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1
Poymanov, V. V., D. S. Grishanova, and S. T. Antipov. "Investigation of the processes of freezing and freeze-drying of bacterial concentrates for the dairy industry." Proceedings of the Voronezh State University of Engineering Technologies 80, no. 4 (March 21, 2019): 19–24. http://dx.doi.org/10.20914/2310-1202-2018-4-19-24.
Повний текст джерелаАнотація:
This project is dedicated to the development of finishing equipment for the production of dry bacterial concentrates. One of the main objects is a quick-freezing apparatus designed for freezing bacterial concentrates, as well as a continuous vacuum freeze dryer. In this market, domestic production takes about 9 ... 12%. Creation of high-tech equipment of a new generation for the production of bacterial concentrates for dairy enterprises will allow to solve the problem of import substitution of this type of product. The main directions for the use of bacterial concentrates in the dairy industry. The analysis of used starter cultures, the range of products manufactured using bacterial concentrates. The classification of bacterial concentrates according to the method of storage and use is given. The methods of using bacterial concentrates at dairy enterprises are considered. The ways to improve the production of bacterial concentrates are proposed. To study the effect of technological parameters of vacuum freeze-drying on the quality of the final bacterial concentrate, a series of experiments was performed. Drying was carried out to a final moisture content of 3.0–3.2%, while the residual pressure in the chamber varied in the range of 10–50 Pa, and the heat flux density ranged from 1.2 to 1.8 kW / m2. The expediency of creating domestic production of baconconcentrates on an industrial scale is substantiated. The results of the study of the kinetics of the freezing of bacterial concentrates are given. The rational parameters of the freezing process and the optimal composition of the cryoprotective medium are proposed. Investigations of the process of vacuum-sublimation dehydration of bacterial concentrate in a layer and granulated form have been conducted. The quality indicators of dry bacterial concentrates are given. The results will allow to carry out engineering calculations and design of equipment for freezing and vacuum sublimation plants with various methods of energy supply.
2
Archibald, Lennox K., L. Clifford McDonald, Rachel M. Addison, Celeste McKnight, Terry Byrne, Hamish Dobbie, Okey Nwanyanwu, Peter Kazembe, L. Barth Reller, and William R. Jarvis. "Comparison of BACTEC MYCO/F LYTIC and WAMPOLE ISOLATOR 10 (Lysis-Centrifugation) Systems for Detection of Bacteremia, Mycobacteremia, and Fungemia in a Developing Country." Journal of Clinical Microbiology 38, no. 8 (2000): 2994–97. http://dx.doi.org/10.1128/jcm.38.8.2994-2997.2000.
Повний текст джерелаАнотація:
In less-developed countries, studies of bloodstream infections (BSI) have been hindered because of the difficulty and costs of culturing blood for bacteria, mycobacteria, and fungi. During two study periods (study period I [1997] and study period II [1998]), we cultured blood from patients in Malawi by using the BACTEC MYCO/F LYTIC (MFL), ISOLATOR 10 (Isolator), Septi-Chek AFB (SC-AFB), and Septi-Chek bacterial (SC-B) systems. During study period I, blood was inoculated at 5 ml into an MFL bottle, 10 ml into an Isolator tube for lysis and centrifugation, and 10 ml into an SC-B bottle. Next, 0.5-ml aliquots of Isolator concentrate were inoculated into an SC-AFB bottle and onto Middlebrook 7H11 agar slants, chocolate agar slants, and Inhibitory Mold Agar (IMA) slants. During study period II, the SC-B and chocolate agar cultures were discontinued. MFL growth was detected by fluorescence caused by shining UV light (λ = 365 nm) onto the indicator on the bottom of the bottle. During study period I, 251 blood cultures yielded 44 bacterial isolates. For bacteremia, the MFL was similar to the Isolator concentrate on chocolate agar (34 of 44 versus 27 of 44; P, not significant [NS]), but more sensitive than the SC-B bottle (34 of 44 versus 24 of 44; P = 0.05). For both study periods combined, 486 blood cultures yielded 37 mycobacterial and 13 fungal isolates. For mycobacteremia, the sensitivities of the MFL and Isolator concentrate in the SC-AFB bottle were similar (30 of 37 versus 29 of 37; P, NS); the MFL bottle was more sensitive than the concentrate on Middlebrook agar (30 of 37 versus 15 of 37; P = 0.002). For fungemia, the MFL bottle was as sensitive as the SC-B bottle or Isolator concentrate on chocolate agar or IMA slants. We conclude that the MFL bottle, inoculated with just 5 ml of blood and examined under UV light, provides a sensitive and uncomplicated method for comprehensive detection of BSI in less-developed countries.
3
Stankovic, Srdjan, Ivana Moric, Aleksandar Pavic, Branka Vasiljevic, Barrie Johnson, and Vladica Cvetkovic. "Investigation of the microbial diversity of an extremely acidic, metal-rich water body (Lake Robule, Bor, Serbia)." Journal of the Serbian Chemical Society 79, no. 6 (2014): 729–41. http://dx.doi.org/10.2298/jsc130605071s.
Повний текст джерелаАнотація:
An investigation of the microbial diversity of the extremely acidic, metal-rich Lake Robule was carried out using culture-dependant and culture-independent (T-RFLP) methods, and the ability of indigenous bacteria from the lake water to leach copper from a mineral concentrate was tested. T-RFLP analysis revealed that the dominant bacteria in lake water samples were the obligate heterotroph Acidiphilium cryptum (~50% of total bacteria) and the iron-oxidizing autotroph Leptospirillum ferrooxidans (~40%) The iron/sulfur-oxidizing autotroph Acidithiobacillus ferrooxidans had been reported to be the most abundant bacteria in the lake in an earlier study by other authors, but it was not detected in the present study using T-RFLP. Although it was isolated on solid media and detected in enrichment (bioleaching) cultures. The presence of the two bacterial species detected by T-RFLP (L. ferrooxidans and A. cryptum) was also confirmed by cultivation on solid media. The presence and relative abundance of bacteria inhabiting Lake Robule was explained by the physiological characteristics of the bacteria and the physico-chemical characteristics of the lake water.
4
Sarlin, Tuija H., Outi K. Priha, Mona E. Arnold, and Päivi Kinnunen. "Bioleaching of Phosphorus from Low Grade Ores and Concentrates with Acidophilic Iron- and Sulphur-Oxidizing Bacteria." Advanced Materials Research 825 (October 2013): 266–69. http://dx.doi.org/10.4028/www.scientific.net/amr.825.266.
Повний текст джерелаАнотація:
Bioleaching experiments of phosphorus from low grade fluorapatite ore containing 8.2% P2O5 and from fluorapatite concentrate containing 29.8% P2O5 were carried out in shake flasks. Elemental sulphur was supplemented as an energy source for acid generation. Mixed and pure acidophilic bacterial cultures consisting of iron-and/or sulphur-oxidizing bacteria Acidithiobacillus ferrooxidans, A. thiooxidans and Leptospirillum ferrooxidans were used in the experiments. These acidophiles are commonly used in bioleaching of sulphide minerals, but their application on phosphorus bioleaching has been limited. Phosphorus leaching was shown to be a pH-dependant phenomenon. Phosphorus leaching yields of up to 97% and 28% were obtained in 3 weeks for low grade fluorapatite ore and concentrate, respectively. These results indicate a potential for applying bioleaching for phosphorus extraction from low grade materials.
5
Ericksen, Bryan. "Quantification of polysaccharides fixed to Gram stained slides using lactophenol cotton blue and digital image processing." F1000Research 4 (April 13, 2015): 1. http://dx.doi.org/10.12688/f1000research.5779.2.
Повний текст джерелаАнотація:
Indigo rings and circles emerged when I added the non-specific polysaccharide stain lactophenol cotton blue to Gram stained slides. I attribute the dark blue staining to the presence of capsular polysaccharides and bacterial slime associated with clumps of Gram-negative bacteria. Since all bacterial cells are glycosylated and concentrate polysaccharides from the media, the majority of cells stain light blue. The contrast between dark and light staining is sufficient to enable a digital image processing thresholding technique to be quantitative with little background noise. Prior to the addition of lactophenol cotton blue, the Gram-stained slides appeared unremarkable, lacking ubiquitous clumps or stained polysaccharides. Adding lactophenol cotton blue to Gram stained slides is a quick and inexpensive way to screen cell cultures for bacterial slime, clumps and biofilms that are invisible using the Gram stain alone.
6
Ericksen, Bryan. "Quantification of polysaccharides fixed to Gram stained slides using lactophenol cotton blue and digital image processing." F1000Research 4 (December 6, 2017): 1. http://dx.doi.org/10.12688/f1000research.5779.5.
Повний текст джерелаАнотація:
Dark blue rings and circles emerged when the non-specific polysaccharide stain lactophenol cotton blue was added to Gram stained slides. The dark blue staining is attributable to the presence of capsular polysaccharides and bacterial slime associated with clumps of Gram-negative bacteria. Since all bacterial cells are glycosylated and concentrate polysaccharides from the media, the majority of cells stain light blue. The contrast between dark and light staining is sufficient to enable a digital image processing thresholding technique to be quantitative with little background noise. Prior to the addition of lactophenol cotton blue, the Gram-stained slides appeared unremarkable, lacking ubiquitous clumps or stained polysaccharides. Adding lactophenol cotton blue to Gram stained slides is a quick and inexpensive way to screen cell cultures for bacterial slime, clumps and biofilms that are invisible using the Gram stain alone.
7
Eiler, Alexander, Silke Langenheder, Stefan Bertilsson, and Lars J. Tranvik. "Heterotrophic Bacterial Growth Efficiency and Community Structure at Different Natural Organic Carbon Concentrations." Applied and Environmental Microbiology 69, no. 7 (July 2003): 3701–9. http://dx.doi.org/10.1128/aem.69.7.3701-3709.2003.
Повний текст джерелаАнотація:
ABSTRACT Batch cultures of aquatic bacteria and dissolved organic matter were used to examine the impact of carbon source concentration on bacterial growth, biomass, growth efficiency, and community composition. An aged concentrate of dissolved organic matter from a humic lake was diluted with organic compound-free artificial lake water to obtain concentrations of dissolved organic carbon (DOC) ranging from 0.04 to 2.53 mM. The bacterial biomass produced in the cultures increased linearly with the DOC concentration, indicating that bacterial biomass production was limited by the supply of carbon. The bacterial growth rate in the exponential growth phase exhibited a hyperbolic response to the DOC concentration, suggesting that the maximum growth rate was constrained by the substrate concentration at low DOC concentrations. Likewise, the bacterial growth efficiency calculated from the production of biomass and CO2 increased asymptotically from 0.4 to 10.4% with increasing DOC concentration. The compositions of the microbial communities that emerged in the cultures were assessed by separation of PCR-amplified 16S rRNA fragments by denaturing gradient gel electrophoresis. Nonmetric multidimensional scaling of the gel profiles showed that there was a gradual change in the community composition along the DOC gradient; members of the β subclass of the class Proteobacteria and members of the Cytophaga-Flavobacterium group were well represented at all concentrations, whereas members of the α subclass of the Proteobacteria were found exclusively at the lowest carbon concentration. The shift in community composition along the DOC gradient was similar to the patterns of growth efficiency and growth rate. The results suggest that the bacterial growth efficiencies, the rates of bacterial growth, and the compositions of bacterial communities are not constrained by substrate concentrations in most natural waters, with the possible exception of the most oligotrophic environments.
