Directing Effect of Bacterial Extracellular Polymeric Substances (EPS) on Calcite Organization and EPS–Carbonate Composite Aggregate Formation

2020 ◽  
Vol 20 (3) ◽  
pp. 1467-1484 ◽  
Author(s):  
Xiaofei Yin ◽  
Florian Weitzel ◽  
Concepción Jiménez-López ◽  
Erika Griesshaber ◽  
Lurdes Fernández-Díaz ◽  
...  
Keyword(s):  
Extracellular Polymeric Substances ◽  
Aggregate Formation ◽  
Directing Effect

scholarly journals Molecular Mechanisms Underpinning Aggregation in Acidiphilium sp. C61 Isolated from Iron-Rich Pelagic Aggregates

2020 ◽  
Vol 8 (3) ◽  
pp. 314
Author(s):  
Qianqian Li ◽  
Rebecca E. Cooper ◽  
Carl-Eric Wegner ◽  
Kirsten Küsel
Keyword(s):  
Hot Spots ◽  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Molecular Mechanisms ◽  
Core Genome ◽  
Gene Clusters ◽  
Microbial Interactions ◽  
Aggregate Formation ◽  
Rna Seq ◽  
Metabolic Potential

Iron-rich pelagic aggregates (iron snow) are hot spots for microbial interactions. Using iron snow isolates, we previously demonstrated that the iron-oxidizer Acidithrix sp. C25 triggers Acidiphilium sp. C61 aggregation by producing the infochemical 2-phenethylamine (PEA). Here, we showed slightly enhanced aggregate formation in the presence of PEA on different Acidiphilium spp. but not other iron-snow microorganisms, including Acidocella sp. C78 and Ferrovum sp. PN-J47. Next, we sequenced the Acidiphilium sp. C61 genome to reconstruct its metabolic potential. Pangenome analyses of Acidiphilium spp. genomes revealed the core genome contained 65 gene clusters associated with aggregation, including autoaggregation, motility, and biofilm formation. Screening the Acidiphilium sp. C61 genome revealed the presence of autotransporter, flagellar, and extracellular polymeric substances (EPS) production genes. RNA-seq analyses of Acidiphilium sp. C61 incubations (+/− 10 µM PEA) indicated genes involved in energy production, respiration, and genetic processing were the most upregulated differentially expressed genes in the presence of PEA. Additionally, genes involved in flagellar basal body synthesis were highly upregulated, whereas the expression pattern of biofilm formation-related genes was inconclusive. Our data shows aggregation is a common trait among Acidiphilium spp. and PEA stimulates the central cellular metabolism, potentially advantageous in aggregates rapidly falling through the water column.

The contribution of earthworms to soil aggregate formation

2020 ◽  
Author(s):  
Tom Guhra ◽  
Katharina Stolze ◽  
Thomas Ritschel ◽  
Kai Uwe Totsche
Keyword(s):  
Extracellular Polymeric Substances ◽  
Water Drop ◽  
Soil Aggregates ◽  
Lumbricus Terrestris ◽  
Soil Aggregate ◽  
Specific Adsorption ◽  
Water Infiltration ◽  
Aggregate Formation ◽  
Surface Charges ◽  
Mineral Associations

<p>Anecic and endogeic earthworm species are known as “ecosystem engineers” that significantly contribute to the porosity and coherence of soil as well as soil water infiltration and the turnover rates of organic matter (OM). Additionally, earthworms actively excrete nutrient rich mucus, release bacteria within casts and translocate litter into the subsurface. In this way, earthworms not only shape the structure of soils but also the chemical milieu of the drilosphere where mucus forms a prominent fraction of OM. Furthermore, other biogenic extracellular polymeric substances (EPS) are known to form organo-mineral associations, which suggests that earthworms also facilitate their further attachment into soil aggregates.</p><p>With this study, we investigated how earthworms contribute to soil aggregate formation and impact aggregate properties by OM translocation and incorporation in the drilosphere. At vertically sampled burrow walls predominantly formed by <em>Lumbricus terrestris</em>, a patchy and depth dependent distribution of hydrophobic and hydrophilic regions was found with the water drop penetration time (WDPT) test. In the hydrophobic regions, we identified an enrichment of carbon and aggregate surface coatings containing plant residuals, bacteria, OM screenings and enmeshments by scanning electron microscopy (SEM) and elemental analysis. These structures were further investigated by factor analysis of Fourier transform infrared (FTIR) spectra that permitted the FTIR-band extraction of earthworm typical aggregation agents as, e.g., bacterial EPS, earthworm mucus and plant components (leaves, roots and sprout). Furthermore, with sorption experiments to typical minerals of temperate soils (e.g. illite and goethite), we found a mineral-specific adsorption of earthworm cutaneous mucus (of <em>Lumbricus terrestris</em> and <em>Aporrectodea caliginosa</em>) and bacterial EPS (of <em>Bacillus subtilis</em>). Specifically, a preferential adsorption of phosphorus containing constituents of mucus and bacterial EPS to goethite has been observed. The resulting formation of organo-mineral associations characterized by screened mineral surface charges was shown by zeta potential measurements.</p><p>We show that besides the active incorporation of particulate OM, as e.g. plant residuals and microorganisms, the mineral specific adsorption of EPS formed by earthworms and bacteria induce the formation of organo-mineral associations and alteration of the physico-chemical properties of earthworm-formed structures and soil aggregates.</p>

