Tag Archives: Antibacterial

Assessment of antibacterial capacity of Vernonia amygdalina against post harvest fruit rot organisms of okra (Abelmoshus esculentus L moench) (Published)

Okra is an economically important vegetable crop cultivated in the tropical and subtropical parts of the world. Advocacy for consumption of local vegetables like okra could help to enhance food security and combat malnutrition in developing countries. Okra is a multipurpose crop due to the various uses of its fresh leaves, buds, flowers, capsules, seeds and seeds. The focus of the study is to evaluate the antimicrobial effects of aqueous leaf extracts of V. amygdalina against post harvest bacterial associated with okra. Fresh leaves of the test plant were collected, air dried, and pulverized. Hundred grams of pulverized leaves of the test plant was mixed with 200ml of cold water a room temperature and left overnight. This was later filtered and the filtrate served as extract.  Five bacterial strains were isolated from the the okra viz: Bacillus subtilis, B. panthotenticus, B. cereus, Psedumonas chlororaphis, Aeromonas hydrophila. Agar well diffusion test method was used to determine the antibacterial capacity of the test plant. 20% aqueous extract of the test plant most inhibited Bacillus subtilis, Pseudomonas chlororaphis, Aeromonas hydrophila,  B. cereus and B. panthotenticus by 0.83, 1.65, 1.19, 1.51 and 1.43% respectively. It is shown from the result that higher concentrations of aqueous extract favoured higher inhibition of bacterial growth.

Keywords: Antibacterial, Okra, V. amygdalina

Phytochemical Screening of Pods of Indigofera Tinctoria L. (Uri) and Its Antibacterial and Antifungal Properties (Published)

The phytochemical screening of Indigofera tinctoria L. (Uri) pod extracts using hot ethanolic, cold ethanolic and aqueous extracts showed the presence of Alkaloids, Flavonoids, Saponins, Tannins and Cardiac glycosides. Alkaloids were present in all the three different extracts, saponins was absent in cold ethanolic extract but present in the others, flavonoids was present in only cold ethanolic extract, cardiac glycosides were present in cold ethanolic and aqueous extract but absent in hot ethanolic extracts. Antimicrobial activity of Soxhlet ethanolic and aqueous extracts in different concentration were used against the following pathogenic bacteria isolates like Escherichia coli, Salmonella typhi, Staphylococcus auerus and Bacillus cereus using Disk diffusion method. The undiluted Soxhlet ethanolic extract showed that S. typhi has the highest zone of inhibition of 25 mm, followed by B. cereus, S. auerus at 11 mm and E. coli having the least zone of inhibition at 8 mm. In undiluted concentration of aqueous extract, B. cereus has the highest zone of inhibition of 11 mm, followed by E. coli at 8 mm, S. auerus at 7 mm and S. typhi at 6 mm being the least. Also in Soxhlet ethanolic extract at dilution 1:1 concentration, the highest zone of inhibition is B. cereus at 10 mm, followed by S. typhi at 7 mm, while there was no zone of inhibition against E. coli and S. auerus. While in aqueous extract at dilution 1:1, B. cereus and S. typhi has the same zone of inhibition of 7 mm and no zone of inhibition was observed against E. coli and S. auerus. Similarly, in Soxlet ethanolic extract of 1:2 dilution concentration, zone of inhibition was observed only on B. cereus as 7 mm and no zone of inhibition was observed in the remaining isolates. For aqueous extract at dilution 1:2, there was no zone of inhibition against all the isolates. Hence the percentage antibacterial activity of both extract indicated that B. cereus with cumulative zone of inhibition of 47 mm has thre highest percentage zone of inhibition at 37.30%, followed by S. typi at 45 mm against 35.71%, S. auerus at 18 mm against 14.29% and E. coli at 16 mm against 12.70% as the least percentage of antibacterial activity. Conversely, same extracts tested against fungal isolate like Aspergillus tereus, did not exhibit antifungal properties. Thus the results obtained from this study suggested that Indigofera tinctoria pod validate the use of undiluted extracts of this species in ethnomedicine and could provide a lead in the treatments of bacterial infections.