8
Soglaeva, A., O. Titova, N. Zhabanos, and N. Furik. "DEVELOPMENT OF A BACTERIAL STEERING STERE FOR A FODDER BALANCING CONCENTRATE «ECOBALANCE» FOR REGULATING MICROBIOLOGICAL PROCESSES IN COW'S PEREASTERS AND INCREASING DAIRY PRODUCTIVITY." Topical issues of processing of meat and milk raw materials, no. 15 (December 21, 2021): 69–78. http://dx.doi.org/10.47612/2220-8755-2020-15-69-78.
Повний текст джерелаАнотація:
Researches of physiological and biochemical characteristics of microorganisms from the Republican collection of industrial strains of starter cultures and their bacteriophages were carried out. Strains of Lactobacillus plantarum, Lactobacillus casei, Lactobacillus fermentum was selected. Consortia of microorganisms for use in the starter culture to regulate microbiological processes in the proventriculus of cows was developed. The effect of various components of the filler on the ability of lactic acid microorganisms to develop in their presence was investigated. The procedure for introducing and mixing technology of the starter culture and dry components of the feed concentrate has been worked out.
9
Ericksen, Bryan. "Quantification of polysaccharides fixed to Gram stained slides using lactophenol cotton blue and digital image processing." F1000Research 4 (May 15, 2017): 1. http://dx.doi.org/10.12688/f1000research.5779.3.
Повний текст джерелаАнотація:
Dark blue rings and circles emerged when the non-specific polysaccharide stain lactophenol cotton blue was added to Gram stained slides. The dark blue staining is attributable to the presence of capsular polysaccharides and bacterial slime associated with clumps of Gram-negative bacteria. Since all bacterial cells are glycosylated and concentrate polysaccharides from the media, the majority of cells stain light blue. The contrast between dark and light staining is sufficient to enable a digital image processing thresholding technique to be quantitative with little background noise. Prior to the addition of lactophenol cotton blue, the Gram-stained slides appeared unremarkable, lacking ubiquitous clumps or stained polysaccharides. Adding lactophenol cotton blue to Gram stained slides is a quick and inexpensive way to screen cell cultures for bacterial slime, clumps and biofilms that are invisible using the Gram stain alone. The presence of cell clumping provides a possible explanation of the presence of persisters and paradoxical points observed in Virtual Colony Count antimicrobial assays, and suggests a phenotypic resistance mechanism to antimicrobial peptides involving capsular polysaccharides.
10
Ericksen, Bryan. "Quantification of polysaccharides fixed to Gram stained slides using lactophenol cotton blue and digital image processing." F1000Research 4 (July 13, 2017): 1. http://dx.doi.org/10.12688/f1000research.5779.4.
Повний текст джерелаАнотація:
Dark blue rings and circles emerged when the non-specific polysaccharide stain lactophenol cotton blue was added to Gram stained slides. The dark blue staining is attributable to the presence of capsular polysaccharides and bacterial slime associated with clumps of Gram-negative bacteria. Since all bacterial cells are glycosylated and concentrate polysaccharides from the media, the majority of cells stain light blue. The contrast between dark and light staining is sufficient to enable a digital image processing thresholding technique to be quantitative with little background noise. Prior to the addition of lactophenol cotton blue, the Gram-stained slides appeared unremarkable, lacking ubiquitous clumps or stained polysaccharides. Adding lactophenol cotton blue to Gram stained slides is a quick and inexpensive way to screen cell cultures for bacterial slime, clumps and biofilms that are invisible using the Gram stain alone. The presence of cell clumping provides a possible explanation of the presence of persisters and paradoxical points observed in Virtual Colony Count antimicrobial assays, and suggests a phenotypic resistance mechanism to antimicrobial peptides involving capsular polysaccharides.
11
Van Gerrewey, Thijs, Christophe El-Nakhel, Stefania De Pascale, Jolien De Paepe, Peter Clauwaert, Frederiek-Maarten Kerckhof, Nico Boon, and Danny Geelen. "Root-Associated Bacterial Community Shifts in Hydroponic Lettuce Cultured with Urine-Derived Fertilizer." Microorganisms 9, no. 6 (June 18, 2021): 1326. http://dx.doi.org/10.3390/microorganisms9061326.
Повний текст джерелаАнотація:
Recovery of nutrients from source-separated urine can truncate our dependency on synthetic fertilizers, contributing to more sustainable food production. Urine-derived fertilizers have been successfully applied in soilless cultures. However, little is known about the adaptation of the plant to the nutrient environment. This study investigated the impact of urine-derived fertilizers on plant performance and the root-associated bacterial community of hydroponically grown lettuce (Lactuca sativa L.). Shoot biomass, chlorophyll, phenolic, antioxidant, and mineral content were associated with shifts in the root-associated bacterial community structures. K-struvite, a high-performing urine-derived fertilizer, supported root-associated bacterial communities that overlapped most strongly with control NPK fertilizer. Contrarily, lettuce performed poorly with electrodialysis (ED) concentrate and hydrolyzed urine and hosted distinct root-associated bacterial communities. Comparing the identified operational taxonomic units (OTU) across the fertilizer conditions revealed strong correlations between specific bacterial genera and the plant physiological characteristics, salinity, and NO3-/NH4+ ratio. The root-associated bacterial community networks of K-struvite and NPK control fertilized plants displayed fewer nodes and node edges, suggesting that good plant growth performance does not require highly complex ecological interactions in hydroponic growth conditions.
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Bychkova, Veronika A., Olga S. Utkina, and Elena V. Achkasova. "The use of acidophilus bacterium for cheese cheddaring." BIO Web of Conferences 17 (2020): 00180. http://dx.doi.org/10.1051/bioconf/20201700180.
Повний текст джерелаАнотація:
One of the promising technologies for cheese making is cheddaring of cheese mass; it is desirable that the cheddaring takes place as soon as possible. The article considers the possibility of using acidophilus bacillus to intensify the cheddaring process. As starter cultures, the bacterial concentrate AiBi LcLS 30.11 and sourdough of acidophilus bacillus with inviscid BK-Uglich-ANV in a ratio of 5:1 were used. The cheddarization of cheese mass using a starter culture with acidophilus bacillus took 3 hours, while the cheddarization time was reduced by 2–4 hours. The optimum acidity of the serum is 65–70 ° T (pH 5.45–5.50), the thermomechanical processing requires water. Cheese produced using acidophilus bacterium meets the organoleptic and physico-chemical parameters.
13
Wang, Yuguang, Weimin Zeng, Guanzhou Qiu, Xinhua Chen, and Hongbo Zhou. "A Moderately Thermophilic Mixed Microbial Culture for Bioleaching of Chalcopyrite Concentrate at High Pulp Density." Applied and Environmental Microbiology 80, no. 2 (November 15, 2013): 741–50. http://dx.doi.org/10.1128/aem.02907-13.
Повний текст джерелаАнотація:
ABSTRACTThree kinds of samples (acid mine drainage, coal mine wastewater, and thermal spring) derived from different sites were collected in China. Thereafter, these samples were combined and then inoculated into a basal salts solution in which different substrates (ferrous sulfate, elemental sulfur, and chalcopyrite) served as energy sources. After that, the mixed cultures growing on different substrates were pooled equally, resulting in a final mixed culture. After being adapted to gradually increasing pulp densities of chalcopyrite concentrate by serial subculturing for more than 2 years, the final culture was able to efficiently leach the chalcopyrite at a pulp density of 20% (wt/vol). At that pulp density, the culture extracted 60.4% of copper from the chalcopyrite in 25 days. The bacterial and archaeal diversities during adaptation were analyzed by denaturing gradient gel electrophoresis and constructing clone libraries of the 16S rRNA gene. The results show that the culture consisted mainly of four species, includingLeptospirillum ferriphilum,Acidithiobacillus caldus,Sulfobacillus acidophilus, andFerroplasma thermophilum, before adapting to a pulp density of 4%. However,L. ferriphilumcould not be detected when the pulp density was greater than 4%. Real-time quantitative PCR was employed to monitor the microbial dynamics during bioleaching at a pulp density of 20%. The results show thatA. calduswas the predominant species in the initial stage, whileS. acidophilusrather thanA. caldusbecame the predominant species in the middle stage.F. thermophilumaccounted for the greatest proportion in the final stage.
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Panyushkina, Anna, Maxim Muravyov, and Natalya Fomchenko. "A Case of Predominance of Alicyclobacillus tolerans in Microbial Community during Bioleaching of Pentlandite-Chalcopyrite Concentrate." Minerals 12, no. 4 (March 23, 2022): 396. http://dx.doi.org/10.3390/min12040396.
Повний текст джерелаАнотація:
Bacterial isolates assigned to the species Alicyclobacillus tolerans, which occupies an intermediate position between an organotrophic genus Alicyclobacillus and mixotrophic genus Sulfobacillus, were revealed as members of the acidophilic chemolithotrophic community during stirred-tank bioleaching of violarite–pentlandite–chalcopyrite concentrate at 40 °C. Surprisingly, this species succeeded more common iron-oxidizing community members after a series of bioleaching processes in bioreactors. The possibility of mixotrophic and organoheterotrophic growth of Al. tolerans, tolerance to low pH values (1.0–1.15), as well as preservation of cells via sporulation under unfavorable conditions, may explain its key role in the bioleaching of the copper–nickel bulk concentrate. Isolation of two other sulfur-oxidizing pure cultures dominating the microbial community, together with their phylogenetic characterization, allowed the assignment of these isolates to the species Acidithiobacillus caldus. This and other studies of acidophilic microbial communities are important for the development and intensification of the bioleaching processes, including a biobeneficiation approach previously proposed by us.
15
Cotsaris, E., A. Bruchet, J. Mallevialle, and D. B. Bursill. "The identification of odorous metabolites produced from algal monocultures." Water Science and Technology 31, no. 11 (June 1, 1995): 251–58. http://dx.doi.org/10.2166/wst.1995.0443.
Повний текст джерелаАнотація:
Four algal species commonly found in the River Seine were cultured for a comprehensive investigation of their odorous metabolites. Closed loop stripping analysis (CLSA), open stripping analysis (OSA) and steam distillation extraction (SDE) were used to extract and concentrate a wide range of metabolites. The odour causing compounds were identified by a combination of chemical (gas chromatography-mass spectrometry (GC-MS)) and sensory (sensory-gas chromatography (sensory-GC), flavour profile analysis (FPA)) analyses. The compounds found responsible for unpleasant odours were alkenes, saturated and unsaturated aliphatic alcohols, aldehydes, ketones, sulphides and pyrazines. Some of the odorous compounds responsible for septic and muddy/musty odours may have been of bacterial or fungal origin as the cultures were non-axenic. Sensory-GC was found to be a valuable tool in identifying compounds of very low odour thresholds, which were present at or below the detection limits of the GC-MS.
