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This paper is aimed at food science or biology students planning a practical independent study into the antimicrobial properties of spices and academic staff wishing to develop a straightforward and reproducible practical activity.

Disc‐diffusion assays are used to investigate the antimicrobial activity of cinnamon and cloves against two bacteria Escherichia coli B and staphylococcus albus and a yeast Saccharomyces cerevisiae. Aqueous and alcoholic extracts of the spices and alcoholic extracts of their essential oils are examined. Minimum inhibitory concentrations of alcoholic extracts of both spices and oils are also determined.

Both spices demonstrated microbial inhibitory effects; alcoholic extracts had greater activity than aqueous extracts. Additionally, essential oils had greater activity than the spices. Minimum inhibitory concentrations were smaller with the oils than with the spices.

Although the research for this paper involved just two spices, such is the size of the plant kingdom that there are wide opportunities for further investigations using this procedure.

Disc‐assays were found to be a simple, cheap and reproducible practical method. For this paper, micro‐organisms available for educational purposes were used; however, other organisms could be investigated depending upon available microbiological expertise and facilities.

The results demonstrate that the antimicrobial effects of spices and particularly their essential oils can be examined using disc‐diffusion assay. The method provides many opportunities for student investigation.

The aim of this study was to investigate the antibacterial activity of original extra virgin olive oil in Iran on some food borne pathogens.

Microbial analysis tests including disk diffusion and detections of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were used. Also the chemical composition analysis of the oil was determined by GC-MS. Results of disk diffusion test confirmed antimicrobial activity for the oil in which S.aureus and E. coli were more resistant than L. innocua.

The MIC and MBC of organic extra virgin olive oil on the studied pathogens were in the range of 12.5-25 and 100 per cent v/v, respectively. The GC-MS analysis showed Z-9-Octadecenal (32.75 per cent), Oleic acid (15.78 per cent), Squalene (11.856 per cent), Phenol (8.392 per cent), Palmitic acid (1.884 per cent) as the main compounds (>0.7 per cent) in organic extra virgin olive oil, which have functional role in the biological activities.

This is the first study on organic extra virgin olive oil from Iran. According to the results, extra virgin olive oil has antimicrobial activity on foodborne pathogens.

Staphylococcus aureus (S. aureus), Klebsiella pneumoniae (K. pneumoniae) and Streptococcus pneumoniae (S. pneumoniae) are among the pathogens detected during Hajj pilgrimage known to cause pneumonia. This study aims to evaluate the antibacterial activity of activated carbon cloth (ACC) with Ag⁺ impregnated with zinc oxide nanoparticles (ZnO NPs) against these pathogens.

ZnO NPs were impregnated into ACC-Ag⁺ via layer-by-layer (LbL) self-assembly. Scanning electron microscope (SEM) was used to observe the fine surface morphological details of the ACC-Ag⁺-ZnO sheets. Antibacterial activity of the ACC-Ag⁺-ZnO sheets was evaluated using the disk-diffusion susceptibility assay. Allergy patch test was done to evaluate allergic reactions of the ACC-Ag⁺-ZnO sheets on human skin.

SEM micrographs showed successful impregnation of ZnO NPs into the ACC-Ag⁺ sheets. Disk-diffusion susceptibility assay results of ACC-Ag⁺-ZnO sheets against S. aureus, K. pneumoniae and S. pneumoniae showed good antibacterial activity; with 1.82 ± 0.13 mm zone of inhibition for S. pneumoniae, at a ZnO concentration of 0.78 mg mL^-1. No signs of human skin irritation were observed throughout the allergy patch test.

Results indicate that ACC-Ag⁺-ZnO sheets could potentially be embedded within surgical face masks (pilgrims’ preferred) to reduce the risks involved with the transmission of respiratory tract infections during and after mass gatherings (e.g. Hajj/Umrah, Olympics).

Kefir is a traditional fermented dairy beverage that has numerous health benefits due to the presence of bacteria and yeasts in an exopolysaccharide matrix. This study aims to isolate and identify beneficial microorganisms and evaluate the antimicrobial activity of kefir beverage against two important food-borne pathogens including Salmonella Typhimurium and Listeria monocytogenes.

Microorganisms were identified by the polymerase chain reaction with specific primers, and antimicrobial activity was evaluated by the disk diffusion method.

The following microorganisms were identified as natural inhabitants of the kefir grains: Leuconostoc lactis, Lactococcus lactis subspecies lactis, Streptococcus cremoris, Enterococcus faecalis, Enterococcus faecium, Lactobacillus helveticus, Leuconostoc mesenteroides, Lactobacillus fermentum, Lactobacillus reuteri, Lactobacillus plantarum, Lactobacillus casei, Bifidobacterium langum, Saccharomyces cerevisiae and Pichia fermentas. Also, the results obtained from the disk diffusion method showed the inhibitory effect of kefir milk on Salmonella Typhimurium and Listeria monocytogenes with an inhibitory average diameter of 8.3 ± 4–9.1 ± 2.8 and 3.4 ± 3–6.6 ± 3 mm, respectively.

