Artykuły w czasopismach na temat „Bacterial metabolic activity”
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Babu, Jegdish, Cohen Blair, Shiloah Jacob i Ofek Itzhak. "Inhibition ofStreptococcus gordoniiMetabolic Activity in Biofilm by Cranberry Juice High-Molecular-Weight Component". Journal of Biomedicine and Biotechnology 2012 (2012): 1–7. http://dx.doi.org/10.1155/2012/590384.
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Previous studies demonstrated that a cranberry high-molecular-mass, nondialyzable material (NDM) can inhibit adhesion of numerous species of bacteria and prevents bacterial coaggregation of bacterial pairs. Bacterial coaggregation leads to plaque formation leading to biofilm development on surfaces of oral cavity. In the present study, we evaluated the effect of low concentrations of NDM onStreptococcus gordoniimetabolic activity and biofilm formation on restorative dental surfaces. We found that the NDM selectively inhibited metabolic activity ofS. gordonii, without affecting bacterial viability. Inhibiting the metabolic activity of bacteria in biofilm may benefit the health of the oral cavity.
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Sabra, Sherifa. "Elimination Virulent-pathogenic-biofilm Bacteria Using Highland-wild Salvia officinalis Preserve Bacterial-infection-control". Biotechnology and Bioprocessing 2, nr 2 (2.02.2021): 01–04. http://dx.doi.org/10.31579/2766-2314/021.
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This work for this title "Elimination Virulent-pathogenic-biofilm (VPB) Bacteria Using Highland-wild (HLW) Salvia officinalis (S. officinalis) Preserve Bacterial-infection-control (BIC)"; the aim was to prove the importance of HLW S. officinalis extracts have therapeutic herbal importance. Through its effected on the isolated VPB bacteria caused infection diseases that may preserve BIC for individuals, which proved the effectiveness of the HLW S. officinalis daily use or therapeutic use. S. officinalis specimens were collected during the flowering period from HLW, Taif, KSA. Essential oils (EOs) were equipped and biofilms preparation, then laboratory methods deputy for anti-biofilms formation activity and biofilms elimination activity, finally biofilms metabolic grades measurement. The bacterial metabolic grades of anti-biofilms formation activity showed the HLW S. officinalis EOs extracts eliminated VPB bacteria and effects were greater. Anywhere Staphylococcous aureus (S. aureus) and Streptococcus pyogenes (S. pyogenes) were eliminated until 60 hours. While Pseudomonas aeruginosa (PA) was eliminated at 72 hours. The bacterial metabolic grades of biofilms elimination activity found the HLW S. officinalis EOs extracts eliminated within 8 hours (S. aureus and S. pyogenes), PA was to 10 hours. Concluded the HLW S. officinalis EOs extracts had proven its ability to eliminate VPB bacteria, and from that, it proven on the type used with healthy characteristics to maintain health and BIC. Recommendation: That topic recommend using the appropriate HLW S. officinalis EOs extracts for individuals daily to maintain the general health. In cases of illness, person must ask the "Specialized Physician" to determine the healthy and curative amount to use.
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Simon, K. S., J. Gibert, P. Petitot i R. Laurent. "Spatial and temporal patterns of bacterial density and metabolic activity in a karst aquifer". Fundamental and Applied Limnology 151, nr 1 (23.03.2001): 67–82. http://dx.doi.org/10.1127/archiv-hydrobiol/151/2001/67.
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Smith, Alexandra H., i Roderick I. Mackie. "Effect of Condensed Tannins on Bacterial Diversity and Metabolic Activity in the Rat Gastrointestinal Tract". Applied and Environmental Microbiology 70, nr 2 (luty 2004): 1104–15. http://dx.doi.org/10.1128/aem.70.2.1104-1115.2004.
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ABSTRACT The effect of dietary condensed tannins (proanthocyanidins) on rat fecal bacterial populations was ascertained in order to determine whether the proportion on tannin-resistant bacteria increased and if there was a change in the predominant bacterial populations. After 3 weeks of tannin diets the proportion of tannin-resistant bacteria increased significantly (P < 0.05) from 0.3% ± 5.5% to 25.3% ± 8.3% with a 0.7% tannin diet and to 47.2% ± 5.1% with a 2% tannin diet. The proportion of tannin-resistant bacteria returned to preexposure levels in the absence of dietary tannins. A shift in bacterial populations was confirmed by molecular fingerprinting of fecal bacterial populations by denaturing gradient gel electrophoresis (DGGE). Posttreatment samples were generally still distinguishable from controls after 3.5 weeks. Sequence analysis of DGGE bands and characterization of tannin-resistant isolates indicated that tannins selected for Enterobacteriaceae and Bacteroides species. Dot blot quantification confirmed that these gram-negative bacterial groups predominated in the presence of dietary tannins and that there was a corresponding decrease in the gram-positive Clostridium leptum group and other groups. Metabolic fingerprint patterns revealed that functional activities of culturable fecal bacteria were affected by the presence of tannins. Condensed tannins of Acacia angustissima altered fecal bacterial populations in the rat gastrointestinal tract, resulting in a shift in the predominant bacteria towards tannin-resistant gram-negative Enterobacteriaceae and Bacteroides species.
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Pope, Emily, Bradley Haltli, Russell G. Kerr i Ali Ahmadi. "Effects of Matrix Composition and Temperature on Viability and Metabolic Activity of Microencapsulated Marine Bacteria". Microorganisms 10, nr 5 (10.05.2022): 996. http://dx.doi.org/10.3390/microorganisms10050996.
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To enhance the discovery of novel natural products, various innovations have been developed to aid in the cultivation of previously unculturable microbial species. One approach involving the microencapsulation of bacteria has been gaining popularity as a new cultivation technique, with promising applications. Previous studies demonstrated the success of bacterial encapsulation; however, they highlighted that a key limitation of encapsulating bacteria within agarose is the high temperature required for encapsulation. Encapsulation of bacteria within agarose typically requires a temperature high enough to maintain the flow of agarose through microfluidic devices without premature gelation. Given the sensitivity of many bacterial taxa to temperature, the effect of various agarose-based encapsulating matrices on marine bacterial viability was assessed to further develop this approach to bacterial culture. It was determined that lowering the temperature of encapsulation via the use of low-gelling-temperature agarose, as well as the addition of nutrients to the matrix, significantly improved the viability of representative marine sediment bacteria in terms of abundance and metabolic activity. Based on these findings, the use of low-gelling-temperature agarose with supplemental nutrients is recommended for the encapsulation of marine bacteria obtained from temperate habitats.
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Unge, Annika, Riccardo Tombolini, Lars Mølbak i Janet K. Jansson. "Simultaneous Monitoring of Cell Number and Metabolic Activity of Specific Bacterial Populations with a Dualgfp-luxAB Marker System". Applied and Environmental Microbiology 65, nr 2 (1.02.1999): 813–21. http://dx.doi.org/10.1128/aem.65.2.813-821.1999.
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ABSTRACT A dual marker system was developed for simultaneous quantification of bacterial cell numbers and their activity with the luxABand gfp genes, encoding bacterial luciferase and green fluorescent protein (GFP), respectively. The bioluminescence phenotype of the luxAB biomarker is dependent on cellular energy status. Since cellular metabolism requires energy, bioluminescence output is directly related to the metabolic activity of the cells. By contrast, GFP fluorescence has no energy requirement. Therefore, by combining these two biomarkers, total cell number and metabolic activity of a specific marked cell population could be monitored simultaneously. Two different bacterial strains, Escherichia coli DH5α and Pseudomonas fluorescens SBW25, were chromosomally tagged with the dual marker cassette, and the cells were monitored under different conditions by flow cytometry, plate counting, and luminometry. During log-phase growth, the luciferase activity was proportional to the number of GFP-fluorescent cells and culturable cells. Upon entrance into stationary phase or during starvation, luciferase activity decreased due to a decrease in cellular metabolic activity of the population, but the number of GFP-fluorescing cells and culturable cells remained relatively stable. In addition, we optimized a procedure for extraction of bacterial cells from soil, allowing GFP-tagged bacteria in soil samples to be quantitated by flow cytometry. After 30 days of incubation of P. fluorescensSBW25::gfp/lux in soil, the cells were still maintained at high population densities, as determined by GFP fluorescence, but there was a slow decline in luciferase activity, implicating nutrient limitation. In conclusion, the dual marker system allowed simultaneous monitoring of the metabolic activity and cell number of a specific bacterial population and is a promising tool for monitoring of specific bacteria in situ in environmental samples.
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Bojic, Gordana, Svetlana Golocorbin-Kohn, Maja Stojancevic, Momir Mikov i Ljiljana Suvajdzic. "Metabolic activity of gut microbiota and xenobiotics". Zbornik Matice srpske za prirodne nauke, nr 128 (2015): 47–55. http://dx.doi.org/10.2298/zmspn1528047b.
