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[en] Turmeric is one of the prominently use herbal plants due to its diverse beneficial effects especially in Indian medicine. The rhizome part of the turmeric contains valuable compounds which have been said to owe its antimicrobial effects, anti-cancer, anti-inflammatory and enhance wound healing. Due to its short-life span and perishable properties, the conversion of the rhizome into turmeric extract is desirable. Several methods have been used for extraction such as Soxhlet extraction and pressurized liquid extraction (PLE). However, these techniques are tedious, laborious, time consuming and involves the usage of toxic organic solvent, of which safeness of the end product is doubtful. In this study, a rapid, reliable and green extraction method of supercritical fluid extraction (SFE) and ultrasonic assisted extraction (UAE) were used. SFE without modifier has resulted in 0.0006 mg/ 100 g of curcuminoids concentration and 5.62 % of yield (dry weight basis). UAE using ethanol was able to produce significantly the highest yield (6.40 %, dry weight basis) and the highest curcuminoids concentration (0.1020 mg/ 100 g). However, SFE was able to produce extract that contain significantly higher major volatile compounds; tumerone, ar-turmerone and curlone. Therefore, this study proves that both extraction methods were able to produce high quality turmeric extract. (author)
[en] Ozone has been widely used in the food industry as an effective antimicrobial agent. In this study the possibilities of using ozone in table olive preservation was investigated for the first time. For this purpose, the Domat variety of table olives was processed according to the Spanish style and treated with aqueous ozone for 5, 10, and 20 minutes at 0.5, 1, 2 and 4 ppm. The effects of ozonation on the microbiological, physical and sensory characteristics of the table olives were evaluated during the storage period (up to 180 days). The pH, color and firmness of the ozone treated table olives showed higher stability. Statistically significant reductions in the total bacteria and yeast/mould counts were obtained (p < 0.05). Enterobacteriaceae and Escherichia coli were not found in the samples. After 60 days of storage the control samples (ozone untreated olives) obtained low values for sensory analysis, and did not meet market requirements. The results indicate that treating green table olive with ozon (1 ppm concentration) for 10 min in aqueous form reduces the microbial population without any negative effects on the firmness, color (L*, a* b*) or sensory attributes of the table olives.
[es]El ozono se ha utilizado ampliamente en la industria alimentaria como un eficaz agente antimicrobiano. En este estudio se investigaron por primera vez las posibilidades de utilizar ozono en la conservación de la aceituna de mesa. Para este propósito, las aceitunas de mesa de la variedad Domat procesadas según el estilo español se trataron con ozono acuoso durante 5, 10 y 20 minutos a 0,5, 1, 2 y 4 ppm. El efecto de la ozonización sobre la calidad microbiológica, física y sensorial de la aceituna de mesa se evaluó durante el período de almacenamiento (hasta 180 días). El pH, color y la firmeza de las aceitunas de mesa tratadas con ozono mostraron una mayor estabilidad. Se obtuvo una reducción estadísticamente significativa en el recuento total de bacterias y levaduras/mohos (p <0,05). No se encontraron enterobacterias ni Escherichia coli en las muestras. Después de 60 días de almacenamiento, las muestras de control (aceitunas sin tratar con ozono) obtuvieron valores bajos para el análisis sensorial, sin cumplir la condición para el mercado. Los resultados indican que el tratamiento de la aceituna de mesa verde con ozono (concentración de 1 ppm) durante 10 min en forma acuosa reduce la población microbiana sin efectos negativos sobre la firmeza, el color (L *, a * b *) y los atributos sensoriales de las aceitunas de mesa.