16
Windschitl, P. M. "Effects of probiotic supplementation of hull-less barley- and corn-based diets on bacterial fermentation in continuous culture of ruminal contents." Canadian Journal of Animal Science 72, no. 2 (June 1, 1992): 265–72. http://dx.doi.org/10.4141/cjas92-033.
Повний текст джерелаАнотація:
A study was conducted using a continuous culture fermentation system to determine effects of probiotic supplementation on ruminal bacterial fermentation of hull-less barley- and corn-based diets. The probiotic contained both a fungal (Aspergillus oryzae) and yeast (Saccharomyces cerevisiae) culture along with several bacterial cultures. Treatments were arranged in a 2 × 2 factorial design with two sources of grain (hull-less barley, B and corn, C) with (+) or without (−) probiotic supplementation. Probiotic was added directly into the fermenter flasks. Diets consisted of (dry matter basis) 46% bromegrass silage, 5% alfalfa meal, and 49% barley- or corn-based concentrate mix. Probiotic supplementation decreased (P < 0.05) dry matter digestibility with the corn diet (C −, 58.6%; C +, 51.4%) but had no significant effect on the barley diet (B −, 48.7%; B +, 51.8%) Dry matter digestibility tended to be higher (P = 0.07) with corn- vs. barley-based diets. Protein degradation and fiber digestibility were not significantly (P > 0.05) affected by probiotic supplementation. Non-fiber carbohydrate digestibility was decreased (P < 0.05) with C + and tended to increase (P = 0.09) with B + compared to C − and B −, respectively (B −, 60.8%; B +, 67.1%; C −, 72.3%; C +, 63.4%). Probiotic supplementation had no significant (P > 0.05) effect on total or individual volatile fatty acids. Although limited, data suggest that type of grain used in the diet can influence the effectiveness of probiotics in altering ruminal metabolism. Key words: Continuous culture, corn, hull-less barley, probiotic, ruminal fermentation
17
MATEOS, I., M. J. RANILLA, C. SARO, and M. D. CARRO. "Comparison of fermentation characteristics and bacterial diversity in the rumen of sheep and in batch cultures of rumen microorganisms." Journal of Agricultural Science 153, no. 6 (April 29, 2015): 1097–106. http://dx.doi.org/10.1017/s0021859615000167.
Повний текст джерелаАнотація:
SUMMARYThe objective of the current study was to assess how closely batch cultures (BC) of rumen microorganisms can mimic the dietary differences in fermentation characteristics found in the rumen, and to analyse changes in bacterial diversity over the in vitro incubation period. Four ruminally and duodenally cannulated sheep were fed four diets having forage : concentrate ratios (FCR) of 70 : 30 or 30 : 70, with either alfalfa hay or grass hay as forage. Rumen fluid from each sheep was used to inoculate BC containing the same diet fed to the donor sheep, and the main rumen fermentation parameters were determined after 24 h of incubation. There were differences between BC and sheep in the magnitude of most measured parameters, but BC detected differences among diets due to forage type similar to those found in sheep. In contrast, BC did not reproduce the dietary differences due to FCR found in sheep for pH, degradability of neutral detergent fibre and total volatile fatty acid (VFA) concentrations. There were differences between systems in the magnitude of most determined parameters and BC showed higher pH values and NH3–N concentrations, but lower fibre degradability and VFA and lactate concentrations compared with sheep. There were significant relationships between in vivo and in vitro values for molar proportions of acetate, propionate and butyrate, and the acetate : propionate ratio. The automated ribosomal intergenic spacer analysis (ARISA) of 16S ribosomal deoxyribonucleic acid showed that FCR had no effect on bacterial diversity either in the sheep rumen fluid used as inoculum (IN) or in BC samples. In contrast, bacterial diversity was greater with alfalfa hay diets than those with grass hay in the IN, but was unaffected by forage type in the BC. Similarity index between the bacterial communities in the inocula and those in the BC ranged from 67·2 to 74·7%, and was unaffected by diet characteristics. Bacterial diversity was lower in BC than in the inocula with 14 peaks out of a total of 181 detected in the ARISA electropherograms never appearing in BC samples, which suggests that incubation conditions in the BC may have caused a selection of some bacterial strains. However, each BC sample showed the highest similarity index with its corresponding rumen IN, which highlights the importance of using rumen fluid from donors fed a diet similar to that being incubated in BC when conducting in vitro experiments.
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Ueki, Y., K. Akiyama, T. Watanabe, and T. Omura. "Genetic analysis of noroviruses taken from gastroenteritis patients, river water and oysters." Water Science and Technology 50, no. 1 (July 1, 2004): 51–56. http://dx.doi.org/10.2166/wst.2004.0016.
Повний текст джерелаАнотація:
As oysters are eaten raw in Japan, their contamination with the non-bacterial agent of gastroenteritis has become a serious health problem. As it is well known that oysters tend to concentrate noroviruses (NV) in their digestive diverticula, NV may be linked with the acute gastroenteritis. However, since NV cannot be cultivated in cell cultures, and they have genetic diversity, the behaviour of NV in the aquatic environment is little known. In this study, NV samples were taken from gastroenteritis patients; from the river flowing into the oyster-farming area; and from oysters harvested from that river. Genetic identities of NV samples were analysed in capsid and RNA-dependent RNA polymerase (RdRp) regions respectively. In both regions, strains taken from patients were >96% identical with those from river and oyster samples. This proved that oysters were contaminated with NV excreted from patients with gastroenteritis.
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Sharov, D. A., A. A. Leshchenko, S. V. Bagin, S. V. Logvinov, D. A. Mokhov, A. V. Ezhov, A. G. Lazykin, V. V. Krupin, and I. V. Kosenkov. "Improvement of Microbial Cell Concentration Technology in the Production of Live Plague Vaccine in the Form of Orodispersible Tablets." Problems of Particularly Dangerous Infections, no. 4 (February 7, 2021): 139–45. http://dx.doi.org/10.21055/0370-1069-2020-4-139-145.
Повний текст джерелаАнотація:
The aim of the study was to improve the procedure for the Yersinia pestis EV strain cell concentration using the system for tangential flow microfiltration with the ASF-020 filter support unit.Materials and methods. The study used the vaccine Y. pestis EV strain derived from NIIEG cell line. Submerged cultivation of the native culture was performed using BIOR-0.25 reactor with automated control system. Microbial suspension concentrate was produced through microfiltration applying (Adaptive filtration system) AFS-009 and AFS-020 installations. The content of live microbial cells was determined by cytorefractometry. Assessment of the resistance of Y. pestis EV strain cells to technological factors was performed by photometric registration of changes in the optical density of bacterial suspension during the lytic response of cells to sodium dodecyl sulfate. Physical-chemical and immunobiological properties of the dry live plague vaccine were determined in accordance with the pharmacopoeial item.3.3.1.0021.15 of the State Pharmacopoeia of the Russian Federation, 14th edition.Results and discussion. The design features of the equipment introduced made it possible to carry out membrane filtration of microbial suspension, using BIOR-0.25 reactor as an intermediate storage unit, thereby excluding three technological stages. The total concentration of microbes in the suspension obtained by routine and improved methods was more than 150 billion microbial cells per ml. A comparative study of the effect of various hydrodynamic regimes in the working cavities of AFS-009 and AFS-020 filter units did not significantly affect the morphometric properties and resistance of microbial cultures to extreme (technological) factors. Based on the experimental data, the mass balance of the membrane filtration process has been determined. The optimized technology gave 0.13 liter yield of concentrate from 1 liter of native culture, and the process duration was reduced to 5 hours, the yield of the finished product in one production cycle was increased by 3 times. Thus, the process of concentrating Y. pestis EV strain cells during the production of the tablet form of live plague vaccine has been enhanced. A comparative study of the morphometric properties and resistance of plague microbe cultures to technological factors in the process of their concentration using optimized technology did not reveal any significant differences as compared to the routine one. Technological stage of concentrating has been reduced to 5 h term with a three-fold increase in the yield of finished product.
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Sallusto, F., M. Cella, C. Danieli, and A. Lanzavecchia. "Dendritic cells use macropinocytosis and the mannose receptor to concentrate macromolecules in the major histocompatibility complex class II compartment: downregulation by cytokines and bacterial products." Journal of Experimental Medicine 182, no. 2 (August 1, 1995): 389–400. http://dx.doi.org/10.1084/jem.182.2.389.
Повний текст джерелаАнотація:
We have previously demonstrated that human peripheral blood low density mononuclear cells cultured in granulocyte/macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-4 develop into dendritic cells (DCs) that are extremely efficient in presenting soluble antigens to T cells. To identify the mechanisms responsible for efficient antigen capture, we studied the endocytic capacity of DCs using fluorescein isothiocyanate-dextran, horseradish peroxidase, and lucifer yellow. We found that DCs use two distinct mechanisms for antigen capture. The first is a high level of fluid phase uptake via macropinocytosis. In contrast to what has been found with other cell types, macropinocytosis in DCs is constitutive and allows continuous internalization of large volumes of fluid. The second mechanism of capture is mediated via the mannose receptor (MR), which is expressed at high levels on DCs. At low ligand concentrations, the MR can deliver a large number of ligands to the cell in successive rounds. Thus, while macropinocytosis endows DCs with a high capacity, nonsaturable mechanism for capture of any soluble antigen, the MR gives an extra capacity for antigen capture with some degree of selectivity for non-self molecules. In addition to their high endocytic capacity, DCs from GM-CSF + IL-4-dependent cultures are characterized by the presence of a large intracellular compartment that contains high levels of class II molecules, cathepsin D, and lysosomal-associated membrane protein-1, and is rapidly accessible to endocytic markers. We investigated whether the capacity of DCs to capture and process antigen could be modulated by exogenous stimuli. We found that DCs respond to tumor necrosis factor alpha, CD40 ligand, IL-1, and lipopolysaccharide with a coordinate series of changes that include downregulation of macropinocytosis and Fc receptors, disappearance of the class II compartment, and upregulation of adhesion and costimulatory molecules. These changes occur within 1-2 d and are irreversible, since neither pinocytosis nor the class II compartment are recovered when the maturation-inducing stimulus is removed. The specificity of the MR and the capacity to respond to inflammatory stimuli maximize the capacity of DCs to present infectious non-self antigens to T cells.
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Stein, Colleen S., Paul H. Yancey, Inês Martins, Rita D. Sigmund, John B. Stokes, and Beverly L. Davidson. "Osmoregulation of ceroid neuronal lipofuscinosis type 3 in the renal medulla." American Journal of Physiology-Cell Physiology 298, no. 6 (June 2010): C1388—C1400. http://dx.doi.org/10.1152/ajpcell.00272.2009.