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The intestine habitat is the natural collection of symbiotic microorganisms. The bacterial population enables many permanent metabolic activities in this environment. Inside the intestine of mammals there are an extended genome of millions of bacterial genes named microbiome. In recent years, there has been an increased interest of scientists to discover the place and the role of bio-ecological content and modulation of gut microbiota in a host organism using prebiotics, probiotics and synbiotics, which may have a great benefit for human health.
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Roth, D., i H. Lemmer. "Biofilms in Sewer Systems – Characterization of the Bacterial Biocenosis and Its Metabolic Activity". Water Science and Technology 29, nr 7 (1.04.1994): 385–88. http://dx.doi.org/10.2166/wst.1994.0367.
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Biofilms sampled from sewers discharging domestic and trade wastewater, respectively, were characterized by determining the population densities of different groups of heterotrophic bacteria as well as by measuring their metabolic activities. Population densities of heterotrophic saprophytes, of proteolytic, amylolytic, and lipolytic bacteria as well as of ammonifying, nitrate reducing and anaerobic bacteria were determined on solid media and by MPN-tests. Metabolic activity was assessed by measuring enzyme activity of esterase, L-alanine-aminopeptidase, phosphatase, as well as of α- and β-glucosidase. Both biofilms revealed high population densities of bacteria from several metabolic groups as well as high enzyme activities. Their heterotrophic activity is in the range of or even higher than that found in high load activated sludges. The high activity of the bacterial biocenosis proves its resistance against high concentrations of chromium and nickel.
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Liu, Yuan, Ruichao Li, Xia Xiao i Zhiqiang Wang. "Bacterial metabolism-inspired molecules to modulate antibiotic efficacy". Journal of Antimicrobial Chemotherapy 74, nr 12 (18.06.2019): 3409–17. http://dx.doi.org/10.1093/jac/dkz230.
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AbstractThe decreasing antibiotic susceptibility of bacterial pathogens calls for novel antimicrobial therapies. Traditional screening pathways based on drug–target interaction have gradually reached the stage of diminishing returns. Thus, novel strategies are urgently needed in the fight against antibiotic-refractory bacteria, particularly for tolerant bacteria. Recently, evidence has accumulated demonstrating that microbial changes caused by bacterial metabolic processes significantly modulate antibiotic killing. A better understanding of these bacterial metabolic processes is indicating a need to screen novel metabolic modulators as potential antibiotic adjuvants. In this review, we describe the state of our current knowledge about how these bacterial metabolism-inspired molecules affect antibiotic efficacy, including potentiation and inhibition activity. In addition, the challenges faced and prospects for bringing them into clinic are also discussed. These examples may provide candidates or targets for the development of novel antibiotic adjuvants.
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Trinh, Kieu The Loan, i Nae Yoon Lee. "Recent Methods for the Viability Assessment of Bacterial Pathogens: Advances, Challenges, and Future Perspectives". Pathogens 11, nr 9 (16.09.2022): 1057. http://dx.doi.org/10.3390/pathogens11091057.
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Viability assessment is a critical step in evaluating bacterial pathogens to determine infectious risks to public health. Based on three accepted viable criteria (culturability, metabolic activity, and membrane integrity), current viability assessments are categorized into three main strategies. The first strategy relies on the culturability of bacteria. The major limitation of this strategy is that it cannot detect viable but nonculturable (VBNC) bacteria. As the second strategy, based on the metabolic activity of bacteria, VBNC bacteria can be detected. However, VBNC bacteria sometimes can enter a dormant state that allows them to silence reproduction and metabolism; therefore, they cannot be detected based on culturability and metabolic activity. In order to overcome this drawback, viability assessments based on membrane integrity (third strategy) have been developed. However, these techniques generally require multiple steps, bulky machines, and laboratory technicians to conduct the tests, making them less attractive and popular applications. With significant advances in microfluidic technology, these limitations of current technologies for viability assessment can be improved. This review summarized and discussed the advances, challenges, and future perspectives of current methods for the viability assessment of bacterial pathogens.
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Lobritz, Michael A., Peter Belenky, Caroline B. M. Porter, Arnaud Gutierrez, Jason H. Yang, Eric G. Schwarz, Daniel J. Dwyer, Ahmad S. Khalil i James J. Collins. "Antibiotic efficacy is linked to bacterial cellular respiration". Proceedings of the National Academy of Sciences 112, nr 27 (22.06.2015): 8173–80. http://dx.doi.org/10.1073/pnas.1509743112.
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Bacteriostatic and bactericidal antibiotic treatments result in two fundamentally different phenotypic outcomes—the inhibition of bacterial growth or, alternatively, cell death. Most antibiotics inhibit processes that are major consumers of cellular energy output, suggesting that antibiotic treatment may have important downstream consequences on bacterial metabolism. We hypothesized that the specific metabolic effects of bacteriostatic and bactericidal antibiotics contribute to their overall efficacy. We leveraged the opposing phenotypes of bacteriostatic and bactericidal drugs in combination to investigate their activity. Growth inhibition from bacteriostatic antibiotics was associated with suppressed cellular respiration whereas cell death from most bactericidal antibiotics was associated with accelerated respiration. In combination, suppression of cellular respiration by the bacteriostatic antibiotic was the dominant effect, blocking bactericidal killing. Global metabolic profiling of bacteriostatic antibiotic treatment revealed that accumulation of metabolites involved in specific drug target activity was linked to the buildup of energy metabolites that feed the electron transport chain. Inhibition of cellular respiration by knockout of the cytochrome oxidases was sufficient to attenuate bactericidal lethality whereas acceleration of basal respiration by genetically uncoupling ATP synthesis from electron transport resulted in potentiation of the killing effect of bactericidal antibiotics. This work identifies a link between antibiotic-induced cellular respiration and bactericidal lethality and demonstrates that bactericidal activity can be arrested by attenuated respiration and potentiated by accelerated respiration. Our data collectively show that antibiotics perturb the metabolic state of bacteria and that the metabolic state of bacteria impacts antibiotic efficacy.
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Przemieniecki, Sebastian Wojciech, Magdalena Oćwieja, Sławomir Ciesielski, Wiktor Halecki, Ewelina Matras i Anna Gorczyca. "Chemical Structure of Stabilizing Layers of Negatively Charged Silver Nanoparticles as an Effector of Shifts in Soil Bacterial Microbiome under Short-Term Exposure". International Journal of Environmental Research and Public Health 19, nr 21 (4.11.2022): 14438. http://dx.doi.org/10.3390/ijerph192114438.
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In this work, we have assessed the exposure of soil bacteria from potato monoculture to three types of silver nanoparticles (AgNPs) as well as silver ions (Ag+ ions) delivered in the form of silver nitrate and a commercially available fungicide. The diversity of the soil microbial community, enzymatic activity, and carbon source utilization were evaluated. It was found that only the fungicide significantly limited the abundance and activity of soil bacteria. Silver ions significantly reduced bacterial metabolic activity. In turn, one type of AgNPs prepared with the use of tannic acid (TA) increased bacterial load and activity. There was found in all AgNPs treated soils (1) a greater proportion of all types of persistent bacteria, i.e., Bacillus, Paenibacillus, and Clostridium; (2) a visible decrease in the proportion of Nocardioides, Arthrobacter, and Candidatus Solibacter; (3) almost complete depletion of Pseudomonas; (4) increase in the number of low-frequency taxa and decrease in dominant taxa compared to the control soil. Despite the general trend of qualitative changes in the bacterial community, it was found that the differences in the chemical structure of the AgNP stabilizing layers had a significant impact on the specific metabolic activity resulting from qualitative changes in the microbiome.
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Orman, Mehmet A., i Mark P. Brynildsen. "Dormancy Is Not Necessary or Sufficient for Bacterial Persistence". Antimicrobial Agents and Chemotherapy 57, nr 7 (29.04.2013): 3230–39. http://dx.doi.org/10.1128/aac.00243-13.
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ABSTRACTThe antibiotic tolerances of bacterial persisters have been attributed to transient dormancy. While persisters have been observed to be growth inhibited prior to antibiotic exposure, we sought to determine whether such a trait was essential to the phenotype. Furthermore, we sought to provide direct experimental evidence of the persister metabolic state so as to determine whether the common assumption of metabolic inactivity was valid. Using fluorescence-activated cell sorting (FACS), a fluorescent indicator of cell division, a fluorescent measure of metabolic activity, and persistence assays, we found that bacteria that are rapidly growing prior to antibiotic exposure can give rise to persisters and that a lack of replication or low metabolic activity prior to antibiotic treatment simply increases the likelihood that a cell is a persister. Interestingly, a lack of significant growth or metabolic activity does not guarantee persistence, as the majority of even “dormant” subpopulations (>99%) were not persisters. These data suggest that persistence is far more complex than dormancy and point to additional characteristics needed to define the persister phenotype.
