SMU Medical Journal

K. A. Arowora ¹, C. O. Adetunji ¹

Affiliations
1 Department of Microbiology and Biotechnology, Nigerian Stored Product Research Institute, Km 3 Asa dam road, P.M.B. 1489, Ilorin, Kwara state, NG

Abstract

This studies was carried out to isolate, identify and establish the pathogenicity of fungi associated with post-harvest rot diseases of onion bulb, a crop which is highly perishable and seasonal in Nigeria, and to determine the effect of various concentrations of crude extracts from the stem and leaves of Moriga olifera in vitro on the causative agents . Fungi associated with onion bulb rots were isolated on Potato Dextrose Agar medium and their pathogenicity was established by testing for their ability to induce rot in healthy onion bulbs. Ethanol extracts of leaves and stems of Moriga olifera were then screened for the potential to control a strain of Aspergillus niger v. Tieghem which had the highest frequency of occurrence on onion bulbs. Plate and broth assays were used at 12.5%, 25%, 50% and 75% concentrations of extract in Potato Dextrose Agar and Potato Dextrose Broth respectively. The stem extracts inhibited the growth of the fungus at all concentrations tested. A progressive inhibition with increasing concentration of the stem extract was observed on both plates and broth cultures. On the other hand, lower concentrations (12.5%, 25%, 50%.) of leaf extract did not inhibit fungal growth on agar plates. Some level of inhibition was however observed at 75% concentration of leave extract. The reality of using antifungal plants to control most especially from moringa olifera is therefore highly recommended as bio protective agent on onion rot which serves as good option to chemical control.

Keywords

Aspergillus niger V. Tieghem, Biocontrol, Onions, Postharvest Disease, Moringa olifera.

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O. O. Olaleye ¹, C. O. Adetunji ², O. M. Kolawole ³

Affiliations
1 Nigerian Institute for Trypanosomiasis Research (NITR), 1, Surame Road, Kaduna, Kaduna State, NG
2 Nigerian Stored Product Research Institute, Department of Microbiology and Biotechnology, Km 3 Asa dam road, P.M.B. 1489, Ilorin, Kwara State, NG
3 University of Ilorin, Department of Microbiology,P.M.B.1515,Ilorin, Kwara State, NG

Abstract

The antimicrobial activities and preliminary phytochemical screening of methanolic extract of Vitellaria paradoxa was performed against clinical isolates obtained from UITH which included Staphylococcus aureus, Escherichia coli, Aspergillus niger and Candida albicans. Leaf extracts of Vitellaria paradoxa were prepared using methanol as solvent. The extracts were tested using agar diffusion and broth dilution method . Escherichia coli was resistant to all the extracts of Vitellaria paradoxa . Antimicrobial activity was recorded by the methanolic extract of Vitellaria paradoxa with zone of inhibition of 19mm on Candida albicans. The minimum inhibitory concentration of the extract ranged from 40mglml to 160mglml for Vitellaria paradoxa leaf extract. Methanolic leaf extract of Vitellaria paradoxa are found to be bactericidal and fungicidal on Staphylococcus aureus and Aspergillus niger, Candida albicans respectively. Vitellaria paradoxaleaf extract contained saponin, tannins, flavonoid, phenolics, steroids, alkaloids, phlobatannins and glycoside.

The result from this study ,therefore suggest the possibility of using Vitellaria paradoxa extracts as antimicrobial agents, which can be a great asset to drug development for purpose of health care delivery in Nigeria

Keywords

Antimicrobial Activity, Minimum Inhibtory Concentration, Phytochemical , Vitellaria paradoxa.

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