15 research outputs found

    Identification of the Antibacterial Compound Produced by the Marine Epiphytic Bacterium Pseudovibrio sp. D323 and Related Sponge-Associated Bacteria

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    Surface-associated marine bacteria often produce secondary metabolites with antagonistic activities. In this study, tropodithietic acid (TDA) was identified to be responsible for the antibacterial activity of the marine epiphytic bacterium Pseudovibrio sp. D323 and related strains. Phenol was also produced by these bacteria but was not directly related to the antibacterial activity. TDA was shown to effectively inhibit a range of marine bacteria from various phylogenetic groups. However TDA-producers themselves were resistant and are likely to possess resistance mechanism preventing autoinhibition. We propose that TDA in isolate D323 and related eukaryote-associated bacteria plays a role in defending the host organism against unwanted microbial colonisation and, possibly, bacterial pathogens

    Dimeric cyanobacterial cyclopent-4-ene-1,3-dione as selective inhibitor of Gram-positive bacteria growth: Bio-production approach and preparative isolation by HPCCC

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    The need for new antimicrobial agents is greater than ever because of the emergence of multidrug resistance in common pathogens and incidence of new infections. Cyclopent-4-ene-1,3-diones (CPDs) have been reported as a new class of compounds with promising antimicrobial and antifungal properties. Herein we report the selective antibiotic properties of nostotrebin 6, a phenolic CPD produced biotechnologically by the culture of cyanobacterium Nostoc sp. str. Lukešová 27/97. High performance countercurrent chromatography (HPCCC) combined with gel permeation chromatography (GPC) was used for the isolation of nostotrebin 6 with a relatively high 0.53 ± 0.1% yield (calculated from dried biomass) and final purity higher than 96%. Nostotrebin 6 was tested for its antimicrobial and antifungal activities by using standard micro-dilution method, and the results were expressed as minimal inhibitory concentrations (MICs). Nostotrebin 6 unequivocally inhibited the growth of Gram-positive reference (Enterococcus faecalis CCM 4224, Staphylococcus aureus CCM 4223 and Staphylococcus aureus CCM 3953) and multidrug-resistant (Staphylococcus haemolyticus A/16568, Staphylococcus aureus MRSA 4591 and Enterococcus faecium VanA 419/ana) strains. Its strongest effect was exerted against the Gram-positive bacteria with MICs ranging between 6.25 and 15.6 μg/mL. There was no effect on Gram-negative strains tested and yeasts. Our results suggest that nostotrebin 6 could serve as basic nucleus for further design of novel antibiotic agents and demonstrate that the bio-production approach based on HPCCC/GPC isolation endpoint is an efficient methodology for obtaining nostotrebin 6 in multi-gram scale. Furthermore, the presented isolation method can be easily up-scaled to process kilograms of the cyanobacterial biomass.This work was supported by the Palacky University Internal Financial Support, project no. IGA_LF_2016_012 (J.V.) and IGA_LF_2016_022 (M.K.), by the project ALGAIN (CZ.1.07/2.3.00/30.0059, J.C.), by the Center for Algal Biotechnology-ALGATECH (CZ. 1.05/21.00/03.0110, J.C., J.K. and P.H.) and by the National Programme of Sustainability I, Ministry of Education Youth and Sports of the Czech Republic, ID: LO1416 (J.C., J.K. and P.H.)

