scholarly journals Recombinant expression of Proteorhodopsin and biofilm regulators in Escherichia coli for nanoparticle binding and removal in a wastewater treatment model

2018 ◽  
Author(s):  
Justin Yang ◽  
Yvonne Wei ◽  
Catherine Yeh ◽  
Florence Liou ◽  
William Chen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Wastewater Treatment ◽  
Recombinant Expression ◽  
High Surface ◽  
Volume Ratio ◽  
Data Availability ◽  
Supplementary Information ◽  
Design Data ◽  
Aquatic Life ◽  
Competing Interests

AbstractThe small size of nanoparticles is both an advantage and a problem. Their high surface-area-to-volume ratio enables novel medical, industrial, and commercial applications. However, their small size also allows them to evade conventional filtration during water treatment, posing health risks to humans, plants, and aquatic life. This project aims to remove nanoparticles during wastewater treatment using genetically modified Escherichia coli in two ways: 1) binding citrate-capped nanoparticles with the membrane protein Proteorhodopsin, and 2) trapping nanoparticles using Escherichia coli biofilm produced by overexpressing two regulators: OmpR234 and CsgD. We demonstrate experimentally that Escherichia coli expressing Proteorhodopsin binds to 60 nm citrate-capped silver nanoparticles. We also successfully upregulate biofilm production and show that Escherichia coli biofilms are able to trap 30 nm gold particles. Finally, both Proteorhodopsin and biofilm approaches are able to bind and remove nanoparticles in simulated wastewater treatment tanks. We envision integrating our trapping system in both rural and urban wastewater treatment plants to efficiently capture all nanoparticles before treated water is released into the environment.Financial DisclosureThis work was funded by the Taipei American School. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Competing InterestsThe authors have declared that no competing interests exist.Ethics StatementN/AData AvailabilityYes – all data are fully available without restriction. Sequences for the plasmids used in this study are available through the Registry of Standard Biological Parts. Links to raw data are included in Supplementary Information.

scholarly journals Recombinant Expression of Aldehyde Dehydrogenase 2 (ALDH2) inEscherichia coliNissle 1917 for Oral Delivery in ALDH2-Deficient Individuals

2019 ◽  
Author(s):  
Tim Ho ◽  
Catherine Chang ◽  
Justin Wu ◽  
Iris Huang ◽  
Leona Tsai ◽  
...  
Keyword(s):  
Aldehyde Dehydrogenase ◽  
Oral Delivery ◽  
Recombinant Expression ◽  
Data Availability ◽  
Supplementary Information ◽  
Aldehyde Dehydrogenase 2 ◽  
Design Data ◽  
E Coli ◽  
Competing Interests ◽  
Oral Conditions

AbstractTurning red after consuming alcohol may seem like a mere social inconvenience. Yet, this flushing response is caused by an accumulation of acetaldehyde, a carcinogenic intermediate of alcohol metabolism. Aldehyde dehydrogenase 2 (ALDH2) deficiency, the result of a point mutation, produces a less efficient ALDH2. The resulting accumulation of acetaldehyde greatly increases the risk of developing esophageal and head and neck cancers. In this study, we produced recombinant ALDH2 in the probioticE. coliNissle 1917, which successfully reduces acetaldehyde levels in simulated oral conditions. Packaged in a hard candy, the ALDH2-probiotic would remain in the mouth to specifically target salivary acetaldehyde. Using mathematical modeling, we also determined how much recombinant ALDH2 is needed to reduce elevated acetaldehyde levels.Financial DisclosureThis work was funded by Taipei American School. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Competing InterestsThe authors have declared that no competing interests exist.Ethics StatementN/AData AvailabilityYes – all data are fully available without restriction. Sequences for the plasmids used in this study are available through the Registry of Standard Biological Parts. Links to raw data are included in Supplementary Information.

scholarly journals Quantification of DNA samples by Ethidium Bromide Spot Technique

2018 ◽  
Author(s):  
Jessica Zhao ◽  
Julian Zhao ◽  
Antoine Cummins ◽  
Tiffany Gonzalez ◽  
Grace Axler-DiPerte ◽  
...  
Keyword(s):  
Ethidium Bromide ◽  
Uv Light ◽  
Spot Size ◽  
Data Availability ◽  
Supplementary Information ◽  
Design Data ◽  
Dna Concentration ◽  
Standard Curve ◽  
Competing Interests ◽  
Concentration Method

