Tag Archives: Antibacterial

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