    Complexity Assessment of Assembly Supply Chains from the Sustainability Viewpoint

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    Assembly supply chain systems are becoming increasingly complex and, as a result, there is more and more need to design and manage them in a way that benefits the producers and also satisfies the interests of community stakeholders. The structural (static) complexity of assembly supply chain networks is one of the most important factors influencing overall system complexity. Structures of such networks can be modeled as a graph, with machines as nodes and material flow between the nodes as links. The purpose of this paper is to analyze existing assembly supply chain complexity assessment methods and propose such complexity metric(s) that will be able to accurately reflect not only specific criteria for static complexity measures, but also selected sustainability aspects. The obtained results of this research showed that selected complexity indicators reflect sustainability facets in different ways, but one of them met the mentioned requirements acceptably

    VALUE STREAM MAPPING AND ITS SIGNIFICANCE IN THE PRODUCTION PROCESS

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    Monitoring of flows (material, information, personal, energy, financial, etc.) in the production process is always inevitable approach while searching for improvements. There are, radical improvements known as innovations, and continuous improvement established by KAIZEN principles and its useful methods. Both approaches focus on processes that add value, and minimise or eliminate those without added value. The main target of this paper is to analyse the Value stream mapping approach and its benefit to the practical world

    Ergonomic Assessment of Physical Load in Slovak Industry Using Wearable Technologies

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    The physical tasks of workers are demanding, particularly when performed long-term in unsuitable working position, with high frequency, heavy load, after injury, with developing damage of health or reduced performance due to advanced age. Work-related musculoskeletal disorders (WMSDs) result from overuse or develop over time. Work activities, which are frequent and repetitive, or activities with awkward postures, cause disorders that may be painful during work or at rest. There is a new technology in the market, occupational exoskeletons, which have the prerequisites for minimizing the negative consequences of workload on WMSDs. We provided pilot quantitative measurements of the ergonomic risk at one selected workplace in a Slovak automotive company with four different workers to prove our methodology using wearable wireless multi-sensor systems Captiv and Actigraph. At first, the test was performed in standard conditions without an exoskeleton. The unacceptable physical load was identified in considerable evaluated body areas—neck, hip, and shoulder. Next, the passive chair exoskeleton Chairless Chair 2.0 was used in trials as an ergonomic measure. Our intention was to determine whether an exoskeleton would be an effective tool for optimizing the workload in selected workplaces and whether the proposed unique quantitative measurement system would give reliable and quick results

    Implementacja metody analizy odchylenia w fazie użytkowania projektu inwestycyjnego : studium przypadku

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    Management of investment projects incorporates phases of pre-investment, investment and utilisation. A well-conducted pre-investment and investment phases reduce the risk of problems that might occur in the utilisation phase, but cannot be eliminated entirely, as the development of internal and external assumptions may not be consistent with the plan. Therefore, even in the utilisation phase, it is necessary to analyse the economic results actually achieved with planned one. The article presents application of the deviation analysis method in the utilisation phase of the assessed investment project. Net Present Value (NPV) deviation analysis is focused on the EBITDA indicator and supplemented by specifying the causes of deviations. The results of the study show that deviations of NPV are caused mainly by lowering the production volume of both products and by a decrease in variable costs per unit. The presented measures lead to the reduction in the probability of the deviations occurrence.Zarządzanie projektami inwestycyjnymi obejmuje etapy: przedinwestycyjny, inwestycjny i wykorzystania. Dobrze prowadzone fazy przedinwestycyjne i inwestycyjne zmniejszają ryzyko pojawienia się problemów, które mogą wystąpić w fazie wykorzystania. Nie można ich jednak całkowicie wyeliminować, ponieważ rozwój wewnętrznych i zewnętrznych założeń może nie być zgodny z planem. Dlatego też, nawet w fazie wykorzystania, konieczne jest dokonanie porównania wyników ekonomicznych faktycznie osiągniętych z planowanymi. W artykule przedstawiono zastosowanie metody analizy odchylenia w fazie wykorzystania projektu inwestycyjnego. Analiza odchylenia wartości bieżącej netto (NPV) koncentruje się na wskaźniku EBITDA i uzupełniona jest poprzez określenie przyczyn odchyleń. Wyniki badania wskazują, że odchylenia wartości bieżącej netto spowodowane są głównie przez obniżenie wielkości produkcji obu produktów i zmniejszenie kosztów zmiennych na jednostkę. Prezentowane działania prowadzą do zmniejszenia prawdopodobieństwa występowania odchyleń
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