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Li, Xin, Khan Zara Ahmad, Jie He, Hongxia Li, Xin Wang, Zijian Feng, Xiansong Wang, Guangxia Shen i Xianting Ding. "Silver nanoflowers coupled with low dose antibiotics enable the highly effective eradication of drug-resistant bacteria". Journal of Materials Chemistry B 9, nr 48 (2021): 9839–51. http://dx.doi.org/10.1039/d1tb01773j.
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Silver nanoflowers restore the susceptibility of drug-resistant bacteria to antibiotics by the enrichment of antibiotics and augmented regulation of bacterial metabolic activity, which achieves eradication of quinolone-resistant Escherichia coli.
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Wos, M. L., i P. C. Pollard. "Cellular nicotinamide adenine dinucleotide (NADH) as an indicator of bacterial metabolic activity dynamics in activated sludge". Water Science and Technology 60, nr 3 (1.07.2009): 783–91. http://dx.doi.org/10.2166/wst.2009.393.
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In this study, native fluorescent nicotinamide adenine dinucleotide (NADH) was used as a direct indicator of bacterial metabolic activity in activated sludge. Specific NADH concentration was dynamic and varied between 106–108 molecules per bacterial cell. Low concentrations (106–107 NADH molecules cell−1) indicate efficient bacterial metabolic activity while high concentrations (107–108 NADH molecules cell−1) indicate inefficient bacterial metabolic activity. Specific [NADH] did not correlate to changes in dissolved organic carbon, but increases correlated to decreases in oxygen uptake rates. Perhaps a lack of oxygen as the terminal electron acceptor prevented efficient reoxidization of NADH to NAD+, which resulted in an accumulation of NADH within the cells. Also, significant amounts of NADH were released and accumulated into the extracellular medium of metabolically active E. coli cells in log phase. Such overflow metabolism may be the product of favourable conditions. Thus, the flux of both specific intracellular and extracellular [NADH] indicates the dynamics of bacterial metabolic activity in activated sludge.
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Kim, Min Jun, i Kenneth S. Breuer. "Use of Bacterial Carpets to Enhance Mixing in Microfluidic Systems". Journal of Fluids Engineering 129, nr 3 (7.09.2006): 319–24. http://dx.doi.org/10.1115/1.2427083.
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We demonstrate that flagellated bacteria can be utilized in surface arrays (carpets) to achieve mixing in a low-Reynolds number fluidic environment. The mixing performance of the system is quantified by measuring the diffusion of small tracer particles. We show that the mixing performance responds to modifications to the chemical and thermal environment of the system, which affects the metabolic activity of the bacteria. Although the mixing performance can be increased by the addition of glucose (food) to the surrounding buffer or by raising the buffer temperature, the initial augmentation is also accompanied by a faster decay in mixing performance, due to falling pH and oxygen starvation, both induced by the higher metabolic activity of the bacterial system.
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Wolińska, Agnieszka, Anna Gałązka, Agnieszka Kuźniar, Weronika Goraj, Natalia Jastrzębska, Jarosław Grządziel i Zofia Stępniewska. "Catabolic Fingerprinting and Diversity of Bacteria in Mollic Gleysol Contaminated with Petroleum Substances". Applied Sciences 8, nr 10 (18.10.2018): 1970. http://dx.doi.org/10.3390/app8101970.
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This study focused on the determination of both catabolic and genetic fingerprinting of bacteria inhabiting soil contaminated with car fuels. A surface layer (0–20 cm) of Mollic Gleysol was used for the experiment and was contaminated with car fuels—unleaded 95-octane petrol and diesel at a dose of 15 g per 10 g of soil. The experiment lasted 42 days and was performed at 20 °C. The metabolic potential of soil bacterial communities was evaluated using the Biolog EcoPlate system. The results demonstrated that petroleum substances influenced the structure of the microbial populations and their catabolic activity. The Arthrobacter, Paenibacillus, and Pseudomonas genera were found in diesel-contaminated soil, whilst Bacillus and Microbacterium were found in petrol-contaminated soil. Rhodococcus species were identified in both variants of impurities, suggesting the widest capability of car fuel degradation by this bacterial genus. The contamination with unleaded 95-octane petrol caused rapid inhibition of the metabolic activity of soil bacteria in contrast to the diesel treatment, where high metabolic activity of bacteria was observed until the end of the incubation period. Higher toxicity of petrol in comparison with diesel car fuel was evidenced.
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Roszak, D. B., i R. R. Colwell. "Metabolic activity of bacterial cells enumerated by direct viable count." Applied and Environmental Microbiology 53, nr 12 (1987): 2889–93. http://dx.doi.org/10.1128/aem.53.12.2889-2893.1987.
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Sycz, Zuzanna, Dorota Wojnicz i Dorota Tichaczek-Goska. "Does Secondary Plant Metabolite Ursolic Acid Exhibit Antibacterial Activity against Uropathogenic Escherichia coli Living in Single- and Multispecies Biofilms?" Pharmaceutics 14, nr 8 (14.08.2022): 1691. http://dx.doi.org/10.3390/pharmaceutics14081691.
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Multispecies bacterial biofilms are the often cause of chronic recurrent urinary tract infections within the human population. Eradicating such a complex bacterial consortium with standard pharmacotherapy is often unsuccessful. Therefore, plant-derived compounds are currently being researched as an alternative strategy to antibiotic therapy for preventing bacterial biofilm formation and facilitating its eradication. Therefore, our research aimed to determine the effect of secondary plant metabolite ursolic acid (UA) on the growth and survival, the quantity of exopolysaccharides formed, metabolic activity, and morphology of uropathogenic Gram-negative rods living in single- and mixed-species biofilms at various stages of their development. Spectrophotometric methods were used for biofilm mass formation and metabolic activity determination. The survival of bacteria was established using the serial dilution assay. The decrease in survival and inhibition of biofilm creation, both single- and multispecies, as well as changes in the morphology of bacterial cells were noticed. As UA exhibited better activity against young biofilms, the use of UA-containing formulations, especially during the initial steps of urinary tract infection, seems to be reasonable. However, the future direction should be a thorough understanding of the mechanisms of UA activity as a bioactive substance.
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Silva, Frederico Sobrinho, José Augusto Pires Bitencourt, Fernanda Savergnini, Leandro Viana Guerra, José Antônio Baptista-Neto i Mirian Araújo Carlos Crapez. "Biodisponibilidade da Matéria Orgânica dos Sedimentos Superficiais da Baía de Guanabara, Rio de Janeiro, Brasil". Anuário do Instituto de Geociências 34, nr 1 (1.01.2011): 52–63. http://dx.doi.org/10.11137/2011_1_52-63.
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Thirty superficial sediment samples were collected in Guanabara Bay in order to identify new trophic state and environmental quality descriptors for coastal systems. A biochemical approach was used for analyzing the quality and quantity of sedimentary organic matter and metabolic bacterial activity. The samples were analyzed for particle size; organic matter, protein, carbohydrate, lipid, biopolymeric carbon, and bioavailable carbon levels; and bacterial metabolic activity. The results show a homogeneous spatial distribution for the anaerobic bacteria web and for biopolymers (carbohydrates>;lipids>;protein). The NE area of the bay displayed sediment lipid levels above 1 mg/g, indicative of organic sewage input. Spatial distribution of the superficial sediments in relation to other variables was not significant (p>;0.05). Biopolymers and labile organic matter showed a significant correlation with the average particle size of 80% of the fine particles. Despite the availability of labile organic matter, under the form of biopolymeric carbon, only 50% of the carbon was available to the trophic web. The bacterial consortia formed by sulfate reducing and denitrifying bacteria sustain the benthic trophic food web in Guanabara Bay.
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Barak, Tamar, Eden Sharon, Doron Steinberg, Mark Feldman, Ronit Vogt Sionov i Miriam Shalish. "Anti-Bacterial Effect of Cannabidiol against the Cariogenic Streptococcus mutans Bacterium: An In Vitro Study". International Journal of Molecular Sciences 23, nr 24 (14.12.2022): 15878. http://dx.doi.org/10.3390/ijms232415878.
