Sorption of Copper(II) and Silver(I) by Four Bacterial Exopolysaccharides

Deschatre, M.; Ghillebaert, F.; Guézennec, Jean; Colin, Christelle Simon

doi:10.1007/s12010-013-0343-7

Cited by 36 publications

(14 citation statements)

References 46 publications

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“…Another advantage to using exopolysaccharide associated with AMP is their binding capability. Bacterial EPSs contain ionizable functional groups such as carboxyl, amine, sulfate and to a lesser extent hydroxyl groups that enable these biopolymers to bind metals [ 30 , 31 ]. Chelation of calcium and magnesium by these exopolysaccharides is in favor of the formation of an homogeneous nacre at the end of the biomineralization process [ 32 ].…”

Section: Resultsmentioning

confidence: 99%

Use of Natural Antimicrobial Peptides and Bacterial Biopolymers for Cultured Pearl Production

et al. 2015

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Cultured pearls are the product of grafting and rearing of Pinctada margaritifera pearl oysters in their natural environment. Nucleus rejections and oyster mortality appear to result from bacterial infections or from an inappropriate grafting practice. To reduce the impact of bacterial infections, synthetic antibiotics have been applied during the grafting practice. However, the use of such antibiotics presents a number of problems associated with their incomplete biodegradability, limited efficacy in some cases, and an increased risk of selecting for antimicrobial resistant bacteria. We investigated the application of a marine antimicrobial peptide, tachyplesin, which is present in the Japanese horseshoe crab Tachypleus tridentatus, in combination with two marine bacterial exopolymers as alternative treatment agents. In field studies, the combination treatment resulted in a significant reduction in graft failures vs. untreated controls. The combination of tachyplesin (73 mg/L) with two bacterial exopolysaccharides (0.5% w/w) acting as filming agents, reduces graft-associated bacterial contamination. The survival data were similar to that reported for antibiotic treatments. These data suggest that non-antibiotic treatments of pearl oysters may provide an effective means of improving oyster survival following grafting procedures.

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Section: Resultsmentioning

confidence: 99%

Use of Natural Antimicrobial Peptides and Bacterial Biopolymers for Cultured Pearl Production

et al. 2015

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“…Bio-generated polymeric substances, such as polysaccharides, are able to bind metals and consequently protect cells from environmental stress (Deschatre et al, 2013;Shuhong et al, 2014). This strategy was also found in Klebsiella oxytoca strain BAS-10, isolated from an acid drainage mining area enriched with toxic metals (Baldi et al, 2001).…”

Section: Introductionmentioning

confidence: 83%

XAS analysis of iron and palladium bonded to a polysaccharide produced anaerobically by a strain ofKlebsiella oxytoca

Arčon

Paganelli

Piccolo

et al. 2015

J Synchrotron Radiat

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Klebsiella oxytoca BAS-10 ferments citrate to acetic acid and CO2, and secretes a specific exopolysaccharide (EPS), which is able to bind different metallic species. These biomaterials may be used for different biotechnological purposes, including applications as innovative green biogenerated catalysts. In production of biogenerated Pd species, the Fe(III) as ferric citrate is added to anaerobic culture of K. oxytoca BAS-10, in the presence of palladium species, to increase the EPS secretion and improve Pd-EPS yield. In this process, bi-metallic (FePd-EPS) biomaterials were produced for the first time. The morphology of bi-metallic EPS, and the chemical state of the two metals in the FePd-EPS, are investigated by transmission electron microscopy, Fourier transform infra-red spectroscopy, micro-X-ray fluorescence, and X-ray absorption spectroscopy methods (XANES and EXAFS), and compared with mono-metallic Pd-EPS and Fe-EPS complexes. Iron in FePd-EPS is in the mineralized form of iron oxides/hydroxides, predominantly in the form of Fe(3+), with a small amount of Fe(2+) in the structure, most probably a mixture of different nano-crystalline iron oxides and hydroxides, as in mono-metallic Fe-EPS. Palladium is found as Pd(0) in the form of metallic nanoparticles with face-centred cubic structure in both bi-metallic (FePd-EPS) and mono-metallic (Pd-EPS) species. In bi-metallic species, Pd and Fe nanoparticles agglomerate in larger clusters, but they remain spatially separated. The catalytic ability of bi-metallic species (FePd-EPS) in a hydrodechlorination reaction is improved in comparison with mono-metallic Pd-EPS.

