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EN
Soil contaminated with crude oil has negatively affected some of the communities in Ekiti State region in Nigeria. There is an increased interest in microbial lipases because of their enormous potential in industrial and biotechnological applications. This study investigated the characteristics of partially-purified lipase from Pseudomonas aeruginosa isolated from oil-contaminated soil in Ado-Ekiti, Ekiti State. The lipase was purified by gel-filtration, having a molecular weight of 39.11 kDa, with Km and Vmax values of 12.50 and 28.86, respectively. The enzyme had an optimal pH of 8.0 and exhibited its maximal activity at 50°C, whereas the relatively stable temperature and pH were 40°C and 5.0, respectively. The enzyme activity was enhanced by olive oil, which served as the carbon source. Sodium chloride enhanced lipase activity, while calcium chloride acted as mild inhibitor, and iron chloride acted a strong inhibitor. The lipase from Pseudomonas aeruginosa possessed properties of an industrial enzyme and will be useful for biodegradation and bioremediation studies.
EN
Aluminium recycling is one of currently growing industries in Indonesia. Abundant amounts of aluminium waste leads to the emergence of new industries. The waste produced from this kind of industry is not well processed yet. Bioremediation using isolated indigenous bacteria is one of the best options from treating the aluminium recycling wastewater. Since biological processes are closely related to the bacterial growth conditions, it is important to understand the effect of pH and aluminium exposure to bacteria. Six potential bacteria strains were obtained from isolation. Vibrio alginolyticus and Brochothrix thermosphacta were shown to be resistant to the aluminium exposure, as well as the acidic conditions. Both types of bacteria were able to survive on acid medium with pH 5. The higher the concentration of aluminium, the slower bacterial growth rate achieved. The MIC value of aluminium for Vibrio alginolyticus was 425 mg/l, Brochothrix thermosphacta was 325 mg/l and Pseudomonas aeruginosa was 200 mg/l.
EN
This study was conducted to investigate the degree of bioremediation that would occur in the samples of soil polluted with raw and treated crude petroleum (oil) with the aid of Aspergillus niger (fungi) and Pseudomonas aeruginosa (bacteria). This was achieved by monitoring the Organic carbon content in the soil over 45 days and pH over 25 days. Four systems of 500 g soil were polluted with 40 g treated crude petroleum, while four systems were contaminated with 40 g raw crude petroleum. The eight systems were labeled accordingly. Two systems for raw crude control and treated crude control (RCC and TCC) were left as control, two systems for raw crude Aspergillus niger and treated crude Aspergillus niger (RCA and TCA) were treated with Aspergillus niger only, two systems for raw crude Pseudomonas aeruginosa and treated crude Pseudomonas aeruginosa (RCP and TCP) were treated with Pseudomonas aeruginosa only and the last two systems for raw crude Aspergillus niger and Pseudomonas aeruginosa (RCAP and TCAP) were treated with both Pseudomonas aeruginosa and Aspergillus niger. At the end of the bioremediation period, the results obtained showed that the pH was not particularly a solid parameter to estimate the degree of bioremediation. This is because a proper trend in the results obtained could not be determined. Additionally, it was observed that Aspergillus niger (fungi) and Pseudomonas aeruginosa (bacteria) alone and separate remediate raw crude polluted soil better than treated crude polluted soil. This was determined by the TOC (Total Organic Carbon) values on the 45th day of the experiment.
