88,811 research outputs found

    Importance of understanding variable and transient energy demand in large multi-product industrial plants for process integration

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    There have been some news releases claiming that Professor Henle in Germany has found the chemical identity of UMF, and that in future chemical analysis will be used instead of assays of antibacterial activity to indicate the level of UMF in manuka honey. Both of these claims are misleading. Because the level of active substance in manuka honey is an unreliable indication of the level of antibacterial activity and can be very misleading, it is hard to see any commercial advantage for it to be used to indicate antibacterial activity other than if someone wanted to fool the consumer into thinking that the higher numbers are giving them a level of antibacterial activity that is far higher than they are really getting

    Soya bean tempe extracts show antibacterial activity against Bacillus cereus cells and spores

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    Aims: Tempe, a Rhizopus ssp.-fermented soya bean food product, was investigated for bacteriostatic and/or bactericidal effects against cells and spores of the food-borne pathogen Bacillus cereus. Methods and results: Tempe extract showed a high antibacterial activity against B. cereus ATCC 14579 based on optical density and viable count measurements. This growth inhibition was manifested by a 4 log CFU ml-1 reduction, within the first 15 min of exposure. Tempe extracts also rapidly inactivated B. cereus spores upon germination. Viability and membrane permeability assessments using fluorescence probes showed rapid inactivation and permeabilization of the cytoplasmic membrane confirming the bactericidal mode of action. Cooked beans and Rhizopus grown on different media did not show antibacterial activity, indicating the unique association of the antibacterial activity with tempe. Subsequent characterization of the antibacterial activity revealed that heat treatment and protease addition nullified the bactericidal effect, indicating the proteinaceous nature of the bioactive compound. Conclusions: During fermentation of soya beans with Rhizopus, compounds are released with extensive antibacterial activity against B. cereus cells and spores. Significance and Impact of Study: The results show the potential of producing natural antibacterial compounds that could be used as ingredients in food preservation and pathogen contro

    Antibacterial Activity Assay of Mangrove Extracts Against Salmonella Typhi and Listeria Monocytogenes

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    The antibacterial activities of mangrove species, Avicennia marina, Sonneratia caseolaris (collected from Teluk Payo, Banyuasin, South Sumatera), Ceriops tagal, Rizhopora apiculata, and Sonneratia alba (collected from Sadai, South Bangka) were screened against Salmonella typhi and Listeria monocytogenes by agar disk diffusion assays. Extractions were conducted using organic solvents (methanol, ethyl acetate, and acetone, subsequently). Most of the extracts tested showed potential antibacterial activity against both pathogens. The methanol extracts of the bark from S. alba and the fruit from A. marina showed particularly large inhibition zones (15 mm) against S. typhi. The acetone extract of S. alba leaves showed the largest inhibition zone (14 mm) when tested against L. Monocy-togenes. Further partial purifications of selected extracts which showed strong inhibition were performed by silica gel column chromatography using various eluent compositions with different polarities. The third fraction of methanol extract from S.alba leaves eluted with chloroform:methanol (1:5) resulted in a remarkably large inhibition zone (23 mm) against S. typhi. The third and seventh fractions of acetone extract from S. alba leaves eluted with ethyl acetate:methanol (7:3) resulted in a large inhibition zones (15 mm) against L. monocytogenes. In addition, the sixth fraction of methanol extract from A. marina fruit eluted with chloroform : methanol (6:4) resulted in the largest inhibition zone (17 mm) against L. monocytogenes. These results indicated that mangrove extracts could be developed as potential biomaterials for biopharmaceutical as well as biopreservation industries

    Antibacterial Activity of Sponge Associated-bacteria Isolated From North Java Sea

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    A total of 90 bacterial isolates were obtained from association with sponges collected from Bandengan water, Jepara and Karimun island of Karimunjawa islands in the north java sea. Antibacterial screening by using a pathogenic Escherichia coli indicated that two isolates BSP.12 and MKSP.5 inhihited the growth of tested strain. Molecular identification based on 16S rDNA approach revealed that isolate BSP.12 was closely related to Vibrio harveyi with a homology of 100% and isolate MKSP.5 showed highest similarity to Brachybacterium rhamnosum (99%), respectively.A PCR-based approach by using specific primers targeting the occurrence of gene fragments necessary for the biosynthesis of major natural products, namely Non-ribosomal peptide synthetases (NRPS) and Polyketide synthases (PKS) was applied to estimate the genetic potential of these active strains. Both isolates were capable of amplifying the NRPS gene fragments but not the PKS gene fragments

    The antibacterial activity of honey: 2. Variation in the potency of the antibacterial activity

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    Honey is gaining acceptance by the medical profession for use as an antibacterial agent for the treatment of ulcers and bed sores, and other surface infections resulting from burns and wounds. In many cases it is being used with success on infections not responding to standard antibiotic and antiseptic therapy. Its effectiveness in rapidly clearing up infection and promoting healing is not surprising in light of the large number of research findings on its antibacterial activity, covered in Part 1 of this review

    Antibacterial Activity for Multi Drug Resistance (Mdr) Bacteria Bysea Cucumber Stichopus Vastus Extract From Karimunjawa Islands – Indonesia

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    The study aims to explore the antibacterial activity of Stichopus vastus against pathogenic MDR bacteria. Analysis of samples of sea cucumbers included extraction, fractionation, and analysis of bacterial sensitivity test Gas Chromatography-Mass Spectrometry (GC-MS), the extraction process is carried out by solid-liquid extraction method. Fractionation was done with Open-Column Chromatography (OCC). Sensitivity test of bacteria was done using an agar diffusion method according to the Kirby-Bauer (Ref). The study revealed that from 5 species MDR bacteria, which are Coagulant negative stapylococi (CNS), E. coli, Enterobacter 5, Klebsiella sp. dan Pseudomonas sp. There are two MDR bacteria had the most sensitive responses by the extract of sea cucumber, which were Enterobacter-5 and Klebsiella sp. The two bacteria were tested against five bioactive fractions obtained from OCC. Fraction criteria-2 had the highest antibacterial activity against Enterobacter-5 and Klebsiella sp, with serial concentration of 20 µg ∙ disc–1, 40 µg. disc–1 and 80 µg. disc–1. Largest inhibition zone were obtained from 80 µg. disc–1 againts the two bacteria were (14.73 ± 0.48) mm and (11.22 ± 0.85) mm respectively. GC-MS Analysis revealed that fraction criteria-2 had (or consisted of) cyclohexhane, ethanol, butanoic and pentanoic acids
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