Mitigation of Biofouling Through In-Plane Application of Weak DC Current in Presence of Antimicrobials

2015 ◽  
Author(s):  
Marshal Shahu Maskarenj ◽  
Ravi Chavali ◽  
Ankita Mathur ◽  
Prakash Chandra Ghosh ◽  
Sushanta Kumar Mitra
Keyword(s):  
Microbial Fuel Cells ◽  
Antimicrobial Agents ◽  
Permeate Flux ◽  
Promising Alternative ◽  
Membrane Biofouling ◽  
Wide Range ◽  
High Concentrations ◽  
Dc Current

Membrane Bio Reactor (MBR) technology is a promising alternative to municipal and industrial wastewater treatment owing to low sludge production and wide range of acceptable influents. Biofouling in MBRs hampers long term functionality of the system through reduction in permeate flux over time. Membrane biofouling could necessitate periodic membrane backwashing or even require membrane replacement, thus increasing operational cost for the systems. Microbe-secreted extracellular polymeric substance (EPS) forms a complex matrix on the surface; is persistent against physical removal and tends to resist high concentrations of antimicrobial agents, thus playing a major role in membrane biofouling. There is a need for developing methods towards efficient removal of biofoulants from surfaces. In tandem with low DC current, the synergistic effect of antimicrobial agents has been reported successful towards reducing biofilm formation leading to biofouling. This paper discusses the application of in-plane bioelectric effect as a solution to biofouling in MBRs; especially Microbial Fuel Cells and Microbial Desalination Cells towards harnessing in-situ current for tackling biofouling, thus facilitating longer system functionality.

scholarly journals Global soil moisture data derived through machine learning trained with in-situ measurements

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Sungmin O. ◽  
Rene Orth
Keyword(s):  
Machine Learning ◽  
Soil Moisture ◽  
Large Scale ◽  
Short Term Memory ◽  
Temporal Dynamics ◽  
Soil Moisture Data ◽  
Wide Range ◽  
Global Soil

AbstractWhile soil moisture information is essential for a wide range of hydrologic and climate applications, spatially-continuous soil moisture data is only available from satellite observations or model simulations. Here we present a global, long-term dataset of soil moisture derived through machine learning trained with in-situ measurements, SoMo.ml. We train a Long Short-Term Memory (LSTM) model to extrapolate daily soil moisture dynamics in space and in time, based on in-situ data collected from more than 1,000 stations across the globe. SoMo.ml provides multi-layer soil moisture data (0–10 cm, 10–30 cm, and 30–50 cm) at 0.25° spatial and daily temporal resolution over the period 2000–2019. The performance of the resulting dataset is evaluated through cross validation and inter-comparison with existing soil moisture datasets. SoMo.ml performs especially well in terms of temporal dynamics, making it particularly useful for applications requiring time-varying soil moisture, such as anomaly detection and memory analyses. SoMo.ml complements the existing suite of modelled and satellite-based datasets given its distinct derivation, to support large-scale hydrological, meteorological, and ecological analyses.

Characteristics of natural neutron radiation background performed within the BSUIN project.

2020 ◽  
Author(s):  
Karol Jedrzejczak ◽  
Marcin Kasztelan ◽  
Jacek Szabelski ◽  
Przemysław Tokarski ◽  
Jerzy Orzechowski ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Background Radiation ◽  
Neutron Radiation ◽  
Radiation Background ◽  
Term Operation ◽  
Baltic Sea Region ◽  
Wide Range ◽  
The Baltic

<p>The BSUIN (Baltic Sea Underground Innovation Network) aims to enhance the accessibility of the underground laboratories in the Baltic Sea region for innovation, business and science. One of the BSUIN project activities is characterization of natural background radiation (NBR) in underground facilities. A specific type of NRB is neutron radiation, whose measurement requires specific instruments and long-term exposure in-situ, in heavy underground conditions.</p><p>In this talk the method of natural neutron radiation background will be presented as well as results of pilot measurements in several underground locations. In order to make this measurements, a measuring setup was designed and made. The setup design is closely matched to the task: the setup is scalable in a wide range, completely remotely controlled (via the Internet) and capable of long-term operation (months).</p><p>The pilot measurements were performed in Callio Lab, Pyhäsalmi, Finland, (4100 m w.e.), in Reiche Zeche mine in Freiberg, Germany (410 m w.e.) and in Experimental Mine “Barbara” in Mikołów, Poland (100 m w.e).</p>

scholarly journals The Shewanella genus: ubiquitous organisms sustaining and preserving aquatic ecosystems