AbstractAccurate and quick determination of DNA concentration is critical for the assembly of synthetic constructs, as well as a multitude of other experiments. We sought to optimize an under-utilized and inexpensive approach for determining DNA concentration: a spotting technique that uses the intercalating dye Ethidium Bromide. This technique does not require specialized equipment such as a spectrophotometer, but instead relies on visualization of dye-DNA complex fluorescence when excited by UV light. We modelled and tested a range of parameters for dye concentration and spot size, finding that 15uL spots with 1.0ug/mL Ethidium Bromide produced the most reliable standard curve. More importantly, we hope that our approach can help other labs optimize this protocol for their own experimental setup. Adoption of this technique may help enable development of iGEM teams in resource limited environments and laboratories which do not or cannot employ a satisfactory method for determining DNA concentration.Financial DisclosureWe obtained funding support from Canon Solutions America, and indirect support for this work through the CUNY Research Scholars Program. However, the funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Competing InterestsThe authors have declared that no competing interests exist.Ethics StatementN/AData AvailabilityYes – all data are fully available without restriction. The data can be found in the associated supplementary materials.Article TagsDNA, Ethidium Bromide, EtBr, Concentration, Method, UV, Gibson AssemblyHeader StatementThis work was assessed during the iGEM/PLOS Realtime Peer Review Jamboree on 23rd February 2018 and has been revised in response to the reviewers. Responses to Reviewers, and supplementary information (including Fig. S1) are available as separate files.

scholarly journals Characterization ofAzotobacter vinelandiiand Kits for Its Synthetic Biology Applications

2017 ◽  
Author(s):  
King Pong Leung ◽  
Jacky Fong Chuen Loo ◽  
Leo Chi U Seak ◽  
Tung Faat Lai ◽  
Kevin Yuk Lap Yip ◽  
...  
Keyword(s):  
Synthetic Biology ◽  
Azotobacter Vinelandii ◽  
Transmembrane Protein ◽  
Data Availability ◽  
Aerobic Bacterium ◽  
Design Data ◽  
Competing Interests ◽  
Enzymatic Cascades ◽  
Oxygen Sensitive ◽  
Anaerobic Environment

AbstractAzotobacter vinelandii, a Gram-negative aerobic bacterium with an intracellular anaerobic environment that maintains the oxygen-sensitive enzymatic cascades for nitrogen fixation, could be used to express oxygen-sensitive proteins. However, little is known about the properties ofA. vinelandiifor synthetic biology applications. We therefore first characterized and optimized the conditions for growing and screening BioBrick constructs inA. vinelandiiin the presence of 2 antibiotics, ampicillin and chloramphenicol, and then developed two sets of BioBricks for regulated protein expression. The first kit used T7 RNA polymerase, whose expression is under the control of a nitrogen-repressiblenifHpromoter. The commonly used T7-dependent system inEscherichia colican then be used inA. vinelandii. Because its intracellular anaerobic environment is favorable for processes such as magnetosome biogenesis, we attempted to migrate the biogenesis machineries from the magnetotactic bacteriumMagnetospirillum gryphiswaldensetoA. vinelandii. During this undertaking, another insertion kit construct was developed to allow protein conjugation onto magnetosomes. The kit consists ofmamC, a gene encoding a transmembrane protein on magnetosomes, and multiple restriction sites downstream ofmamCfor fusing a gene of interest. This insertion kit allows the attachment of any desired protein onto the magnetosome membrane by fusing with the mamC protein. We demonstrated the function of this kit by fusing mamC to a GFP nanobody. This kit will facilitate the conjugation of any target protein onto magnetosomes for downstream applications in the future.Financial DisclosureWe received sponsorship from the 2012–15 Teaching Development Grants Triennium, Faculty of Engineering and Biochemistry Program, School of Life Sciences, The Chinese University of Hong Kong. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.Competing InterestsThe authors declare that no competing interests exist.Ethics StatementN/A.Data AvailabilityAll data are fully available without restriction.

scholarly journals Nanotechnology in Wastewater Management: A New Paradigm Towards Wastewater Treatment

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1797
Author(s):  
Keerti Jain ◽  
Anand S. Patel ◽  
Vishwas P. Pardhi ◽  
Swaran Jeet Singh Flora
Keyword(s):  
Wastewater Treatment ◽  
High Surface ◽  
Volume Ratio ◽  
High Sensitivity ◽  
Wastewater Management ◽  
High Adsorption ◽  
New Paradigm ◽  
Sensing Technology ◽  
Human Need ◽  
By Products