scholarly journals The role of SOM and CaCO3 on soil aggregate development in reclaimed soils

2020 ◽  
Author(s):  
Evelin Pihlap ◽  
Markus Steffens ◽  
Ingrid Kögel-Knabner
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Extracellular Polymeric Substances ◽  
Aggregate Size ◽  
Soil Aggregate ◽  
Parent Material ◽  
Size Class ◽  
Aggregate Formation ◽  
Structural Formation ◽  
Size Classes

<p>Soil organic matter (SOM) and extracellular polymeric substances (EPS) from biological processes are considered to be major contributors in aggregate formation. But there is limited knowledge on soil structural formation after reclamation – the step when SOM content is low and soil properties are mostly controlled by the parent material. In our study we used a chronosequence approach in the reclaimed open-cast mining area near Cologne, Germany to elucidate the development of soil structure and soil organic matter during initial soil formation in a loess material. We selected six plots with different ages of agricultural management after reclamation (0, 1, 3, 6, 12, and 24 years after first seeding). In each reclaimed field 12 spatially independent locations were sampled with stainless steel cylinders (100 cm<sup>3</sup>) at two depths in the topsoil (1-5 cm and 16-20 cm). Samples were wet sieved into four aggregate size classes of <63 µm, 63-200 µm, 200-630 µm and 630-2000 µm. Each aggregate size class was characterized by organic carbon (OC), total nitrogen (TN) and CaCO<sub>3</sub> concentration. The chemical composition of the SOM of selected samples was characterized using solid-state 13C NMR spectroscopy.</p><p>Wet sieving into aggregate size classes showed different trends along the chronosequence. Contradicting relation between CaCO<sub>3</sub> and OC contribution to aggregate size classes display two different mechanisms on soil aggregate formation in young loess derived soils. CaCO<sub>3</sub> influenced aggregation predominantly in finer aggregate size classes, where the highest concentration and contribution was measured. SOM, on the other hand, played an important role on formation of large macro-aggregates after organic manure application in year 4. Furthermore, the loss of total OC after year 12 was connected with the loss of OC contributing to the largest aggregate size class. Our findings reveal that SOM and CaCO<sub>3</sub> role on stabilizing aggregates is not equally distributed and is aggregate size class dependent.</p>

A Simple and Rapid Method to Determine GPIIb/IIIa-Receptor Inhibitor Activity in Whole Blood

1999 ◽  
Vol 19 (03) ◽  
pp. 134-138
Author(s):  
Gitta Kühnel ◽  
A. C. Matzdorff
Keyword(s):  
Flow Cytometry ◽  
Platelet Count ◽  
Blood Sample ◽  
Platelet Activation ◽  
Whole Blood ◽  
Receptor Occupancy ◽  
Aggregate Formation ◽  
Inhibitor Activity ◽  
Receptor Inhibitor

SummaryWe studied the effect of GPIIb/IIIa-inhibitors on platelet activation with flow cytometry in vitro. Citrated whole blood was incubated with increasing concentrations of three different GPIIb/IIIa-inhibitors (c7E3, DMP728, XJ757), then thrombin or ADP were added and after 1 min the sample was fixed. Samples without c7E3 but with 0.1 U/ml thrombin had a decrease in platelet count. Samples with increasing concentrations of c7E3 had a lesser or no decrease in platelet count. The two other inhibitors (DMP 725, XJ757) gave similar results. GPIIb/IIIa-inhibitors prevent aggregate formation and more single platelets remain in the blood sample. The agonist-induced decrease in platelet count correlates closely with the concentration of the GPIIb/IIIa inhibitor and receptor occupancy. This correlation may be used as a simple measure for inhibitor activity in whole blood.