4
Content available remote New approach for n-hexadecane biodegradation by sol-gel entrapped bacterial cells
EN
In this study sol-gel hybrid materials in the system SiO2-chitosan (CS) - polyethylene glycol (PEG), as novel structures with potential application in bioremediation were investigated. The organic components - CS and PEG were used as structural modifiers for functionality improvement. The catabolic activity to n-hexadecane of Pseudomonas aeruginosa BN10 free and immobilized cells was estimated. The cell immobilization technique was employed to evaluate its efficiency on biodegradation and protective effect from high levels of hydrocarbons. The characteristics of obtained hybrid materials were investigated via X-ray Diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Atomic-force microscopy (AFM) analyses. The obtained results revealed that the organic part in the synthesized hybrids is important for microstructure and defined properties creation. The rate of n-hexadecane mineralization by the bacterial strain was influenced by variation in cell densities applied in the immobilization procedures. Semi-continuous processes with multiple xenobiotic supplies were carried out. The synthesized by the sol-gel method hybrid matrices proved to be suitable carriers for realizing an effective biodegradation process of n-hexadecane by Pseudomonas aeruginosa BN10. Biodegradation of 50 kg/m3 of n-hexadecane was realized by free cells. Significantly greater quantity (150 kg/m3) was mineralized for 15 active cycles by entrapped bacterial cells. Biodegradation process with gradual increase of xenobiotic concentration reaching 30 kg/m3 for 120 h was also accomplished.
EN
The suitability of low-cost impedance sensors for microbiological purposes and biofilm growth monitoring was evaluated. The sensors with interdigitated electrodes were fabricated in PCB and LTCC technologies. The electrodes were golden (LTCC) or gold-plated (PCB) to provide surface stability. The sensors were used for monitoring growth and degradation of the reference ATCC 15442 Pseudomonas aeruginosa strain biofilm in invitro setting. During the experiment, the impedance spectra of the sensors were measured and analysed using electrical equivalent circuit (EEC) modelling. Additionally, the process of adhesion and growth of bacteria on a sensor’s surface was assessed by means of the optical and SEM microscopy. EEC and SEM microscopic analysis revealed that the gold layer on copper electrodes was not tight, making the PCB sensors susceptible to corrosion while the LTCC sensors had good surface stability. It turned out that the LTCC sensors are suitable for monitoring pseudomonal biofilm and the PCB sensors are good detectors of ongoing stages of biofilm formation.
EN
A new biodesulphurization method has been considered using Pseudomonas aeruginosa supported on polyethylene (PE) for biodesulphurization (BDS) of thiophene as an aromatic sulphur model compound of crude oils. Also the biodegradation of thiophene has been modified in the presence of potassium hexacyanoferrate(III) as a terminal electron acceptor to approach the maximum biodesulphurization efficiency. The obtaining results according to UV-Spectrophotometry at 240 nm, 83.3% of thiophene at the primary concentration of 50 mg/dm3, pH = 7, by 0.5 g of biocatalyst in 37°C after 4 h of contact time has been removed. The bacterial cells exhibited a greater and faster biodegradation in the presence of potassium hexacyanoferrate(III) and 94.8% of thiophene has been removed after 3 h of contact time. Kinetic study predicted chemisorption of thiophene on the surface of the biocatalyst, as it followed the pseudo-second-order rate equation. Morphology and surface functional groups of the biocatalyst have been investigated by SEM and FT-IR, respectively.
EN
Bioremediation is based on microorganisms able to use pollutants either as a source of carbon or in co-metabolism, and is a promising strategy in cleaning the environment. Using soil contaminated with petroleum products from an industrial area in Saudi Arabia (Jubail), and after enrichment with the polycyclic aromatic hydrocarbon (PAH) naphthalene, a Methylobacterium radiotolerans strain (N7A0) was isolated that can grow in the presence of naphthalene as the sole source of carbon. M. radiotolerans is known to be resistant to gamma radiation, and this is the first documented report of a strain of this bacterium using a PAH as the sole source of carbon. The commonly reported Pseudomonas aeruginosa (strain N7B1) that biodegrades naphthalene was also identified, and gas chromatography analyses have shown that the biodegradation of naphthalene by M. radiotolerans and P. aeruginosa did follow both the salicylate and phthalate pathways.
