ABSTRACT
This work aims to study the bioactivity of five plant extracts against the 3 fungal species of Aspergillus flavus, Asp. parasiticus and Asp. ochraceus, as well as 3 bacterial species Escherichia coli, Pseudomonas aeruginosa and staphylococcus aureus. Both the fungal and bacterial isolates were identified as undesirable and toxin producing microorganisms. The five plants of clove [Syzygiurn aromaticum], sage [Salvia officinalis], rosmary [Rosmariinus officinalis], basil [Ocimum basilicurn] and lemon grass [Cymbopogon citrates] were collected from local markets then extracted to obtain the oil fraction. The crude oil extracts were used to determine its inhibitory effects on the previous strains of fungi and bacteria. Also, the minimum inhibitory concentration [MIC] of each extract and its content of the phytochemicals of plenols, flavonoids and terpenoids were determined. Data exhibited wide range of the bioactivity of the 5 plants, reached its maximum using clove and its minimum using sage extracts against the tested microorganisms. No antimicrobial activity was observed in the treatment[s] of sage extract against the mold Asp. ochraceus. The other 3 extracts of rosmary, basil and lemon grass showed roughly the same bioactivity. Also, data obtained from MIC and semi-quantitative determinations confirmed the results obtained from the antimicrobial bioactivity study. Except sage extract, the MIC of the other 4 extracts ranged between 0.2-1.5 mg/me, reached, its maximum using clove and its minimum using lemon grass extracts. As well, the semi-quantitative determination of the phytochemicals of phenols, flavonides and terpenoids proved that clove extract had the highest concentration of terpenoids, while sage extract showed traces from the 3 phytochemicals. The other 3 extracts of basil, rosmary and lemon grass showed roughly the same content of the sum of the 3 phytochemicals