2020 ◽  
Vol 44 (2) ◽  
pp. 155-170 ◽  
Author(s):  
Olivier N Lemaire ◽  
Vincent Méjean ◽  
Chantal Iobbi-Nivol
Keyword(s):  
Microbial Fuel Cells ◽  
Aquatic Ecosystems ◽  
Ecological Niches ◽  
Biological Interactions ◽  
Biotechnological Applications ◽  
Inorganic Matter ◽  
Wide Range ◽  
Molecular Determinants ◽  
Metallic Pollutants

ABSTRACT The Gram-negative Shewanella bacterial genus currently includes about 70 species of mostly aquatic γ­-proteobacteria, which were isolated around the globe in a multitude of environments such as surface freshwater and the deepest marine trenches. Their survival in such a wide range of ecological niches is due to their impressive physiological and respiratory versatility. Some strains are among the organisms with the highest number of respiratory systems, depending on a complex and rich metabolic network. Implicated in the recycling of organic and inorganic matter, they are important components of organism-rich oxic/anoxic interfaces, but they also belong to the microflora of a broad group of eukaryotes from metazoans to green algae. Examples of long-term biological interactions like mutualism or pathogeny have been described, although molecular determinants of such symbioses are still poorly understood. Some of these bacteria are key organisms for various biotechnological applications, especially the bioremediation of hydrocarbons and metallic pollutants. The natural ability of these prokaryotes to thrive and detoxify deleterious compounds explains their use in wastewater treatment, their use in energy generation by microbial fuel cells and their importance for resilience of aquatic ecosystems.

scholarly journals Survival of and In Situ Gene Expression by Vibrio vulnificus at Varying Salinities in Estuarine Environments

2007 ◽  
Vol 74 (1) ◽  
pp. 182-187 ◽  
Author(s):  
Melissa K. Jones ◽  
Elizabeth Warner ◽  
James D. Oliver
Keyword(s):  
Gene Expression ◽  
Vibrio Vulnificus ◽  
Natural Habitat ◽  
Term Survival ◽  
Long Term Survival ◽  
Wide Range ◽  
Opportunistic Human Pathogen

ABSTRACT The opportunistic human pathogen Vibrio vulnificus survives in a wide range of ecological environments, which demonstrates its ability to adapt to highly variable conditions. Survival and gene expression under various conditions have been extensively studied in vitro; however, little work has been done to evaluate this bacterium in its natural habitat. Therefore, this study monitored the long-term survival of V. vulnificus in situ and simultaneously evaluated the expression of stress (rpoS, relA, hfq, and groEL) and putative virulence (vvpE, smcR, viuB, and trkA) genes at estuarine sites of varying salinity. Additionally, the survival and gene expression of an rpoS and an oxyR mutant were examined under the same conditions. Differences between the sampling sites in the long-term survival of any strain were not seen. However, differences were seen in the expression of viuB, trkA, and relA but our findings differed from what has been previously shown in vitro. These results also routinely demonstrated that genes required for survival under in vitro stress or host conditions are not necessarily required for survival in the water column. Overall, this study highlights the need for further in situ evaluation of this bacterium in order to gain a true understanding of its ecology and how it relates to its natural habitat.

Coupling anaerobic bacteria and microbial fuel cells as whole-cell environmental biosensors

2015 ◽  
Vol 36 (3) ◽  
pp. 129 ◽  
Author(s):  
Lara T Bereza-Malcolm ◽  
Ashley E Franks
Keyword(s):  
Environmental Factors ◽  
Microbial Fuel Cells ◽  
Abiotic Factors ◽  
Anaerobic Bacteria ◽  
Whole Cell ◽  
Biologically Relevant ◽  
Anaerobic Microorganisms ◽  
Wide Range ◽  
Relevant Factors

Microorganisms have evolved to respond to environmental factors allowing adaption to changing conditions and minimisation of potential harm. Microbes have the ability to sense a wide range of biotic and abiotic factors including nutrient levels, analytes, temperature, contaminants, community quorum, and metabolic activity. Due to this ability, the use of whole-cell microbes as biosensors is attractive as it can provide real-time in situ information on biologically relevant factors through qualitative and quantitative outputs. Interestingly, many of the environments where these biosensors will be of most of use lack oxygen; and as such the use of anaerobic microorganisms to sense environmental factors with easy to use outputs is essential. Furthermore, sensing of contaminants can be linked with bioremediation of known contaminated environments, allowing a flexible, multiplexed device.

scholarly journals Tracing the Acetalization of Cyclohexanone in CO2-Expanded Alcohols by Attenuated Total Reflection Infrared Spectroscopy

2009 ◽  
Vol 63 (9) ◽  
pp. 1008-1014 ◽  
Author(s):  
Tsunetake Seki ◽  
Jean-Michel Andanson ◽  
Fabian Jutz ◽  
Alfons Baiker
Keyword(s):  
Ir Spectroscopy ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Znse Crystal ◽  
Promising Alternative ◽  
Practical Tool ◽  
Acidic Conditions ◽  
Kinetics Of