Clean and safe water is a fundamental human need for multi-faceted development of society and a thriving economy. Brisk rises in populations, expanding industrialization, urbanization and extensive agriculture practices have resulted in the generation of wastewater which have not only made the water dirty or polluted, but also deadly. Millions of people die every year due to diseases communicated through consumption of water contaminated by deleterious pathogens. Although various methods for wastewater treatment have been explored in the last few decades but their use is restrained by many limitations including use of chemicals, formation of disinfection by-products (DBPs), time consumption and expensiveness. Nanotechnology, manipulation of matter at a molecular or an atomic level to craft new structures, devices and systems having superior electronic, optical, magnetic, conductive and mechanical properties, is emerging as a promising technology, which has demonstrated remarkable feats in various fields including wastewater treatment. Nanomaterials encompass a high surface to volume ratio, a high sensitivity and reactivity, a high adsorption capacity, and ease of functionalization which makes them suitable for application in wastewater treatment. In this article we have reviewed the techniques being developed for wastewater treatment using nanotechnology based on adsorption and biosorption, nanofiltration, photocatalysis, disinfection and sensing technology. Furthermore, this review also highlights the fate of the nanomaterials in wastewater treatment as well as risks associated with their use.

scholarly journals One-Pot Synthesis of SiO2@Ag Mesoporous Nanoparticle Coating for Inhibition of Escherichia coli Bacteria on Various Surfaces

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 549
Author(s):  
Sukhbayar Gankhuyag ◽  
Dong Sik Bae ◽  
Kyoung Lee ◽  
Seunghyun Lee
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Impregnation Method ◽  
Ag Nps ◽  
One Pot ◽  
E Coli ◽  
Escherichia Coli Bacteria

Silver nanoparticles (Ag NPs) as antibacterial agents are of considerable interest owing to their simplicity, high surface area to volume ratio, and efficient oligodynamic properties. Hence, we investigated the synthesis of silica-supported Ag NPs (SiO2@Ag) as an effective antibacterial agent by using a wet-impregnation method. The formation of SiO2@Ag with Ag NP (5–15 nm diameter) on the silica particle (100–130 nm diameter) was confirmed with transmission electron microscopy (TEM). The study on antibacterial activity was performed in a liquid culture to determine the minimum inhibitory concentration (MIC) against Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) bacteria. Both bacteria are chosen to understand difference in the effect of Ag NPs against Gram-negative (E. coli) and Gram-positive (B. subtilis) bacteria. SiO2@Ag mesoporous nanoparticles had excellent antibacterial activity against E. coli bacteria and fully restricted the bacterial growth when the material concentration was increased up to 1.00 mg/mL. In addition, the obtained material had good adhesion to both steel and polyethylene substrates and exhibited a high inhibition effect against E. coli bacteria.

scholarly journals Electrospun Nanofibers for Sensing and Biosensing Applications—A Review

2021 ◽  
Vol 22 (12) ◽  
pp. 6357
Author(s):  
Kinga Halicka ◽  
Joanna Cabaj
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Toxic Metal ◽  
Volume Ratio ◽  
Electrospun Nanofibers ◽  
Clinical Diagnostics ◽  
Loading Capacity ◽  
Electrospun Nanofiber ◽  
Sensing Platforms ◽  
Different Types

Sensors and biosensors have found applications in many areas, e.g., in medicine and clinical diagnostics, or in environmental monitoring. To expand this field, nanotechnology has been employed in the construction of sensing platforms. Because of their properties, such as high surface area to volume ratio, nanofibers (NFs) have been studied and used to develop sensors with higher loading capacity, better sensitivity, and faster response time. They also allow to miniaturize designed platforms. One of the most commonly used techniques of the fabrication of NFs is electrospinning. Electrospun NFs can be used in different types of sensors and biosensors. This review presents recent studies concerning electrospun nanofiber-based electrochemical and optical sensing platforms for the detection of various medically and environmentally relevant compounds, including glucose, drugs, microorganisms, and toxic metal ions.

scholarly journals Study of the geometry of open channels in a layer-bed-type microfluidic immobilized enzyme reactor

2021 ◽  
Author(s):  
Cynthia Nagy ◽  
Robert Huszank ◽  
Attila Gaspar
Keyword(s):  
Immobilized Enzyme ◽  
High Surface ◽  
Volume Ratio ◽  
Volumetric Flow Rate ◽  
Enzyme Reactor ◽  
Channel Pattern ◽  
Immobilized Enzyme Reactor ◽  
Split Flow ◽  
Parallel Streams ◽  
Enzymatic Microreactors