Повний текст джерелаАнотація:
Recessive inheritance of mutations in ceroid neuronal lipofuscinosis type 3 ( CLN3) results in juvenile neuronal ceroid lipofuscinosis (JNCL), a childhood neurodegenerative disease with symptoms including loss of vision, seizures, and motor and mental decline. CLN3p is a transmembrane protein with undefined function. Using a Cln3 reporter mouse harboring a nuclear-localized bacterial β-galactosidase (β-Gal) gene driven by the native Cln3 promoter, we detected β-Gal most prominently in epithelial cells of skin, colon, lung, and kidney. In the kidney, β-Gal-positive nuclei were predominant in medullary collecting duct principal cells, with increased expression along the medullary osmotic gradient. Quantification of Cln3 transcript levels from kidneys of wild-type ( Cln3+/+) mice corroborated this expression gradient. Reporter mouse-derived renal epithelial cultures demonstrated a tonicity-dependent increase in β-Gal expression. RT-quantitative PCR determination of Cln3 transcript levels further supported osmoregulation at the Cln3 locus. In vivo, osmoresponsiveness of Cln3 was demonstrated by reduction of medullary Cln3 transcript abundance after furosemide administration. Primary cultures of epithelial cells of the inner medulla from Cln3lacZ/lacZ (CLN3p-null) mice showed no defect in osmolyte accumulation or taurine flux, arguing against a requirement for CLN3p in osmolyte import or synthesis. CLN3p-deficient mice with free access to water showed a mild urine-concentrating defect but, upon water deprivation, were able to concentrate their urine normally. Unexpectedly, we found that CLN3p-deficient mice were hyperkalemic and had a low fractional excretion of K+. Together, these findings suggest an osmoregulated role for CLN3p in renal control of water and K+ balance.
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Benoit, Yves, Inge Van Haute, Els Vandecruys, Barbara De Moerloose, Sophie Van Lancker, Kristien Mattheeus, and Bart Vandekerckhove. "Safety and Efficacy of Pathogen-Inactivated Platelets Transfused in Routine Use to Pediatric Patients: An Interim Report." Blood 104, no. 11 (November 16, 2004): 3639. http://dx.doi.org/10.1182/blood.v104.11.3639.3639.
Повний текст джерелаАнотація:
Abstract Background. A pathogen inactivation (PI) process to treat platelet concentrates (INTERCEPT, Baxter Healthcare Corporation and Cerus Corporation) is certified for use in Europe (CE Mark 2002). No labeling restriction exists regarding pediatric patients. In the three clinical trials supporting regulatory approval, patient age eligibility was ≥ 16 years (yrs). We initiated an ongoing study to specifically examine the safety and efficacy of transfusion (txn) of PI platelets (plts) in a pediatric population. This is an observational, single arm, open label study that will evaluate 500 transfusion episodes. Methods. Buffy coat plts are collected, pooled, leuko-depleted, and PI-treated with 150 uM amotosalen and 3,9 joules/cm² UVA illumination. Amotosalen was removed by overnight adsorption. Plts did not require gamma irradiation. Plt txns are ordered according to hospital guidelines and patients (pts) are managed according to hospital clinical practice. Eligible pts are thrombocytopenic, expected to develop thrombocytopenia requiring plt txn, diagnosed with a condition associated with thrombocytopenia or receiving therapy that will result in severe thrombocytopenia. Plt txn are given for prophylactic and therapeutic needs. Safety assessed by txn reaction within 24hrs of txn completion and efficacy assessed by count increment [CI] and corrected count increment [CCI] ≤1.5hr post txn are monitored. Results. Pts range in age from 1 to 16 yrs. One hundred fifty-eight PI-treated plt concentrates have been transfused into 21 pts (13 leukemias, 7 solid tumors and 1 aplastic anemia). Plt concentrates are transfused as units of 0.5 x 1011 plts. Txn episodes per patient (receipt of one or more concentrates) range from 1 to 45. One of the frequently transfused patient (45 txn episodes) had a prolonged cytopenia (resistant leukaemia) and had a refractory thrombocytopenia. The number of platelets transfused per episode range from 1.0 to 6.8 x 1011 (2 to 13.6 units). Six txn reactions in 6 pts have been noted and include fever (5), urticaria (1) and itching (2). For the patients experiencing fever, bacterial cultures were done on patient blood samples and plt concentrate samples; all cultures were negative. Mean plt CI was 44,400 per μL (range −11,000 to 216,000). Mean plt CCI was 11,780 (range −3,020 to 45,170). If we exclude the refractory patient from this CI and CCI analysis the mean plt CI was 58,000 per μL (range −11,000 to 216,000). The mean plt CCI was 14,250 (range −2,750 to 45,170). Conclusions. To date, txn of PI plts in this pediatric oncology pt population has been safe and efficacious, with no transfusion reactions specifically related to PI observed. Post-txn plt count increment, corrected count increments and hemostasis have been similar to that observed with conventional platelets. The introduction of PI platelets has not resulted in increased platelet component utilization.
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te Boekhorst, Peter A. W., Erik A. M. Beckers, Greet C. Vos, Hans Vermeij, Frank W. G. Leebeek, and Dick J. van Rhenen. "Relevance of Routine Bacterial Screening of Pooled Random Platelet Concentrates with the Bactalert® System." Blood 104, no. 11 (November 16, 2004): 3626. http://dx.doi.org/10.1182/blood.v104.11.3626.3626.
Повний текст джерелаАнотація:
Abstract Background: Transfusion of bacterial contaminated platelet (PLT) units can cause serious transfusion reactions. To prevent this complication, bacterial screening by the automated BacTalert® system of platelet concentrates was implemented in the southwest part of the Netherlands since october 2001. Despite this system, two severe transfusion reactions caused by bacterial contaminated PLT units occurred. Therefore, evaluation of the efficacy of this approach was done. Material and Methods: PLT products in the Netherlands are produced by the Sanquin Bloodbanks. In the Southwest part of the Netherlands PLT products mainly consist of pooled products derived from five random donors. Of all produced platelet products, samples were taken and cultured (aerobic and anaerobic) for seven days using the automated BacTalert® system. The PLT products were issued to the hospitals on a "negative-to-date" basis. In case of positive cultures, conformation and identification cultures were taken. At the same time, involved and related products thet were derived from the same donor were also withdrawn. In case of delivery of possibly contaminated products to the hospitals, these were notified and the products were recalled. If the products were already transfused, treating physicians were notified and asked if adverse reactions had occurred in these patients. Results: From October 2001 to 2003, a total of 28,104 produced pooled PLT units were tested for bacterial contamination using the BacTalert® system. Positive signals were found in 203 (0,72%) samples. At the time of a positive signal, 125 PLT products were already issued to the hospitals and of these 125 products, 113 units were already administered to patients. Analysis of all positive cultures revealed mainly skin-derived bacteria, but in 15 sample Bacillus cereus (7%). In 9.4% (=19) of the samples with a postive BacTalert® signal, bacterial growth could not be confirmed. None of the PLT units with a postive bacterial culture that were already administered to patients caused clinically significant transfusion reactions. Nevertheless, two neutropenic patients due to leukemia treatment, suffered from life-threatening B. cereus sepsis after PLT transfusion. In both cases, B.cereus was cultured from the PLT bags, whereas the BacTalert® tested samples remained negative. Conclusions: Issuing pooled PLT units on a negative-to-date basis for bacterial screening resulted in a significant amount of recall procedures. The BacTalert® system failed to detect B. cereus contamination in at least two cases that resulted in sever transfusion reactions. Other strategies, including pathogen reduction, might be applied to guarantee a better degree of bacterial safety.
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Francy, Donna S., Erin A. Stelzer, Amie M. G. Brady, Carrie Huitger, Rebecca N. Bushon, Hon S. Ip, Michael W. Ware, Eric N. Villegas, Vicente Gallardo, and H. D. Alan Lindquist. "Comparison of Filters for Concentrating Microbial Indicators and Pathogens in Lake Water Samples." Applied and Environmental Microbiology 79, no. 4 (December 21, 2012): 1342–52. http://dx.doi.org/10.1128/aem.03117-12.
Повний текст джерелаАнотація:
ABSTRACTBacterial indicators are used to indicate increased health risk from pathogens and to make beach closure and advisory decisions; however, beaches are seldom monitored for the pathogens themselves. Studies of sources and types of pathogens at beaches are needed to improve estimates of swimming-associated health risks. It would be advantageous and cost-effective, especially for studies conducted on a regional scale, to use a method that can simultaneously filter and concentrate all classes of pathogens from the large volumes of water needed to detect pathogens. In seven recovery experiments, stock cultures of viruses and protozoa were seeded into 10-liter lake water samples, and concentrations of naturally occurring bacterial indicators were used to determine recoveries. For the five filtration methods tested, the highest median recoveries were as follows: glass wool for adenovirus (4.7%); NanoCeram for enterovirus (14.5%) and MS2 coliphage (84%); continuous-flow centrifugation (CFC) plus Virocap (CFC+ViroCap) forEscherichia coli(68.3%) andCryptosporidium(54%); automatic ultrafiltration (UF) for norovirus GII (2.4%); and dead-end UF forEnterococcus faecalis(80.5%), avian influenza virus (0.02%), andGiardia(57%). In evaluating filter performance in terms of both recovery and variability, the automatic UF resulted in the highest recovery while maintaining low variability for all nine microorganisms. The automatic UF was used to demonstrate that filtration can be scaled up to field deployment and the collection of 200-liter lake water samples.
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Magalhaes, Renata Ferreira, Luiza Helena Urso Pitassi, Marizete Salvadego, Aparecida Machado Moraes, Maria Lourdes Barjas-Castro, and Paulo Eduardo Ferreira Velho. "Bartonella Henselae Survives after the Storage Period of the Red Blood Cell Units." Blood 110, no. 11 (November 16, 2007): 2906. http://dx.doi.org/10.1182/blood.v110.11.2906.2906.
Повний текст джерелаАнотація:
Abstract Introduction: The genus Bartonella comprises a unique group of emerging, Gram-negative, facultative intracellular bacteria, which can cause Carrión’s disease, trench fever, cat scratch disease and bacillary angiomatosis. Man is a reservoir host of Bartonella species. Ten to 15% of the populations in areas that are hyperendemic for Carrión’s disease are asymptomatic carriers of B. bacilliformis. In addition, positive serologic tests for B. henselae were found in 2 to 6% of Americans, 48% of Swiss, 19% of Germans, and 13.7% of Brazilians. Blood donors can be asymptomatic carrier of Bartonella spp. and the risk for transmission by transfusion should be considered. The aim of this study was to demonstrate that B. henselae remains viable in red blood cell (RBC) units at the end of the storage period. Methods: Two RBC units from healthy blood donors were collected in CPDA1 and each one split into two portions via a sterile connecting device. One bag from each split unit received experimentally B. henselae (Adolpho Lutz Institute, Sao Paulo, Brazil) and the second one served as a control. A brain and heart infusion (BHI) suspension of B. henselae colonies (Houston 1, American Type Culture Collection, Rockville, MD, ATCC 49882T) was used to obtain equivalence with tube 10 of McFarland scale, which determined an initial suspension with approximately 3×109 colony-forming units (CFU)/mL. This bacterial suspension was inoculated (0,33mL of the initial suspension) in one split RBC unit using a Sampling Site Coupler. Thus approximately 5,5×106 CFU of B. henselae were obtained per mL of RBC concentrate. All split units were stored (4 ±2°C) for 35 days. Aliquots were collected weekly using, Sample Site Coupler for, culture in dish with chocolate agar (incubated at 37°C in environment with 5% CO2), samples for blood culture bottles Bact/Alert (BioMérieux, Inc, USA) and Karnovisky medium for future evaluation by transmission electron microscopy. Results: All dishes with chocolate agar culture medium from infected units (seeded on days D0, D7, D14, D21, D28 and D35) presented growth of exuberant and mucoid colonies, after the fourth day of incubation. The electron microscopy from these samples showed typical Gram-negative cell wall in the interior of red blood cells. Samples from infected units presented negative blood culture bottles. All cultures from control units had negative results. Discussion: Bartonella ssp. is fastidious bacteria. Incubation for a short period of time and in standard medium does not allow for B. henselae growth as observed in the bottle culture of this study. Cultivation in blood-enriched media and incubation in environment with high CO2 levels of infected smears resulted positive. In conclusion, this study has demonstrated that B. henselae remain viable in RBC units during the storage period, at 4±2°C. These data reinforce the possibility of infection by transfusion of blood units collected from asymptomatic blood donors. Receptors of blood transfusion many times are or may become immunocompromissed, with risk of developing severe forms of bartonelloses.
