scholarly journals Light-induced Patterning of Electroactive Bacterial Biofilms

2021 ◽  
Author(s):  
Fengjie Zhao ◽  
Marko S Chavez ◽  
Kyle L Naughton ◽  
Christina M Cole ◽  
Jeffrey A Gralnick ◽  
...  
Keyword(s):  
Shewanella Oneidensis ◽  
Transparent Electrode ◽  
Genetic Circuit ◽  
Bacterial Biofilms ◽  
Intrinsic Conductivity ◽  
Electrode Surfaces ◽  
Pattern Size ◽  
Controlled Deposition ◽  
First Time ◽  
Size Controlling

Electroactive bacterial biofilms can function as living biomaterials that merge the functionality of living cells with electronic components. However, the development of such advanced living electronics has been challenged by the inability to control the geometry of electroactive biofilms relative to solid-state electrodes. Here, we developed a lithographic strategy to pattern conductive biofilms of Shewanella oneidensis by controlling aggregation protein CdrAB expression with a blue light-induced genetic circuit. This controlled deposition enabled S. oneidensis biofilm patterning on transparent electrode surfaces and measurements demonstrated tunable biofilm conduction dependent on pattern size. Controlling biofilm geometry also enabled us, for the first time, to quantify the intrinsic conductivity of living S. oneidensis biofilms and experimentally confirm predictions based on simulations of a recently proposed collision-exchange electron transport mechanism. Overall, we developed a facile technique for controlling electroactive biofilm formation on electrodes, with implications for both studying and harnessing bioelectronics.

scholarly journals Scribing Method for Carbon Perovskite Solar Modules

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1589 ◽  
Author(s):  
Simone M. P. Meroni ◽  
Katherine E. A. Hooper ◽  
Tom Dunlop ◽  
Jenny A. Baker ◽  
David Worsley ◽  
...  
Keyword(s):  
Screen Printing ◽  
Fill Factor ◽  
Transparent Electrode ◽  
Perovskite Solar Cell ◽  
Metal Contacts ◽  
Good Efficiency ◽  
Long Term Stability ◽  
First Time

The fully printable carbon triple-mesoscopic perovskite solar cell (C-PSC) has already demonstrated good efficiency and long-term stability, opening the possibility of lab-to-fab transition. Modules based on C-PSC architecture have been reported and, at present, are achieved through the accurate registration of each of the patterned layers using screen-printing. Modules based on this approach were reported with geometric fill factor (g-FF) as high as 70%. Another approach to create the interconnects, the so-called scribing method, was reported to achieve more than 90% g-FF for architectures based on evaporated metal contacts, i.e., without a carbon counter electrode. Here, for the first time, we adopt the scribing method to selectively remove materials within a C-PSC. This approach allowed a deep and selective scribe to open an aperture from the transparent electrode through all the layers, including the blocking layer, enabling a direct contact between the electrodes in the interconnects. In this work, a systematic study of the interconnection area between cells is discussed, showing the key role of the FTO/carbon contact. Furthermore, a module on 10 × 10 cm2 substrate with the optimised design showing efficiency over 10% is also demonstrated.

scholarly journals Persistence of antibiotic resistance plasmids in bacterial biofilms

2017 ◽  
Author(s):  
Benjamin J. Ridenhour ◽  
Genevieve A. Metzger ◽  
Michael France ◽  
Karol Gliniewicz ◽  
Jack Millstein ◽  
...  
Keyword(s):  
Health Care ◽  
Drug Resistance ◽  
Antibiotic Resistance ◽  
Multi Drug Resistance ◽  
Bacterial Biofilms ◽  
Antibiotic Selection ◽  
Batch Cultures ◽  
Liquid Cultures ◽  
Resistance Plasmids ◽  
First Time

ABSTRACTThe emergence and spread of antibiotic resistance is a crisis in health care today. Antibiotic resistance is often horizontally transferred to susceptible bacteria by means of multi-drug resistance plasmids that may or may not persist in the absence of antibiotics. Because bacterial pathogens often grow as biofilms, there is a need to better understand the evolution of plasmid persistence in these environments. Here we compared the evolution of plasmid persistence in the pathogen Acinetobacter baumannii when grown under antibiotic selection in biofilms versus well-mixed liquid cultures. After four weeks, clones in which the plasmid was more stably maintained in the absence of antibiotic selection were present in both populations. On average plasmid persistence increased more in liquid batch cultures, but variation in the degree of persistence was greater among biofilm-derived clones. The results of this study show for the first time that the persistence of MDR plasmids improves in biofilms.

scholarly journals In Situ Optical Quantification of Extracellular Electron Transfer from Shewanella oneidensis using Plasmonic Metal Oxide Nanocrystals

