ACTIVITIES OF SOME ANTIFUNGAL AGENTS AGAINST PHYTOPATHOGENIC YAM ROT FUNGI SPORES IN ZARIA, NIGERIA
ACTIVITIES OF SOME ANTIFUNGAL AGENTS AGAINST PHYTOPATHOGENIC YAM ROT FUNGI SPORES IN ZARIA, NIGERIA
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Date
2011-08
Authors
CELESTINA, OTEGWU TEMILOLA
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Abstract
Postharvest deterioration has been a major problem associated with yam storage for both
farmers and traders and it is caused mostly by micro-organisms especially fungi. The
antifungal activity of some commonly used anti-dermatophytic agents (Fluconazole,
Terbinafine Hcl, Ketoconazole, Sodium propionate and Griseofulvin) against
phytopathogenic fungi such as Aspergillus flavus, Aspergillus niger, Penicillium citrinum
and Rhizopus stolonifer spores were investigated.
The sensitivity of phytopathogenic isolated fungi spores to test antifungal agents were carried
out using zone of inhibition, Minimum Inhibition Concentrations (MICs), Minimum
Fungicidal Concentrations (MFCs), Fractional Inhibitory Concentrations (FICs) and
Fractional Fungicidal Concentrations (FFCs) to measure the antifungal activities of the test
antifungal agents, their fungi toxic effects against A. flavus, A. niger, P. citrinum and R.
stolonifer was found to be in the order of:
Terbinafine Hcl > Fluconazole > Ketoconazole > Sodium propionate > Griseofulvin
The in-vitro MICs of the antifungal agents for example Terbinafine Hcl against A. flavus, A.
niger, P. citrinum and R. stolonifer were 1.0, 10.0, 1.0, and 50.0μg/ml respectively. This is
an indication that R. stolonifer is the most resistant phytopathogenic fungal spores in this
investigation against the observed potent antifungal agents in this study.
The effects of fungicidal concentration of the different antifungal agents against viable test
fungi spores number at different time interval showed rapid lethal effects.
The six potential fungicides combination observed in this study, viz: Terbinafine Hcl,
Fluconazole and Ketoconazole in combination each with either Sodium propionate or
Griseofulvin displayed synergistic activity with value of FIC 0.19 to 0.83 against the test
phytopathogenic fungal spores.
The antifungal effects of evaluated fungicide combinations were observed to be stable at
temperature ranges of 35-70ºC, but effect reduced as the temperature increased to 100 ºC.
At acidic pH, there was general reduction in the antifungal effects of these combinations, but
at neutral and alkaline pH the antifungal effects increased.
Within six months storage of these combinations, antifungal effects were stable and
sustainable.
The in-vivo antifungal activity shows that these formulated fungicide combinations can be
used to preserve yam as they inhibited Aspergillus niger and Rhizopus stolonifer (1.5 x
106cfu/ml) spores on sliced old and new yam.
Description
A THESIS SUBMITTED TO THE POSTGRADUATE
SCHOOL, AHMADU BELLO UNIVERSITY ZARIA, IN
PARTIAL FULFILLMENT FOR THE AWARD MASTER OF
SCIENCE IN PHARMACEUTICAL MICROBIOLOGY.
DEPARTMENT OF PHARMACEUTICS AND
PHARMACEUTICAL MICROBIOLOGY, FACULTY OF
PHARMACEUTICAL SCIENCES, AHMADU BELLO
UNIVERSITY ZARIA, KADUNA, NIGERIA.
Keywords
ACTIVITIES,, ANTIFUNGAL,, AGENTS,, AGAINST,, PHYTOPATHOGENIC,, YAM,, ROT,, FUNGI,, SPORES,, ZARIA,, NIGERIA