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| Registros recuperados: 107 | |
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| Nabizadeh,Ramin; Naddafi,Kazem; Mesdaghinia,Alireza; Nafez,Amir Hosien. |
| Biofilm systems are efficient in the removal of organic matter and ammonium from wastewaters. In this study, loofa sponge, a natural product, was used as a supporting medium in an aerated submerged fixed-film reactor to evaluate its performance in removing organic matter and nitrogen from wastewater. Four pilot runs were performed with chemical oxygen demand (COD) concentrations of 100, 200, 300 and 400 mg l-1 to provide an organic loading rate of 0.6, 1.2, 1.8, and 2.4 kg m-3d-1 respectively. In these pilot runs, the influent ammonium nitrogen concentrations were justified to 5, 10, 15 and 20 mg l-1 as N to provide an influent nitrogen loading of 30, 60, 90 and 120 g m-3.d-1 respectively. Although soluble COD removal efficiency greater than 80 percent was... |
| Tipo: Journal article |
Palavras-chave: Aerated submerged fixed-film reactor; Biofilm; Fixed-Film; Loofa; Organic matter removal; Sponge. |
| Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582008000400006 |
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| Devadhanam Joubert,Esther; Pillay,Balakrishna. |
| The removal of contaminants in slow sand filters occurs mainly in the colmation layer or schmutzdecke - a biologically active layer consisting of algae, bacteria, diatoms and zooplankton. A ripening period of 6 - 8 weeks is required for this layer to form, during which time filter performance is sub-optimal. In the current study, an environmental scanning electron microscope was used to visualise the ripening process of a pilot-scale slow sand filter over a period of eight weeks. To achieve this, sand particles were removed at weekly intervals and observed for biofilm development. Biological mechanisms of removal in slow sand filtration are not fully understood. A visualisation of the colonisation process would enhance the knowledge and understanding of... |
| Tipo: Journal article |
Palavras-chave: Biofilm; Microbial biodiversity; Schmutzdecke. |
| Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582008000200014 |
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| Villena,Gretty K; Gutiérrez-Correa,Marcel. |
| Lignocellulolytic enzyme production by Aspergillus niger was compared both in submerged fermentation (SF) and biofilm fermentation (BF) at varying water activities. Maximal filter paper activity, endoglucanase and xylanase activities were much higher in BF (2.96, 4.7 and 4.61 IU ml-1, respectively) than in SF cultures (1.71, 1.31 and 2.3 IU ml-1, respectively) but biomass yields were lower in BF than in SF (0.338 g g-1 and 0.431 g g-1, respectively). In the presence of 20% ethylene glycol (a w = 0.942) the enzyme activities decreased in both systems but BF still had higher levels (1.0, 1.0 and 2.6 IU ml-1, respectively) than SF cultures (0.6, 0.7 and 1.5 IU ml-1, respectively). An increase in xylanase specific activity of more than 2 fold (from 4.2 to 10.2... |
| Tipo: Journal article |
Palavras-chave: Biofilm; Cellulase; Ethylene glycol; Water activity; Xylanase. |
| Ano: 2007 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582007000100012 |
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| Aroca,Germán; Urrutia,Homero; Núñez,Dariela; Oyarzún,Patricio; Arancibia,Alejandra; Guerrero,Karlo. |
| Emissions of hydrogen sulfide (H2S) by industrial activities is frequent cause of corrosion and unpleasant odours. Treatment of gaseous emissions contaminated with H2S by biotrickling filters inoculated with single cultures of sulfur oxidizer bacteria exhibit several advantages over physicochemical methods, such as shorter adaptation times and higher removal ability. Biofilms of Thiobacillus thioparus and Acidithiobacillus thiooxidans have proved to exhibit high removal capacities, yet no comparative studies between them have been reported. This article reports the efficiency of biotrickling filters inoculated with T. thioparus and A. thiooxidans under similar conditions excepting the pH, that was the optimal for the bacterial growth, for the removal of... |
| Tipo: Journal article |
Palavras-chave: Acidithiobacillus thiooxidans; Biofilm; Biofiltration; Hydrogen sulfide; Thiobacillus thioparus. |
| Ano: 2007 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582007000400005 |
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| Rossi,Ciro César; Pereira,Monalessa Fábia; Giambiagi-deMarval,Marcia. |
| Abstract The increasing threat of antimicrobial resistance has shed light on the interconnection between humans, animals, the environment, and their roles in the exchange and spreading of resistance genes. In this review, we present evidences that show that Staphylococcus species, usually referred to as harmless or opportunistic pathogens, represent a threat to human and animal health for acting as reservoirs of antimicrobial resistance genes. The capacity of genetic exchange between isolates of different sources and species of the Staphylococcus genus is discussed with emphasis on mobile genetic elements, the contribution of biofilm formation, and evidences obtained either experimentally or through genome analyses. We also discuss the involvement of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Horizontal gene transfer; Antimicrobial resistance; Coagulase negative staphylococcus; Biofilm; CRISPR; One Health. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572020000300303 |