Keywords: Antibacterial, Antifungi, Indigofera Tinctoria L. (Uri), Phytochemical, Pods

Physico-Chemical, Antibacteriail Activity and Fatty Acid Composition of Oil Extracted From Sprouted Ackee Apple (Blighia sapida) (Published)

Blighia sapida seed has been reported to have some levels of toxic substances when consumed. Most of these substances can be transferred to the oil during extraction thereby increasing the health risk of the oil. Sprouted Blighia sapida seed oil was evaluated to see if the reactions that take place during germination could reduce this toxic effect and increase its industrial values. These results were obtained for the physico-chemical properties: Oil Yield (%)(15.500±0.02), Refractive index (1.4615±0.01), Specific gravity (0.9140±0.01), Acid value(mg/g)(25.10000.10), Iodine value(g/100g)(27.50100.20), Saponification value(mg/g)(225.30000.20), Peroxide value(mmol/kg)(4.24000.20) and Free fatty acid(mg/g)(oleic)( 7.07820.10) respectively. The Fatty acid composition of the oil were Palmitic Acid (C16:0)( 32.3349), Stearic Acid (C18:0)( 5.2555), Arachidic Acid(C20:0)(0.8528), Behenic Acid (C22:0)(0.6326) and Lignoceric acid(C24:0)(0.3061) as polysaturated fatty acid with abundance in Palmitic Acid  respectively. The monounsaturated fatty acid were Oleic Acid (C18:1)( 45.7362), Palmitoleic Acid (C16:1)(0.7655), Erucic Acid (C22:1)(0.4601) and Linoleic Acid (C18:2)(11.6010) and Lenolenic Acid (C18:3)(0.9773) as polyunsaturated fatty acid. The antibacterial activity of the oil from Blighia sapida seed indicated that the oil is susceptible to some pathogenic organism like Escherichia Coli(4.00  0.01) and Staphylococcus aureus (2.00  0.02), but had no effect on Proteus, Pseudomonas Spp  and Klebsiella pneumonia. These results indicated that the oil from sprouted Blighia sapida seed had industrial and pharmaceutical value than the raw Blighia sapida seed oil.

Keywords: Akee apple, Antibacterial, Sprouted, fatty acid, oil, physico - chemical

Phytochemical And Antimicrobial Activity of Neem Seed Oil (Azadirachta Indica) On Bacteria Isolates (Published)

Antibacterial activity of neem (Azadirachta indica) seed oil extract was investigated using microbial growth inhibition zone. The  neem seed oil was obtained by the cold extraction method using ethanol as an organic solvent of which 42ml of oil was obtained from 70g of neem seeds, with 40g (57%) of residue. Oil extracted was screened for its antibacterial properties and phytochemical components. The test organisms used were Salmonella typhi, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus.  Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi had the highest zones of inhibition while Escherichia coli had the least zone of inhibition. The minimum inhibitory concentration (MIC) and  minimum bactericidal concentration (MBC) were determined.  The Phytochemical screening of the sample revealed the presence of Tannin, Alkaloid and Hydrogen cyanide.

Keywords: Antibacterial, Inhibition, Phytochemical, extract, neem

Evaluation of the Potential of Daqu-Derived Actinobacteria for Light-Flavour Chinese Liquor (Published)

The 15 Actinobacteria strains isolated from the Daqu for light-flavour Chinese liquor, were identified on the basis of 16S rDNA gene sequence analysis and investigated from morphological, physiological and biochemical characteristics to analyze the role in Fenjiu liquor brewing. The research results demonstrated the 10 strains have the ability to produce exo-enzymes, amylase, protease, cellulose simultaneously. The 15 strains showed a wide spectrum of antifungal and antibacteria properties on tests of antagonisma against phytopathogenic fungi and bacteria. The 16S rDNA sequencing analysis revealed that Streptomyceswas is the predominant genus in culture-dependent Actinobacteria strains  in Daqu ecosystem. We speculated the Actinobacteria play a very important role on two aspects: one is the ability to produce amylase, protease, cellulase to participate in the process of saccharification; the other is the inhibition of harmful microorganisms in the production of Daqu, and these isolates may have strong biotechnological potential in agriculture.


Keywords: Actinobacteria, Antibacterial, Antifungal, Daqu, Streptomyces

Anti-Bacterial Effect of Cold Water Extract of Bitter Leaf (Vernonia Amygdalina) on Some Selected Micro Organisms (Published)

Anti-bacterial activities of the leaf of V.amygdalina (bitter leaf) was tested on some microorganisms. Five concentrations 0.5g/ml, 1.0g/ml, 1.5g/m, 2.0g/ml and 2.5g/ml were used and the control experiment was carried out to  compare the diameter zones or clearing from the extracts and already standardized antibiotics. Agar well plug method was used for the tests. The bitter leaf extract was made with cold water. Nutrient agar were prepared and inoculated with the different bacteria strains after which wells were made in the in the media and bitter leaf extracts were poured on them. The cold water extracts of V.amygdalina showed inhibitions on the five organisms according to concentration. The organism susceptibility varied with more inhibition to E.Coli, P.aeruginosa, Salmonella typhi, Klebsiella pneumoniae and least to Styaphalococcus aureus.