2020 ◽  
Author(s):  
Austin J. Graham ◽  
Stephen L. Gibbs ◽  
Camila A. Saez Cabezas ◽  
Yongdan Wang ◽  
Allison M. Green ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Metal Oxide ◽  
Shewanella Oneidensis ◽  
Genetic Circuit ◽  
Extracellular Electron Transfer ◽  
Materials Synthesis ◽  
Electron Model ◽  
Time Resolved ◽  
Optical Extinction

AbstractExtracellular electron transfer (EET) is a critical form of microbial metabolism that enables respiration on a variety of inorganic substrates, including metal oxides. For this reason, engineering EET processes has garnered significant interest for applications ranging from bioelectronics to materials synthesis. These applications require a strong understanding of electron flux from EET-relevant microbes. However, quantifying current generated by electroactive bacteria has been predominately limited to biofilms formed on electrodes, which require long incubation times, electrode colonization, and convolute contributions to EET from planktonic cells. To address this, we developed a platform for quantifying time-resolved EET flux from cell suspensions using aqueous dispersions of plasmonic tin-doped indium oxide nanocrystals. Tracking the change in optical extinction during electron transfer and fitting the optical response to a free electron model enabled quantification of current generation and electron transfer rate constants from planktonic Shewanella oneidensis cultures. Using this method, we differentiated between starved and actively respiring S. oneidensis, and between cells of varying genotype using an EET knockout strain. In addition, we quantified current production ranging from 0.12 – 0.68 fA • cell−1 from S. oneidensis cells engineered to differentially express a key EET gene using an inducible genetic circuit. Overall, our results validate the utility of colloidally stable plasmonic metal oxide nanocrystals as quantitative biosensors in native biological environments and contribute to a fundamental understanding of planktonic S. oneidensis electrophysiology using simple in situ spectroscopy.

Extending the shell-isolated nanoparticle-enhanced Raman spectroscopy approach to interfacial ionic liquids at single crystal electrode surfaces

2014 ◽  
Vol 50 (94) ◽  
pp. 14740-14743 ◽  
Author(s):  
Meng Zhang ◽  
Li-Juan Yu ◽  
Yi-Fan Huang ◽  
Jia-Wei Yan ◽  
Guo-Kun Liu ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Dft Calculations ◽  
Single Crystal ◽  
Electrode Surfaces ◽  
Structural Details ◽  
Single Crystal Electrode ◽  
First Time

We employ, for the first time, SHINERS to study single crystal electrode surfaces in ionic liquids, and combine DFT calculations to elucidate the structural details of imidazolium-based ionic liquid–Au single crystal electrode interfaces.

scholarly journals Depolymerization of β-1,6-N-Acetyl-d-Glucosamine Disrupts the Integrity of Diverse Bacterial Biofilms

2005 ◽  
Vol 187 (1) ◽  
pp. 382-387 ◽  
Author(s):  
Yoshikane Itoh ◽  
Xin Wang ◽  
B. Joseph Hinnebusch ◽  
James F. Preston ◽  
Tony Romeo
Keyword(s):  
Mass Spectrometry ◽  
Escherichia Coli ◽  
Enzymatic Hydrolysis ◽  
Pseudomonas Fluorescens ◽  
Yersinia Pestis ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Bacterial Biofilms ◽  
First Time ◽  
Hydrolysis Of

ABSTRACT Polymeric β-1,6-N-acetyl-d-glucosamine (poly-β-1,6-GlcNAc) has been implicated as an Escherichia coli and Staphylococcus epidermidis biofilm adhesin, the formation of which requires the pgaABCD and icaABCD loci, respectively. Enzymatic hydrolysis of poly-β-1,6-GlcNAc, demonstrated for the first time by chromatography and mass spectrometry, disrupts biofilm formation by these species and by Yersinia pestis and Pseudomonas fluorescens, which possess pgaABCD homologues.

13C pathway analysis of biofilm metabolism of Shewanella oneidensis MR-1

RSC Advances ◽  
2015 ◽  
Vol 5 (50) ◽  
pp. 39840-39843 ◽  
Author(s):  
Weihua Guo ◽  
Shuai Luo ◽  
Zhen He ◽  
Xueyang Feng
Keyword(s):  
Pathway Analysis ◽  
Shewanella Oneidensis ◽  
First Time

Biofilm metabolism ofShewanellawas analyzedvia13C tracing experiments for the first time.

scholarly journals Prevention of Encrustation on Ureteral Stents: Which Surface Parameters Provide Guidance for the Development of Novel Stent Materials?

