G. O. ORIBHABOR

Zinc oxide nanoparticles (ZnONPs) have been investigated for their great antimicrobial effect against multiple pathogens. Bacterial pathogens used for this research were isolated from African black soap samples and characterized using the phenotypic method. The antibacterial activity of biologically synthesized zinc oxide nanoparticles (ZnONPs) against the isolates; Pseudomonas amygdali 35-1 CP084212, Micrococcus sp. and Staphylococcus aureus was investigated in-vitro. Nanoparticle treatments were applied at different concentrations (25%, 50%, and 100%) and an antibacterial agent Ampicillin was used as a control. The zones of inhibition were measured in millimeters. ZnONPs at all concentrations had insignificant inhibitory effect on Micrococcus sp. and Staphylococcus aureus (p>0.05) compared to the control. However, ZnONPs (100%) demonstrated significantly higher inhibitory activity on Pseudomonas amygdali 35-1 CP084212 (p<0.05) compared to the control. The zones of inhibition ranged from 3.33 ± 0.54 to 18.00 ± 0.94 mm while the zones of inhibition for the control were 6.33 ± 1.09 mm (Pseudomonas amygdali 35-1 CP084212), 18.67 ± 1.09 mm (Micrococcus sp.) and 16.00 ± 4.10 (Staphylococcus aureus). The findings obtained from this investigation demonstrated the antimicrobial efficacy of zinc oxide nanoparticles against the selected bacterial isolates.

Carrot (Daucus carota) is one of the most important economical root vegetable crops worldwide and the largest source of provitamin A and carotenoids in the human diet. Storage is a prerequisite for a year-round supply of Carrot, but longer duration can affect its quality. Essential oils also has diverse and relevant biological activities. This study was aimed towards isolating the bacteria associated with rotted carrot, characterizing and isolating three bacteria isolate and determining the antibacterial properties of selected essential oils against the isolates using Agar well diffusion method. Suspected bacteria pathogens were isolated from a diseased carrot tuber, the isolates were identified using biochemical and cultural characterization. Essential oils were used in the antimicrobial sensitivity treatment using agar well diffusion method against the isolated bacteria to determine the antibacterial property of the essential oils. The results showed that Enterobacter sp., Pseudomonas sp. and Agrobacterium tumenfacienwere the isolated pathogenic bacteria from the carrot tubers. The essential oils which are (Neem oil, Tea tree oil and Bergamot oil), showed no antibacterial activity on the isolated bacteria pathogens. Further investigations can be done using essential oils against bacterial isolates but it should be extracted from the plant source to avoid destroying its potential antimicrobial properties.

Zinc oxide nanoparticles (ZnONPs) have been investigated for their great antimicrobial effect against multiple pathogens. Bacterial pathogens used for this research were isolated from African black soap samples and characterized using the phenotypic method. The antibacterial activity of biologically synthesized zinc oxide nanoparticles (ZnONPs) against the isolates; Pseudomonas amygdali 35-1 CP084212, Micrococcus sp. and Staphylococcus aureus was investigated in-vitro. Nanoparticle treatments were applied at different concentrations (25%, 50%, and 100%) and an antibacterial agent Ampicillin was used as a control. The zones of inhibition were measured in millimeters. ZnONPs at all concentrations had insignificant inhibitory effect on Micrococcus sp. and Staphylococcus aureus (p>0.05) compared to the control. However, ZnONPs (100%)demonstrated significantly higher inhibitory activity on Pseudomonas amygdali 35-1 CP084212 (p<0.05) compared to the control. The zones of inhibition ranged from 3.33 ± 0.54 to 18.00 ± 0.94 mm while the zones of inhibition for the control were 6.33 ± 1.09 mm(Pseudomonas amygdali 35-1 CP084212), 18.67 ± 1.09 mm (Micrococcus sp.) and 16.00 ± 4.10 (Staphylococcus aureus). The findings obtained from this investigation demonstrated the antimicrobial efficacy of zinc oxide nanoparticles against the selected bacterial isolates

Carrot (Daucus carota) is one of the most important economical root vegetable crops worldwide and the largest source of provitamin A and carotenoids in the human diet. Storage is a prerequisite for a year-round supply of Carrot, but longer duration can affect its quality. Essential oils also has diverse and relevant biological activities. This study was aimed towards isolating the bacteria associated with rotted carrot, characterizing and isolating three bacteria isolate and determining the antibacterial properties of selected essential oils against the isolates using Agar well diffusion method. Suspected bacteria pathogens were isolated from a diseased carrot tuber, the isolates were identified using biochemical and cultural characterization. Essential oils were used in the antimicrobial sensitivity treatment using agar well diffusion method against the isolated bacteria to determine the antibacterial property of the essential oils. The results showed that Enterobacter sp., Pseudomonas sp. and Agrobacterium tumenfacien were the isolated pathogenic bacteria from the carrot tubers. The essential oils which are (Neem oil, Tea tree oil and Bergamot oil), showed no antibacterial activity on the isolated bacteria pathogens. Further investigations can be done using essential oils against bacterial isolates but it should be extracted from the plant source to avoid destroying its potential antimicrobial properties