of endophytic fungi isolated from medicinal herb Ocimum sanctum with emphasis on
Candida albicans
Mat Jalil Mohd Taufiq and Ibrahim Darah
Res. J. Biotech.; Vol. 17(1); 1-12;
doi: https://doi.org/10.25303/1701rjbt001012; (2022)
Abstract
Endophytic fungi, Lasiodiplodia pseudotheobromae IBRL OS-64 and Muscodor sp. IBRL
OS-94 were previously isolated from the leaf of medicinal plant, Ocimum sanctum
was screened for their anti-yeast activity against pathogenic yeast. Both fungal
isolates were cultivated in submerged fermentation using yeast extract sucrose broth
as culture medium enriched with plant water extract and incubated for 20 d at 30°C
with an agitation speed of 120 rpm. Preliminary study via agar plug diffusion assay
revealed that both fungal isolates possess a fair anti-yeast activity against three
out of four test yeast including Candida albicans, C. utilis and Rhodotorula rubra.
On the disk diffusion assay, the ethyl acetate extract of L. pseudotheobromae IBRL
OS-64 and Muscodor sp. IBRL OS-94 showed significant anti-yeast activity with the
size of the inhibition zone ranging in between 9.6±0.5 - 21.3±0.5 mm and 14.4±0.5
- 20.2±0.7 mm respectively. As for ethyl acetate extract from L. pseudotheobromae
OS-64, the MIC and MYC values were in the range of 500 – 1000 μg/mL and 2000 – 8000
μg/mL respectively.
On the other hand, the MIC and MYC values of ethyl acetate extract of Muscodor sp.
OS-94 ranged between 250 – 500 μg/mL and 1000 – 4000 μg/mL respectively. The time-kill
assay demonstrated that the growth of C. albicans cell was dose-dependent in which
the extract concentration was lower and higher than the MIC value showing yeastostatic
and yeastocidal effects respectively. The scanning and transmission electron microscopes
observation revealed that the candidal cells expose to extract experienced severity
of morphological deterioration which led to cell death beyond repair and thus suggesting
that the fungal extract could be a potential anti-candidal agent.