[en] The exploration of nanocomposites has gained a strong research following over the last decade. These materials have been heavily exploited in several fields, with applications ranging from biosensors to biomedicine. Among these applications, great advances have been made in the field of microbiology, specifically as antimicrobial agents. This review aims to provide a comprehensive account of various nanocomposites that elucidate promising antimicrobial activity. The composition, physical and chemical properties, as well as the antimicrobial performance of these nanocomposites, are discussed in detail. (topical review)
[en] The principle aim of the program was to produce a novel, non-leaching antimicrobial surface for commercial development and future use in the liquid food packaging industry. Antimicrobial surfaces which exist presently have been produced to combat the growth of prokaryotic organisms and usually function as slow release systems. A system which could inhibit eukaryotic growth without contaminating the surrounding 'environment' with the inhibitor was considered of great commercial importance. The remit of this study was concerned with creating a surface which could control the growth of eukaryotic organisms found in fruit juice with particular interest in the yeast, Saccharomyces cerevisiae. Putative antimicrobial surfaces were created by the chemical modification of the test substrate polymers; nylon and ethylvinyl alcohol (EVOH). Surfaces were chemically modified by the covalent coupling of antimicrobial agents known to be active against the yeast Saccharomyces cerevisiae as ascertained by the screening process determining the minimum inhibitory concentration (MIC) values of agents in the desired test medium. During the study it was found that a number of surfaces did appear to inhibit yeast growth in fruit juice, however on further investigation the apparent inhibitory effect was discovered to be the result of un-bound material free in the test medium. On removing the possibility of any un-bound material present on the test surface, by a series of surface washings, the inhibitory effect on yeast growth was eliminated. Of the agents tested only one appeared to have an inhibitory effect which could be attributed to a true antimicrobial surface effect, Amical 48. As there is little known about this agent in the literature, its affect on yeast growth was examined and in particular a proposal for the mode of action on yeast is discussed, providing a plausible explanation for the inhibitory effect observed when this agent is covalently immobilised onto nylon. (author)
[en] To determine the in vitro susceptibility of chloramphenicol against methicillin-resistant Staphylococcus aureus. Study Design: Cross-sectional study. Place and Duration of Study: Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi, from January to June 2012. Methodology: One hundred and seventy four isolates of methicillin-resistant Staphylococcus aureus were included in this study using cefoxitin (30 A g) disc for detection. Minimum inhibitory concentration (MIC) of chloramphenicol against MRSA was determined by using E-strip (AB BIO DISK). The susceptibility was determined by swabbing the Mueller-Hinton agar (MHA) plates with the resultant saline suspension of MRSA and applying E-strip of chloramphenicol from AB Biodisk Sweden and determining the MIC of chloramphenicol (in A g/ml). Clinical and Laboratory Standards Institute (CLSI) recommendations of A=8 A g/ml being sensitive, 16 A g/ml as intermediate and A 32 A g/ml as resistant were followed in interpreting the results. Results: Out of the 174 MRSA isolates, 132 (75.86%) isolates were susceptible to chloramphenicol with MICs of A=8 A g/ml, 38 (21.84%) were resistant A=32 A g/ml while 4 (2.30%) were in intermediate range with MIC of 16 A g/ml. Conclusion: Chloramphenicol has shown good in vitro activity against MRSA and is likely to have a key role in the treatment of MRSA infections providing us a good alternative to newer expensive antimicrobials in resource limited countries. (author)
[en] Crude extracts of curcuminoids and essential oil of Curcuma long varieties Kasur, Faisalabad and Bannu were studied for their antibacterial activity against 4 bacterial strains viz., Bacillus subtilis, Bacillus macerans, Bacillus licheniformis and Azotobacter using agar well diffusion method. Solvents used to determine antibacterial activity were ethanol and methanol. Ethanol was used for the extraction of curcuminoids. Essential oil was extracted by hydrodistillation and diluted in methanol by serial dilution method. Both Curcuminoids and oil showed zone of inhibition against all tested strains of bacteria. Among all the three turmeric varieties, Kasur variety had the most inhibitory effect on the growth of all bacterial strains tested as compared to Faisalabad and Bannu varieties. Among all the bacterial strains B. subtilis was the most sensitive to turmeric extracts of curcuminoids and oil. The MIC value for different strains and varieties ranged from 3.0 to 20.6 mm in diameter. (author)
