Joseph Kletzer, Y. Raval, A. Mohamed et al.

Journal of Applied Microbiology • 2023

AIMS As antimicrobial resistance is on the rise, treating chronic wound infections is becoming more complex. The presence of biofilms in wound beds contributes to this challenge. Here, the activity of a novel hypochlorous acid (HOCl) producing electrochemical bandage (e-bandage) against monospecies and dual-species bacterial biofilms formed by bacteria commonly found in wound infections was assessed. METHODS AND RESULTS The system was controlled by a wearable potentiostat powered by a 3V lithium-ion battery and maintaining a constant voltage of +1.5VAg/AgCl, allowing continuous generation of HOCl. 19 monospecies and 10 dual-species bacterial biofilms grown on polycarbonate membranes placed on tryptic soy agar (TSA) plates were used as wound biofilm models, with HOCl producing e-bandages placed over the biofilms. Viable cell counts were quantified after e-bandages were continuously polarized for 2, 4, 6, and 12 hours. Time-dependent reductions in colony forming units (CFUs) were observed for all studied isolates. After 12 hours, average CFU reductions of 7.75 ±1.37 log10 CFU/cm2 and 7.74 ±0.60 log10 CFU/cm2 were observed for monospecies and dual-species biofilms, respectively. CONCLUSIONS HOCl producing e-bandages reduce viable cell counts of in vitro monospecies and dual-species bacterial biofilms in a time-dependent manner in vitro. After 12 hours, >99.999% reduction in cell viability was observed for both monospecies and dual-species biofilms.

Zhong Zeyu, Haiying Guo, Chunfeng Huang et al.

Water Science and Technology • 2023

The single-chamber bio-electrical systems can degrade oily sludge in sediments while generating electricity from the microbial fuel cells (MFCs) and their characteristics in energy and environmental effects have attracted wide international attention in recent years. To explore the influence of the power generation period on the oily sludge bio-electrical system, an oily sludge bio-electrical system was constructed. The output voltage, polarization curve, power density curve, crude oil removal rate and microflora were detected during different power generation periods, respectively. The results of this study showed that under the stable power generation period, the power generation and oily sludge degradation performance of MFC are higher than the voltage rise period and voltage attenuation period. Besides, the oily sludge bio-electrical system during the stable period contained more electricity-producing bacteria than the other two periods. The voltage in the stable period of oily sludge bio-electrical system is about 280 mV, the electromotive force is 493.1 mV and the power density is 134.93 mW·m-3. It lays a foundation for the improvement of degradation of crude oil and power generation performance in oily sludge bio-electrical system.

Ilya Getsin, Gina H Nalbandian, D. Yee et al.

BMC Microbiology • 2013

Two of the largest fully sequenced prokaryotic genomes are those of the actinobacterium, Streptomyces coelicolor (Sco), and the δ-proteobacterium, Myxococcus xanthus (Mxa), both differentiating, sporulating, antibiotic producing, soil microbes. Although the genomes of Sco and Mxa are the same size (~9 Mbp), Sco has 10% more genes that are on average 10% smaller than those in Mxa. Surprisingly, Sco has 93% more identifiable transport proteins than Mxa. This is because Sco has amplified several specific types of its transport protein genes, while Mxa has done so to a much lesser extent. Amplification is substrate- and family-specific. For example, Sco but not Mxa has amplified its voltage-gated ion channels but not its aquaporins and mechano-sensitive channels. Sco but not Mxa has also amplified drug efflux pumps of the DHA2 Family of the Major Facilitator Superfamily (MFS) (49 versus 6), amino acid transporters of the APC Family (17 versus 2), ABC-type sugar transport proteins (85 versus 6), and organic anion transporters of several families. Sco has not amplified most other types of transporters. Mxa has selectively amplified one family of macrolid exporters relative to Sco (16 versus 1), consistent with the observation that Mxa makes more macrolids than does Sco. Except for electron transport carriers, there is a poor correlation between the types of transporters found in these two organisms, suggesting that their solutions to differentiative and metabolic needs evolved independently. A number of unexpected and surprising observations are presented, and predictions are made regarding the physiological functions of recognizable transporters as well as the existence of yet to be discovered transport systems in these two important model organisms and their relatives. The results provide insight into the evolutionary processes by which two dissimilar prokaryotes evolved complexity, particularly through selective chromosomal gene amplification.