AbstractThis paper aims at studying open channel geometries in a layer-bed-type immobilized enzyme reactor with computer-aided simulations. The main properties of these reactors are their simple channel pattern, simple immobilization procedure, regenerability, and disposability; all these features make these devices one of the simplest yet efficient enzymatic microreactors. The high surface-to-volume ratio of the reactor was achieved using narrow (25–75 μm wide) channels. The simulation demonstrated that curves support the mixing of solutions in the channel even in strong laminar flow conditions; thus, it is worth including several curves in the channel system. In the three different designs of microreactor proposed, the lengths of the channels were identical, but in two reactors, the liquid flow was split to 8 or 32 parallel streams at the inlet of the reactor. Despite their overall higher volumetric flow rate, the split-flow structures are advantageous due to the increased contact time. Saliva samples were used to test the efficiencies of the digestions in the microreactors. Graphical abstract

scholarly journals A Review on Biosensors and Recent Development of Nanostructured Materials-Enabled Biosensors

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1109
Author(s):  
Varnakavi. Naresh ◽  
Nohyun Lee
Keyword(s):  
High Surface ◽  
Three Dimensional ◽  
Biological Response ◽  
Volume Ratio ◽  
Recent Decade ◽  
Disease Diagnosis ◽  
Electrical Signal ◽  
Detection Sensitivity ◽  
Wide Range ◽  
Color Tunability

A biosensor is an integrated receptor-transducer device, which can convert a biological response into an electrical signal. The design and development of biosensors have taken a center stage for researchers or scientists in the recent decade owing to the wide range of biosensor applications, such as health care and disease diagnosis, environmental monitoring, water and food quality monitoring, and drug delivery. The main challenges involved in the biosensor progress are (i) the efficient capturing of biorecognition signals and the transformation of these signals into electrochemical, electrical, optical, gravimetric, or acoustic signals (transduction process), (ii) enhancing transducer performance i.e., increasing sensitivity, shorter response time, reproducibility, and low detection limits even to detect individual molecules, and (iii) miniaturization of the biosensing devices using micro-and nano-fabrication technologies. Those challenges can be met through the integration of sensing technology with nanomaterials, which range from zero- to three-dimensional, possessing a high surface-to-volume ratio, good conductivities, shock-bearing abilities, and color tunability. Nanomaterials (NMs) employed in the fabrication and nanobiosensors include nanoparticles (NPs) (high stability and high carrier capacity), nanowires (NWs) and nanorods (NRs) (capable of high detection sensitivity), carbon nanotubes (CNTs) (large surface area, high electrical and thermal conductivity), and quantum dots (QDs) (color tunability). Furthermore, these nanomaterials can themselves act as transduction elements. This review summarizes the evolution of biosensors, the types of biosensors based on their receptors, transducers, and modern approaches employed in biosensors using nanomaterials such as NPs (e.g., noble metal NPs and metal oxide NPs), NWs, NRs, CNTs, QDs, and dendrimers and their recent advancement in biosensing technology with the expansion of nanotechnology.

scholarly journals Water uptake of various electrospun nonwovens

2020 ◽  
Vol 6 (3) ◽  
pp. 155-158
Author(s):  
Katharina Wulf ◽  
Volkmar Senz ◽  
Thomas Eickner ◽  
Sabine Illner
Keyword(s):  
Contact Angle ◽  
Surface Modification ◽  
Water Absorption ◽  
Water Uptake ◽  
Biomedical Applications ◽  
High Surface ◽  
Volume Ratio ◽  
Polymer Composition ◽  
Water Wetting ◽  
Morphology Changes

AbstractIn recent years, nanofiber based materials have emerged as especially interesting for several biomedical applications, regarding their high surface to volume ratio. Due to the superficial nano- and microstructuring and the different wettability compared to nonstructured surfaces, the water absorption is an important parameter with respect to the degradation stability, thermomechanic properties and drug release properties, depending on the type of polymer [1]. In this investigation, the water absorption of different non- and plasma modified biostable nanofiber nonwovens based on polyurethane, polyester and polyamide were analysed and compared. Also, the water absorption by specified water wetting, the contact angle and morphology changes were examined. The results show that the water uptake is highly dependent on the surface modification and the polymer composition itself and can therefore be partially changed.

Recombinant expression of computationally designed peptide-bundlemers in Escherichia coli

2021 ◽  
Vol 330 ◽  
pp. 57-60
Author(s):  
Nairiti J. Sinha ◽  
Christopher J. Kloxin ◽  
Jeffery G. Saven ◽  
Grethe V. Jensen ◽  
Zvi Kelman ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Recombinant Expression
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