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Dental caries is caused by biofilm-forming acidogenic bacteria, especially Streptococcus mutans, and is still one of the most prevalent human bacterial diseases. The potential use of cannabidiol (CBD) in anti-bacterial therapies has recently emerged. Here we have studied the anti-bacterial and anti-biofilm activity of CBD against S. mutans. We measured minimum inhibitory concentration (MIC) and minimum biofilm inhibitory concentration (MBIC). The bacterial growth and changes in pH values were measured in a kinetic study. The biofilm biomass was assessed by Crystal Violet staining and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) metabolic assay. Spinning Disk Confocal Microscopy (SDCM) was used to assess biofilm structure, bacterial viability and extracellular polysaccharide (EPS) production. CBD inhibited S. mutans planktonic growth and biofilm formation in a dose-dependent manner, with similar MIC and MBIC values (5 µg/mL). CBD prevented the bacteria-mediated reduction in pH values that correlated with bacterial growth inhibition. SDCM showed a decrease of 50-fold in live bacteria and EPS production. CBD significantly reduced the viability of preformed biofilms at 7.5 µg/mL with an 80 ± 3.1% reduction of metabolic activity. At concentrations above 20 µg/mL, there was almost no bacterial recovery in the CBD-treated preformed biofilms even 48 h after drug withdrawal. Notably, precoating of the culture plate surfaces with CBD prior to incubation with bacteria inhibited biofilm development. Additionally, CBD was found to induce membrane hyperpolarization in S. mutans. Thus, CBD affects multiple processes in S. mutans including its cariogenic properties. In conclusion, we show that CBD has a strong inhibitory effect against cariogenic bacteria, suggesting that it is a potential drug adjuvant for reducing oral pathogenic bacterial load as well as protecting against dental caries.
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González-Muñoz, Maria Teresa, Belén Fernández-Luque, Francisca Martínez-Ruiz, Kaoutar Ben Chekroun, José María Arias, Manuel Rodríguez-Gallego, Magdalena Martínez-Cañamero, Concepción de Linares i Adina Paytan. "Precipitation of Barite by Myxococcus xanthus: Possible Implications for the Biogeochemical Cycle of Barium". Applied and Environmental Microbiology 69, nr 9 (wrzesień 2003): 5722–25. http://dx.doi.org/10.1128/aem.69.9.5722-5725.2003.
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ABSTRACT Bacterial precipitation of barite (BaSO4) under laboratory conditions is reported for the first time. The bacterium Myxococcus xanthus was cultivated in a solid medium with a diluted solution of barium chloride. Crystallization occurred as a result of the presence of live bacteria and the bacterial metabolic activity. A phosphorous-rich amorphous phase preceded the more crystalline barite formation. These experiments may indicate the involvement of bacteria in the barium biogeochemical cycle, which is closely related to the carbon cycle.
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Martin, Andrew, Andrew McMinn, Simon K. Davy, Marti J. Anderson, Hilary C. Miller, Julie A. Hall i Ken G. Ryan. "Preliminary evidence for the microbial loop in Antarctic sea ice using microcosm simulations". Antarctic Science 24, nr 6 (13.07.2012): 547–53. http://dx.doi.org/10.1017/s0954102012000491.
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AbstractSea ice microalgae actively contribute to the pool of dissolved organic matter (DOM) available for bacterial metabolism, but this link has historically relied on bulk correlations between chlorophylla(a surrogate for algal biomass) and bacterial abundance. We incubated microbes from both the bottom (congelation layer) and surface brine region of Antarctic fast ice for nine days. Algal-derived DOM was manipulated by varying the duration of irradiance, restricting photosynthesis with 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) or incubating in the dark. The bacterial response to changes in DOM availability was examined by performing cell counts, quantifying bacterial metabolic activity and examining community composition with denaturing gradient gel electrophoresis. The percentage of metabolically active bacteria was relatively low in the surface brine microcosm (10–20% of the bacterial community), the treatment with DCMU indirectly restricted bacterial growth and there was some evidence for changes in community structure. Metabolic activity was higher (35–69%) in the bottom ice microcosm, and while there was no variation in community structure, bacterial growth was restricted in the treatment with DCMU compared to the light/dark treatment. These results are considered preliminary, but provide a useful illustration of sea ice microbial dynamics beyond the use of ‘snapshot’ biomass correlations.
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Haranaga, Shusaku, Hideaki Ikejima, Hiroyuki Yamaguchi, Herman Friedman i Yoshimasa Yamamoto. "Analysis of Chlamydia pneumoniae Growth in Cells by Reverse Transcription-PCR Targeted to Bacterial Gene Transcripts". Clinical and Vaccine Immunology 9, nr 2 (marzec 2002): 313–19. http://dx.doi.org/10.1128/cdli.9.2.313-319.2002.
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ABSTRACT Chlamydia pneumoniae is an obligate intracellular bacterium and has a unique development cycle consisting of an elementary body (EB) and reticular body (RB). EBs survive in extracellular environments as well as infect susceptible host cells. However, EBs display no measurable metabolic activity. In contrast, RBs are metabolically active and can replicate in a host cell but are noninfectious. Therefore, analysis of C. pneumoniae growth in infected cells by conventional bacterial culture may not permit sufficient information about growth of the bacteria in cells. In this study, therefore, we examined the usefulness of the reverse transcription (RT)-PCR method for analysis of bacterial transcripts to evaluate C. pneumoniae growth in HEp-2 cells because the levels of bacterial gene transcripts are known to show the metabolic activity of bacteria. The transcripts for the C. pneumoniae hsp60 gene and 16S rRNA in the cells were easily detected just after infection, followed by a marked increase. In contrast, pyk and omcB transcripts slowly increased after a latent period. The hydrocortisone treatment of C. pneumoniae-infected cells induced an increase of all bacterial transcripts tested compared with the control group. The treatment of the infected cells with the antibiotic minocycline showed a selective inhibition of bacterial gene transcripts, even though the complete inhibition of EB production determined by the bacterial culture assay was evident. These results indicate that the determination of bacterial gene transcripts by RT-PCR might be a powerful method to analyze in detail growth of C. pneumoniae in host cells, particularly altered bacterial growth caused by agents such as antimicrobials.
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Bahuguna, Shivohum, Magda Atilano, Marcus Glittenberg, Dohun Lee, Srishti Arora, Lihui Wang, Jun Zhou, Siamak Redhai, Michael Boutros i Petros Ligoxygakis. "Bacterial recognition by PGRP-SA and downstream signalling by Toll/DIF sustain commensal gut bacteria in Drosophila". PLOS Genetics 18, nr 1 (10.01.2022): e1009992. http://dx.doi.org/10.1371/journal.pgen.1009992.
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The gut sets the immune and metabolic parameters for the survival of commensal bacteria. We report that in Drosophila, deficiency in bacterial recognition upstream of Toll/NF-κB signalling resulted in reduced density and diversity of gut bacteria. Translational regulation factor 4E-BP, a transcriptional target of Toll/NF-κB, mediated this host-bacteriome interaction. In healthy flies, Toll activated 4E-BP, which enabled fat catabolism, which resulted in sustaining of the bacteriome. The presence of gut bacteria kept Toll signalling activity thus ensuring the feedback loop of their own preservation. When Toll activity was absent, TOR-mediated suppression of 4E-BP made fat resources inaccessible and this correlated with loss of intestinal bacterial density. This could be overcome by genetic or pharmacological inhibition of TOR, which restored bacterial density. Our results give insights into how an animal integrates immune sensing and metabolism to maintain indigenous bacteria in a healthy gut.
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Jaggessar, Alka, Asha Mathew, Tuquabo Tesfamichael, Hongxia Wang, Cheng Yan i Prasad KDV Yarlagadda. "Bacteria Death and Osteoblast Metabolic Activity Correlated to Hydrothermally Synthesised TiO2 Surface Properties". Molecules 24, nr 7 (27.03.2019): 1201. http://dx.doi.org/10.3390/molecules24071201.
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Orthopaedic surgery comes with an inherent risk of bacterial infection, prolonged antibiotic therapy and revision surgery. Recent research has focused on nanostructured surfaces to improve the bactericidal and osseointegrational properties of implants. However, an understanding of the mechanical properties of bactericidal materials is lacking. In this work, the surface properties of hydrothermal TiO2 nanostructured surfaces are investigated for their effect on bactericidal efficiency and cellular metabolic activity of human osteoblast cells. TiO2 nanostructures, approximately 307 nm in height and 14 GPa stiffness, were the most effective structures against both gram-positive (Staphylococcus aureus) and gram-negative (Pseudomonas aeruginosa) bacteria. Statistical analysis significantly correlated structure height to the death of both bacteria strains. In addition, the surface contact angle and Young’s modulus were correlated to osteoblast metabolic activity. Hydrophilic surfaces with a contact angle between 35 and 50° produced the highest cellular metabolic activity rates after 24 hours of incubation. The mechanical tests showed that nanostructures retain their mechanical stability and integrity over a long time-period, reaffirming the surfaces’ applicability for implants. This work provides a thorough examination of the surface, mechanical and wettability properties of multifunctional hydrothermally synthesised nanostructured materials, capable of killing bacteria whilst improving osteoblast metabolic rates, leading to improved osseointegration and antibacterial properties of orthopaedic implants.
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Forster, Scott, Jason R. Snape, Hilary M. Lappin-Scott i Jonathan Porter. "Simultaneous Fluorescent Gram Staining and Activity Assessment of Activated Sludge Bacteria". Applied and Environmental Microbiology 68, nr 10 (październik 2002): 4772–79. http://dx.doi.org/10.1128/aem.68.10.4772-4779.2002.
