The impact of growth history and flagellation on the adhesion of variousListeria monocytogenesstrains to polystyrene

2009 ◽  
Vol 55 (2) ◽  
pp. 189-196 ◽  
Author(s):  
Odile Tresse ◽  
Véronique Lebret ◽  
Dominique Garmyn ◽  
Olivier Dussurget

The contribution of growth history and flagella to adhesion of Listeria monocytogenes was analysed. An in-frame deletion on the flagellin encoding gene (flaA) was performed in L. monocytogenes EGD-e to compare its adhesion ability with the parental strain, after cultivation at various pH values and temperatures. The pH, as well as the temperature, affected the adhesion of L. monocytogenes EGD-e. In addition, the adhesion of L. monocytogenes EGD-e was reduced in energy-depressed cells. Conversely, the physicochemical bacterial surface characteristics affected by growth history did not influence the adhesion. Adhesion variations observed among environmental and clinical strains was attributed to the flagella. The naturally aflagellated strains resulted in an adhesion capacity similar to that observed for mutants and parental strains cultivated under flagellum expression repressing conditions. However, L. monocytogenes is able to adhere to inert surfaces through a residual adhesion process without flagella. All these observations emphasize the importance to consider the food environmental factors in the risk assessment of L. monocytogenes in food industry.

2002 ◽  
Vol 65 (3) ◽  
pp. 534-539 ◽  
Author(s):  
GABRIELA ZÁRATE ◽  
VILMA I. MORATA de AMBROSINI ◽  
ADRIANA PEREZ CHAIA ◽  
SILVIA N. GONZÁLEZ

Adhesion to the intestinal mucosa is a desirable property for probiotic microorganisms and has been related to many of their health benefits. In the present study, 24 dairy Propionibacterium strains were assessed with regard to their hydrophobic characteristics and their autoaggregation and hemagglutination abilities, since these traits have been shown to be indicative of adherence in other microorganisms. Six strains were further tested for their capacity to adhere to ileal epithelial cells in vitro and in vivo. The results of the study showed that propionibacteria were highly hydrophilic, and hemagglutination and autoaggregation were properties not commonly found among these microorganisms. No relationship was found between surface characteristics and adhesion ability, since hemagglutinating, autoaggregating, and nonautoaggregating bacteria were able to adhere to intestinal cells both in vitro and in vivo. Microscopic examination revealed that autoaggregating cells adhered in clusters, with adhesion being mediated by only a few bacteria, whereas the hemagglutinating and nonautoaggregating strains adhered individually or in small groups making contact with each epithelial cell with the entire bacterial surface. The in vitro assessment of adhesion was a good indication of the in vivo association of propionibacteria with the intestinal epithelium. Therefore, the in vitro method presented here should be valuable in screening routinely adhesive properties of propionibacteria for probiotic purposes. The adhesion ability of dairy propionibacteria would prolong their maintenance in the gut and increase the duration of their provision of beneficial effects in the host, supporting the potential of Propionibacterium in the development of new probiotic products.


2019 ◽  
Vol 13 (3) ◽  
pp. 5653-5664
Author(s):  
M. S. M. Al-Jethelah ◽  
H. S. Dheyab ◽  
S. Khudhayer ◽  
T. K. Ibrahim ◽  
A. T. Al-Sammarraie

Latent heat storage has shown a great potential in many engineering applications. The utilization of latent heat storage has been extended from small scales to large scales of thermal engineering applications. In food industry, latent heat has been applied in food storage. Another potential application of latent heat storage is to maintain hot beverages at a reasonable drinking temperature for longer periods. In the present work, a numerical calculation was performed to investigate the impact of utilizing encapsulated phase change material PCM on the temperature of hot beverage. The PCM was encapsulated in rings inside the cup. The results showed that the encapsulated PCM reduced the coffee temperature to an acceptable temperature in shorter time. In addition, the PCM maintained the hot beverage temperature at an acceptable drinking temperature for rational time.


Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 975
Author(s):  
Antonio Copak ◽  
Vlatka Jirouš-Rajković ◽  
Nikola Španić ◽  
Josip Miklečić

Oriented strand board (OSB) is a commonly used structural wood-based panel for walls and roof siding, but recently the industry has become interested in OSB as a substrate for indoor and outdoor furniture. Particleboard is mainly used in furniture productions and has become popular as a construction material due to its numerous usage possibilities and inexpensive cost. Moisture is one of the most important factors affecting wood-based panel performance and the post-treatment conditions affected their affinity to water. When OSB and particleboard are used as substrates for coatings, their surface characteristics play an important role in determining the quality of the final product. Furthermore, roughness can significantly affect the interfacial phenomena such as adsorption, wetting, and adhesion which may have an impact on the coating performance. In this research particleboard and OSB panels were sanded, re-pressed and IR heated and the influence of surface treatments on hardness, roughness, wetting, water, and water vapour absorption was studied. Results showed that sanding improved the wetting of particleboard and OSB with water. Moreover, studied surface treatments increased water absorption and water penetration depth of OSB panels, and re-pressing had a positive effect on reducing the water vapour absorption of particleboard and OSB panels.


2021 ◽  
Vol 88 (1) ◽  
pp. 98-104
Author(s):  
Sofia Sestito Dias ◽  
Damarys de Souza Vergílio ◽  
Arthur Marroni Pereira ◽  
Suellen Jensen Klososki ◽  
Vanessa Aparecida Marcolino ◽  
...  

AbstractIn this research communication we evaluate the impact of the addition of prebiotic components (inulin, polydextrose, and modified starch, 40 g/l) as fat substitutes on the physicochemical characteristics, probiotic survival, and sensory acceptance of probiotic (Lacticaseibacillus casei 01, 108 CFU/ml) Greek yogurts during storage (7 °C, 28 d). All formulations had probiotic counts higher than 107 CFU/ml during storage and simulated gastrointestinal conditions (SGIC). The prebiotic components increased the probiotic survival to the enteric phase of the SGIC, with inulin producing the most pronounced effect. Inulin addition resulted in products with lower pH values and consistency and higher titratable acidity during storage, with negative impact on the sensory acceptance (flavor, texture, and overall impression) at the end of the storage period. Modified starch addition impacted negatively on the acceptance of the products (appearance, flavor, texture, and overall impression). Polydextrose addition resulted in products with lower consistency, but similar sensory acceptance to the full-fat yogurt. It can be concluded that it is possible to prepare potentially synbiotic Greek yogurts by desorption technique using L. casei as probiotic culture and inulin, polydextrose or modified starch as prebiotic components, with the utilization of polydextrose being advisable.


2021 ◽  
Vol 9 (5) ◽  
pp. 1013
Author(s):  
Karina Arellano-Ayala ◽  
Juhwan Lim ◽  
Subin Yeo ◽  
Jorge Enrique Vazquez Bucheli ◽  
Svetoslav Dimitrov Todorov ◽  
...  

Preservation of probiotics by lyophilization is considered a method of choice for developing stable products. However, both direct consumption and reconstitution of dehydrated probiotic preparations before application “compromise” the survival and functional characteristics of the microorganisms under the stress of the upper gastro-intestinal tract. We evaluated the impact of different food additives on the viability, mucin adhesion, and zeta potential of a freeze-dried putative probiotic, Lactiplantibacillus (Lp.) plantarum HAC03. HAC03-compatible ingredients for the formulation of ten rehydration mixtures could be selected. Elevated efficacy was achieved by the B-active formulation, a mixture of non-protein nitrogen compounds, sugars, and salts. The survival of Lp. plantarum HAC03 increased by 36.36% compared rehydration with distilled water (4.92%) after passing simulated gastro-intestinal stress conditions. Cell viability determined by plate counting was confirmed by flow cytometry. B-active formulation also influenced Lp. plantarum HAC03 functionality by increasing its adherence to a Caco-2 cell-line and by changing the bacterial surface charge, measured as zeta potential.Hydrophobicity, mucin adhesion and immunomodulatory properties of Lp. plantarum HAC03 were not affected by the B-active formulation. The rehydration medium also effectively protected Lp. plantarum ATCC14917, Lp. plantarum 299v, Latilactobacillus sakei (Lt.) HAC11, Lacticaseibacillus (Lc.) paracasei 532, Enterococcus faecium 200, and Lc. rhamnosus BFE5263.