EN
In our previous work we reported the impact of hydrofluoric and nitric acid used for chemical polishing of Ti-6Al-7Nb scaffolds on decrease of the number of Staphylococcus aureus biofilm forming cells. Herein, we tested impact of the aforementioned substances on biofilm of Gram-negative microorganism, Pseudomonas aeruginosa, dangerous pathogen responsible for plethora of implant-related infections. The Ti-6Al-7Nb scaffolds were manufactured using Selective Laser Melting method. Scaffolds were subjected to chemical polishing using a mixture of nitric acid and fluoride or left intact (control group). Pseudomonal biofilm was allowed to form on scaffolds for 24 hours and was removed by mechanical vortex shaking. The number of pseudomonal cells was estimated by means of quantitative culture and Scanning Electron Microscopy. The presence of nitric acid and fluoride on scaffold surfaces was assessed by means of IR and rentgen spetorscopy. Quantitative data were analysed using the Mann–Whitney test (P ≤ 0.05). Our results indicate that application of chemical polishing correlates with significant drop of biofilm-forming pseudomonal cells on the manufactured Ti-6Al-7Nb scaffolds ( p = 0.0133, Mann–Whitney test) compared to the number of biofilm-forming cells on non-polished scaffolds. As X-ray photoelectron spectroscopy revealed the presence of fluoride and nitrogen on the surface of scaffold, we speculate that drop of biofilm forming cells may be caused by biofilm-supressing activity of these two elements.
PL
Woda przeznaczona do spożycia przez ludzi musi gwarantować bezpieczeństwo zdrowotne konsumentom, dlatego niezbędny jest stały monitoring wody pod względem fizykochemicznym oraz mikrobiologicznym. W mikrobiologicznej analizie wody ze zbiorników magazynujących w środkach transportu lądowego, powietrznego i wodnego, z cystern i wód butelkowanych, oprócz wykrywania bakterii wskaźnikowych Escherichia coli i enterokoków fekalnych dodatkowo oznacza się obecność pałeczek Pseudomonas aeruginosa. Są to bakterie oportunistyczne wywołujące stany chorobowe u osób o obniżonej odporności. Ich naturalnym środowiskiem występowania są wodne ekosystemy. Wykrywanie P. aeruginosa metodą referencyjną jest trudne, ze względu na zmiany filogenetyczne, jakim podlegają te bakterie oraz występowanie mikroflory towarzyszącej. Konieczność przeprowadzania testów potwierdzających znacznie wydłuża czas analizy, a tym samym otrzymanie ostatecznego wyniku świadczącego o bezpieczeństwie bądź zagrożeniu zdrowotnym wody butelkowanej. Pseudalert® oparty na technologii zdefiniowanych substratów to nowy, alternatywny system, który może usprawnić ocenę jakości mikrobiologicznej wody w kierunku obecności P. aeruginosa.
EN
Water intended for human consumption should be safe for consumers. Therefore, the permanent monitoring of water is necessary for determination of its physico-chemical and microbiological characteristic. The microbiological analysis of water from the storage tanks in different means of transport by land, air and water, from cisterns and bottled waters, is based on detection of sanitary indicators: Escherichia coli, enterococci and Pseudomonas aeruginosa rods. The mentioned bacteria are opportunistic pathogens that cause diseases in people with decreased immunity. Aquatic ecosystems are their natural habitat. Detection of P. aeruginosa by reference method is difficult, due to the changes in phylogenetic characteristics, and the presence of accompanying microflora in water. The need for confirmatory testing significantly increases the time of analysis. Pseudalert® test based on Defined Substrates Technology is a new alternative system that can improve the assessment of the microbiological quality of water for P. aeruginosa detection.
PL
Pseudomonas aeruginosa to tlenowe bakterie oportunistyczne, których typowym siedliskiem są zbiorniki wody, systemy dystrybucji oraz złoża filtracyjne. Bakterie te są znane ze swych wyjątkowych zdolności adhezyjnych oraz odporności na środki dezynfekcyjne. Wykrywanie P. aeruginosa jest trudne ze względu na ich częste zmiany fenotypowe i genotypowe oraz występowanie mikroflory towarzyszącej. Technologia Zdefiniowanych Substratów zastosowana w teście Pseudalert® znacznie ułatwia ocenę jakości mikrobiologicznej wody w kierunku obecności P. aeruginosa.
EN
Pseudomonas aeruginosa is an opportunistic aerobic pathogen. The typical habitat of these bacteria are water tanks, distribution systems, and filter beds. Pseudomonas cells are known for their adhesive abilities and resistance to disinfectants. Detection of P. aeruginosa is difficult due to frequent changes in their phenotypic and genotypic characteristics, and the presence of accompanying microfl ora. Test Pseudalert®, based on Defined Substrates Technology, facilitates the assessment of the microbiological quality of water in the direction of P. aeruginosa.