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Ha, Y., A. Fessehaie, K. S. Ling, W. P. Wechter, A. P. Keinath, and R. R. Walcott. "Simultaneous Detection of Acidovorax avenae subsp. citrulli and Didymella bryoniae in Cucurbit Seedlots Using Magnetic Capture Hybridization and Real-Time Polymerase Chain Reaction." Phytopathology® 99, no. 6 (June 2009): 666–78. http://dx.doi.org/10.1094/phyto-99-6-0666.
Повний текст джерелаАнотація:
To improve the simultaneous detection of two pathogens in cucurbit seed, a combination of magnetic capture hybridization (MCH) and multiplex real-time polymerase chain reaction (PCR) was developed. Single-stranded DNA hybridization capture probes targeting DNA of Acidovorax avenae subsp. citrulli, causal agent of bacterial fruit blotch, and Didymella bryoniae, causal agent of gummy stem blight, were covalently attached to magnetic particles and used to selectively concentrate template DNA from cucurbit seed samples. Sequestered template DNAs were subsequently amplified by multiplex real-time PCR using pathogen-specific TaqMan PCR assays. The MCH multiplex real-time PCR assay displayed a detection threshold of A. avenae subsp. citrulli at 10 CFU/ml and D. bryoniae at 105 conidia/ml in mixtures of pure cultures of the two pathogens, which was 10-fold more sensitive than the direct real-time PCR assays for the two pathogens separately. Although the direct real-time PCR assay displayed a detection threshold for A. avenae subsp. citrulli DNA of 100 fg/μl in 25% (1/4 samples) of the samples assayed, MCH real-time PCR demonstrated 100% detection frequency (4/4 samples) at the same DNA concentration. MCH did not improve detection sensitivity for D. bryoniae relative to direct real-time PCR using conidial suspensions or seed washes from D. bryoniae-infested cucurbit seed. However, MCH real-time PCR facilitated detection of both target pathogens in watermelon and melon seed samples (n = 5,000 seeds/sample) in which 0.02% of the seed were infested with A. avenae subsp. citrulli and 0.02% were infested with D. bryoniae.
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Uhlmann, Julia, Manfred Rohde, Nikolai Siemens, Bernd Kreikemeyer, Peter Bergman, Linda Johansson, and Anna Norrby-Teglund. "LL-37 Triggers Formation of Streptococcus pyogenes Extracellular Vesicle-Like Structures with Immune Stimulatory Properties." Journal of Innate Immunity 8, no. 3 (December 8, 2015): 243–57. http://dx.doi.org/10.1159/000441896.
Повний текст джерелаАнотація:
Reports have shown that the antimicrobial peptide LL-37 is abundantly expressed but has limited bactericidal effect in Streptococcus pyogenes infections. At sub-inhibitory concentrations, LL-37 has been reported to alter virulence gene expression. Here, we explored the interaction of S. pyogenes strains with LL-37, focusing on bacterial growth, cell surface alterations and pro-inflammatory responses. Bioscreen turbidity measurements of strain 5448 cultured in the presence or absence of LL-37 confirmed the poor antimicrobial effect, and revealed a significant increase in turbidity of bacterial cultures exposed to sub-inhibitory concentrations of LL-37. However, this was not linked to increased bacterial counts. Electron microscopy of LL-37-exposed bacteria revealed the presence of vesicle-like structures on the bacterial surface. The vesicles stained positive for LL-37 and were released from the bacterial surface. Concentrated supernatants enriched in these structures had a broader protein content, including several virulence factors, compared to supernatants from untreated bacteria. The supernatants from LL-37-exposed bacteria were pro-inflammatory and elicited resistin and myeloperoxidase release from neutrophils. This is the first report on S. pyogenes extracellular vesicle-like structures formed at the bacterial surface in response to LL-37. The associated increased pro-inflammatory activity further implicates LL-37 as a potential factor involved in S. pyogenes pathogenesis.
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Zhao, Yu, Martien P. M. Caspers, Karin I. Metselaar, Paulo de Boer, Guus Roeselers, Roy Moezelaar, Masja Nierop Groot, Roy C. Montijn, Tjakko Abee, and Remco Kort. "Abiotic and Microbiotic Factors Controlling Biofilm Formation by Thermophilic Sporeformers." Applied and Environmental Microbiology 79, no. 18 (July 12, 2013): 5652–60. http://dx.doi.org/10.1128/aem.00949-13.
Повний текст джерелаАнотація:
ABSTRACTOne of the major concerns in the production of dairy concentrates is the risk of contamination by heat-resistant spores from thermophilic bacteria. In order to acquire more insight in the composition of microbial communities occurring in the dairy concentrate industry, a bar-coded 16S amplicon sequencing analysis was carried out on milk, final products, and fouling samples taken from dairy concentrate production lines. The analysis of these samples revealed the presence of DNA from a broad range of bacterial taxa, including a majority of mesophiles and a minority of (thermophilic) spore-forming bacteria. Enrichments of fouling samples at 55°C showed the accumulation of predominantlyBrevibacillusandBacillus, whereas enrichments at 65°C led to the accumulation ofAnoxybacillusandGeobacillusspecies. Bacterial population analysis of biofilms grown using fouling samples as an inoculum indicated that bothAnoxybacillusandGeobacilluspreferentially form biofilms on surfaces at air-liquid interfaces rather than on submerged surfaces. Three of the most potent biofilm-forming strains isolated from the dairy factory industrial samples, includingGeobacillus thermoglucosidans,Geobacillus stearothermophilus, andAnoxybacillus flavithermus, have been characterized in detail with respect to their growth conditions and spore resistance. Strikingly,Geobacillus thermoglucosidans, which forms the most thermostable spores of these three species, is not able to grow in dairy intermediates as a pure culture but appears to be dependent for growth on other spoilage organisms present, probably as a result of their proteolytic activity. These results underscore the importance of abiotic and microbiotic factors in niche colonization in dairy factories, where the presence of thermophilic sporeformers can affect the quality of end products.
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Mahmudov, G. B., A. Kh Saidova, and N. T. Mokhilova. "Modeling of fuzzy logic for control of the process of bacterial oxidation of concentrates in reactors with a mixer." Modern Innovations, Systems and Technologies 2, no. 2 (May 3, 2022): 0201–14. http://dx.doi.org/10.47813/2782-2818-2022-2-2-0201-0214.
Повний текст джерелаАнотація:
The multiplicity of chemical, biological, technological parameters and the nonlinear dependence in the extraction of metals in bacterial oxidation media complicate the mathematical modeling of these systems. This study was conducted to control the recovery of gold and iron from flotation concentrate in a stirred bioreactor using a fuzzy logic model. The experiments were carried out in the presence of a mixed culture of acidophilic bacteria (Lactobacillus acidophilus) at 42°C and a mixed culture of moderately thermophilic bacteria at 48°C. The input variables were: operation method, type of bacteria and time. The extracted gold and iron were the output. The connection between the specified input data and the output data was provided using the developed "IF-THEN" rules. The resulting fuzzy model showed a satisfactory prediction of gold and iron recovery and had a good correlation of experimental data with R-square (more than 0.97). The results of the study showed that fuzzy logic is a powerful and reliable tool for predicting nonlinear and time-varying bacterial oxidation processes.
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Khachatryan, Anna, Narine Vardanyan, Arevik Vardanyan, Ruiyong Zhang, and Laura Castro. "The Effect of Metal Ions on the Growth and Ferrous IronOxidation by Leptospirillum ferriphilum CC Isolated from Armenia Mine Sites." Metals 11, no. 3 (March 5, 2021): 425. http://dx.doi.org/10.3390/met11030425.
Повний текст джерелаАнотація:
The aim of this study is to investigate the potential of newly isolated strain Leptospirillum (L.) ferriphilum CC for bioleaching of pyrite and chalcopyrite in pure or mixed culture with other iron- and/or sulfur-oxidizing bacteria. In this paper, kinetics of ferrous iron (Fe2+) oxidation by newly isolated strain Leptospirillum (L.) ferriphilum CC was studied. The effect of initial Fe2+ in the concentration range of 50–400 mM on bacterial growth and iron oxidation was studied. It was shown that microbial Fe2+ oxidation was competitively inhibited by Fe3+. The influence of copper, zinc, nickel and cobalt ions on the oxidation of Fe2+ by L. ferriphilum CC was also studied. Minimal inhibitory concentrations (MIC) for each metal ion were determined. The toxicity of the ions was found to be as follows: Co > Zn > Ni > Cu. The comparison of iron oxidation kinetic parameters of L. ferriphilum CC with other strains of L. ferriphilum indicates the high potential of strain L. ferriphilum CC for biogenic regeneration of concentrated ferric iron (Fe3+) in bioleaching processes of ores and ore concentrates. Bioleaching tests indicated that the newly isolated L. ferriphilum CC can be a prospective strain for the bioleaching of sulfide minerals in pure culture or in association with other iron- and/or sulfur-oxidizing bacteria.
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Wu, Zeng Ling, Wei Zhang Kong, Jin Yan Liu, Zhi Wu, Shui Ping Zhong, and Yong Guan Zhu. "Adsorption Kinetics and Surface Characterization of Microorganisms Grown under Different Conditions." Advanced Materials Research 1130 (November 2015): 519–23. http://dx.doi.org/10.4028/www.scientific.net/amr.1130.519.