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ABSTRACT Wastewater treatment is one of the most important commercial biotechnological processes, and yet the component bacterial populations and their associated metabolic activities are poorly understood. The novel fluorescent dye hexidium iodide allows assessment of Gram status by differential absorption through bacterial cell walls. Differentiation between gram-positive and gram-negative wastewater bacteria was achieved after flow cytometric analysis. This study shows that the relative proportions of gram-positive and gram-negative bacterial cells identified by traditional microscopy and hexidium iodide staining were not significantly different. Dual staining of cells for Gram status and activity proved effective in analyzing mixtures of cultured bacteria and wastewater populations. Levels of highly active organisms at two wastewater treatment plants, both gram positive and gram negative, ranged from 1.5% in activated sludge flocs to 16% in the activated sludge fluid. Gram-positive organisms comprised <5% of the total bacterial numbers but accounted for 19 and 55% of the highly active organisms within flocs at the two plants. Assessment of Gram status and activity within activated sludge samples over a 4-day period showed significant differences over time. This method provides a rapid, quantitative measure of Gram status linked with in situ activity within wastewater systems.
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Julian, William T., Anastasia V. Vasilchenko, Daniil D. Shpindyuk, Darya V. Poshvina i Alexey S. Vasilchenko. "Bacterial-Derived Plant Protection Metabolite 2,4-Diacetylphloroglucinol: Effects on Bacterial Cells at Inhibitory and Subinhibitory Concentrations". Biomolecules 11, nr 1 (25.12.2020): 13. http://dx.doi.org/10.3390/biom11010013.
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2,4-Diacetylphloroglucinol (2,4-DAPG) is a well-known bacterial secondary metabolite, however, its mechanism of inhibitory and subinhibitory action on bacterial cells is still poorly understood. The mechanism of 2,4-DAPG action on model bacterial strains was investigated using fluorescent spectroscopy and the action of the antibiotic was found to involve a rapid increase in membrane permeability that was accompanied by a reduction in its viability in nutrient-poor medium. At the same time, antibacterial action in nutrient-rich medium developed for several hours. Atomic force microscopy demonstrated time-dependent disturbances in the outer membrane of Escherichia coli when exposed to 2,4-DAPG, while Staphylococcusaureus cells have been visualized with signs of intracellular leakage. In addition, 2,4-DAPG inhibited the metabolic activity of S. aureus and E. coli bacterial cells in mature biofilms. Observed differences in the antibiofilm activity were dependent upon antibiotic concentration. The intracellular targets of the action of 2,4-DAPG were assessed using bacterial biosensors with inducible bioluminescence corresponding to DNA and protein damage. It was unable to register any positive response from either sensor. As a result, the bactericidal action of 2,4-DAPG is believed to be associated with the destruction of the bacterial barrier structures. The subinhibitory effect of 2,4-diacetylphloroglucinol was tested on quorum-sensing mediated processes in Pectobacterium carotovorum. Subinhibitory concentrations of 2,4-DAPG were found to lower the biosynthesis of acyl-homoserine lactones in P. carotovorum in a dose-dependent manner. Further investigation elucidated that 2,4-DAPG inhibits the metabolic activity of bacteria without affecting their viability.
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Wos, Melissa, i Peter Pollard. "Sensitive and meaningful measures of bacterial metabolic activity using NADH fluorescence". Water Research 40, nr 10 (czerwiec 2006): 2084–92. http://dx.doi.org/10.1016/j.watres.2006.03.020.
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Kogure, Kazuhiro, i Minoru Wada. "Impacts of Macrobenthic Bioturbation in Marine Sediment on Bacterial Metabolic Activity". Microbes and Environments 20, nr 4 (2005): 191–99. http://dx.doi.org/10.1264/jsme2.20.191.
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Xu, Jie, Hongmei Jing, Mingming Sun, Paul J. Harrison i Hongbin Liu. "Regulation of bacterial metabolic activity by dissolved organic carbon and viruses". Journal of Geophysical Research: Biogeosciences 118, nr 4 (25.11.2013): 1573–83. http://dx.doi.org/10.1002/2013jg002296.
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Sycz, Zuzanna, Dorota Tichaczek-Goska, Anna Jezierska-Domaradzka i Dorota Wojnicz. "Are Uropathogenic Bacteria Living in Multispecies Biofilm Susceptible to Active Plant Ingredient—Asiatic Acid?" Biomolecules 11, nr 12 (24.11.2021): 1754. http://dx.doi.org/10.3390/biom11121754.
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Urinary tract infections (UTIs) are a serious health problem in the human population due to their chronic and recurrent nature. Bacteria causing UTIs form multispecies biofilms being resistant to the activity of the conventionally used antibiotics. Therefore, compounds of plant origin are currently being searched for, which could constitute an alternative strategy to antibiotic therapy. Our study aimed to determine the activity of asiatic acid (AA) against biofilms formed by uropathogenic Escherichia coli, Enterobacter cloacae, and Pseudomonas aeruginosa. The influence of AA on the survival, biofilm mass formation by bacteria living in mono-, dual-, and triple-species consortia as well as the metabolic activity and bacterial cell morphology were determined. The spectrophotometric methods were used for biofilm mass synthesis and metabolic activity determination. The survival of bacteria was established using the serial dilution assay. The decrease in survival and a weakening of the ability to create biofilms, both single and multi-species, as well as changes in the morphology of bacterial cells were noticed. As AA works best against young biofilms, the use of AA-containing formulations, especially during the initial stages of infection, seems to be reasonable. However, there is a need for further research concerning AA especially regarding its antibacterial mechanisms of action.
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Akimov, O. Y., A. O. Mykytenko, A. V. Mischenko i V. O. Kostenko. "EFFECT OF STIMULATING ORGANISM WITH BACTERIAL LIPOPOLYSACCHARIDE ON DEVELOPMENT OF OXIDATIVE STRESS IN BICEPS FEMORIS OF RAT UNDER MODELLED METABOLIC SYNDROME". Актуальні проблеми сучасної медицини: Вісник Української медичної стоматологічної академії 22, nr 3-4 (29.11.2022): 148–52. http://dx.doi.org/10.31718/2077-1096.22.3.4.148.
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Metabolic syndrome is one of the most widespread non-infectious pathologies in the world. Metabolic syndrome is quite often accompanied by an increase in body weight and can lead to the development of type 2 diabetes. Between 1990 and 2015, global mortality associated with high body mass index increased by 28.3%.
The purpose of this work is to determine the activity of antioxidant enzymes, the production of superoxide anion radical, the content of oxidatively modified proteins and the concentration of malondialdehyde in the biceps femoris of rats under experimental metabolic syndrome and stimulation of the organism with bacterial lipopolysaccharide.
The study was conducted on 24 sexually mature male Wistar rats weighing 200-260 g. The animals were divided into 4 groups of 6 animals each. The first group was the control group. The second group was the test metabolic syndrome group. Metabolic syndrome was modelled by using a 20% fructose solution as the only source of water for 60 days. The third group received S. typhi bacterial lipopolysaccharide in the first week in a dose of 0.4 μg/kg intraperitonealy three times a week, then once a week throughout the experiment. The fourth group underwent the combined exposure to lipopolysaccharide and metabolic syndrome. The development of oxidative stress was observed in the three experimental groups. During modelling of the metabolic syndrome, oxidative stress was characterized by an increase in the production of the superoxide anion radical whilst the activity of the studied antioxidant enzymes decreased. During bacterial lipopolysaccharide stimulation, oxidative stress was characterized by an increase in the production of superoxide anion radical under an increase in superoxide dismutase activity and a decrease in catalase activity. Combined stimulation of the organism by bacterial lipopolysaccharide and modelled metabolic syndrome on the oxidative stress was characterized by an increase in the production of the superoxide anion radical under an increase in the activity of the studied antioxidant enzymes.
The combined stimulation by bacterial lipopolysaccharide and modelled metabolic syndrome leads to the development of oxidative damage to the lipid and protein components of biceps femoris that is a consequence of an increase in the production of reactive oxygen species under a compensatory increase in the activity of antioxidant enzymes.
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Longnecker, K., B. F. Sherr i E. B. Sherr. "Activity and Phylogenetic Diversity of Bacterial Cells with High and Low Nucleic Acid Content and Electron Transport System Activity in an Upwelling Ecosystem". Applied and Environmental Microbiology 71, nr 12 (grudzień 2005): 7737–49. http://dx.doi.org/10.1128/aem.71.12.7737-7749.2005.