2020 ◽  
Vol 11 (1) ◽  
pp. 67
Author(s):  
Ján Iždinský ◽  
Ladislav Reinprecht ◽  
Ján Sedliačik ◽  
Jozef Kúdela ◽  
Viera Kučerová

The bonding of wood with assembly adhesives is crucial for manufacturing wood composites, such as solid wood panels, glulam, furniture parts, and sport and musical instruments. This work investigates 13 hardwoods—bangkirai, beech, black locust, bubinga, ipé, iroko, maçaranduba, meranti, oak, palisander, sapelli, wengé and zebrano—and analyzes the impact of their selected structural and physical characteristics (e.g., the density, cold water extract, pH value, roughness, and wettability) on the adhesion strength with the polyvinyl acetate (PVAc) adhesive Multibond SK8. The adhesion strength of the bonded hardwoods, determined by the standard EN 205, ranged in the dry state from 9.5 MPa to 17.2 MPa, from 0.6 MPa to 2.6 MPa in the wet state, and from 8.5 MPa to 19.2 MPa in the reconditioned state. The adhesion strength in the dry state of the bonded hardwoods was not influenced by their cold water extracts, pH values, or roughness parallel with the grain. On the contrary, the adhesion strength was significantly with positive tendency influenced by their higher densities, lower roughness parameters perpendicular to the grain, and lower water contact angles.


2020 ◽  
pp. 074391562098384
Author(s):  
Norah Campbell ◽  
Sarah Browne ◽  
Marius Claudy ◽  
Melissa Mialon ◽  
Hercberg Serge ◽  
...  

Ultra-processed food manufacturers have proposed that product reformulation should be a key strategy to tackle obesity. In determining the impact of reformulation on population dietary behaviours, policy makers are often dependant on data provided by these manufacturers. Where such data are “gifted” to regulators there may be an implicit expectation of reciprocity that adversely influences nutrition policies. We sought to assess Europe’s industry-led reformulation strategy in five countries deploying critical policy studies as an approach. We found that interim results on industry-led food reformulation did not meet their targets. Information asymmetries exist between food industry and policy makers: the latter are not privy to marketing intelligence and must instead rely on data that are voluntarily donated by food industry actors. These data represent a distorted snippet of the marketing intelligence system from whence they came. Because these data indeed bear all the hallmarks of a gift, regulatory and public health authorities operate within a gift economy. The implications of this “data gift economy” are strategic delay and goal-setting when the field is not visible. Ultimately, this could diminish the implementation of public health nutrition policies that are contrary to the commercial interests of ultra-processed food producers.


2017 ◽  
Vol 123 ◽  
pp. 30-35 ◽  
Author(s):  
Baboo L. Gowreesunker ◽  
Sam Mudie ◽  
Savvas A. Tassou

2007 ◽  
Vol 8 (3) ◽  
pp. 439-446 ◽  
Author(s):  
Dagang Wang ◽  
Guiling Wang

Abstract Representation of the canopy hydrological processes has been challenging in land surface modeling due to the subgrid heterogeneity in both precipitation and surface characteristics. The Shuttleworth dynamic–statistical method is widely used to represent the impact of the precipitation subgrid variability on canopy hydrological processes but shows unwanted sensitivity to temporal resolution when implemented into land surface models. This paper presents a canopy hydrology scheme that is robust at different temporal resolutions. This scheme is devised by applying two physically based treatments to the Shuttleworth scheme: 1) the canopy hydrological processes within the rain-covered area are treated separately from those within the nonrain area, and the scheme tracks the relative rain location between adjacent time steps; and 2) within the rain-covered area, the canopy interception is so determined as to sustain the potential evaporation from the wetted canopy or is equal to precipitation, whichever is less, to maintain somewhat wet canopy during any rainy time step. When applied to the Amazon region, the new scheme establishes interception loss ratios of 0.3 at a 10-min time step and 0.23 at a 2-h time step. Compared to interception loss ratios of 0.45 and 0.09 at the corresponding time steps established by the original Shuttleworth scheme, the new scheme is much more stable under different temporal resolutions.


Author(s):  
Е.В. Бурденко ◽  
А.Т. Кадиева

Проводится анализ и изучение степени влияния введенных карантинных мер из-за начала и вспышки коронавирусной инфекции на отрасль общественного питания в России и других странах. В статье приведены статистические данные о текущей ситуации в данной отрасли, а также описаны варианты антикризисных мероприятий для предотвращения дальнейшего ухудшения положения предприятий ресторанного бизнеса. The analysis and study of the impact of the introduced quarantine measures due to the onset and outbreak of coronavirus infection on the catering industry in Russia and other countries is being carried out. The article provides statistical data on the current situation in this industry, as well as describes options for anti-crisis measures to prevent further deterioration of the restaurant business.


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