The CO2-catalyzed acetalization is regarded as a promising alternative to the conventional acid-catalyzed method from a viewpoint of green chemistry (C. A. Eckert et al., Ind. Eng. Chem. Res. 43, 2605 (2004)). We have applied in situ attenuated total reflection infrared (ATR-IR) spectroscopy for elucidating and monitoring the acetalization of cyclohexanone in CO2-expanded ethylene glycol and methanol at 50 °C and 3 MPa. The ATR-IR spectra of the reaction mixtures periodically recorded with a ZnSe crystal demonstrate that ATR-IR spectroscopy is a practical tool for tracing the kinetics of acetalizations in situ. In addition, the rate of CO2 dissolution as well as CO2 solubility into the cyclohexanone–alcohol mixtures could be evaluated from the CO2-v3-antisymmetric stretching band. The ZnSe ATR crystal, however, was corroded during longer use under the acidic conditions realized by the dissolution of CO2 in the alcohols. In contrast, the corrosion did not occur when a Ge crystal was used instead of a ZnSe crystal, and therefore the application of a Ge ATR crystal is recommended for continuous long-term experiments with these media.

Mesenchymal stem cells distribute to a wide range of tissues following systemic infusion into nonhuman primates

Blood ◽  
2003 ◽  
Vol 101 (8) ◽  
pp. 2999-3001 ◽  
Author(s):  
Steven M. Devine ◽  
Carrington Cobbs ◽  
Matt Jennings ◽  
Amelia Bartholomew ◽  
Ron Hoffman
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Fluorescent Protein ◽  
Ex Vivo ◽  
Wide Range ◽  
High Concentrations ◽  
Cellular Turnover ◽  
Total Body ◽  
Green Fluorescent

Abstract Ex vivo–expanded mesenchymal stem cells (MSCs) were transduced with a green fluorescent protein (GFP) retroviral construct and subsequently infused into 3 adult baboons following lethal total body irradiation and hematopoietic support or without any prior conditioning. To study the long-term fate of these MSCs, necropsies were performed between 9 and 21 months following MSC infusion, and an average of 16 distinct tissues were recovered from each recipient and evaluated for the presence of the GFP transgene in purified genomic DNA by sensitive real-time polymerase chain reaction (PCR). Two baboons received autologous and one allogeneic GFP-transduced MSCs. Both allogeneic and autologous MSCs appeared to distribute in a similar manner. Gastrointestinal tissues harbored high concentrations of transgene per microgram of DNA. Additional tissues including kidney, lung, liver, thymus, and skin were also found to contain relatively high amounts of DNA equivalents. Estimated levels of engraftment in these tissues ranged from 0.1% to 2.7%. The nonconditioned recipient appeared to have less abundant engraftment. These data suggest that MSCs initially distribute broadly following systemic infusion and later may participate in ongoing cellular turnover and replacement in a wide variety of tissues.

scholarly journals A Liquid Hydrogel to Restore Long Term Corneal Integrity After Perforating and Non-Perforating Trauma in Feline Eyes

2021 ◽  
Vol 9 ◽  
Author(s):  
Alejandro Juarez ◽  
Mohamed Djallali ◽  
Marilyse Piché ◽  
Mathieu Thériault ◽  
Marc Groleau ◽  
...  
Keyword(s):  
Corneal Transplantation ◽  
Specular Microscopy ◽  
Slit Lamp ◽  
Cyanoacrylate Glue ◽  
Promising Alternative ◽  
A Cell ◽  
Feline Model

Purpose: To evaluate long-term in vivo functionality of corneas regenerated using a cell-free, liquid hydrogel filler (LiQD Cornea) after deep corneal trauma in the feline model.Methods: Two healthy cats underwent 4 mm diameter stepwise 250/450 µm deep surgical corneal ablation with and without needle perforation. The filler comprising 10% (w/w) collagen-like peptide conjugated to polyethylene glycol (CLP-PEG) and 1% fibrinogen and crosslinked with 2% (w/w) 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM), was applied to the wound bed previously coated with thrombin (250 U/ml). In situ gelation occurred within 5 min, and a temporary tarsorrhaphy was performed. Eyes were examined weekly for 1 month, then monthly over 12 months. Outcome parameters included slit-lamp, Scheimpflug tomography, optical coherence tomography, confocal and specular microscopy, and immunohistochemistry studies.Results: The gelled filler was seamlessly incorporated, supporting smooth corneal re-epithelialization. Progressive in-growth of keratocytes and nerves into the filler corresponding to the mild haze observed faded with time. The regenerated neo-cornea remained stably integrated throughout the 12 months, without swelling, inflammation, infection, neovascularization, or rejection. The surrounding host stroma and endothelium remained normal at all times. Tomography confirmed restoration of a smooth surface curvature.Conclusion: Biointegration of this hydrogel filler allowed stable restoration of corneal shape and transparency in the feline model, with less inflammation and no neovascularization compared to previous reports in the minipig and rabbit models. It offers a promising alternative to cyanoacrylate glue and corneal transplantation for ulcerated and traumatized corneas in human patients.