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ABSTRACT We evaluated whether bacteria with higher cell-specific nucleic acid content (HNA) or an active electron transport system, i.e., positive for reduction of 5-cyano-2,3-ditolyl tetrazolium chloride (CTC), were responsible for the bulk of bacterioplankton metabolic activity. We also examined whether the phylogenetic diversity of HNA and CTC-positive cells differed from the diversity of Bacteria with low nucleic acid content (LNA). Bacterial assemblages were sampled both in eutrophic shelf waters and in mesotrophic offshore waters in the Oregon coastal upwelling region. Cytometrically sorted HNA, LNA, and CTC-positive cells were assayed for their cell-specific [3H]leucine incorporation rates. Phylogenetic diversity in sorted non-radioactively labeled samples was assayed using denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA genes. Cell-specific rates of leucine incorporation of HNA and CTC-positive cells were on average only slightly greater than the cell-specific rates of LNA cells. HNA cells accounted for most bacterioplankton substrate incorporation due to high abundances, while the low abundances of CTC-positive cells resulted in only a small contribution by these cells to total bacterial activity. The proportion of the total bacterial leucine incorporation attributable to LNA cells was higher in offshore regions than in shelf waters. Sequence data obtained from DGGE bands showed broadly similar phylogenetic diversity across HNA, LNA, and CTC-positive cells, with between-sample and between-region variability in the distribution of phylotypes. Our results suggest that LNA bacteria are not substantially different from HNA bacteria in either cell-specific rates of substrate incorporation or phylogenetic composition and that they can be significant contributors to bacterial metabolism in the sea.
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Kim, Lan Hee, i Johannes S. Vrouwenvelder. "Insignificant Impact of Chemotactic Responses of Pseudomonas aeruginosa on the Bacterial Attachment to Organic Pre-Conditioned RO Membranes". Membranes 9, nr 12 (2.12.2019): 162. http://dx.doi.org/10.3390/membranes9120162.
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We investigated the impact of conditioning compositions on the way bacteria move and adhere to reverse osmosis (RO) membranes that have been pre-conditioned by organic compounds. We used humic acid (HA), bovine serum albumin (BSA), and sodium alginate (SA) to simulate conditioning layers on the RO membranes. First, we investigated the chemotactic responses of Pseudomonas aeruginosa PAO1 to the organic substances and the impact of changes in physicochemical characteristics of pre-conditioned membranes on bacterial attachment. Second, we observed bacterial attachment under the presence or absence of nutrients or microbial metabolic activity. Results showed that there was no relationship between the chemotactic response of P. aeruginosa PAO1 and the organic substances, and the changes in hydrophobicity, surface free energy, and surface charge resulting from changing the composition of the conditioning layer did not seem to affect bacterial attachment, whereas changing the roughness of the conditioned membrane exponentially did (exponential correlation coefficient, R2 = 0.85). We found that the initial bacterial attachment on the membrane surface is influenced by (i) the nutrients in the feed solution and (ii) the microbial metabolic activity, whereas the chemotaxis response has a negligible impact. This study would help to establish a suitable strategy to manage bacterial attachment.
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Brinkmann, Nicole, Rainer Martens i Christoph C. Tebbe. "Origin and Diversity of Metabolically Active Gut Bacteria from Laboratory-Bred Larvae of Manduca sexta (Sphingidae, Lepidoptera, Insecta)". Applied and Environmental Microbiology 74, nr 23 (10.10.2008): 7189–96. http://dx.doi.org/10.1128/aem.01464-08.
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ABSTRACT Cultivation-independent analyses based on genetic profiling of partial bacterial 16S rRNA genes by PCR-single-strand conformation polymorphism (PCR-SSCP), reverse transcriptase (RT)-PCR-SSCP of the 16S rRNA itself, and stable isotope probing (SIP), followed by RT-PCR-SSCP, were applied to characterize the diversity of metabolically active bacteria in the larval gut of Manduca sexta bred on tobacco leaves under greenhouse conditions. For SIP, hatching larvae were fed with leaves from tobacco plants grown in a 13CO2-enriched atmosphere. Dominant SSCP bands were sequenced and phylogenetically analyzed. Only one major gut colonizer, an Enterococcus relative, was detected; it occurred in the heavy RNA fraction, demonstrating its metabolic activity, and it originated from eggs, where its metabolic activity was also indicated by rRNA-based SSCP profiles. In contrast, a Citrobacter sedlakii relative was detected on eggs by DNA-SSCP, but rRNA-SSCP and SIP-rRNA-SSCP were negative, suggesting that these bacterial cells were inactive. A Burkholderia relative was dominant and metabolically active on the tobacco leaves but inactive inside the gut, where it was also quantitatively reduced, as suggested by lower band intensities in the DNA-based SSCP profiles. SIP-RNA-SSCP detected another metabolically active gut bacterium (Enterobacter sp.) and more bacteria in the light RNA fraction, indicating low or no metabolic activity of the latter inside the gut. We conclude that the larval gut supported only a low diversity of metabolically active bacteria.
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Jarzembowski, Tomasz, Agnieszka Daca, Wiesław J. Cubała, Marek Bronk i Łukasz Naumiuk. "Ketamine used in the therapy of depressive disorders impacts protein profile, proliferation rate, and phagocytosis resistance of enterococci". Postępy Higieny i Medycyny Doświadczalnej 76, nr 1 (1.01.2022): 333–38. http://dx.doi.org/10.2478/ahem-2022-0047.
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Abstract Introduction A low concentration of ketamine is used to cause an anti-depressive effect. The mechanism of ketamine's action in depression is believed to result, among others, from its anti-inflammatory activity. Despite the fact that only high concentrations of ketamine inhibit bacterial growth, it is clear that even a sub-inhibitory concentration of chemicals may change bacterial properties. Considering the above, in the current study we aimed to evaluate the in vitro influence of ketamine on proliferation of enterococci and their interactions with monocytes. Materials and Methods The studied strains were isolated as etiological agents of infection at Medical University of Gdansk. The proliferation and metabolic activity were determined using the FACSVerse flow cytometer after addition of CFDA-SE to bacterial suspension. For the determination of phagocytosis resistance, THP-1 human monocytes cell line was used. Suspension of monocytes which engulfed CFDA-SE–stained bacteria was then stained with propidium iodide to evaluate cytotoxicity of enterococci. Results The result of the study showed unexpected response of bacterial cells to ketamine at an early stage of culture. In 57.7% of strains, both proliferation rate and metabolic activity were boosted. This group of strains was also less susceptible to phagocytosis than in culture without ketamine. Different response of isolates to ketamine was also visible in changes of proteins’ profile determined by MALDI-TOF. Conclusions The analysis of bacteria at an early stage in the growth curve demonstrated the bacterial diversity in response to ketamine and let us set the hypothesis that microbiome susceptibility to ketamine may be one of the elements which should be taken into consideration when planning the successful pharmacotherapy of depression
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Sakalauskaite, Sandra, Deimante Vasiliauske, Emilija Demikyte, Rimantas Daugelavicius i Martynas Lelis. "Influence of the Metabolic Activity of Microorganisms on Disinfection Efficiency of the Visible Light and P25 TiO2 Photocatalyst". Catalysts 11, nr 12 (25.11.2021): 1432. http://dx.doi.org/10.3390/catal11121432.
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The beneficial photocatalytic properties of UV light activated TiO2 powder are well-known and have been demonstrated with various pollutants and pathogens. However, traditionally observed photocatalytic activity of visible light activated pristine TiO2 is insignificant but there are a few studies which have reported that under some specific conditions commercially available TiO2 powder could at least partially disinfect microorganisms even under visible light. To better understand this phenomenon, in the current study we focused on bacteria response to the treatment by visible light and P25 TiO2 powder. More specifically, we analyzed the relationship between the bacteria viability, outer membrane permeability, metabolism, and its capacity to generate intracellular reactive oxygen species. During the study we assayed the viability of treated bacteria by the spread plate technique and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction method. Changes in bacterial outer membrane permeability were determined by measuring the fluorescence of N-phenyl-1-naphthylamine (NPN). To detect intracellular reactive oxygen species formation, the fluorescence of dichlorodihydrofluorescein diacetate (DCFH-DA) was assayed. Results of our study indicated that TiO2 and wide spectrum visible light irradiation damaged the integrity of the outer membrane and caused oxidative stress in the metabolizing bacteria. When favorable conditions were created, these effects added up and unexpectedly high bacterial inactivation was achieved.
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Chen, Wenxue, Lan Zou, Weijun Chen, Yueying Hu i Haiming Chen. "Effects of Black Pepper (Piper nigrum L.) Chloroform Extract on the Enzymatic Activity and Metabolism of Escherichia coli and Staphylococcus aureus". Journal of Food Quality 2018 (2018): 1–9. http://dx.doi.org/10.1155/2018/9635184.