PL
Oporność patogenów na karbapenemy, uznawane za leki "ostatniej szansy", stanowi poważny problem kliniczny dla współczesnej medycyny. Ponadto niewrażliwość na tę grupę antybiotyków przyczynia się do powstawania szczepów opornych również na inne dostępne leki.
EN
Pathogens’ resistance to carbapenems (considered as a drug of the "last resort") is a major clinical problem in a modern medicine. Furthermore, the insusceptibility of the bacteria to this group of antibiotics contributes to the formation of strains that are resistant to other available drugs.
PL
Jakość wody w krytych obiektach rekreacyjnych (pływalnie, SPA, parki wodne) ma bardzo istotne znaczenie zdrowotne. Niewłaściwie prowadzony proces dezynfekcji wody basenowej może powodować zakażenia bakteriologiczne, przy czym stosowanie środków dezynfekcyjnych w nadmiernych ilościach może również powodować schorzenia u ludzi. W pracy dokonano oceny jakości wody w wybranej pływalni na podstawie rutynowej oraz rozszerzonej analizy mikrobiologicznej i fizyczno-chemicznej. Wykazano, że rutynowa analiza mikrobiologiczna wody basenowej nie pozwala na prawidłową ocenę jej stanu sanitarnego. Rutynowe wskaźniki mikrobiologiczne osiągnęły bowiem poziom potwierdzający zadowalającą jakość wody w odniesieniu do prawie wszystkich punktów pomiarowych badanego obiektu. Wyjątek stanowiły wanny SPA oraz brodzik dla dzieci, gdzie odnotowano jedynie ponadnormatywną liczbę bakterii mezofilnych (115÷1000 jtk/cm3). Jednak dopiero rozszerzona analiza mikrobiologiczna wody pozwoliła na wykrycie obecności bakterii z rodzaju Pseudomonas, w tym Pseudomonas aeruginosa. Badane próbki wody charakteryzowały się także niższą wartością potencjału redoks (507÷582 mV) oraz mniejszą zawartością chloru wolnego (0÷0,1 gCl2/m3). Jedną z przyczyn okresowego pojawiania się bakterii Pseudomonas był zastój wody w elementach instalacji, w których następował rozwój tych bakterii w ilościach przekraczających 100 jtk/cm3, a także gronkowców koagulazododatnich. Bakterie z rodzaju Pseudomonas obecne były również w próbkach wody pochodzących z urządzeń do jej rozdeszczania. Otrzymane wyniki wykazały możliwość zasiedlania urządzeń basenowych - w przypadku niewłaściwie prowadzonego procesu dezynfekcji - przez mikroorganizmy stanowiące zagrożenie dla zdrowia użytkowników obiektów rekreacyjnych.
EN
Water quality in indoor recreational objects (swimming pool, SPA, aquapark) is of paramount importance to the health of the users. Inadequate disinfection of swimming pool water may be the underlying cause of various diseases or afflictions. In the recreational object chosen for the study reported on here, water quality assessments were carried out using routine and extended microbiological and physicochemical analyses. It has been demonstrated that routine microbiological analysis failed to reliably assess the sanitary condition of the swimming pool water. In terms of routine microbiological indicators, water quality was satisfactory at all sampling sites but two. The two exceptions were in the SPA tubs and wading pools, where mesophilic bacteria alone were found to occur in excessive numbers (115 to 1000 cfu/cm3). Only with extended microbiological analysis was it possible to detect the occurrence of bacteria of the Pseudomonas genus, including Pseudomonas aeruginosa. The water samples examined in this mode also displayed lower redox potential values (507 to 582 mV) and a lower free chlorine content (0 to 0.1 gCl2/m3). The periodical occurrence of Pseudomonas bacteria should, inter alia, be attributed to the stagnation of water in some parts of the installation, where their growth rate was found to exceed 100 cfu/cm3, and where the presence of coagulase-positive staphylococci was detected. Pseudomonas bacteria were also present in the water samples collected from spray irrigators and rain showers. The results obtained make it clear that if the disinfection process is conducted without sufficient efficacy, the microorganisms growing in the swimming pool develop the potential for colonizing the installations, and thus pose health hazards to the swimmer.