B. Lapizco-Encinas, B. Simmons, E. Cummings et al.

Analytical Chemistry • 2004

Insulator-based (electrodeless) dielectrophoresis (iDEP) is an innovative approach in which the nonuniform electric field needed to drive DEP is produced by insulators, avoiding problems associated with the use of electrodes. Live and dead Escherichia coli were concentrated and selectively released by applying stepped DC voltages across a microchannel containing an array of insulating posts etched in glass. The only electrodes present were two platinum wires placed in the inlet and outlet reservoirs, producing mean electric fields of up to 200 V/mm across the insulators. The cells were labeled with Syto 9 and propidium iodide and imaged through a fluorescent microscope. Cell trapping and release were controlled by modifying the relative responses of electrokinesis and DEP by adjusting the magnitude of the applied voltage. Dead cells were observed to have significantly lower dielectrophoretic mobility than live cells, whereas the electrokinetic mobilities of live and dead cells were indistinguishable. The locations of the bands of differentially trapped cells were consistent with predictions. In addition, cells were selectively trapped and concentrated against backgrounds of 1- and 0.2-microm carboxylate-modified polystyrene particles. This first application of iDEP for simultaneous live/dead bacteria separation and concentration illustrates its potential as a front-end method for bacterial analysis.

Xuehua Li, Zhiwei Zhao, C. Pan

Microchimica Acta • 2016

AbstractAn electrochemical approach is introduced for synthesis of carbon dots (CDs) by exfoliating graphite rods at a voltage of 15 V in an electrolyte consisting of a mixture of water and two ionic liquids. It is found that the size of the CDs can be tuned by varying the fraction of water in the mixed electrolyte; CDs in sizes of 4.9, 4.1 and 3.1 nm are obtained if the electrolyte contains water in fractions of 24, 38 and 56 %, respectively. The CDs have a quantum yield of almost 10 % and display the typical excitation wavelength-dependent maxima of photoluminescence, strongest at excitation/emission wavelengths of 360/440 nm. Fourier transform infrared and X-ray photoelectron spectroscopy show the CDs to have oxygen functional groups on their surface which strongly improve solubility. The CDs were applied to image cells of the electricity-producing bacteria Shewanellaoneidensis MR-1. Graphical AbstractAn electrochemical approach is introduced to synthesize carbon dots by exfoliating graphite rods in mixed electrolyte of water and ionic liquids. The increasing size of carbon dots was realized by reducing the volume of water in the mixed electrolyte. The carbon dots were used to fluorescently image the electricity-producing bacterium Shewanellaoneidensis MR-1.

Zhicheng Cai, Jiamei Wang, Chencheng Liu et al.

Foods • 2022

In order to investigate the effects of high voltage atmospheric cold plasma (HVACP) treatment on the number of microorganisms in and the quality of Trachinotus ovatus during refrigerator storage, fresh fish was packaged with gases CO2:O2:N2 (80%:10%:10%) and treated by HVACP at 75 kV for 3 min; then, the samples were stored at 4 ± 1 °C for nine days. The microbial numbers, water content, color value, texture, pH value, thiobarbituric acid reactive substance (TBARS), and total volatile base nitrogen (TVB-N) values of the fish were analyzed during storage. The results showed the growth of the total viable bacteria (TVB), psychrophilic bacteria, Pseudomonas spp., H2S-producing bacteria, yeast, and lactic acid bacteria in the treated samples was limited, and they were 1.11, 1.01, 1.04, 1.13, 0.77, and 0.80 log CFU/g−1 lower than those in the control group after nine days of storage, respectively. The hardness, springiness, and chewiness of the treated fish decreased slowly as the storage time extended, and no significant changes in either pH or water content were found. The lightness (L*) value increased and the yellowness (b*) value decreased after treatment, while no changes in the redness (a*) value were found. The TBARS and TVB-N of the treated samples increased to 0.79 mg/kg and 21.99 mg/100 g, respectively, after nine days of refrigerator storage. In conclusion, HVACP can limit the growth of the main microorganisms in fish samples effectively during nine days of refrigerator storage with no significant negative impact on their quality. Therefore, HVACP is a useful nonthermal technology to extend the refrigerator shelf-life of Trachinotus ovatus.