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The chemical composition and antimicrobial mechanism of action of black pepper chloroform extract (BPCE) were investigated, as well as the potential antibacterial activities of BPCE against Escherichia coli and Staphylococcus aureus. The results showed that 1H-Cycloprop[e]azulen-7-ol, decahydro-1,1,7-trimethyl-4-methylene-, [1ar-(1aα,4aα,7β,7a,β,7bα.)]- (8.39%) and 2-methylene-4,8,8-trimethyl-4-vinyl-bicyclo[5.2.0]nonane (6.92%) were identified as the two primary components of BPCE. The release of intracellular transaminases from bacteria after being incubated with BPCE revealed that the bacterial cell walls and membranes were degraded and that protein synthesis was inhibited to some extent. The inhibition of bacterial Na+/K+-ATPase activity upon the addition of BPCE also indicated an enhanced permeability of bacterial cell membranes. Moreover, an analysis of hexokinase and pyruvate kinase activities showed that BPCE affected the metabolic rate of glycolysis and disrupted the normal metabolism of bacteria. This phenomenon was supported by an observed accumulation of lactic acid (LA) in the treated bacterial cells. Overall, our results indicated that BPCE damaged bacterial cell walls and membranes, which was followed by a disruption of bacterial cell respiration.
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Henderson, Brian, i Andrew Martin. "Bacterial Virulence in the Moonlight: Multitasking Bacterial Moonlighting Proteins Are Virulence Determinants in Infectious Disease". Infection and Immunity 79, nr 9 (6.06.2011): 3476–91. http://dx.doi.org/10.1128/iai.00179-11.
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ABSTRACTMen may not be able to multitask, but it is emerging that proteins can. This capacity of proteins to exhibit more than one function is termed protein moonlighting, and, surprisingly, many highly conserved proteins involved in metabolic regulation or the cell stress response have a range of additional biological actions which are involved in bacterial virulence. This review highlights the multiple roles exhibited by a range of bacterial proteins, such as glycolytic and other metabolic enzymes and molecular chaperones, and the role that such moonlighting activity plays in the virulence characteristics of a number of important human pathogens, includingStaphylococcus aureus,Streptococcus pyogenes,Streptococcus pneumoniae,Helicobacter pylori, andMycobacterium tuberculosis.
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Osbeck, Christofer M. G., Daniel Lundin, Camilla Karlsson, Jonna E. Teikari, Mary Ann Moran i Jarone Pinhassi. "Divergent gene expression responses in two Baltic Sea heterotrophic model bacteria to dinoflagellate dissolved organic matter". PLOS ONE 17, nr 11 (17.11.2022): e0243406. http://dx.doi.org/10.1371/journal.pone.0243406.
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Phytoplankton release massive amounts of dissolved organic matter (DOM) into the water column during recurring blooms in coastal waters and inland seas. The released DOM encompasses a complex mixture of both known and unknown compounds, and is a rich nutrient source for heterotrophic bacteria. The metabolic activity of bacteria during and after phytoplankton blooms can hence be expected to reflect the characteristics of the released DOM. We therefore investigated if bacterioplankton could be used as “living sensors” of phytoplankton DOM quantity and/or quality, by applying gene expression analyses to identify bacterial metabolisms induced by DOM. We used transcriptional analysis of two Baltic Sea bacterial isolates (Polaribacter sp. BAL334 [Flavobacteriia] and Brevundimonas sp. BAL450 [Alphaproteobacteria]) growing with DOM from axenic cultures of the dinoflagellate Prorocentrum minimum. We observed pronounced differences between the two bacteria both in growth and the expressed metabolic pathways in cultures exposed to dinoflagellate DOM compared with controls. Differences in metabolic responses between the two isolates were caused both by differences in gene repertoire between them (e.g. in the SEED categories for membrane transport, motility and photoheterotrophy) and the regulation of expression (e.g. fatty acid metabolism), emphasizing the importance of separating the responses of different taxa in analyses of community sequence data. Similarities between the bacteria included substantially increased expression of genes for Ton and Tol transport systems in both isolates, which are commonly associated with uptake of complex organic molecules. Polaribacter sp. BAL334 showed stronger metabolic responses to DOM harvested from exponential than stationary phase dinoflagellates (128 compared to 26 differentially expressed genes), whereas Brevundimonas sp. BAL450 responded more to the DOM from stationary than exponential phase dinoflagellates (33 compared to 6 differentially expressed genes). These findings suggest that shifts in bacterial metabolisms during different phases of phytoplankton blooms can be detected in individual bacterial species and can provide insights into their involvement in DOM transformations.
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Zhang, Wenwen, Gomez Escalada Margarita, Di Wu, Wenqin Yuan, Sha Yan, Suzhen Qi, Xiaofeng Xue, Kai Wang i Liming Wu. "Antibacterial Activity of Chinese Red Propolis against Staphylococcus aureus and MRSA". Molecules 27, nr 5 (4.03.2022): 1693. http://dx.doi.org/10.3390/molecules27051693.
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The antibacterial activity of propolis has long been of great interest, and the chemical composition of propolis is directly dependent on its source. We recently obtained a type of propolis from China with a red color. Firstly, the antibacterial properties of this unusual propolis were determined against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA). Studies on its composition identified and quantified 14 main polyphenols of Chinese red propolis extracts (RPE); quantification was carried out using liquid chromatography triple quadrupole tandem mass spectrometry (LC-QQQ-MS/MS) and RPE was found to be rich in pinobanksin, pinobanksin-3-acetate, and chrysin. In vitro investigations of its antibacterial activity revealed that its activity against S. aureus and MRSA is due to disruption of the cell wall and cell membrane, which then inhibits bacterial growth. Despite its similar antibacterial activities against S. aureus and MRSA, metabolomic analysis further revealed the effects of RPE on bacteria metabolism were different. The untargeted metabolomic results showed that a total of 7 metabolites in 12 metabolic pathways had significant changes (Fold change > 2, p < 0.05 *) after RPE treatment in S. aureus, while 11 metabolites in 9 metabolic pathways had significant changes (Fold change > 2, p < 0.05 *) after RPE treated on MRSA. Furthermore, RPE downregulated several specific genes related to bacterial biofilm formation, autolysis, cell wall synthesis, and bacterial virulence in MRSA. In conclusion, the data obtained indicate that RPE may be a promising therapeutic agent against S. aureus and MRSA.
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Kovrizhnikov, Aleksandr V., Timofey E. Pylaev, Andrey M. Zaharevich, Svetlana A. Konnova i Maria A. Kupryashina. "Obtaining viable Azospirillum brasilense SR80 cells encapsulated in alginate hydrogel". Izvestiya of Saratov University. New Series. Series: Chemistry. Biology. Ecology 21, nr 3 (24.09.2021): 298–303. http://dx.doi.org/10.18500/1816-9775-2021-21-3-298-303.
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Significant researches aimed at the greening of agro-industrial production are focused on obtaining immobilized bacterial preparations with preserved proliferative function and metabolic activity. Herein, we investigated the possibility of bacteria of the genus Azospirillum to be immobilized in Ca-alginate beads. A. brasilense SR80 cells, encapsulated in an alginate hydrogel, were obtained using the “soft” immobilization method based on physical binding. We demonstrated the retained respiratory activity and growth ability of the bacteria during immobilization, thus confirming the advantageous prospects of alginate templates for azospirilla encapsulation.
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Lu, Yang, Shuang Rao, Fei Huang, Yixia Cai, Guoping Wang i Kunzheng Cai. "Effects of Biochar Amendment on Tomato Bacterial Wilt Resistance and Soil Microbial Amount and Activity". International Journal of Agronomy 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/2938282.
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Bacterial wilt is a serious soilborne disease of Solanaceae crops which is caused byRalstonia solanacearum. The important role of biochar in enhancing disease resistance in plants has been verified; however, the underlying mechanism remains not fully understood. In this study, two different biochars, made from peanut shell (BC1) and wheat straw (BC2), were added toRalstonia solanacearum-infected soil to explore the interrelation among biochar, tomato bacterial wilt, and soil microbial properties. The results showed that both BC1 and BC2 treatments significantly reduced the disease index of bacterial wilt by 28.6% and 65.7%, respectively. The populations ofR. solanacearumin soil were also significantly decreased by biochar application.Ralstonia solanacearuminfection significantly reduced the densities of soil bacteria and actinomycetes and increased the ratio of soil fungi/bacteria in the soil. By contrast, BC1 and BC2 addition to pathogen-infected soil significantly increased the densities of soil bacteria and actinomycetes but decreased the density of fungi and the ratios of soil fungi/bacteria and fungi/actinomycetes. Biochar treatments also increased soil neutral phosphatase and urease activity. Furthermore, higher metabolic capabilities of microorganisms by biochar application were found at 96 and 144 h in Biolog EcoPlates. These results suggest that both peanut and wheat biochar amendments were effective in inhibiting tomato bacterial wilt caused byR. solanacearum. The results suggest a relationship between the disease resistance of the plants and the changes in soil microbial population densities and activity.
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Weiss, Anna S., Anna G. Burrichter, Abilash Chakravarthy Durai Raj, Alexandra von Strempel, Chen Meng, Karin Kleigrewe, Philipp C. Münch i in. "In vitro interaction network of a synthetic gut bacterial community". ISME Journal 16, nr 4 (2.12.2021): 1095–109. http://dx.doi.org/10.1038/s41396-021-01153-z.