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 558 ◽  
Author(s):  
Henrike Rebl ◽  
Jürgen Renner ◽  
Wolfgang Kram ◽  
Armin Springer ◽  
Nele Fritsch ◽  
...  
Keyword(s):  
Dry Mass ◽  
Ureteral Stent ◽  
Mineral Deposits ◽  
Bacterial Biofilms ◽  
Ureteral Stents ◽  
Surface Parameters ◽  
X Ray ◽  
Chemical Surface ◽  
First Time

Encrustations of ureteral stents are one of the biggest problems with urological implants. Crystalline biofilms can occur alone or in combination with bacterial biofilms. To identify which surface parameters provide guidance for the development of novel stent materials, we used an in vitro encrustation system. Synthetic urine with increasing pH to simulate an infection situation was pumped over the polymer samples with adjusted flow rates at 37 °C to mimic the native body urine flow. Chemical surface features (contact angle, surface charge), as well as encrustations were characterized. The encrustations on the materials were analyzed quantitatively (dry mass) and qualitatively using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR). The aim of this comparative study was to identify crucial surface parameters that might predict the quantity and type of mineral deposits in vitro and provide guidance for the development and screening of new polymer-based biomaterials for ureteral stent design. For the first time, we could identify that, within the range of our polymers, those materials with a slight hydrophilicity and a strong negative zeta potential (around −60 mV) were most favorable for use as ureteral stent materials, as the deposition of crystalline biofilms was minimized.

scholarly journals Geobacter sulfurreducensextracellular multiheme cytochrome PgcA facilitates respiration to Fe(III) oxides but not electrodes

2017 ◽  
Author(s):  
Lori Zacharoff ◽  
Dana Morrone ◽  
Daniel R. Bond
Keyword(s):  
Electron Transfer ◽  
Metal Oxides ◽  
Solid Phase ◽  
Shewanella Oneidensis ◽  
Helical Structure ◽  
Geobacter Sulfurreducens ◽  
Extracellular Electron Transfer ◽  
Mineral Surfaces ◽  
Electrode Surfaces ◽  
Multiheme Cytochrome

AbstractExtracellular cytochromes are hypothesized to facilitate the final steps of electron transfer between the outer membrane of the metal-reducing bacteriumGeobacter sulfurreducensand solid-phase electron acceptors such as metal oxides and electrode surfaces during the course of respiration. The trihemec-type cytochrome PgcA exists in the extracellular space ofG. sulfurreducens, and is one of many multihemec-type cytochromes known to be loosely bound to the bacterial outer surface. Deletion ofpgcAusing a markerless method resulted in mutants unable to transfer electrons to Fe(III) and Mn(IV) oxides; yet the same mutants maintained the ability to respire electrode surfaces and soluble Fe(III) citrate. When expressed and purified fromShewanella oneidensis, PgcA demonstrated a primarily alpha helical structure, three bound hemes, and was processed into a shorter 41 kDa form lacking the lipodomain. Purified PgcA bound Fe(III) oxides, but not magnetite, and when PgcA was added to cell suspensions ofG. sulfurreducens,PgcA accelerated Fe(III) reduction similar to addition of FMN. Addition of soluble PgcA to ∆pgcAmutants also restored Fe(III) reduction. This report highlights a distinction between proteins involved in extracellular electron transfer to metal oxides and poised electrodes, and suggests a specific role for PgcA in facilitating electron transfer at mineral surfaces.

scholarly journals FEATURES OF FORMATION OF BACTERIAL BIOFILMS IN CONDITIONS OF SPACE FLIGHT

2016 ◽  
pp. 3-10
Author(s):  
O. V. Rybalchenko ◽  
O. G. Orlova ◽  
O. N. Vishnevskaya ◽  
V. V. Kapustina ◽  
I. L. Potokin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
International Space Station ◽  
Space Flight ◽  
Space Station ◽  
Space Experiment ◽  
Bacterial Biofilms ◽  
Surface Conditions ◽  
International Space ◽  
Space Experiments ◽  
First Time

Aim. Study the effect of microgravitation on the formation of Lactobacillus plantarum 8PA-3 bacterial biofilms in the conditions of space flight. Materials and methods. Information on the effect of microgravitation on the development of biofilms was obtained during study of L. plantarum 8PA-3 probiotic lactobacilli in special equipment in the process of execution of space experiments in the Russian segment of the International Space Station. Comparative analysis of growth of plankton and biofilm forms of cells developing in the conditions of space flight and surface conditions was carried out by microbiologic and electron-microscopy methods using scanning and transmission electron microscopy. Results. Accelerated dynamics of formation of L. plantarum 8PA-3 lactobacilli biofilm on the surface of polymer substrate was shown for the first time during the space experiment. Microbiological analysis of the bacterial culture has also confirmed the accelerated growth of L. plantarum 8PA-3 under microgravitation compared with surface conditions. Ultrastructure of plankton form of L. plantarum 8PA-3 taking part in formation of biofilms in conditions of microgravitation was detected for the first time in the space experiment. Conclusion. Data on comparative electron-microscopic analysis obtained in space experiments are important for scientific justification of the effect of microgravitation on bacterial communities developing as biofilms - the most natural form of existence of microorganisms. The results obtained could be taken into consideration during creation of novel antibacterial means and disinfectants as well as methods of treatment of surfaces of modules of piloted space complexes that could allow to clarify methods of effective prophylaxis of biofilm spread which pose a risk of health of the crew and normal functioning of equipment in the International Space Station.

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