Priscila A. Rodriguez, Serena Abbondante, M. Marshall et al.

bioRxiv (Cold Spring Harbor Laboratory) • 2024

Assembly of NADPH oxidase 2 (NOX2) proteins in neutrophils plays an essential role in controlling microbial infections by producing high levels of reactive oxygen species (ROS). We reported that neutrophils and NOX2 are required to control P. aeruginosa in a clinically relevant murine model of blinding corneal infection. Given the published role for the voltage-gated proton channel Hv1 in sustaining NOX2 production, we examined the role of Hv1 in P. aeruginosa keratitis. Hvcn1−/− mice exhibited an impaired ability to kill bacteria that was associated with reduced neutrophil recruitment to infected corneas. Unlike earlier reports, we found that Hvcn1−/− neutrophils produce more rather than less ROS compared with control neutrophils infected with P. aeruginosa or stimulated with PMA or zymosan. Collectively, we demonstrate that Hv1 has an important role in control of bacterial growth by neutrophils in bacterial infection beyond the regulation of ROS production.

M. Trevisani, C. Cevoli, L. Ragni et al.

Frontiers in Microbiology • 2021

Non-thermal atmospheric plasma (NTAP) has gained attention as a decontamination and shelf-life extension technology. In this study its effect on psychrotrophic histamine-producing bacteria (HPB) and histamine formation in fish stored at 0–5°C was evaluated. Mackerel filets were artificially inoculated with Morganella psychrotolerans and Photobacterium phosphoreum and exposed to NTAP to evaluate its effect on their viability and the histidine decarboxylase (HDC) activity in broth cultures and the accumulation of histamine in fish samples, stored on melting ice or at fridge temperature (5°C). NTAP treatment was made under wet conditions for 30 min, using a dielectric barrier discharge (DBD) reactor. The voltage output was characterized by a peak-to-peak value of 13.8 kV (fundamental frequency around 12.7 KHz). This treatment resulted in a significant reduction of the number of M. psychrotolerans and P. phosphoreum (≈3 log cfu/cm2) on skin samples that have been prewashed with surfactant (SDS) or SDS and lactic acid. A marked reduction of their histamine-producing potential was also observed in HDC broth incubated at either 20 or 5°C. Lower accumulation of histamine was observed in NTAP-treated mackerel filets that have been inoculated with M. psychrotolerans or P. phosphoreum and pre-washed with either normal saline or SDS solution (0.05% w/v) and stored at 5°C for 10 days. Mean histamine level in treated and control groups for the samples inoculated with either M. psychrotolerans or P. phosphoreum (≈5 log cfu/g) varied from 7 to 32 and from 49 to 66 μg/g, respectively. No synergistic effect of SDS was observed in the challenge test on meat samples. Any detectable amount of histamine was produced in the meat samples held at melting ice temperature (0–2°C) for 7 days. The effects of NTAP on the quality properties of mackerel’s filets were negligible, whereas its effect on the psychrotrophic HPB might be useful when time and environmental conditions are challenging for the cool-keeping capacity throughout the transport/storage period.

S. Kumari, N. Mangwani, Surajit Das

Current Science • 2015

Biofilm-forming marine bacterial isolates Paenibacillus lautus NE3B01, Pseudomonas mendocina NR802, Stenotrophomonas acidaminiphila NCW702 and Pseudomonas pseudoalcaligenes NP103 in microbial fuel cell (MFC) were investigated for low-voltage power generation. Biofilm formation by the isolates was evaluated by glass tube assay, microtitre plate assay and fluorescence microscopy. A dual chamber MFC of 2 litre capacity was constructed for low-voltage power generation and current output. Two chambers were internally connected by salt bridge and externally the circuit was connected with copper wires which were joined to the electrodes at the two ends and to the multimeter. Maximum current was generated when the salt bridge was constructed using 1 M KCl for all the four bacterial isolates. With Paenibacillus lautus NE3B01, a maximum voltage of 727.5 ± 13.4 mV in 6 h with 7 g/l of glucose as the sole source of carbon was recorded. However, Pseudomonas mendocina NR802 MFC was the most stable in terms of potential generation among all the isolates used for MFC studies. The experimental data for current and voltage showed that the biofilm-forming marine bacterial isolates are useful in MFC technology.