PL
Pseudomonas aeruginosa to powszechnie występujący w środowisku patogen oportunistyczny, który często przyczynia się do poważnych zakażeń u pacjentów z obniżonym poziomem odporności. Liczne przystosowania morfologiczne i fizjologiczne tej bakterii, a w szczególności zdolność do wytwarzania czynników wirulencji, znajdujących się pod kontrolą systemu quorum sensing, umożliwiają skuteczną kolonizację organizmu gospodarza. Dodatkowo naturalna oporność P. aeruginosa na stosowane w terapii antybiotyki utrudnia skuteczne zwalczanie zakażeń wywoływanych przez te bakterie.
EN
Pseudomonas aeruginosa is an opportunistic pathogen commonly found in environment. These bacteria are able to cause serious infections in hosts with defective immune systems. Numerous morphological and physiological adaptations of this species, especially ability to produce virulence factors, which are dependent on quorum sensing, allows efficient colonization of host organism by this pathogen. Moreover, P. aeruginosa is naturally resistant to many antibiotics and causes serious problems in therapies.
PL
Pseudomonas aeruginosa to powszechnie występujący w środowisku patogen oportunistyczny, który często przyczynia się do poważnych zakażeń u pacjentów z obniżonym poziomem odporności. Liczne przystosowania morfologiczne i fizjologiczne tej bakterii, a w szczególności zdolność do wytwarzania czynników wirulencji, znajdujących się pod kontrolą systemu quorum sensing, umożliwiają skuteczną kolonizację organizmu gospodarza. Dodatkowo naturalna oporność P. aeruginosa na stosowane w terapii antybiotyki utrudnia skuteczne zwalczanie zakażeń wywoływanych przez te bakterie.
EN
Pseudomonas aeruginosa is an opportunistic pathogen commonly found in environment. These bacteria are able to cause serious infections in hosts with defective immune systems. Numerous morphological and physiological adaptations of this species, especially ability to produce virulence factors, which are dependent on quorum sensing, allows efficient colonization of host organism by this pathogen. Moreover, P. aeruginosa is naturally resistant to many antibiotics and causes serious problems in therapies.
EN
Shortage in drinking water supply led to an increase of pumping water to storage tanks and its redistribution to the consumers. The water quality may be changed according to the storage condition and to the deficiency in cleaning of those tanks. Water samples were taken from the tanks of Helwan and El-Giza governorates (Cairo, Egypt) and examined to evaluate microbial water quality. The results revealed that all water samples were free from total coliforms, faecal streptococci, sulphite reducing bacteria (clostridia), salmonellae groups and total vibrios. The total bacterial counts at 37°C and 22°C were 32 to 185 and 11 to 135 cfu*100ml-1, respectively. The total yeast and fungi counts were 9 to 66 and 4 to 35 cfu*100ml-1, respectively. Total counts of staphylococci (from 2 to 17 cfu*100ml-1), Pseudomonas aeruginosa (from 33 to 58 cfu*100ml-1), and coliphage (from 7 to 13 cfu*100ml-1) were also estimated. The free-living amoebae were detected in 75% of the examined storage water tank samples. According to the Egyptian standard for drinking water, most of the examined water samples were not acceptable for human consumption.
17
Content available remote Isolation and kinetic characteristics of styrene-decomposing bacteria
EN
Two bacterial strains effectively decomposing styrene at the concentrations ranging from 0.37 to 1.8 g/m3, i.e. Agrobacterium rhizogenes and Pseudomonas aeruginosa, were isolated. This compound was degraded by them at maximum decomposition rates, i.e. 110.5 and 98.5 g/m3źh, respectively. Its biodegradation was very strongly inhibited by the reduction of the culture medium pH to approx. 4.6.
