This study was designed to evaluate the phytochemical and antibacterial properties of Garcina kola (Orogbo) and Cola nitida (Obi) extracts. Fresh seeds of Cola nitida and Garcinia kola were collected from Ago-Iwoye market, Ogun State. The ethanolic and aqueous extracts of the test plants were used against selected test organisms, Streptococcus pneumonia, Staphylococcus aureus, Salmonella typhi, Pseudomonas euriginosa and Escherichia coli. Disc diffusion method was adopted to test for susceptibility of the selected test bacteria to the extracts. Minimum inhibition concentration (MIC) and Minimum bactericidal concentration (MBC) were determined. Bioassay data were statistically analyzed using two-way ANOVA. The result of the phytochemical screening confirmed the presence of flavonoid, phenol, alkaloid, saponins, tannins and phlobatanins. The result of the antibacterial activity showed that the ethanolic extract of the test plants recorded highest antimicrobial activity against test isolates compared to aqueous extracts. The tested plant seeds of both plants posses reasonable antibacterial activity but to varied zones of inhibition, with Staphylococcus aureus isolate having the highest inhibitory zones (21.33) mm while Pseudomonas aeuruginosa had the least inhibitory zone (6.00) mm. The antibacterial activity were however found to be concentration dependent (Fvalue= 3.996, Pvalue= < 0.05). All tested organisms were found to have definite MIC and MBC activities which ranges between 125 and 1000μg/ml for MIC except for Kola nitida that has no definite MBC below 1000μg/ml. The result confirms the potential of antibacterial activity of Garcinia kola and Cola nitida extracts. Keywords: Antimicrobial, Cola nitida, Garcinia kola, Phytochemical, Plant extracts

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Aims: The aim of this study is to investigate the antimicrobial activities of aqueous and ethanolic (EtOH) extracts of orange (C. sinensis Pers.) and lime (C.aurantifolia (Christm.) Swingle) peels on some selected pathogenic bacteria isolated from jollof rice. Study Design: Antimicrobial analysis, phytochemical analysis Place and Duration of Study: Microbiology Laboratory, Department of Biological Sciences, Wesley University Ondo, Ondo State, Nigeria, between June and July 2017. Methodology: Antimicrobial analysis of aqueous and EtOH extracts prepared from orange and lime peels were done by using the agar well diffusion method against the selected pathogenic bacteria. The extracts were screened for anti-nutrients such as alkaloids, tannins, oxalate, phytate and glycosides. Results: The EtOH extracts of orange peel showed a remarkable zone of inhibition against Escherichia coli (23.5 ± 0.1 mm) followed by Staphylococcus aureus (11.4 ± 0.0 mm) and Bacillus cereus (9.8 ± 0.0 mm). Whereas, the aqueous extracts of orange showed no zone of inhibition against the tested pathogenic bacteria. In addition the EtOH peel extract of lime showed maximum zone of inhibition against  S. aureus (15.5 ± 0.0 mm) followed by E. coli (14.3 ± 0.1 mm) and B. cereus (12.1 ± 0.2 mm), whereas its aqueous peel extract showed no zone of inhibition against K. pneumonia, S. aureus, E. coli and B. cereus. Both EtOH extracts of orange and lime peels showed no zone of inhibition against K. pneumonia. Streptomycin, the reference antibiotic, had no zone of inhibition against B. cereus and S. aureus whereas it recorded maximum zone of inhibition against E. coli (24.0 ± 0.0 mm) and K. pneumonia (25.1 ± 0.1 mm). The phytochemical analysis showed presence of oxalate, alkaloids, phytate, tannins and glycoside in the aqueous and EtOH extracts of lime and orange peels. The antimicrobial activities of EtOH extracts of both lime and orange peels demonstrated inhibitory effect against the targeted organisms such as B. cereus, S. aureus and E. coli. Conclusion: The exploration of novel antimicrobial agents from natural resources such as plant like Lime and sweet orange as food preservative is due to the presence of various secondary metabolites.