The results of this study showed that Iranian traditional kefir beverage contained different species of lactic acid bacteria and yeasts and has antimicrobial activity against two important food-borne pathogens, Salmonella Typhimurium and Listeria monocytogenes, which the highest inhibitory effect was observed against Salmonella Typhimurium.

The purpose of this paper is to determine the antimicrobial compounds extracted from various types of soybean materials; raw soybean, soybean flour and roasted soybean. Bacteria growth inhibition was tested in E.coli and S. aureus by disk diffusion method. Efficiency of antimicrobial activities were compared among the extracted solution.

Soybean (Glycine max) isoflavones contain the ability to inhibit the growth of many strains of microorganisms. The solid-liquid extraction, ethanol-hexane extraction, was modified to isolate the inhibitory compounds from the three different types of soybean materials. All crude extracts at various concentrations performed under different extracted solutions (75, 50, 25, 12.5, 6.25 and 3.125 percent) were tested with E. coli. and S. aureus to determine the antimicrobial activities and the minimum inhibition concentration (MIC). Disk diffusion method was chosen to study the antimicrobial activity of isoflavones.

Soybean flour extract inhibited the growth of E. coli and S. aureus more effective than roasted soybean and raw soybean, respectively. The MIC of inhibitory compounds extracted from soybean flour was 6.25 percent (0.031 mg/ml), roasted soybean was 25 percent (0.125 mg/ml) and raw soybean was 50 percent (0.250 mg/ml). Crude extracts of soybean flour and roasted soybean showed better results than raw soybean. All the three of extracted soybeans inhibited the growth of E. coli better than S. aureus.

Ethanol-hexane extraction was successfully used to isolate the antimicrobial compounds from raw soybean, soybean flour and roasted soybean. Comparison of antimicrobial activity showed that soybean flour contained the highest inhibition activity.

The aim of this study was to evaluate anti-bacterial anti-fungal activity of six Lamiaceae family coleus plants based on their traditional uses (breast-milk stimulants) from two Asian countries (Malaysia and Indonesia).

Plants leaves of coleus species were collected from Kuantan (Malaysia) and Jakarta (Indonesia). From Kuantan, Coleus aromaticus – Malaysia (CATM), Pogostemon cablin – Malaysia (PCM), Coleus blumei-purple leaves – Malaysia (CBPM), Coleus blumei-red leaves – Malaysia (CBRM), Coleus amboinicus – Malaysia (CALM) and from Jakarta Coleus amboinicus – Indonesia (CALI) were collected freeze dried and extracted with aqueous methanol. The antimicrobial activity of the extract was determined by making use of macro dilution and disc diffusion methods. The selected bacteria and fungus used were namely Bacillus subtilis and Staphylococcus aureus (gram positive) and Escherichia coli and Pseudomonas aeruginosa (gram negative) and Candida albicans (a fungi).

All leaf extracts showed activity at least against one strain of bacteria and the result shows that there were significant differences (p<0.05) between the activities on microorganism. The minimum inhibitory concentration of all leaves extracts ranged from 1.0 to 2.0 mg/ml in inhibiting the growth of S. aureus, E. coli, P. aeruginosa and B. subtilis. This study shows that the coleus plants leaves can be used as anti-bacterial anti-fungal agent apart from the breast-milk stimulation properties.

This research was carried out with a limited grant and it was not possible to study some more aspects, for example, the composition and the active components isolation, etc. Furthermore, to establish the relationship among the components and bacteria or fungus, etc.

This research would have greater impact since the leaves of coleus plants are already in use in some communities for the purpose of breast-milk stimulation and insect bite therapy and many more.

This research takes into consideration the effect of coleus plants on a few bacteria and a fungus which have never been studied before.

This study aims to investigate the potential use of potato peel extracts as antibacterial finishes for cotton fabrics against Staphylococcus aureus and Escherichia coli. Potato peels are abundant as waste and provide a natural, cheaper and sustainable alternative means of preventing the spread of bacterial infections on cotton fabric.

This research included the characterization of potato peel extracts, application of the extract onto cotton fabric and efficacy testing of the treated cotton fabric against bacteria. Phytochemical screening, agar well diffusion antibacterial test, minimum inhibitory concentration and Fourier transform infrared (FTIR) tests were used to characterize the extract. Antibacterial efficacy of the treated fabric was determined qualitatively using the disc diffusion assay and quantitatively using the bacteria reduction test.

