A new method for extraction of extracellular polymeric substances from biofilms and activated sludge suitable for direct quantification of sorbed metals

Wuertz, Stefan; Spaeth, R.; Hinderberger, A.; Griebe, Thomas; Flemming, Hans‐Curt; Wilderer, P.A.

doi:10.2166/wst.2001.0332

Cited by 59 publications

(22 citation statements)

References 13 publications

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“…However, these data did not answer the question whether Ni 2ϩ might be retained on the cell surface by proteins other than MHC. To answer this question, we made use of the fluorescent dye NPG, which has been used for quantitative determinations of Ni 2ϩ and Zn 2ϩ in aqueous solutions (42,43).…”

Section: Determination Of Surface-bound Ni 2ϩ On B Cells With Npgmentioning

confidence: 99%

Metal-Protein Complex-Mediated Transport and Delivery of Ni2+ to TCR/MHC Contact Sites in Nickel-Specific Human T Cell Activation

Thierse

Moulon

Allespach

et al. 2004

The Journal of Immunology

100

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Nickel allergy clearly involves the activation of HLA-restricted, skin-homing, Ni-specific T cells by professional APCs. Nevertheless, knowledge concerning the molecular details of metal-protein interactions underlying the transport and delivery of metal ions to APC during the early sensitization phase and their interactions with HLA and TCRs is still fragmentary. This study investigates the role of human serum albumin (HSA), a known shuttling molecule for Ni2+ and an often-disregarded, major component of skin, in these processes. We show that Ni-saturated HSA complexes (HSA-Ni) induce and activate Ni-specific human T cells as potently as Ni salt solutions when present at equimolar concentrations classically used for in vitro T cell stimulation. However, neither HSA itself nor its Ni-binding N-terminal peptide are involved in determining the specificity of antigenic determinants. In fact, HSA could be replaced by xenogeneic albumins exhibiting sufficient affinity for Ni2+ as determined by surface plasmon resonance (Biacore technology) or atomic absorption spectroscopy. Moreover, despite rapid internalization of HSA-Ni by APC, it was not processed into HLA-associated epitopes recognizable by Ni-specific T cells. In contrast, the presence of HSA-Ni in the vicinity of transient contacts between TCR and APC-exposed HLA molecules appeared to facilitate a specific transfer of Ni2+ from HSA to high-affinity coordination sites created at the TCR/HLA-interface.

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Section: Determination Of Surface-bound Ni 2ϩ On B Cells With Npgmentioning

confidence: 99%

Metal-Protein Complex-Mediated Transport and Delivery of Ni2+ to TCR/MHC Contact Sites in Nickel-Specific Human T Cell Activation

Thierse

Moulon

Allespach

et al. 2004

The Journal of Immunology

100

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“…Palmer and Sternberg (43) argued that conclusions regarding architecture of the extracellular matrix of biofilms would be speculative, unless explored using appropriate techniques, such as fluorescent lectins. EPS have been quantified by various methods, but different methods give different results (36,47,67,71).…”

Section: Flow Cell Biofilmsmentioning

confidence: 99%

Architecture of a Nascent Sphingomonas sp. Biofilm under Varied Hydrodynamic Conditions