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“…However, other important ions (at a given pH) may ‘outcompete’ Ca 2+ and Mg 2+ for binding sites. The binding of transition and other metals, such as Th, Cd, Cu, Ag, Fe, and Se, to EPS isolated from different environments, such as hydrothermal vents, microbial mats, and other areas, has been described (Schlekat et al, 1998; Zhang et al, 2008; Moppert et al, 2009; Deschatre et al, 2013). Metal binding to EPS of surface floc material (i.e., marine snow) in the surface waters of oceans, and subsequent sinking of flocs may result in significant vertical transport (flux) of trace elements to ocean floor, a process of global biogeochemical significance (as mentioned above).…”

Section: Physical/chemical Properties Of Epsmentioning

confidence: 99%

Microbial Extracellular Polymeric Substances (EPSs) in Ocean Systems

2017

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Microbial cells (i.e., bacteria, archaea, microeukaryotes) in oceans secrete a diverse array of large molecules, collectively called extracellular polymeric substances (EPSs) or simply exopolymers. These secretions facilitate attachment to surfaces that lead to the formation of structured ‘biofilm’ communities. In open-water environments, they also lead to formation of organic colloids, and larger aggregations of cells, called ‘marine snow.’ Secretion of EPS is now recognized as a fundamental microbial adaptation, occurring under many environmental conditions, and one that influences many ocean processes. This relatively recent realization has revolutionized our understanding of microbial impacts on ocean systems. EPS occur in a range of molecular sizes, conformations and physical/chemical properties, and polysaccharides, proteins, lipids, and even nucleic acids are actively secreted components. Interestingly, however, the physical ultrastructure of how individual EPS interact with each other is poorly understood. Together, the EPS matrix molecules form a three-dimensional architecture from which cells may localize extracellular activities and conduct cooperative/antagonistic interactions that cannot be accomplished efficiently by free-living cells. EPS alter optical signatures of sediments and seawater, and are involved in biogeomineral precipitation and the construction of microbial macrostructures, and horizontal-transfers of genetic information. In the water-column, they contribute to the formation of marine snow, transparent exopolymer particles (TEPs), sea-surface microlayer biofilm, and marine oil snow. Excessive production of EPS occurs during later-stages of phytoplankton blooms as an excess metabolic by product and releases a carbon pool that transitions among dissolved-, colloidal-, and gel-states. Some EPS are highly labile carbon forms, while other forms appear quite refractory to degradation. Emerging studies suggest that EPS contribute to efficient trophic-transfer of environmental contaminants, and may provide a protective refugia for pathogenic cells within marine systems; one that enhances their survival/persistence. Finally, these secretions are prominent in ‘extreme’ environments ranging from sea-ice communities to hypersaline systems to the high-temperatures/pressures of hydrothermal-vent systems. This overview summarizes some of the roles of exopolymer in oceans.

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Sorption of Copper(II) and Silver(I) by Four Bacterial Exopolysaccharides

Cited by 36 publications

References 46 publications

Use of Natural Antimicrobial Peptides and Bacterial Biopolymers for Cultured Pearl Production

Use of Natural Antimicrobial Peptides and Bacterial Biopolymers for Cultured Pearl Production

XAS analysis of iron and palladium bonded to a polysaccharide produced anaerobically by a strain ofKlebsiella oxytoca

Microbial Extracellular Polymeric Substances (EPSs) in Ocean Systems

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