ABSTRACT
This research was conducted in Microbiology Laboratory of Godfrey Okoye University to determine the antimicrobial efficacy of aqueous, methanol, ethanol of Pisdium guajava and Citrus x sinensis on the pathogenic Streptococcus mutans and Candida albicans. The Dimethyl sulfoxide was used for dissolving the plant extracts. Pisdium guajava showed antimicrobial activity against C. albicans with the exception of methanol showing no zone of inhibition to any of the isolates. The aqueous and methanol plant extract of Citrus x sinensis showed antimicrobial activity against S. mutans and C. albicans. Citrus x sinensis showed highest inhibition with MIC concentration of 0.256g/ml, 0.064g/ml, 0.032g/ml showed slight growth while concentration 0.016g/ml and 0.008g/ml showed heavy growth, there were scanty growths in the MBC and MFC plates. Phytochemical screening, proximate, chromatographic analyses, and the antimicrobial activities of the tender stem of Psidium guajava and Citrus x sinesis, were carried out. The phytochemical screening revealed the presence of all metabolites and compounds tested for such as flavonoids, tannins, reducing sugar, terpenes, saponins, anthraquinone, and alkaloids. The antimicrobial screening of methanol extract showed activity against the tested organisms. The antimicrobial screening of ethanol and aqueous also showed activity against the tested organisms. The result indicated that the plants had a potential antimicrobial activity and were concentration-dependent. The chromatographic analysis of the extracts showed the presence of a variety of compounds. This, therefore, supports the traditional medical use of Psidium guajava and Citrus x sisnesis