Venugopalan

Kuehn

Hausner

et al. 2005

Appl Environ Microbiol

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The architecture of a Sphingomonas biofilm was studied during early phases of its formation, using strain L138, a gfp-tagged derivative of Sphingomonas sp. strain LB126, as a model organism and flow cells and confocal laser scanning microscopy as experimental tools. Spatial and temporal distribution of cells and exopolymer secretions (EPS) within the biofilm, development of microcolonies under flow conditions representing varied Reynolds numbers, and changes in diffusion length with reference to EPS production were studied by sequential sacrificing of biofilms grown in multichannel flow cells and by time-lapse confocal imaging. The area of biofilm in terms of microscopic images required to ensure representative sampling varied by an order of magnitude when area of cell coverage (2 ؋ 10 5 m 2 ) or microcolony size (1 ؋ 10 6 m 2 ) was the biofilm parameter under investigation. Hence, it is necessary to establish the inherent variability of any biofilm metric one is attempting to quantify. Sphingomonas sp. strain L138 biofilm architecture consisted of microcolonies and extensive water channels. Biomass and EPS distribution were maximal at 8 to 9 m above the substratum, with a high void fraction near the substratum. Time-lapse confocal imaging and digital image analysis showed that growth of the microcolonies was not uniform: adjacently located colonies registered significant growth or no growth at all. Microcolonies in the biofilm had the ability to move across the attachment surface as a unit, irrespective of fluid flow direction, indicating that movement of microcolonies is an inherent property of the biofilm. Width of water channels decreased as EPS production increased, resulting in increased diffusion distances in the biofilm. Changing hydrodynamic conditions (Reynolds numbers of 0.07, 52, and 87) had no discernible influence on the characteristics of microcolonies (size, shape, or orientation with respect to flow) during the first 24 h of biofilm development. Inherent factors appear to have overriding influence, vis-à-vis environmental factors, on early stages of microcolony development under these laminar flow conditions.Biofilms are ubiquitous in all natural and many industrial environments. Researchers study different aspects of biofilm development and processes in fields such as biofouling (3), biocorrosion (23, 35), bioremediation (13), wastewater treatment (62, 68), human health (59), and ecology (37). Earlier work on biofilms focused on elucidation of the process of adhesion of bacteria to surfaces (6). However, more recent research has dealt with complexities of the structural and functional aspects of biofilms (42,48,65), associations between different physiological and metabolic groups of microorganisms (60), material traffic into and out of biofilm matrices (34, 41), involvement of genetic factors on biofilm formation (46), response of biofilms to changing environmental conditions (40), and cell-cell communication systems (9,25,63).Biofilms are characterized by a complex architecture. Biofilm archi...

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“…Nevertheless, the method used during ECS extraction plays an important role in their quantification (Wuertz et al 2001;McSwain et al 2005).…”

Section: Characterization Of Extracellular Polymersmentioning

confidence: 99%

Effect of Environmental Conditions on Hydrophobicity of Marine Bacteria Adapted to Textile Effluent Treatment

Khemakhem

Ammar²,

Bakhrouf

2005

World J Microbiol Biotechnol

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Bioflocculation of bacteria isolated from the marine biomass acclimatized to textile wastewater has been achieved. Pseudomonas was the main genus found in the marine biomass. This bacterium showed an important hydrophobicity but slightly weaker than that of pilot plant genera adapted to the conventional sewage. This hydrophobicity provided the bacteria with hydrophobic characters, especially those of the polymeric extracellular substances (ECS) released in the sewage. Whereas some factors such as the divalent cations, calcium and magnesium had an effect on this bacterial hydrophobicity, glucose concentration did not have any impact. Furthermore, the physiological state of the cells hatched in the sewage had an impact on the hydrophobicity. Indeed, during the logarithmic growth phase, cell hydrophobicity increase enhanced floc formation, thus improving wastewater treatment.

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A new method for extraction of extracellular polymeric substances from biofilms and activated sludge suitable for direct quantification of sorbed metals

Cited by 59 publications

References 13 publications

Metal-Protein Complex-Mediated Transport and Delivery of Ni2+ to TCR/MHC Contact Sites in Nickel-Specific Human T Cell Activation

Metal-Protein Complex-Mediated Transport and Delivery of Ni2+ to TCR/MHC Contact Sites in Nickel-Specific Human T Cell Activation

Architecture of a Nascent Sphingomonas sp. Biofilm under Varied Hydrodynamic Conditions

Effect of Environmental Conditions on Hydrophobicity of Marine Bacteria Adapted to Textile Effluent Treatment

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