Silver Sink Effect of Humic Acid on Bacterial Surface Colonization in the Presence of Silver Ions and Nanoparticles

2017 ◽  
Vol 51 (3) ◽  
pp. 1754-1763 ◽  
Author(s):  
Alex J. Bertuccio ◽  
Robert D. Tilton
Keyword(s):  
Humic Acid ◽  
Silver Ions ◽  
Surface Colonization ◽  
Bacterial Surface ◽  
Sink Effect

scholarly journals Effects of Caribbean sponge secondary metabolites on bacterial surface colonization

2005 ◽  
Vol 40 ◽  
pp. 191-203 ◽  
Author(s):  
SR Kelly ◽  
E Garo ◽  
PR Jensen ◽  
W Fenical ◽  
JR Pawlik
Keyword(s):  
Secondary Metabolites ◽  
Surface Colonization ◽  
Bacterial Surface

scholarly journals Tad pili play a dynamic role in Caulobacter crescentus surface colonization

2019 ◽  
Author(s):  
Matteo Sangermani ◽  
Isabelle Hug ◽  
Nora Sauter ◽  
Thomas Pfohl ◽  
Urs Jenal
Keyword(s):  
Caulobacter Crescentus ◽  
Optical Trap ◽  
Natural Environments ◽  
Surface Attachment ◽  
Surface Colonization ◽  
Bacterial Surface ◽  
Controlled Flow ◽  
Mechanical Sensing

ABSTRACTBacterial surface attachment is mediated by rotary flagella and filamentous appendages called pili. Here, we describe the role of Tad pili during surface colonization of Caulobacter crescentus. Using an optical trap and microfluidic controlled flow conditions as a mimic of natural environments, we demonstrate that Tad pili undergo repeated cycles of extension and retraction. Within seconds after establishing surface contact, pili reorient cells into an upright position promoting walking-like movements against the medium flow. Pili-mediated positioning of the flagellated pole close to the surface facilitates motor-mediated mechanical sensing and promotes anchoring of the holdfast, an adhesive substance that affords long-term attachment. We present evidence that the second messenger c-di-GMP regulates pili dynamics during surface encounter in distinct ways, promoting increased activity at intermediate levels and retraction of pili at peak concentrations. We propose a model, in which flagellum and Tad pili functionally interact and together impose a ratchet-like mechanism that progressively drives C. crescentus cells towards permanent surface attachment.

scholarly journals Cross-Ocean Distribution of Rhodobacterales Bacteria as Primary Surface Colonizers in Temperate Coastal Marine Waters

2007 ◽  
Vol 74 (1) ◽  
pp. 52-60 ◽  
Author(s):  
Hongyue Dang ◽  
Tiegang Li ◽  
Mingna Chen ◽  
Guiqiao Huang
Keyword(s):  
Atlantic Coast ◽  
Adaptation Strategy ◽  
Current Data ◽  
Control Surface ◽  
Rrna Gene ◽  
Multivariate Statistical ◽  
Surface Colonization ◽  
Bacterial Surface ◽  
West Pacific Ocean ◽  
Bacterial Assemblages

ABSTRACT Bacterial surface colonization is a universal adaptation strategy in aquatic environments. However, neither the identities of early colonizers nor the temporal changes in surface assemblages are well understood. To determine the identities of the most common bacterial primary colonizers and to assess the succession process, if any, of the bacterial assemblages during early stages of surface colonization in coastal water of the West Pacific Ocean, nonnutritive inert materials (glass, Plexiglas, and polyvinyl chloride) were employed as test surfaces and incubated in seawater off the Qingdao coast in the spring of 2005 for 24 and 72 h. Phylogenetic analysis of the 16S rRNA gene sequences amplified from the recovered surface-colonizing microbiota indicated that diverse bacteria colonized the submerged surfaces. Multivariate statistical cluster analyses indicated that the succession of early surface-colonizing bacterial assemblages followed sequential steps on all types of test surfaces. The Rhodobacterales, especially the marine Roseobacter clade members, formed the most common and dominant primary surface-colonizing bacterial group. Our current data, along with previous studies of the Atlantic coast, indicate that the Rhodobacterales bacteria are the dominant and ubiquitous primary surface colonizers in temperate coastal waters of the world and that microbial surface colonization follows a succession sequence. A conceptual model is proposed based on these findings, which may have important implications for understanding the structure, dynamics, and function of marine biofilms and for developing strategies to harness or control surface-associated microbial communities.