Phytochemical screening confirmed the presence of several secondary metabolites including phenols and flavonoids. Antibacterial tests revealed a positive response in Escherichia coli and Staphylococcus aureus with a zone of inhibition of 6.50 mm and 5.60 mm, respectively. Additional peaks on the FTIR spectroscopy confirmed the presence of potato peel extract on the treated cotton fabric. The treated cotton fabrics showed efficacy against Staphylococcus aureus and Escherichia coli up to 20 washes.

This study introduced the application of potato peel extracts onto cotton fabrics and assessment of the antibacterial properties before and after washing. Results of this study suggest that potato peel extracts can be used as an organic eco-friendly antibacterial finish for cotton fabrics.

In the present study, cotton fabrics are dyed with extracts obtained from the rinds of the pomegranate fruit, Punica (P.) granatum. The fabrics are then assessed for antimicrobial, dyeability and fastness properties. The colour strength (K/S) of the dyed fabric is assessed through a dyeability test. The finished fabrics are qualitatively assessed for antibacterial activity by the disc diffusion and parallel streak methods (AATCC 147) and quantitatively by the percentage reduction test (AATCC 100) against the test organisms, Escherichia coli and Staphylococcus aureus. The fabrics are also assessed for fastness properties, such as wash, light and rubbing fastness per AATCC standards. The fabrics are then finally subjected to wash durability tests. The dyeability results show that the fabrics dyed with P. granatum rind extracts have a high K/S value when compared with the untreated control fabric. The natural extract dyed fabric has prominent antimicrobial activity which is evidenced by a clear zone of bacterial inhibition in qualitative tests and bacterial reduction in quantitative tests whereas the control fabrics have no antibacterial activity. Wash durability testing shows that the antimicrobial activity of the fabrics is durable up to 10 wash cycles.

The inclusion of natural antioxidants and nanoparticles into edible coatings can improve their structure, functionality and applicability in foods. This study aims to determine the antibacterial effect of new nano-composite based on bean pod shell gum (BPSG), silver nanoparticle (SNP) and herbal essential oil (EO).

For this purpose, BPSG (4 per cent w/v), SNP (0.5-1 per cent w/v) and Helichrysum arenarium EO (1-2 per cent v/v) were mixed. After preparation the edible film, the antibacterial activity was tested on five food-borne pathogenic bacteria in two categories including two-gram positives and three-gram negatives bacteria. The EO composition was determined by GC–mass spectrometry and the antibacterial activity was tested using disk diffusion test.

Results showed that gram-positive bacteria were more susceptible than gram-negative bacteria. Increasing Helichrysum arenarium EO and SNP content increased antimicrobial activity of the edible film based on BPSG, so that the treatment containing 2 per cent v/v Helichrysum arenarium EO and 1 per cent w/v SNP led to the highest inhibition zone (8.1-13.1 mm) compared to treatment containing 1 per cent v/v Helichrysum arenarium EO and 0.5 per cent w/v SNP with inhibition zone range of 5.4-9.9 mm and the difference was statistically significant (p = 0.41). Also, the chemical composition analysis of the EO identified a total of 38 compounds in which a-pinene (32 per cent), 1,8-cineole (16 per cent), α-humulene (15 per cent) and ß-caryophyllene (8 per cent) were the main fractions. Other separated components accounted less than 29 per cent of the oil.

In general, SNP and Helichrysum arenarium EO improved the functional properties including the antimicrobial activity of the edible film based on BPSG, which increases the potential to be used as active packaging for fresh products.

Paper aims to evaluate the efficiency of traditional chitosan, nano chitosan, and chitosan nanocomposites for consolidating aged papyrus samples. Cellulose-based materials, such as papyrus sheets and paper, which are the most common types of writing supports for works of art in many museums and archive. They are subjected to different types of deterioration factors that may lead to many conservation problems. Consolidation treatment is one of the most common conservation treatments, which should have perform after much testing to select the appropriate consolidants.

This research paper aims to evaluate the resistance of traditional chitosan, nanochitosan and chitosan/zinc oxide nanocomposite as an eco-friendly papyrus strengthening. Untreated and treated papyrus was thermally aged and characterized via scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). Antimicrobial activity of the papyrus specimens was also determined against four tested pathogenic bacteria by disc diffusion method: MRSA, Staphylococcus aureus, E. coli and P. aeruginosa.

The results revealed that chitosan nanocomposite showed a remarkable enhancement of papyrus tensile properties and presence of ZnO prevents the effects of biodeterioration.

Zinc oxide nanoparticles enhance the optical properties and increase the chemical reactions between the consolidating material and the treated papyrus.