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| Passerini, Delphine; Fecamp, Florian; Marchand, Laetitia; Kolypczuk, Laetitia; Bonnetot, Sandrine; Sinquin, Corinne; Verrez-bagnis, Veronique; Hervio Heath, Dominique; Colliec Jouault, Sylvia; Delbarre Ladrat, Christine. |
| In the marine environment, biofilm formation is an important lifestyle for microorganisms. A biofilm is comprised of cells embedded in an extracellular matrix that holds them close together and keeps the biofilm attached to the colonized surface. This predominant lifestyle and its main regulation pathway, namely quorum-sensing (QS), have been shown to induce specific bioactive metabolites. In this study, we investigated the biofilm formation by two marine bacteria belonging to the Vibrio species to discover potentially innovative bioactive compounds. We proposed a protocol to isolate biofilm extracts, to analyze their biochemical composition, and to compare them to planktonic cell extracts. Cells were grown attached to a plastic surface; extracts were... |
| Tipo: Text |
Palavras-chave: Vibrio; Biofilm; Polysaccharide; Quorum-sensing; Activity. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00592/70381/68461.pdf |
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| Gobet, Angelique; Barbeyron, Tristan; Matard-mann, Maria; Magdelenat, Ghislaine; Vallenet, David; Duchaud, Eric; Michel, Gurvan. |
| About half of seaweed biomass is composed of polysaccharides. Most of these complex polymers have a marked polyanionic character. For instance, the red algal cell wall is mainly composed of sulfated galactans, agars and carrageenans, while brown algae contain alginate and fucose-containing sulfated polysaccharides (FCSP) as cell wall polysaccharides. Some marine heterotrophic bacteria have developed abilities to grow on such macroalgal polysaccharides. This is the case of Pseudoalteromonas carrageenovora 9(T) (ATCC 43555(T)), a marine gammaproteobacterium isolated in 1955 and which was an early model organism for studying carrageenan catabolism. We present here the genomic analysis of P. carrageenovora. Its genome is composed of two chromosomes and of a... |
| Tipo: Text |
Palavras-chave: Carrageenan; CAZymes; Alginate; Gammaproteobacteria; Pseudoalteromonas; Marine bacteria; Algal holobiont; Biofilm. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00489/60070/63377.pdf |
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| Rodrigues, Sophie; Paillard, Christine; Van Dillen, Sabine; Tahrioui, Ali; Berjeaud, Jean-marc; Dufour, Alain; Bazire, Alexis. |
| Marine pathogenic bacteria are able to form biofilms on many surfaces, such as mollusc shells, and they can wait for the appropriate opportunity to induce their virulence. Vibrio tapetis can develop such biofilms on the inner surface of shells of the Ruditapes philippinarum clam, leading to the formation of a brown conchiolin deposit in the form of a ring, hence the name of the disease: Brown Ring Disease. The virulence of V. tapetis is presumed to be related to its capacity to form biofilms, but the link has never been clearly established at the physiological or genetic level. In the present study, we used RNA-seq analysis to identify biofilm- and virulence-related genes displaying altered expression in biofilms compared to the planktonic condition. A... |
| Tipo: Text |
Palavras-chave: Biofilm; Virulence; Vibrio tapetis; Transcriptome; Quorum sensing; Type VI secretion system; Brown ring disease. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00470/58140/60611.pdf |
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| Jouault, Albane; Gobet, Angelique; Simon, Marjolaine; Portier, Emilie; Perennou, Morgan; Corre, Erwan; Gaillard, Fanny; Vallenet, David; Michel, Gurvan; Fleury, Yannick; Bazire, Alexis; Dufour, Alain. |
| The aim was to identify and study the antibiofilm protein secreted by the marine bacterium Pseudoalteromonas sp. 3J6. The latter is active against marine and terrestrial bacteria, including Pseudomonas aeruginosa clinical strains forming different biofilm types. Several amino acid sequences were obtained from the partially purified antibiofilm protein, named alterocin. The Pseudoalteromonas sp. 3J6 genome was sequenced and a candidate alt gene was identified by comparing the genome-encoded proteins to the sequences from purified alterocin. Expressing the alt gene in another non-active Pseudoalteromonas sp. strain, 3J3, demonstrated that it is responsible for the antibiofilm activity. Alterocin is a 139-residue protein including a predicted 20-residue... |
| Tipo: Text |
Palavras-chave: Antibiofilm protein; Pseudoalteromonas; Pseudomonas aeruginosa; Biofilm. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00643/75517/76405.pdf |
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| Nassif, L. Abi; Rioual, S.; Trepos, Rozenn; Fauchon, M.; Farah, W.; Hellio, C.; Abboud, M.; Lescop, B.. |
| Microorganisms have the ability to settle on nearly all man-made surfaces in contact with seawater and subsequently to form biofilm. Biofilms control and removal is necessary in the sectors of maritime transport, energy... In this work, we present the development of new pure calcium, zinc or copper alginate, but also mixed Ca/Cu and Ca/Zn alginate hydrogels. These materials have been evaluated for their potential inhibition of adhesion of two key biofilm-forming microalgae Halamphora coffeaeformis and Cylindrotheca closterium). All the tested materials have presented high adhesion inhibition about 80%). Copper-base materials present a high toxicity against H. coffeaeformis. Pure zinc alginate is also toxic for this strain. However, the addition of calcium... |