Glycoproteins IIb and IIIa and Platelet Thrombospondin in a Liposome Model of Platelet Aggregation

1986 ◽  
Vol 55 (02) ◽  
pp. 240-245 ◽  
Author(s):  
M E Rybak
Keyword(s):  
Platelet Aggregation ◽  
Direct Evidence ◽  
Phospholipid Vesicles ◽  
Aggregate Formation ◽  
Membrane Glycoproteins ◽  
Protein Orientation ◽  
Phosphatidylcholine Liposomes ◽  
Calcium Dependent ◽  
Lentil Lectin ◽  
Complete Reversal

SummaryPlatelet membrane glycoproteins IIb and IIIa and platelet thrombospondin were incorporated onto phosphatidylcholine liposomes, by freeze thawing and sonication. Protein orientation on the liposomes was confirmed by susceptibility to neuraminidase cleavage and binding to lentil lectin-Sepharose (GPIIb-IIIa liposomes) and to heparin-Sepharose (thrombospondin liposomes). Glycoproteins Ilb-IIIa bound 125I-fibrinogen with Kd of 7.5 × 10™7M. Binding was reversible and calcium-dependent. Ilb-IIIa liposomes underwent fibrinogen-dependent aggregation in the presence of 10 mM CaCl2. Maximal aggregate formation was observed with a combination of IIb-IIIa liposomes and thrombospondin liposomes. This aggregation was partially inhibited by preincubation with monoclonal antibodies to the IIb-IIIa complex. Addition of EDTA caused complete reversal of aggregates. Thrombospondin liposomes also underwent fibrinogen and calcium dependent aggregation, however, this aggregation was less than that observed with the GPIIb-IIIa liposomes. Maximal aggregate formation was observed with a mixture of IIb-IIIa liposomes and thrombospondin liposomes. These studies demonstrate that GPIIb-IIIa and thrombospondin can be incorporated into phospholipid vesicles with preservation of function. Direct evidence is provided to demonstrate that glycoprotein lib and Ilia and fibrinogen are sufficient for platelet aggregation and to demonstrate that thrombospondin may also contribute to platelet aggregation.

Process Description of an Unconventional Biofilm Formation by Bacterial Cells Autoagglutinating Through Sticky, Long, and Peritrichate Nanofibers

2019 ◽  
Author(s):  
Yoshihide Furuichi ◽  
Shogo Yoshimoto ◽  
Tomohiro Inaba ◽  
Nobuhiko Nomura ◽  
Katsutoshi Hori
Keyword(s):  
Formation Process ◽  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Waste Treatment ◽  
Large Cell ◽  
Dlvo Theory ◽  
Bacterial Cells ◽  
Chemical Production ◽  
Discontinuous Surface ◽  
Cell Cell

<p></p><p>Biofilms are used in environmental biotechnologies including waste treatment and environmentally friendly chemical production. Understanding the mechanisms of biofilm formation is essential to control microbial behavior and improve environmental biotechnologies. <i>Acinetobacter </i>sp. Tol 5 autoagglutinate through the interaction of the long, peritrichate nanofiber protein AtaA, a trimeric autotransporter adhesin. Using AtaA, without cell growth or the production of extracellular polymeric substances, Tol 5 cells quickly form an unconventional biofilm. In this study, we investigated the formation process of this unconventional biofilm, which started with cell–cell interactions, proceeded to cell clumping, and led to the formation of large cell aggregates. The cell–cell interaction was described by DLVO theory based on a new concept, which considers two independent interactions between two cell bodies and between two AtaA fiber tips forming a virtual discontinuous surface. If cell bodies cannot collide owing to an energy barrier at low ionic strengths but approach within the interactive distance of AtaA fibers, cells can agglutinate through their contact. Cell clumping proceeds following the cluster–cluster aggregation model, and an unconventional biofilm containing void spaces and a fractal nature develops. Understanding its formation process would extend the utilization of various types of biofilms, enhancing environmental biotechnologies.</p><p></p>