Повний текст джерелаАнотація:
The adsorption of bacteria onto minerals is the premise for bioleaching and plays an important role in minerals oxidation. Understanding of the adsorption kinetics onto the surface will give information on the effectiveness of bioleaching. Three kinds of mixed bacteria (Acidithiobacillus ferrooxidans, Leptospirillum ferrooxidans, Sulfobacillus) were cultured in different substrates - copper concentrate, elemental sulfur and ferrous iron and adsorbed onto different solid surface of elemental sulfur, silica and copper concentrate. Adsorption kinetics was examined and surface properties were investigated by Zeta-potential and FT-IR spectroscopy. Bacterial adsorption equilibrium data for bacteria grown on three different substrates were well fitted to Freundlich isotherms, indicating inhomogeneous and selective adsorption. Microorganisms grown on copper concentrate and S0 showed similar adsorption kinetics whereby cell adsorptions proceeded rapidly and reached equilibrium within 30 mins of interaction. With the average KF value of 46.2, most copper concentrate-grown cells were strongly adsorbed to three solid surfaces. Microorganisms grown on copper concentrate and S0 also showed higher hydrophobicity and higher isoelectric point (IEP) (pH 3.4-3.8) as compared to the soluble Fe2+-grown cells (pH 2.1), indicating higher amount of EPS and proteins on the surfaces. The FT-IR spectra indicated the presence of COOH, NH2, OH and PO4 groups on all cell surfaces. However, more proteinaceous compounds were found on cells grown on copper concentrate and S0 substrates.
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Pathak, Manju, and Danik Martirosyan. "Optimization of an effective growth medium for culturing probiotic bacteria for applications in strict vegetarian food products." Functional Foods in Health and Disease 2, no. 10 (October 30, 2012): 369. http://dx.doi.org/10.31989/ffhd.v2i10.75.
Повний текст джерелаАнотація:
Background: This study aimed to modify de Man Rogosa Sharpe culture medium (termed MRS) for selective cultivation of probiotics strain for the consumption by the strictly vegetarian human population. Vegetarian probiotic foods by definition must be free from all animal-derived ingredients. This not only includes the product ingredients but the probiotic inoculum as well. Probiotic starter cultures are traditionally grown and stored in media containing milk or meat-derived ingredients. The presence of these ingredients makes the probiotic cell concentrates unsuitable for use in vegetarian products and thus creates the need for a growth medium which is free from animal-derived ingredients. Present study investigated the growth of a strain of Lactobacillus lactis in MRS. The present invention relates in general to a bacterial culture media, and more specifically a complex microbial culture media, based on plant seed powder extract in place of animal extract for probiotic bacterial growth.Methods: Lactobacillus lactis, a probiotic, was grown in standard MRS culture medium as well as in our various test media (TM) containing various vegetal source in place of beef extract, yeast extract and peptone as in case of MRS. The inoculated culture mediums were incubated at 37C for 72 hours and growth of probiotic is recorded at regular intervals. The growth was recorded as Colony Forming Units (CFUs).Results: The best growth of probiotic is observed in TM 2. TM 2 is the leguminous seed extract. Starter culture mediums for probiotics or other bacteria primarily contain protein from animal source. The possibility of using vegetal protein from TM 2 extract in place of peptones and meat extract for the nitrogen supplementation of culture media for the growth of lactic acid bacteria has been demonstrated. Conclusion: The absolute vegetarian culture medium containing TM 2 is better than standard MRS for the growth of probiotics.Abbreviations: de Man Rogosa Sharpe (MRS), Colony Forming Units (CFU), test media (TM), National Dairy Research Institute (NDRI), Tamarind seed powder (TSP), solid-state fermentation (SSF), Lactobacillus casei Shirota (LcS)Keywords: probiotics, lactic acid bacteria, vegetarian
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Vukovic, Milovan, Nada Strbac, Miroslav Sokic, Vesna Grekulovic, and Vladimir Cvetkovski. "Bioleaching of pollymetallic sulphide concentrate using thermophilic bacteria." Chemical Industry 68, no. 5 (2014): 575–83. http://dx.doi.org/10.2298/hemind130905087v.
Повний текст джерелаАнотація:
An extreme thermophilic, iron-sulphur oxidising bacterial culture was isolated and adapted to tolerate high metal and solids concentrations at 70?C. Following isolation and adaptation, the culture was used in a batch bioleach test employing a 5-l glass standard magnetic agitated and aerated reactor, for the bioleaching of a copper-lead-zinc collective concentrate. The culture exhibited stable leach performance over the period of leach operation and overall copper and zinc extractions higher than 97%. Lead sulphide is transformed into lead sulphate remaining in the bioleach residue due to the low solubility in sulphate media. Brine leaching of bioleach residue yields 95% lead extraction.
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Yamasaki, Takashi, Yuka Miyazaki, and Yuto Kamei. "Isolation of bacteria that decompose major polysaccharides in the cell wall of the marine red alga Porphyra yezoensis and their application for protoplast production." Canadian Journal of Microbiology 44, no. 8 (August 1, 1998): 789–94. http://dx.doi.org/10.1139/w98-070.
Повний текст джерелаАнотація:
We attempted to screen for bacteria that could decompose major polysaccharides in the cell wall of the marine red alga Porphyra yezoensis from Porphyra-culturing farms to enable simple and high-yield preparation of protoplasts with the crude enzyme from a single bacterial origin. A total of 275 positive bacterial strains were isolated by enrichment culture supplemented with Porphyra powder or xylan. Nine strains were capable of producing protoplasts from Porphyra thalli in a 10-fold concentrated culture broth. These strains were identified as two Flavobacterium spp., one Alteromonas sp., four Acinetobacter spp., and two Vibrio spp. The crude enzymes of these bacteria could release 106 protoplast cells from 0.1 g of Porphyra thalli. The crude enzyme from Alteromonas sp. strain ND137 produced the most protoplasts among the nine strains tested. Moreover, an assay of the crude enzymes from the nine bacterial strains for glycosidase activity against four major polysaccharides (xylan, mannan, porphyran, and cellulose) of P. yezoensis revealed strong decomposing activity against these polysaccharides. Xylanase activity was highest in these glycosidases, suggesting that xylanase might be a very important factor in producing protoplasts from Porphyra thalli.Key words: Porphyra, cell wall, bacteria, decomposing polysaccharide.
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Chen, Lianmin, Yang Luo, Hongrong Wang, Shimin Liu, Yizhao Shen, and Mengzhi Wang. "Effects of Glucose and Starch on Lactate Production by Newly Isolated Streptococcus bovis S1 from Saanen Goats." Applied and Environmental Microbiology 82, no. 19 (July 29, 2016): 5982–89. http://dx.doi.org/10.1128/aem.01994-16.
Повний текст джерелаАнотація:
ABSTRACTWhen ruminants are fed high-concentrate diets,Streptococcus bovisproliferates rapidly and produces lactate, potentially causing rumen acidosis. Understanding the regulatory mechanisms of the metabolism of this species might help in developing dietary strategies to alleviate rumen acidosis.S. bovisstrain S1 was newly isolated from the ruminal fluid of Saanen dairy goats and then used to examine the effects of glucose and starch on bacterial metabolism and gene regulation of the organic acid-producing pathway in cultures at a pH of 6.5. Glucose or starch was added to the culture medium at 1 g/liter, 3 g/liter (close to a normal range in the rumen fluid), or 9 g/liter (excessive level). Lactate was the dominant acid produced during the fermentation, and levels increased with the amount of glucose or starch in a dose-dependent manner (P< 0.001). The production of formate and acetate in the fermentation media fluctuated slightly with the dose but accounted for small fractions of the total acids. The activities of lactate dehydrogenase (LDH) and α-amylase (α-AMY) increased with the starch dose (P< 0.05), but the α-AMY activity did not change with the glucose dose. The relative expression levels of the genesldh,pfl(encoding pyruvate formate lyase),ccpA(encoding catabolite control protein A), and α-amywere higher at a dose of 9 g/liter than at 1 g/liter (P< 0.05). Expression levels ofpfland α-amygenes were higher at 3 g/liter than at 1 g/liter (P< 0.05). The fructose 1,6-diphosphate (FDP) concentration tended to increase with the glucose and starch concentrations. In addition, theS. bovisS1 isolate fermented glucose much faster than starch. We conclude that the quantities of glucose and soluble starch had a major effect on lactate production due to the transcriptional regulation of metabolic genes.IMPORTANCEThis work used a newly isolatedS. bovisstrain S1 from the rumen fluid of Saanen goats and examined the effects of glucose and soluble starch on organic acid patterns, enzyme activity, and expression of genes forin vitrofermentation. It was found that lactate was the dominant product fromS. bovisstrain S1, and the quantities of both glucose and starch in the medium were highly correlated with lactate production and with the corresponding changes in associated enzymes and genes. Therefore, manipulating the metabolic pathway ofS. bovisto alter the dietary level of readily fermentable sugar and carbohydrates may be a strategy to alleviate rumen acidosis.
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RIDWAN, RONI, IMAN RUSMANA, YANTYATI WIDYASTUTI, KOMANG G. WIRYAWAN, BAMBANG PRASETYA, MITSUO SAKAMOTO, and MORIYA OHKUMA. "Bacteria and methanogen community in the rumen fed different levels of grass-legume silages." Biodiversitas Journal of Biological Diversity 20, no. 4 (March 22, 2019): 1055–62. http://dx.doi.org/10.13057/biodiv/d200417.
Повний текст джерелаАнотація:
Abstract. Ridwan R, Rusmana I, Widyastuti Y, Wiryawan KG, Prasetya B, Sakamoto M, Ohkuma M. 2019. Bacteria and methanogen community in the rumen fed different levels of grass-legume silages. Biodiversitas 20: 1055-1062. This study aimed to investigate the effects of dietary grass-legume silages on the microbial community by using a culture-independent approach. Treatments consisted of R0: 50% Pennisetum purpureum and 50 % concentrate; R1: 20% P. purpureum, 50 % concentrate, and 30% grass-legumes silage; R2: 20% P. purpureum, 35 % concentrate, and 45% grass-legumes silage; and R3; 20% P. purpureum, 20 % concentrate, and 60% grass-legumes silage. The rumen fluid obtained from fistulated cattle was used for T-RFLP, 16S rDNA clone library, and qPCR analyses. The results indicated that bacterial diversity was dominated by Bacteroidetes, Firmicutes, and methanogen by Methanobacteriales, based on partial 16S rDNA sequences. The microbial communities were dominated by Prevotella brevis, P. ruminicola, Succiniclasticum ruminis, and Methanobrevibacter ruminantium, M. smithi, M. thueri, and M. millerae. The increasing silage diet in a rumen suppressed methanogenesis by reducing population distribution of Methanobacteriales, directly or indirectly, by reducing the diversity of bacterial populations. Generally, the increase silage in the diet changed the bacterial and methanogen community. Grass-legume silage diets of less than 45% are potential for ruminant diet to reduce methane production by a decrease of 4% in the relative distribution of methanogens in the rumen.
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Shimoni, Moria, Noel Axelrod, David Nuttman, Jerome Orlin, and Bruria Shalev. "A Non-Invasive Method for the Detection of Bacterial Contamination of Platelet Apheresis Concentrates." Blood 120, no. 21 (November 16, 2012): 1177. http://dx.doi.org/10.1182/blood.v120.21.1177.1177.