PL
W czasie badań wyizolowano dwa szczepy bakterii, to jest Agrobacterium rhizogenes i Pseudomonas aeruginosa, rozkładających efektywnie styren w zakresie stężeń od 0,37 do 1,8 g/m3. Związek ten był degradowany z maksymalnymi szybkościami 110,5 and 98,5 g/m3źh. Szybkość biodegradacji znacząco malała po obniżeniu pH pożywki do około 4,6.
EN
Studies were carried out in the summer seasons of 1995-1999 (from June to September) on the quantitative and qualitative composition of Enterobacleriaceae bacteria (including Escherichia coli and Salmonella sp.), and potentially pathogenic bacteria Aeromonas hydrophila, Pseudomonas aeruginosa and Staphylococcus sp. in the water of 8 bathing sites of the Lake Wigry. Aeromonas hydrophila occurred in the all samples of studied water and was the most numerous in water sampled from sites of increased trophic levels. Irrespective of the site and time of sampling Pseudomonas aeruginosa was rarely isolated.In the total of 160 samples of water analysed Salmonella sp., Escherichia coli and Staphyloccocus aureus were determined in 32 (22.6%), 68 (42.4%) and 90 (55%) samples, respectively. Pathogenic bacteria of the genus Salmonella sp. and potentially pathogenic Staphylococcus aureus and Aeromonas hydmphila identified in the analysed offshore waters (also when Escherichia coli were absent) suggest that the use of the Lake Wigry waters for swimming, falling into account faecal bacterial counts, may not be sufficient to fully reflect safety conditions for bathers. The results of the research suggest that the evaluation of the Lake Wigry surface waters for recreational use should include the frequency of the occurrence of Salmonella sp., Staphylococcus aureus, Aeromonas hydrophila and Pseudomunas aeruginosa. These three species, which arc not directly linked to faecal contamination, can cause various diseases of the skin, nasal and oral cavities, eyes, internal car and other problems in people swimming in contaminated water.
PL
W sezonie letnim (od czerwca do września) 1995-1999 prowadzono badania składu ilościowego i jakościowego bakterii z rodziny Enterobacleriaceae (w tym Escherichia coli i Salmonella sp.) oraz bakterii potencjalnie chorobotwórczych Aeromonas hydrophila, Pseudomonas aeruginosa i Slaphylococcus sp. w wodzie 8 wybranych kąpielisk jeziora Wigry. Bakterie Aeromonas hydrophila występowały w wodzie wszystkich kąpielisk, najliczniej zaś w wodzie pobieranej z miejsc o zwiększonej trofii. Bakterie Pseudomonas aeruginosa izolowano rzadko, niezależnie od czasu i miejsca poboru prób. Bakterie z rodzaju Salmonella, gatunku Escherichia coli i Staphylococcus aureus stwierdzano odpowiednio w 37 (22,6%), 68 (42,4%) i 90 (55%) na ogólną liczbę 160 przebadanych prób wody kąpielisk jeziora Wigry. Stwierdzane w wodzie badanych kąpielisk (zwłaszcza w miejscowościach Stary Folwark, Leszczewek, i Rosochaty Róg) bakterie Salmonella sp., Staphylococcus aureus i Aeromonas hydrophila (nawet przy braku bakterii z gatunku Escherichia coli) sugerują, iż ocena przydatności wód jeziora Wigry dla celów kąpielowych na podstawie liczebności bakterii grupy coli typu kałowego może nie odzwierciedlać w pełni jej bezpieczeństwa dla kąpiących się. Wyniki przeprowadzonych badań sugerują konieczność uwzględnienia w ocenie przydatności wód powierzchniowych jeziora Wigry dla celów rekreacji (zwłaszcza kąpieli) badań na obecność Salmonella sp., Slaphylococcus aureus, Aeromonas hydrophila i Pseudomonas aeruginosa. Ostatnie 3 gatunki niezwiązane bezpośrednio z zanieczyszczeniami kałowymi bywają, bowiem przyczyną różnorodnych schorzeń skórnych, jamy nosowo-gardzielowej, oczu, ucha środkowego i szeregu innych spotykanych wśród kąpiących się w zanieczyszczonej wodzie.
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