[en] Complete text of publication follows. Nanogels are swollen networks of hydrophilic polymers generally developed to carry drugs, proteins and biologically active substances for biomedical applications. They can be prepared by 1) physical assembling of interactive polymers, 2) polymerization of monomers in micro or nanoscale environment, 3) crosslinking of preformed polymers, 4) template-assisted nanofabrication of nanogel particles. Among these methods crosslinking of preformed polymer chains provide excellent applications, especially when ionizing radiation is used as the tool to induce crosslinking. Due to its low cytotoxicity, excellent biocompatibility and non-carcinogenic and non-allergic properties, poly(N-vinyl pyrrolidone) (PVP) has been widely used in biomedical applications, hence the main reason for its selection in this work for the synthesis of its nanogels. PVP nanogels were prepared by gamma irradiation of its dilute aqueous solutions up to 15 kGy. The coil sizes of PVP chains were initially controlled by using acetone/water mixture as the solvent and further irradiations fixed the sizes by intramolecular crosslinking. By changing the concentration of PVP solutions, solvent composition and dose it was possible to prepare nanogels within 40-230 nm sizes. The nanogels were characterized by dynamic light scattering, scanning electron microscopy and atomic force microscopy. GPC has also been used to follow the changes in the coil sizes and distributions upon irradiations. The PVP nanogels thus synthesized were complexed with iodine in aqueous KI-I2 solutions. Nanogels comprised of typical PVP-iodine complexes were tested for their antiseptic properties.
[en] The synthesis of biologically active 1H-1,4-diazepines 4a-d and 3H-1,5-benzodiazepines 5a-d in good yields, from the heterocyclization reaction of 2-(4-methylthio benzenesulfonyl)-1,3-dimethyl/1-methyl-3-phenyl/1,3-diphenyl/1-methyl-3- ethoxy propane-1,3-dione 3a-d with ethylenediamine (EDA) and o-phenylenediamine (o-PDA), respectively, in the presence of silica sulfuric acid (SSA) is described. The novel β-diketones/β-ketoesters 3a-d were synthesized by the condensation reaction of 4-methylthio benzenesulfonyl chloride 1 with various β-diketones/β-ketoesters 2a-d. All structures of the newly synthesized compounds were elucidated by elemental analysis and spectral studies. The compounds 4a-d and 5a-d have been screened for antimicrobial, antifungal and anthelmintic activity
[en] Six microbial strains called 'Culti-loops' (A. brasiliensis, B. subtilis, C. albicans, P. aeruginosa, S. aureus and E. coli) were used to verify the efficiency of the culture media, however, USP indicates to use less than 100 cfu / strain; to achieve it increasing dilutions were performed for each strain and according to the obtained results that grew from 1 x 10"4 to 30 x 10"6 cfu / strain and by means of calculation, volumes were determined (µL), seeded in culture medium for each of the listed microorganisms. Practical values were determined and according to the results, a dilution value of less than 100 cfu was obtained for each strain. (authors).
[en] In a screening program for new active secondary metabolites producers, a strain of Streptomyces called TN262 was isolated from Tunisian soil and selected for its ability to produce eleven active compounds in pure culture conditions. In this work, the effect of different concentrations of heat-killed fungus Fusarium sp. on the production of active compounds by TN262 strain was studied. The ethyl acetate extract from the culture of Streptomyces sp. TN262 combined with heat-killed Fusarium sp. at 50 micro g/ml inhibited the growth of the three used indicator microorganisms. In fact, an increase of 36%, 21% and 20% in inhibitory activity was obtained against Micrococcus luteus LB 14110, Escherichia coli ATCC 8739 and Fusarium sp. respectively. The HPLC chromatographic profiles of the ethyl acetate extracts from both culture conditions were different and an additional active compound was produced only under induced conditions. This active component was isolated and identified as Cyclo (L-Leu-L-Arg) (1), a diketopiperazine derivative, possessing antibacterial and antifungal activity. Consequently, this study showed that the addition of heat-killed fungus is a useful method for inducing the production of bioactive compounds. (author)