Повний текст джерелаАнотація:
Abstract Abstract 1177 Introduction: Allogeneic blood transfusion is a potential source of infection via a variety of known and unknown transmissible agents. Over the last three decades, pre-transfusion donor screening for viral agents has led to a dramatic reduction in the risk of virally transmitted diseases. Bacterial contamination, on the other hand, has proved more difficult to address and remains the most prevalent transfusion-associated infectious risk. This is especially true for platelet components whose storage conditions (22°C, for up to 5 days, with agitation) facilitate bacterial proliferation throughout the storage period. Reported here are the results of initial testing using a novel, noninvasive, real time, rapid screening device for the detection of bacterial contamination of platelet units. Methods and Results: This detection method is based on measuring absorption of an infrared beam that is transmitted through the gaseous atmosphere above the platelets. Living microorganisms produce metabolic gases such as carbon dioxide (CO2) during respiration. By means of infrared absorption the concentration of metabolic gases can be measured inside the platelet storage bag. The methodology consists of an apparatus which uses a tunable monochromatic mid-IR light source, IR detector and electronic signal processor. The light source emits light in frequency range overlapping at least with one absorption line of CO2gas. Use of the tunable light source allows the determination of metabolic gas concentration within the container without etalon use. In this method, the light from the light source is transmitted through the gaseous part of storage bag is measured by means of an IR detector. The concentration of CO2gas inside the platelet bag is determined by equilibrium conditions between the release rate and the rate of diffusion of the metabolic gases through the bag walls. Staphylococcus epidermidis obtained from the American Type Culture Collection (ATCC) were used to contaminate platelets bags. The bacterially inoculated apheresis platelets were agitated at 22°C and measurements were performed using a laser instrument. Each platelet unit was measured before and during bacterial contamination. Samples were taken from each contaminated platelet bag and a standard culture plate count was used for determining bacterial concentration in the platelet medium. Using this device we have succeeded to detect bacterial concentration of above 3*106 CFU/mL staphylococcus epidermidis (Figure 1). Conclusions: Although methods to detect platelet bacterial contamination have received much attention, bacterial contamination of platelet components remains a persistent problem. The methodology described in this report detects staphylococcus epidermidis in apheresis platelet bags. The method allows for testing in real time - at issue or during storage, and it provides immediate results. This device is expected to be successful in detecting most prevalent types of bacteria strains. The test is easy to perform and does not require pre-incubation of samples or handling of the bag's contents. The device is specific and sensitive, allowing bacteria screening, ensuring increased safety of platelet transfusions. The device is able to detect bacteria in platelets, and other blood constituents, through the storage bag, without contacting, harming, or handling the bag's contents. Since there is no direct interaction of the laser light beam with the platelet media and the laser power is low (approximately 10 mW) thermal effects are avoided. By allowing real-time, sensitive detection of bacterial contamination of platelet products, wastage can be reduced, platelet shortage can be alleviated and the adverse outcomes associated with platelet transfusion contamination can be prevented. Further studies are required to evaluate the sensitivity limits for the detection of other bacterial strains that have been reported to contaminate platelet products. Disclosures: No relevant conflicts of interest to declare.
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Malkova, A. V., I. Yu Evdokimov, M. V. Shirmanov, A. N. Irkitova, and D. E. Dudnik. "Development of a probiotic for animals and aquaculture based on Bacillus toyonensis B-13249 and Bacillus pumilus B-13250 strains." Proceedings of Universities. Applied Chemistry and Biotechnology 11, no. 3 (October 7, 2021): 393–402. http://dx.doi.org/10.21285/2227-2925-2021-11-3-393-402.
Повний текст джерелаАнотація:
Abstract: This article aims to develop a probiotic for animals and aquaculture based on the Bacillus toyonensis B-13249 and Bacillus pumilus B-13250 strains. The selection of a nutrient medium was conducted for cultivating the inoculum of these microorganisms. Several bacteria fermentations of the Bacillus genus were performed in biological reactors with a capacity of 15 and 250 l. A technology for obtaining a finished probiotic for animals and aquaculture was developed. The results indicate that L-broth is the most optimal nutrient medium for cultivating the studied strains. The cultivation of B. toyonensis B-13249 and B. pumilus B-13250 strains in fermenters revealed that sporulation begins after 4–8 hours of fermentation. In contrast to the vegetative medium, the fermentative medium helped the bacilli develop a higher optical density (the maximum value in the B. pumilus strain – 2.400±0.149), pH value (maximum value in the B. toyonensis strain – 8.483±0.609) and titer (at least 1010 CFU/g). After 20–24 hours of incubation, both strains of bacilli in the fermenter, almost completely pass into endospores, which serve as a signal for the start of biomass centrifugation. This was indicated by the following: from a 15 l fermenter – 83.3±6.1 g of concentrate, from a 250 l fermenter – 499.8±51.4 g. The number of bacilli in a concentrated state was at least 1·1011 CFU/g for both strains. Obtaining a finished preparation required mixing bacterial concentrates with maltodextrin to a titer of at least 1·1010 CFU/g. The number of bacteria in the preparation checked every month during the year, recorded no value less than 1·1010 CFU/g. Thus, L-broth is most favorable for growing the mother culture of the B. toyonensis B-13249 and B. pumilus B-13250 strains, and fermentative nutrient medium – for the cultivation in fermenters. The expiry date of the bacilli-based biological preparation is at least 12 months, during which the drug’s polycomponence, color and consistency are preserved, in addition to the bacteria titer (at least 1·1010 CFU/g) and their viability.
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Someh Sarai Sabet, Shahrzad, Teena Dadgar, and Hadi Bazzazi. "Antibacterial Effect of Platelet Concentrate and Amniotic Membrane as two Human-derived Biological Products." Jundishapur Journal of Medical Sciences 20, no. 3 (August 1, 2021): 262–71. http://dx.doi.org/10.32598/jsmj.20.3.2058.
Повний текст джерелаАнотація:
Background and Objectives: Regarding the increasing spread of bacterial resistance, researchers are always interested in finding effective antibiotics of natural origin. The amniotic membrane and blood platelet concentrate are two biological products with an antibacterial effect. The present study aimed to investigate the antibacterial effect of the biological products on broad-spectrum MBL-producing Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus. Subjects and Methods The amniotic membrane, blood platelet concentrate, S. aureus, and P. aeruginosa isolates were collected from hospitals in Gorgan City, Iran. The isolates were identified using the biochemical tests. The methicillin-resistant S. aureus and MBL-producing P. aeruginosa strains were collected by the combined disk and iodometric methods. The antibacterial effects of platelet serial dilutions of bacteria were prepared using 0.5 McFarland turbidity standard suspension in tubes. Then, different concentrations of bacteria were mixed with platelet. After four different encounter durations, a sample was obtained and cultured on medium and bacterial growth was examined. The amniotic membrane was assessed by disk diffusion methods. Results The results showed that all isolates of P. aeruginosa and S. aureus were MBL producers. The platelet concentrate showed the antibacterial effect on all S. aureus isolates, whereas it lacked such an effect on P. aeruginosa isolates. It indicates that the amniotic membrane has an antibacterial effect on all S. aureus and P. aeruginosa isolates. Conclusion The amniotic membrane and platelet concentrate showed high antimicrobial potential against multidrug-resistant S. aureus and P. aeruginosa pathogens. Therefore, human-derived natural products can be used as a source for efficient antibiotics.
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Yang, Danting, Haibo Zhou, Nicoleta E. Dina, and Christoph Haisch. "Portable bacteria-capturing chip for direct surface-enhanced Raman scattering identification of urinary tract infection pathogens." Royal Society Open Science 5, no. 9 (September 2018): 180955. http://dx.doi.org/10.1098/rsos.180955.
Повний текст джерелаАнотація:
Acute urinary tract infections (UTIs) are one of the most common nosocomial bacterial infections, which affect almost 50% of the population at least once in their lifetime. UTIs may lead to lethal consequences if they are left undiagnosed and not properly treated. Early, rapid and accurate uropathogens detection methods play a pivotal role in clinical process. In this work, a portable bacteria-grasping surface-enhanced Raman scattering (SERS) chip for identification of three species of uropathogens ( Escherichia coli CFT 073, Pseudomonas aeruginosa PAO1 and Proteus mirabilis PRM1) directly from culture matrix was reported. The chip was firstly modified with a positively charged NH 3 + group, which enables itself grasp the negatively charged bacterial cells through the electrostatic adsorption principle. After the bacterial cells were captured by the chip, concentrated Ag nanoparticles (NPs) were used to obtain their Raman fingerprint spectra with recognizable characteristic peaks and good reproducibility. With the help of chemometric method such as discriminant analysis (DA), the SERS-based chip allows a rapid, successful identification of three species of UTI bacteria with a minimal bacterial concentration (10 5 cells ml −1 ) required for clinical diagnostics. In addition, this chip could spot the bacterial SERS fingerprints information directly from LB culture medium and artificial urine without sample pre-treatment. The portable bacteria-grasping SERS-based chip provides a possibility for fast and easy detection of uropathogens, and viability of future development in healthcare applications.
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Wyn-Jones, A. P., J. Watkins, C. Francis, M. Laverick, and J. Sellwood. "Enteric viruses in drinking water supplies." Water Supply 2, no. 3 (July 1, 2002): 17–22. http://dx.doi.org/10.2166/ws.2002.0080.
Повний текст джерелаАнотація:
Two rural spring drinking water supplies were studied for their enteric virus levels. In one, serving about 30 dwellings, the water was chlorinated before distribution; in the other, which served a dairy and six dwellings the water was not treated. Samples of treated (40 l) and untreated (20 l) water were taken under normal and heavy rainfall conditions over a six weeks period and concentrated by adsorption/elution and organic flocculation. Infectious enterovirus in concentrates was detected in liquid culture and enumerated by plaque assay, both in BGM cells, and concentrates were also analysed by RT-PCR. Viruses were found in both raw water supplies. Rural supplies need to be analysed for viruses as well as bacterial and protozoan pathogens if the full microbial hazard is to be determined.
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Darmawati, Sri, Eko Naning Sofyanita, and Sri Sinto Dewi. "The Effectiveness of Wild Honey In Inhibiting The Growth of Bacterium on The Positive Widal Blood Culture of Enterobacteriaceae Familia." Jaringan Laboratorium Medis 1, no. 2 (November 1, 2019): 91–97. http://dx.doi.org/10.31983/jlm.v1i2.5885.
Повний текст джерелаАнотація:
Honey is a product produced by bees which is believed has many benefits in the medical field. Wild honeys are more natural than livestock honey, and it has high antimicroba activities, but the effect of the antimicroba towards the bacteria on the positive widal blood culture of Enterobacteriaceae familia member was not clear yet. This research was to find out The effectiveness of wild honey in inhibiting the growth of bacteria on the positive widal blood culture of Enterobacteriaceae familia member. Method in this research was an experimental research which was using combination of diffusion and draw well method using Klebsiella pneumonia, Esherichia coli, Salmonella typhi, Serratia marcescens, and Enterobacter cloacae bacteria sample. Wild honey as a test solution with a 25%, 40%, 55%, 70%, 85% and 100% concentrate. The result is that wild honey is effective to inhibit the growth of the Enterobacteriaceae bacteria familia, the inhibition zone which is performed on the 70% Nutrien Agar Plate (NAP) concentrate medium is a minimal concentrate that sensitive to all bacteria with the inhibition zone similar to Kloramfinekol antibiotics. S. typhi is sensitive to all wild honey concentrate within 26,5mm, 29mm, 31,5mm, 32mm, 35mm, and 38mm inhibition zone. Wild honey on E.coli and Serratia marescens is sensitive in all concentrate except on the 25% concentrate. On the Klebsiella pneumonia the wild honey is sensitive on the 70%, 85%, and 100% concentrate while on the Enterobacter cloacae the wild honey is sensitive on 55%, 70%, 85% and 100% concentrate. Conclusion : wild honey is effective to inhibit bacteria growth on the positive widal blood culture of Enterobacteriaceae familia member and there are effect of various wild honey concentrate with the growth of Enterobacteriaceae bacteria which the higher concentrate of the wild honey, the greater inhibition potency towards the bacteria.