| Tipo: Text |
Palavras-chave: Biofilm; Adhesion; Alginate; Zinc; Biomaterials; Microalgae. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00605/71671/70168.pdf |
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| Lepinay, Alexandra; Capiaux, Herve; Turpin, Vincent; Mondeguer, Florence; Lebeau, Thierry. |
| Haslea ostrearia produces a water-soluble, blue-green pigment, called marennine, with proven economic benefits (as a bioactive compound used to green oysters, which improves their market value). Incomplete knowledge of the ecological features of this marine diatom complicates its cultivation. More specifically, the ecology of bacteria surrounding H. ostrearia in ponds is what remains unknown. The structure of this bacterial community was previously analyzed by means of PCR-TTGE before and after isolating H. ostrearia cells recovered from 4 localities in order to distinguish the relative parts of the biotope and biocenose and to describe the temporal dynamics of the bacterial community structure at two time scales (2 weeks vs. 9 months). The bacterial... |
| Tipo: Text |
Palavras-chave: Biofilm; Ecology; Metabolic fingerprinting; Microalgae; Phycosphere; TTGE. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00326/43737/43344.pdf |
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| Compere, Chantal. |
| Introduction: Almost all submerged surfaces in the marine environment are subject to developing an organic film, with the exception of some living organisms, such as sponges, which do not undergo any great colonization, for no currently-known scientific reason. The presence of this biofilm is at the source of many problems in the oceanographic field and for marine business. This article introduces some drawbacks relating to the existence of this fouling and elaborates upon the main studies conducted at IFREMER concerning the most-used methods for combating it. However, the anti-fouling agents that are generally used for protecting facilities are toxic and can have disastrous consequences on the marine environment's fauna and flora. Moreover, the use of... |
| Tipo: Text |
Palavras-chave: Biofilm; Seawater. |
| Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/1999/publication-1698.pdf |
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| Abi Nassif, L.; Rioual, S.; Farah, W.; Hellio, C.; Fauchon, M.; Trepos, R; Abboud, M.; Diler, E.; Thierry, D.; Lescop, B.. |
| The effect of biofilm formation on passive stainless steel in seawater environments is of primary importance since it leads to potential ennoblement of surfaces and subsequently to localized corrosion such as pitting and crevice corrosion. This study aims at developing an ecofriendly alginate biopolymer containing both non-toxic calcium and a limited amount of biocidal zinc ions which inhibits this effect. For this purpose, calcium alginate containing less than 1 % of zinc ions localized in the vicinity of the steel surface in natural and renewed seawater is demonstrated to reduce significantly the ennoblement process of steel. After 1 month of immersion, a mass loss of only 4 % of the active material is observed authorizing thereby long-term protection of... |
| Tipo: Text |
Palavras-chave: Biopolymer; Steel; Ennoblement; Antimicrobial; Alginate; Biofilm. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00604/71607/73083.pdf |
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| Fechner, Lise C.; Versace, Francois; Gourlay-france, Catherine; Tusseau-vuillemin, Marie-helene. |
| The Water Framework Directive requires the development of biological tools which can act as early-warning indicators of a sudden increase (accidental pollution) or decrease (recovery due to prevention) of the chemical status of aquatic systems. River biofilms, which respond quickly to modifications of environmental parameters and also play a key part in the functioning of aquatic ecosystems, are therefore good candidates to monitor an increase or a decrease of water pollution. In the present study, we investigated the biological response of biofilms transplanted either upstream (recovery) or downstream (deterioration of exposure levels) the urban area of Paris (France). Both modifications of Cu community tolerance levels and of global bacterial and... |
| Tipo: Text |
Palavras-chave: River; Biofilm; PICT; ARISA; Urban contamination; Transplantation. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00070/18129/16053.pdf |
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| Macé, Sabrina; Truelstrup Hansen, Lisbeth; Rupasinghe, H. P. Vasantha. |
| Background: Worldwide, Streptococcus pyogenes is the leading cause of bacterial pharyngitis. To reduce the use of antibiotics, antimicrobial phytochemical-containing remedies, which have long been in use in traditional medicine, may provide new approaches for management of streptococcal pharyngitis. The objective of this study was to assess the inhibitory activities of 25 natural phenolic compounds against three strains of S. pyogenes. Methods: After an initial screening, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the nine most effective phenolic compounds were determined. The effect of four compounds with the lowest MIC and MBC on streptococcal growth and biofilm formation was also studied. Results:... |
| Tipo: Text |
Palavras-chave: Pharyngitis; Strep throat; Biofilm; Naphthoquinone; Infection; Disease; Polyphenols. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00603/71515/69934.pdf |
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| Registros recuperados: 107 | |
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