Phytochemical Determination and Antibacterial Activity of <i>Punica granatum</i> Peel Extracts against Plant Pathogenic Bacteria

Abstract

Plant pathogenic bacteria are recognized to be harmful microbes able to decrease the quantity and quality of crop production in the world. Punica granatum peel was screened for its potential use as biological control agent for plant pathogenic bacteria. P. granatum peel was successfully extract using n-hexane, methanol and ethyl acetate by maceration. The highest yield obtained by ethyl acetate showed that ethyl acetate extracted more compounds that readily soluble to methanol and n-hexane. For in-vitro antibacterial activity, three different species of plant pathogenic bacteria were used namely Erwinia carotovorum subsp. Carotovorum, Ralstonia solanacearum, and Xanthomonas gardneri. For all crude extracts, four different concentrations 25, 50, 100 and 200 mg/ml were used in cup-plate agar diffusion method. Streptomycin sulfate at concentration 30 µg/ml was used as positive control while each respective solvent used for peel extraction was used as negative control. The results obtained from in vitro studies showed only ethyl acetate extract possessed antibacterial activity tested on the plant pathogenic bacteria. Methanol and n-hexane did not show any antibacterial activity against plant pathogenic bacteria selected where no inhibition zones were recorded. R. solanacearum recorded the highest diameter of inhibition zones for all range of concentrations introduced followed by E. carotovorum subsp. Carotovorum and X. gardneri. For the minimum inhbitory concentration (MIC) and minimum bactericidal concentration (MBC), only the ethyl acetate extract was subjected to the assay as only ethyl acetate extract exhibited antibacterial activity. The minimum concentration of ethyl acetate extract that was able to inhibit plant pathogenic bacteria was recorded at a concentration of 3.12 mg/ml which inhibited R. solancearum and E. carotovorum subsp. Carotovorum, followed by X. gardneri at concentration 6.25 mg/ml. For the minimum bactericidal concentration (MBC), the results showed that at A. I. Khaleel et al. 160the concentration of 12.5 mg/ml, the extract was still capable of killing the pathogenic bacteria, R. solanacearum, and P. caratovora sub.sp. caratovora while for the bacteria X. gardneri, the concentration that was able to kill the bacteria was 25 mg/ml. The qualitative estimation of phytochemical constituents within P. granatum L. ethyl acetate peel extracts had revealed the presence of tannins, flavonoids, phenols alkaloid, Saponins, and terpenoids. This study has demonstrated that Ethyl Acetate peel extracts of P. granatum has significant antibacterial activity against pathogenic plant bacterial, and it could be of high agricultural value.

Antifungal Activities of Some Plant Extracts against Pathogenic Fungi

“…The results were in a close agreement with that of Foss et al, (2014) and Barathikannan et al, (2016) who reported that hydroalcoholic and alcoholic extract of pomegranate fruit peels showed activity against the dermatophytes Trichophyton mentagrophytes, Trichophyton rubrum, Microsporum canis, and Microsporum gypseum. Mahajan et al, (2014); Khaleel et al, (2016); Mohammed et al, (2016); Akroum, (2017); Mostafa et al, (2017); Rosas-Burgos et al, (2017) The present study showed that hexane, ethyl acetate, and 80% ethanol extracts of fennel fruits did not affect the tested fungi. These results were in agreement with the study of Benlafya et al, (2015) and Thakur et al, (2013) who demonstrated that alcoholic extract of fennel seeds was ineffective against tested bacterial and fungal strains such as Escherichia coli, Bacillus subtilis, Salmonella abony, Candida albicans, and Aspergillus flavus.…”

Dwarf Pomegranate (Punica granatum L. var. nana): Source of 5-HMF and Bioactive Compounds with Applications in the Protection of Woody Crops

“…However, none of these studies reported MIC values. The only study in which such information was available was the one by Khaleel et al [50], who tested the efficacy of the ethyl acetate extract of P. granatum peel against E. carotovorum and X. gardneri, finding MIC values of 3.125 and 6.25 mg•mL −1 , respectively. In comparison, the hydromethanolic extracts of P. granatum var.…”

In vitro antibacterial and antidiarraheic activity of root bark extract of Anogeissus leiocarpa (Combretaceae) during an experimental bacterial diarrhea induced by Escherichia coli extended-spectrum -lactamases (ESBL) in albino Wistar rats

“…The slope of the experimental tubes and that of the TC tube was seeded. The tubes were incubated at 37°C for 24 h. The MIC was the concentration of the first tube from which no microbial visible growth (Khaleel et al, 2016).…”