scholarly journals Patients with Long-Term Oral Carriage Harbor High-Persister Mutants of Candida albicans

2009 ◽  
Vol 54 (1) ◽  
pp. 39-44 ◽  
Author(s):  
Michael D. LaFleur ◽  
Qingguo Qi ◽  
Kim Lewis
Keyword(s):  
Candida Albicans ◽  
Amphotericin B ◽  
Antimicrobial Agents ◽  
Oral Candidiasis ◽  
Wild Type ◽  
Persister Cells ◽  
Microtiter Plates ◽  
High Concentrations

ABSTRACT Fungal biofilms produce a small number of persister cells which can tolerate high concentrations of fungicidal agents. Persisters form upon attachment to a surface, an important step in the pathogenesis of Candida strains. The periodic application of antimicrobial agents may select for strains with increased levels of persister cells. In order to test this possibility, 150 isolates of Candida albicans and C. glabrata were obtained from cancer patients who were at high risk for the development of oral candidiasis and who had been treated with topical chlorhexidine once a day. Persister levels were measured by exposing biofilms growing in the wells of microtiter plates to high concentrations of amphotericin B and plating for survivors. The persister levels of the isolates varied from 0.2 to 9%, and strains isolated from patients with long-term carriage had high levels of persisters. High-persister strains were isolated from every patient with Candida carriage of more than 8 consecutive weeks but from no patients with transient carriage. All of the high-persister isolates had an amphotericin B MIC that was the same as that for the wild type, indicating that these strains were drug-tolerant rather than drug-resistant mutants. Biofilms of the majority of high-persister strains also showed an increased tolerance to chlorhexidine and had the same MIC for this antimicrobial as the wild type. This study suggests that persister cells are clinically relevant, and antimicrobial therapy selects for high-persister strains in vivo. The drug tolerance of persisters may be a critical but overlooked component responsible for antimicrobial drug failure and relapsing infections.

scholarly journals Functional Analysis and Antivirulence Properties of a New Depolymerase from a Myovirus That Infects Acinetobacter baumannii Capsule K45

2018 ◽  
Vol 93 (4) ◽  
Author(s):  
Hugo Oliveira ◽  
Ana Rita Costa ◽  
Alice Ferreira ◽  
Nico Konstantinides ◽  
Sílvio B. Santos ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Therapeutic Potential ◽  
Host Immune System ◽  
Promising Alternative ◽  
Content Type ◽  
A Genome ◽  
Wide Range

ABSTRACT Acinetobacter baumannii is an important pathogen causative of health care-associated infections and is able to rapidly develop resistance to all known antibiotics, including colistin. As an alternative therapeutic agent, we have isolated a novel myovirus (vB_AbaM_B9) which specifically infects and makes lysis from without in strains of the K45 and K30 capsule types, respectively. Phage B9 has a genome of 93,641 bp and encodes 167 predicted proteins, of which 29 were identified by mass spectrometry. This phage holds a capsule depolymerase (B9gp69) able to digest extracted exopolysaccharides of both K30 and K45 strains and remains active in a wide range of pH values (5 to 9), ionic strengths (0 to 500 mM), and temperatures (20 to 80°C). B9gp69 was demonstrated to be nontoxic in a cell line model of the human lung and to make the K45 strain fully susceptible to serum killing in vitro. Contrary to the case with phage, no resistance development was observed by bacteria targeted with the B9gp69. Therefore, capsular depolymerases may represent attractive antimicrobial agents against A. baumannii infections. IMPORTANCE Currently, phage therapy has revived interest for controlling hard-to-treat bacterial infections. Acinetobacter baumannii is an emerging Gram-negative pathogen able to cause a variety of nosocomial infections. Additionally, this species is becoming more resistant to several classes of antibiotics. Here we describe the isolation of a novel lytic myophage B9 and its recombinant depolymerase. While the phage can be a promising alternative antibacterial agent, its success in the market will ultimately depend on new regulatory frameworks and general public acceptance. We therefore characterized the phage-encoded depolymerase, which is a natural enzyme that can be more easily managed and used. To our knowledge, the therapeutic potential of phage depolymerase against A. baumannii is still unknown. We show for the first time that the K45 capsule type is an important virulence factor of A. baumannii and that capsule removal via the recombinant depolymerase activity helps the host immune system to combat the bacterial infection.

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