Keywords: Antibacterial, Bitter Leaf, Cold Water Extract, Micro Organisms

New Heterocyclic Schiff Base and Azetidinone as Antibacterial Agents (Published)

New heterocyclic Schiff base were synthesized from metronidazole and aldehyde, further this heterocyclic Schiff base was converted into 2-azetidinone by the action of chloroacetyl chloride. The biological screening data of the synthesized compounds were also presented.

Keywords: 2-Azetidinone, Antibacterial, Schiff Base


Methanolic extract of the plant Alternanthera repens was obtained using the cold method of extraction. The bioactivity of the extracts was tested against bacterial isolates namely: Staphylococcus aureus, Streptococcus faecalis, Escherichia coli, Bacillus subtilis, Bacillus cereus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, and Proteus mirabilis. The agar well diffusion method was used for the in-vitro antibacterial bioassay and it revealed that the extract was able to inhibit the growth of the test organisms at a concentration of 25.0 mg/ml except Escherichia coli, Streptococcus faecalis, and Salmonella typhi which were resistant. The extract had the highest zone of inhibition (30mm) on Staphylococcus aureus, followed by Klebsiella pneumonia and Bacillus subtilis with 26.0 mm and 25.0 mm respectively. The minimum inhibitory concentration (MIC) of the plant extract ranged from 25.0 to 3.125 mg/ml. The antibacterial activity of the methanolic plant extract compared favourably well with commercial antibiotics. The rate of killing of the plant extract on the isolates showed a decrease in the bacterial count with an increase in the exposure time to the extract. Phytochemical screening tests showed the presence of saponins, alkaloids, salkowski, and keller killianie in the plant extract

Keywords: Antibacterial, Phytochemical screening, Rate of killing, Zone of inhibition


A-new series of transition metal (Cr(III),Fe(III), Co(III), Ni(II)and Cu(II) ) complexes of ligand4-{[(Z)-(2-methoxyphenyl)methylidene]amino}-5-phenyl4H-1,2,4-triazole-3-thiolwere synthesized. All the synthesized complexes were characterized by analytical techniques, magnetic susceptibility measurements, elemental analyses, and conductance, IR, 1HNMR and mass spectra. The electrolytic behavior was confirmed from their conductance data. It may be concluded that the ligand coordinate through nitrogen and sulfur atoms. For all complexes. The ligand acts as a didentate ligand coordinating through the sulfur [S6] and the nitrogen atom of Schiff base [N5]. This view is further supported by the appearance of a band corresponding to the metal–nitrogen stretching vibration at (560–570) cm–1 in the complexes. From results it was suggested tetrahedral geometry for Ni (II) and Cu (II) complexes, while Cr(III),Fe(III) and Co (III)complexes were assigned octahedral geometrics. All complexes and their parent organic moiety have been screened for antibacterial activity by using spread method and inhibition zone measurement by using (DMSO). This study showed positivite inhibition zone results, for both ligand and complexes with E-coli and staph aurens.

Keywords: Antibacterial, Transitions metal complexes, Triazole

Assessment of Date Kernel as Natural Antioxidant and Anti-pathogenic Bacteria Source (Review Completed - Accepted)

Date (Phoenix dactylifera L.) kernels were assessed for their chemical composition, phenolics, antioxidant capacity, inhibiting lipid peroxidation and antibacterial activity against some pathogenic Gram-positive (Listeria monocytogenes, Staph. saprophyticus) and Gram-negative bacteria (E. coli, Salmonella enteric). Kernels from four cultivars Shishi, Menaify, Barhee and Khulas were used in this study, Phenolic compounds ranged from 740 to 1200 mg/100g in Menaify and Khulas cultivars, respectively. Ethanol extract of date kernels showed high antioxidant capacity against 1, 1-diphenyl-2 picryl hydrazyl from all tested cultivars with means of 88.88% at 500ppm and strong reducing power at concentration of 200ppm. Lipid peroxidation inhibition was recorded for all tested cultivars with means of 90.2% inhibition. Ethanol extract of date kernels was effective against Listeria monocytogenes, Staph. saprophyticus, Salmonella enteric but not against E. coli. Date kernels were more effective in inhibiting growth of Staph. saprophyticus bacteria than antibiotic chloramphenicol in this study. The results revealed that date kernels extract may have a good potential role in preventing the free radical species in food systems as well as the antibacterial role against some pathogenic bacteria.

Keywords: Anti lipid peroxidation, Antibacterial, Antioxidant, Date kernels, Ethanolic extract