Filtration resistance induced by ammonia oxidizers accumulating on the rotating membrane disk

1998 ◽  
Vol 38 (4-5) ◽  
pp. 443-452
Author(s):  
Katsuki Kimura ◽  
Yoshimasa Watanabe ◽  
Naoki Ohkuma
Keyword(s):  
Membrane Filtration ◽  
Extracellular Polymeric Substances ◽  
Drinking Water Treatment ◽  
Treatment Method ◽  
Operating Conditions ◽  
Transmembrane Pressure ◽  
Ammonia Oxidizers ◽  
Filtration Resistance ◽  
Rotating Membrane Disk ◽  
Membrane Disk

Membrane filtration and oxidation of ammonia were simultaneously performed by using a rotating membrane disk module. Nitrification performance, composition of the accumulated cakes on the membrane and the filtration resistances were investigated under five different operating conditions. The filtration resistance due to the accumulated cake on the membrane was found to be dominant in this treatment method, compared to the resistance due to the micropore plugging or irreversible adherence. The cake consisted mainly of iron, humic substances and bacteria. The possibility that extracellular polymeric substances were related to the cake resistance was also shown. The composition of the cake depended on the length and the condition of operation. Accumulation of ammonia oxidizers caused by oxidation of low concentrations of ammonia (less than 1 mg/l) did not increase transmembrane pressure significantly. Therefore, the application of this treatment method for drinking water treatment is feasible. Filtration resistance due to the micropore plugging or irreversible adherence to the membrane was caused by organic substances.

In Vitro Elucidation of the Folding Intermediates and Aggregate Formation of Hemoglobin Induced by Acetonitrile: A Multispectroscopic Approach

2016 ◽  
Vol 23 (10) ◽  
pp. 884-891 ◽  
Author(s):  
Mohammad Furkan ◽  
Asim Rizvi ◽  
Mohammad Afsar ◽  
Mohammad Rehan Ajmal ◽  
Rizwan H. Khan ◽  
...  
Keyword(s):  
Aggregate Formation ◽  
Folding Intermediates

Antibiotics Application Strategies to Control Biofilm Formation in Pathogenic Bacteria

2020 ◽  
Vol 21 (4) ◽  
pp. 270-286 ◽  
Author(s):  
Fazlurrahman Khan ◽  
Dung T.N. Pham ◽  
Sandra F. Oloketuyi ◽  
Young-Mog Kim
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Extracellular Polymeric Substances ◽  
Quorum Quenching ◽  
Resistance Mechanisms ◽  
Bacterial Biofilm ◽  
Bacterial Cells ◽  
High Concentration ◽  
Biofilm Inhibition ◽  
Abiotic Surfaces

Background: The establishment of a biofilm by most pathogenic bacteria has been known as one of the resistance mechanisms against antibiotics. A biofilm is a structural component where the bacterial community adheres to the biotic or abiotic surfaces by the help of Extracellular Polymeric Substances (EPS) produced by bacterial cells. The biofilm matrix possesses the ability to resist several adverse environmental factors, including the effect of antibiotics. Therefore, the resistance of bacterial biofilm-forming cells could be increased up to 1000 times than the planktonic cells, hence requiring a significantly high concentration of antibiotics for treatment. Methods: Up to the present, several methodologies employing antibiotics as an anti-biofilm, antivirulence or quorum quenching agent have been developed for biofilm inhibition and eradication of a pre-formed mature biofilm. Results: Among the anti-biofilm strategies being tested, the sub-minimal inhibitory concentration of several antibiotics either alone or in combination has been shown to inhibit biofilm formation and down-regulate the production of virulence factors. The combinatorial strategies include (1) combination of multiple antibiotics, (2) combination of antibiotics with non-antibiotic agents and (3) loading of antibiotics onto a carrier. Conclusion: The present review paper describes the role of several antibiotics as biofilm inhibitors and also the alternative strategies adopted for applications in eradicating and inhibiting the formation of biofilm by pathogenic bacteria.

The roles of extracellular polymeric substances of Pandoraea sp. XY-2 in the removal of tetracycline

2020 ◽  
Vol 43 (11) ◽  
pp. 1951-1960
Author(s):  
Xueling Wu ◽  
Xiaoyan Wu ◽  
Xiangyu Zhou ◽  
Yichao Gu ◽  
Han Zhou ◽  
...  
Keyword(s):  
Extracellular Polymeric Substances
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