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AbstractA key challenge in microbiome research is to predict the functionality of microbial communities based on community membership and (meta)-genomic data. As central microbiota functions are determined by bacterial community networks, it is important to gain insight into the principles that govern bacteria-bacteria interactions. Here, we focused on the growth and metabolic interactions of the Oligo-Mouse-Microbiota (OMM12) synthetic bacterial community, which is increasingly used as a model system in gut microbiome research. Using a bottom-up approach, we uncovered the directionality of strain-strain interactions in mono- and pairwise co-culture experiments as well as in community batch culture. Metabolic network reconstruction in combination with metabolomics analysis of bacterial culture supernatants provided insights into the metabolic potential and activity of the individual community members. Thereby, we could show that the OMM12 interaction network is shaped by both exploitative and interference competition in vitro in nutrient-rich culture media and demonstrate how community structure can be shifted by changing the nutritional environment. In particular, Enterococcus faecalis KB1 was identified as an important driver of community composition by affecting the abundance of several other consortium members in vitro. As a result, this study gives fundamental insight into key drivers and mechanistic basis of the OMM12 interaction network in vitro, which serves as a knowledge base for future mechanistic in vivo studies.
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Abu Bakar, F., R. R. Hafidh i A. S. Abdulamir. "Phenotype microarray profiling of the antibacterial activity of red cabbage". Functional Foods in Health and Disease 2, nr 6 (14.06.2012): 212. http://dx.doi.org/10.31989/ffhd.v2i6.88.
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Background: Functional food can be a potent source of wide array of biocomonents with antimicrobial activity. We investigated the antibacterial activity of red cabbage (RC) extract on Gram negative and positive ATCC strains. Most intersting, we, for the first time, explored and analysed the complete phenotypic profile of RC-treated bacteria using Omnilog Phenotype Microarray.Results: This study revealed that the phenotype microarray (PM) screen was a valuable tool in the search for compounds and their antibacterial mechanisms that can inhibit bacterial growth by affecting certain metabolic pathways. It was shown that RC exerted remarkable antibacterial effect on S. aureus and E. coli bacteria, and PM showed a wide range phenotypic profile of the exerted RC antibacterial activity. RC targeted the peptide, carbon, nutriontional assembly, and sulfur metbolic pathways altogether. The peptidoglycan synthesis pathway was inferred to be targeted by RC extract at a metabolic point different from other available cell wall-targeting drugs; these could be hot targets for the discovery of new therapy for many problematic microbes.Conclusions: Taken together, the phenotype microarray for functional food and medicinal plants can be a very useful tool for profiling their antimicrobial activity. Moreover, extracts of functional food can exert antibacterial activity by hitting a wide range of metabolic pathways, at the same time leading to very difficult condition for bacteria to rapidly develop resistance. Therefore, using functional foods or medicinal plants as such, or as extracts, can be superior on mono-targeting antibiotics if the optimal concentrations and conditions of these functional foods were sought.Key words: red cabbage, bacteria, antibacterial, phenotype microarray, Omnilog, Biolog
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Çandiroğlu, Begüm, i Nihal Doğruöz Güngör. "The Biotechnological Potentials of Bacteria Isolated from Parsık Cave, Turkey : Measuring the enzyme profiles, antibiotic resistance and antimicrobial activity in bacteria". Johnson Matthey Technology Review 64, nr 4 (1.10.2020): 466–79. http://dx.doi.org/10.1595/205651320x15923194903811.
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Since cave ecosystems have extraordinary environmental conditions, these ecosystems offer opportunities for microbiological studies. In this study, cultivable bacteria isolated from Parsık cave, Turkey, were investigated regarding enzyme profiles, antibiotic resistance and potential for production of antimicrobial agents. The metabolic properties of 321 bacterial isolates were determined. The most produced enzyme by the isolates was found to be tyrosine arylamidase. The enzymatic reactions of the bacteria showed that Parsık cave isolates have high aminopeptidase activity. The highest antibiotic resistance frequency of the isolates was 38.6% against ampicillin. While the isolates displayed variable inhibition rates against tested pathogenic microorganisms, they showed the highest inhibition against Candida albicans. The results show that the bacteria isolated from Parsık cave have potential for further studies related to biotechnological applications. The study findings contribute increased knowledge on metabolic peculiarities of bacteria isolated from cave ecosystems.
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Papaianni, Marina, Paola Cuomo, Andrea Fulgione, Donatella Albanese, Monica Gallo, Debora Paris, Andrea Motta, Domenico Iannelli i Rosanna Capparelli. "Bacteriophages Promote Metabolic Changes in Bacteria Biofilm". Microorganisms 8, nr 4 (28.03.2020): 480. http://dx.doi.org/10.3390/microorganisms8040480.
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Bacterial biofilm provides bacteria with resistance and protection against conventional antimicrobial agents and the host immune system. Bacteriophages are known to move across the biofilm to make it permeable to antimicrobials. Mineral hydroxyapatite (HA) can improve the lytic activity of bacteriophages, and, together with eicosanoic acid (C20:0), can destroy the biofilm structure. Here, we demonstrate the efficacy of the combined use of phage, HA and C20:0 against Xanthomonas campestris pv campestris (Xcc) biofilm. We used nuclear magnetic resonance (NMR)-based metabolomics to investigate the molecular determinants related to the lytic action, aiming at identifying the metabolic pathways dysregulated by phage treatment. Furthermore, we identified specific markers (amino acids, lactate and galactomannan) which are involved in the control of biofilm stability. Our data show that Xccφ1, alone or in combination with HA and C20:0, interferes with the metabolic pathways involved in biofilm formation. The approach described here might be extended to other biofilm-producing bacteria.
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Reichardt, Nicole, Andrew R. Barclay, Lawrence T. Weaver i Douglas J. Morrison. "Use of Stable Isotopes To Measure the Metabolic Activity of the Human Intestinal Microbiota". Applied and Environmental Microbiology 77, nr 22 (23.09.2011): 8009–14. http://dx.doi.org/10.1128/aem.05573-11.
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ABSTRACTThe human intestinal microbiota is a complex biological system comprising a vast repertoire of microbes with considerable metabolic activity relevant to both bacterial growth and host health. Greater strides have been made in the analysis of microbial diversity than in the measurement of functional activity, particularlyin vivo. Stable isotope probing offers a new approach by coupling measurements of metabolic activity with microbial identification. Using a low-enrichment labeling strategyin vitro, this study has identified metabolically active bacterial groups via magnetic-bead capture methodology and stable isotope ratio analysis. Using five probes (EUB338, Bac303, Bif164, EREC482, and Clep866), changes in the activities of key intestinal microbial groups were successfully measured by exploiting tracers ofde novoRNA synthesis. Perturbation of the nutrient source with oligofructose generated changes in the activity of bifidobacteria as expected, but also in theBacteroides-Prevotellagroup, theEubacterium rectale-Clostridium coccoidesgroup, and theClostridium leptumsubgroup. Changes in activity were also observed in response to the medium type. This study suggests that changes in the functional activity of the gut microbiota can be assessed using tracers ofde novonucleic acid synthesis combined with measurement of low isotopic enrichment in 16S rRNA. Such tracers potentially limit substrate bias because they are universally available to bacteria. This low-enrichment labeling approach does not depend on the commercial availability of specific labeled substrates and can be easily translated toin vivoprobing experiments of the functional activity of the microbiota in the human gut.
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Andrews, George, Olga Neveling, Dirk Johannes De Beer, Evans M. N. Chirwa, Hendrik G. Brink i Trudi-Heleen Joubert. "Non-Destructive Impedance Monitoring of Bacterial Metabolic Activity towards Continuous Lead Biorecovery". Sensors 22, nr 18 (17.09.2022): 7045. http://dx.doi.org/10.3390/s22187045.
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The adverse health effects of the presence of lead in wastewater streams are well documented, with conventional methods of lead recovery and removal suffering from disadvantages such as high energy costs, the production of toxic sludge, and low lead selectivity. Klebsiella pneumoniae and Paraclostridium bifermentans have been identified as potential lead-precipitating species for use in a lead recovery bioreactor. Electrical impedance spectroscopy (EIS) on a low-cost device is used to determine the potential for the probe-free and label-free monitoring of cell growth in a bioreactor containing these bacteria. A complex polynomial is fit for several reactive equivalent circuit components. A direct correlation is found between the extracted supercapacitance and the plated colony-forming unit count during the exponential growth phase, and a qualitative correlation is found between all elements of the measured reactance outside the exponential growth phase. Strong evidence is found that Pb(II) ions act as an anaerobic respiration co-substrate for both cells observed, with changes in plated count qualitatively mirrored in the Pb(II) concentration. Guidance is given on the implementation of EIS devices for continuous impedance monitoring.