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Toranzos, Gary A., and Abdiel J. Alvarez. "Solid-phase polymerase chain reaction: applications for direct detection of enteric pathogens in waters." Canadian Journal of Microbiology 38, no. 5 (May 1, 1992): 365–69. http://dx.doi.org/10.1139/m92-062.
Повний текст джерелаАнотація:
The techniques in current use for detection of pathogens in environmental samples are restricted to those organisms whose replication in either culture media or cell culture is feasible. These methods lack the selectivity and sensitivity necessary for their unequivocal detection and identification. We have developed an assay for the detection of bacterial cells in large volumes of water. Low concentrations of cells containing target sequences were concentrated on membrane filters and were subjected to amplification directly using a stepwise polymerase chain reaction. This procedure, together with nucleic acid probes, has enhanced the limit of detection to the level of a single bacterial cell. This technique could be used for the detection of any bacteria or virus in water or air. Key words: polymerase chain reaction, waterborne pathogens, water.
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Pathirana, Hansani N. K. S., Sudu H. M. P. Wimalasena, Benthotage C. J. De Silva, Sabrina Hossain, and Gang-Joon Heo. "Antibacterial activity of lime (Citrus aurantifolia) essential oil and limonene against fish pathogenic bacteria isolated from cultured olive flounder (Paralichthys olivaceus)." Archives of Polish Fisheries 26, no. 2 (June 1, 2018): 131–39. http://dx.doi.org/10.2478/aopf-2018-0014.
Повний текст джерелаАнотація:
Abstract The antibacterial activity of lime (Citrus aurantifolia) essential oil (LEO) and limonene was tested against seven Gram-negative and nine Gram-positive fish pathogenic bacteria isolated from cultured olive flounder, Paralichthys olivaceus (Temminck & Schlegel) in Korea. Limonene was >99% concentrated and LEO consisted of eleven chemical compounds including 56.22% of limonene. Disk diffusion assay, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) tests were done. LEO and limonene inhibited the growth of both Gram-negative and Gram-positive bacteria. LEO and limonene (MBC/MIC= 2-8) were both bactericidal and bacteriostatic for the strains tested. In every fish pathogenic bacteria, the inhibition zone diameter (IZD) increased in proportion to the oil concentration and the maximum effect was found at 100% (V/V) concentrations of LEO and limonene. The antibiogram pattern indicated that all the bacterial strains, excluding three strains of S. iniae (S186, S530, and S131), showed resistance to one or more antibiotics. The percentage of the relative inhibition zone diameter (RIZD %) exhibited high values at higher concentrations of all the agents. Since antibacterial activities of LEO and limonene were considerably effective against fish pathogenic bacteria, they could be used as alternatives to treat bacterial infections in aquaculture.
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Brychcy, Ewa, Andrzej Jarmoluk, and Krzysztof Marycz. "Impact of low-concentrated acidic electrolysed water obtained by membrane electrolysis on the decontamination of meat microbiota." Bulletin of the Veterinary Institute in Pulawy 59, no. 3 (September 1, 2015): 369–76. http://dx.doi.org/10.1515/bvip-2015-0055.
Повний текст джерелаАнотація:
AbstractThe influence of acidic electrolysed water (AEW) treatment on inactivation of pure bacterial cultures inoculated onto the surface of agarised media and surface microbiota of pork meat were examined. Low-concentrated AEW (low concentration of sodium chloride and low current electrolysis) was generated by electrolysis (5 or 10 min) of 0.001% or 0.01% NaCl solution. The number of viable microorganisms was determined using a plate count method. The effect of AEW on bacterial cell morphology were investigated using scanning electron microscopy (SEM). After treatment with AEW, a significant, about 3.00 log reduction ofPseudomonas fluorescens, Yersinia enterocolitica, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Listeria monocytogenes,andMicrococcus luteuspopulations was observed. In the AEW treatment of pork, the highest reduction of total number of microorganisms (2.1 log reduction), yeast and moulds (2.5-2.6 log reduction), and psychrotrophs (more than 1 log reduction) was observed after spraying with 0.001% NaCl subjected to 10 min electrolysis. SEM revealed disruption and lysis ofE. coliandS. aureuscells treated with AEW, suggesting a bactericidal effect. Higher available chlorine concentration (0.37-8.45 mg/L), redox potential (863.1-1049.8 mV), and lower pH (2.73-3.70) had an influence on the shape of bacteria and the number of breaks in the bacterial membrane.
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Soto, E. C., D. R. Yáñez-Ruiz, G. Cantalapiedra-Hijar, A. Vivas, and E. Molina-Alcaide. "Changes in ruminal microbiota due to rumen content processing and incubation in single-flow continuous-culture fermenters." Animal Production Science 52, no. 9 (2012): 813. http://dx.doi.org/10.1071/an11312.
Повний текст джерелаАнотація:
The aim of this study was to investigate the impact of rumen content manipulation and its incubation in an in vitro system on the abundance of some microbial groups and the bacterial diversity of goat rumens. Animals and single-flow continuous-culture fermenters were fed diets differing in forage to concentrate ratio (70 : 30; LC and 30 : 70; HC). Rumen contents were sampled after animals’ adaptation to the experimental diets, processed for inoculum preparation and inoculated into fermenters. Fermenter contents were sampled 1 and 7 days after inoculation. Total bacteria, Fibrobacter succinogenes, fungi and methanogen abundances were lower in the fermenter than in goat rumens, but no differences were found for Ruminococcus flavefaciens. The abundances of all these microorganisms were similar at 1 and 7 days of rumen content incubation in fermenters. Bacterial species richness did not change due to rumen content processing or the in vitro incubation. Shannon–Wiener index and Pielou evenness were lower in the fermenter than in rumen only when the enzyme HaeIII was used in terminal-restriction fragment length polymorphism analysis. Non-metric multidimensional scaling analysis, both in denaturing gradient gel electrophoresis and terminal-restriction fragment length polymorphism, showed a segregation of in vivo and in vitro samples, but no trends of grouping for fermenter samples was observed. The HC diet promoted higher abundance of total bacteria than LC in rumen but not in fermenters. Diet only had an effect on bacterial diversity when the enzyme HaeIII was considered. Rumen content processing and incubation in fermenters caused an important decline of the studied ruminal microbial groups although bacterial community structure and diversity did not significantly change.
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Abela, Mark, and Lolito Bestil. "Effects of Cultured Yeast Supplementation on Growing Kids Fed With Napier Grass-Concentrate Ration." Science and Humanities Journal 10, no. 1 (December 1, 2013): 1–15. http://dx.doi.org/10.47773/shj.1998.101.1.
Повний текст джерелаАнотація:
An In vivo experiment was conducted to assess the effects of live yeast supplementation on the performance of six-month-old young goats. Specifically, it investigated the effects of cultured yeast (Saccharomyces cerevisiae) supplementation of the dry matter intake, growth performance, fluctuation in ruminal fluid pH and rumen bacterial count, as well as on the digestibility of dry matter, organic matter, and crude protein of the napier grass-concentrate ration. The addition of cultured yeast at two grams/ 10 mL distilled water generally increased dry matter intake and weight gain of the young goats, but did not significantly affected bacterial count and ruminal fluid pH. The digestibility of dry matter, organic matter, and crude protein of the napier grass-concentrate ration increased with the addition of cultured yeast. Yeast supplementation of one gram/ 10 mL distilled water enhaced nutrient intake and utilization of the napier grass-concentrate ration.
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Yatsiuk, K. M., M. I. Feodorovska, and R. V. Kutsyk. "The investigation of the cranberry (Vaccinium oxycoccos L.) concentrated juice antimicrobial activity." Farmatsevtychnyi zhurnal, no. 1 (August 14, 2018): 84–92. http://dx.doi.org/10.32352/0367-3057.1.17.11.
Повний текст джерелаАнотація:
The urinary system infections is one of the most common diseases of the genitourinary system in women. Of particular interest in the prevention and treatment of chronic cystitis is the consumption of the cranberry (Vaccinium oxycoccos L.) fruits. This plant has long been used in urological practice due to the content of proantocianidins, flavonoids, organic acids (benzoic, citric, quinic, ursolic), pectin substances, vitamins, microelements etc. Numerous clinical studies (including randomized, double-blind, placebo-controlled) reveal statistically reliable efficiency of cranberry juice in the forms of concentrates, cocktails and capsules to urinary system infections prevention in women.
Since the main pathogens of urinary system infections are Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, Staphylococcus aureus, the aim of our work was to study the antimicrobial properties of the cranberry concentrated juice.
Comparative testing of antimicrobial activity was performed using micromethod of diffusion in agar.
The carried out study indicates that the concentrated juice maintains antimicrobial properties to the most common uropathogenic microorganisms. Effective antimicrobial concentration was found according with analysis of microbial cultures growth curves in a nutrient medium with various juice dilutions. Gram-positive bacteria (S. aureus, E. faecalis) are more sensitive to the cranberry concentrated juice than gram-negative (E. coli and P. aeruginosa).
The adhere ability to a solid surface with the subsequent formation of biofilm is an important factor in the uropathogenic bacteria virulence. Therefore, the next step was to study the effect of cranberry juice biologically active compounds on the biofilms formation in the uropathogenic bacteria broth cultures. It was determined that cranberry juice suppresses the biofilm formation of S. aureus with the greatest intensity. It was observed the 45,3–55,8% reduction of the biofilm creating intensity in the presence of the condensed juice subbacteriostatic dilutions. When the condensed juice was diluted as 1:160, inhibition of E. faecalis biofilm formation ability on 44,90% was detected. The effect of cranberry biologically active compounds on the biofilms formation by gram-negative bacteria was observed in the range of 20%.
Thus, the obtained cranberry concentrated juice can be recommended as the remedy for application in prevention of recurrent urinary system infections.
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Lee, C. K., P. L. Ho, K. Y. Lee, G. T. F. Tsui, E. Chua, W. C. Tsoi, and C. K. Lin. "Value of anaerobic culture in bacterial surveillance program for platelet concentrates." Transfusion 48, no. 12 (December 2008): 2606–11. http://dx.doi.org/10.1111/j.1537-2995.2008.01887.x.
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Hoorzook, K. B., and T. G. Barnard. "Culture independent DNA extraction method for bacterial cells concentrated from water." MethodsX 9 (2022): 101653. http://dx.doi.org/10.1016/j.mex.2022.101653.
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