Silver ion desorption kinetics from iron oxides and soil organic matter: effect of adsorption period

Soil Research ◽  
2004 ◽  
Vol 42 (1) ◽  
pp. 59 ◽  
Author(s):  
Jian Li ◽  
Andrew W. Rate ◽  
Robert J. Gilkes
Keyword(s):  
Experimental Data ◽  
Humic Acid ◽  
Significant Proportion ◽  
Silver Ions ◽  
Reaction Rates ◽  
Contact Period ◽  
Desorption Kinetics ◽  
Fe Oxides ◽  
Desorption Reaction ◽  
Soil Constituents

In order to have a better understanding of the mobility and bioavailability of silver in the environment, it is important to investigate the desorption behaviour of silver from some environmentally relevant soil components. Four single soil constituents (charcoal, humic acid, ferrihydrite, goethite) were chosen to investigate the rate of desorption of silver ions. The effect of reaction period between silver and the soil constituents on subsequent desorption was also investigated. A significant proportion of Ag+ sorbed by Fe oxides, humic acid, and charcoal cannot readily be desorbed back into solution. For goethite and humic acid, a longer contact period between Ag+ and the adsorbing phase caused subsequent slower rates of desorption, and a smaller proportion of adsorbed Ag+ was desorbed back into solution. Two-site and log-normal equations, assuming the desorption reaction was first-order, gave excellent fits to experimental data, except for Ag+ desorption from charcoal, in which case the kinetic experimental data fitted to a 1-site model better. The parameters obtained from the modelling provide information regarding the possible changes in metal–oxide binding and metal–humic acid complexing mechanisms, and these changes can be interpreted as a re-arrangement of Ag ions to sites with slower desorption reaction rates. All the reaction sites on charcoal have very similar desorption rates (rate constants), and these sites are relatively slow to desorb Ag. Fe oxides, and humic acid and charcoal could be very important sinks for Ag. The longer the Ag interacts with soils in environment, the less mobile Ag becomes, and the less toxic and bioavailable it will be to living organisms.

scholarly journals Characterization of initial events in bacterial surface colonization by twoPseudomonas species using image analysis

1992 ◽  
Vol 39 (11) ◽  
pp. 1161-1170 ◽  
Author(s):  
Robert F. Mueller ◽  
William G. Characklis ◽  
Warren L. Jones ◽  
John T. Sears
Keyword(s):  
Image Analysis ◽  
Surface Colonization ◽  
Bacterial Surface

scholarly journals Bacterial Surface Colonization of Sputter-Coated Platinum Films

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2674
Author(s):  
Dominika Czerwińska-Główka ◽  
Wioletta Przystaś ◽  
Ewa Zabłocka-Godlewska ◽  
Sebastian Student ◽  
Beata Cwalina ◽  
...  
Keyword(s):  
Thin Layer ◽  
Orthopedic Implants ◽  
Bacterial Biofilm ◽  
Surgical Instruments ◽  
Bacterial Cells ◽  
Biomedical Devices ◽  
Surface Colonization ◽  
Bacterial Surface ◽  
Coated Glass ◽  
Short Time

Due to its biocompatibility and advantageous electrochemical properties, platinum is commonly used in the design of biomedical devices, e.g., surgical instruments, as well as electro-medical or orthopedic implants. This article verifies the hypothesis that a thin layer of sputter-coated platinum may possess antibacterial effects. The purpose of this research was to investigate the adhesion and growth ability of a model strain of Gram-negative bacteria, Escherichia coli, on a surface of a platinum-coated glass slide. Although some previous literature reports suggests that a thin layer of platinum would inhibit the formation of bacterial biofilm, the results of this study suggest otherwise. The decrease in the number of bacterial cells attached to the platinum-coated glass, which was observed within first three hours of culturing, was found to be a short-time effect, vanishing after 24 h. Consequently, it was shown that a thin layer of sputter-coated platinum did not exhibit any antibacterial effect. For this reason, this study indicates an urgent need for the development of new methods of surface modification that could reduce bacterial surface colonization of platinum-based biomedical devices.

Effects of reduced graphene oxide on humic acid-mediated transformation and environmental risks of silver ions

2020 ◽  
Vol 385 ◽  
pp. 121597 ◽  
Author(s):  
Bin Dong ◽  
Guangfei Liu ◽  
Jiti Zhou ◽  
Jing Wang ◽  
Ruofei Jin ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Humic Acid ◽  
Reduced Graphene Oxide ◽  
Silver Ions ◽  
Environmental Risks ◽  
Reduced Graphene
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