Chandran Masi, Getachew Gemechu, Mesfin Tafesse

Research Square • 2021

Abstract BackgroundA wide variety of Bacterial species produces protease enzyme and the application of same enzyme have been manipulated precisely and used in various biotechnological areas including industrial and environmental sectors. The main aim of this research study was to isolate, screen and identify protease producing bacteria which were sampled from leather industry effluent present in the outer skirts of Addis Ababa, Ethiopia.PurposeTo isolated alkaline protease producing bacteria from leather industrial effluents and to characterization (Secreening and identification).MethodsSample collected from Modji leather industrial effluents and stored in the microbiology lab. After isolated bacteria from effluent using serial dilution and followed by isolate protease producing bacteria using skim milk agar media. After studying Primary and secondary screening using zonal inhibition methods to select potential protease producing bacteria using skim milk agar media. Finally to characterization and identification of potential bacteria using biochemical methods, protein estimation, biomass, protease assay and gene sequencing (16S rRNA) method to finalized best protease producing bacteria. ResultsTwenty-eight different bacterial colonies were isolated initially from the leather industry effluent sample situated at Modjo town of Ethiopia. The isolated bacteria were screened using primary screening method with skim milk agar medium. Three isolates namely MS12, ML5 and ML12 showing highest zone of proteolysis as a result of casein degradation on the agar plates were selected and subjected to secondary screening. Further secondary secreening confirmed that MS12, ML5 and ML12 has efficient proteolytic activity and can be considered as potent protease producer. The three isolates were then subjected to morphological and biochemical tests to identify probably bacterial species and all the three bacterial isolates were found out to be of Bacillus species. Shake flask method was carried out to identify the most potent one having greater biomass production capabilities, protein quantity and protease activity. ML12 isolated from leather effluent waste showed highest Protein(170mg/ml), Protease activity(19U/ml), high biomass production and the same was subjected to molecular identification using 16s sequencing and a Phylogenetic tree was constructed to identify the closest neighbor. The isolate ML12 is 97.87% homologous to Bacillus cereus strain (KY995152.1) and 97.86% homologous to Bacillus cereus strain (MK968813.1).ConclusionsThis study has revealed that the leather industry effluent site has significant feature of housing potent bacterial species producing protease of commercial value. Being one among the most widely used enzyme, comparatively. Protease holds a larger scope for research and commercialization any other type of enzymes. There is a need to develop novel protease enzymes for further necessary applications of these enzymes. Moreover, enzyme produced by bacteria which are present in effluents are a greater boon to establish the significance of converting industrial wastes to a highly valuable enzymes especially like proteases.

M. Ghirardi, Sergey N Kosourov, P. Maness et al.

Encyclopedia of Industrial Biotechnology • 2010

The reduction of carbon dioxide emissions that are responsible for global climate change is currently the major scientific challenge facing the world. Harvesting solar energy via photosynthesis and converting it directly into fuel is a natural means of producing clean, renewable energy. Oxygenic photosynthetic microbes, such as green algae, are capable of simultaneously splitting water and generating oxygen and hydrogen. The harnessed energy, in the form of hydrogen gas, can then be directly coupled to a fuel cell for electricity generation, or used as a feedstock for the synthesis of more complex carbon fuels. At the moment, the efficiency of hydrogen photoproduction from green algae is very low. This article summarizes the biochemical pathway for hydrogen production from algae and the challenges that must be overcome to raise the conversion efficiency to a level that will support a commercial process.

Zixiang Xu, Jing Guo, Yunxia Yue et al.

Journal of Biological Systems • 2018

Microbial Fuel Cells (MFCs) are devices that generate electricity directly from organic compounds with microbes (electricigens) serving as anodic catalysts. As a novel environment-friendly energy source, MFCs have extensive practical value. Since the biological features and metabolic mechanism of electricigens have a great effect on the electricity production of MFCs, it is a big deal to screen strains with high electricity productivity for improving the power output of MFC. Reconstructions and simulations of metabolic networks are of significant help in studying the metabolism of microorganisms so as to guide gene engineering and metabolic engineering to improve their power-generating efficiency. Herein, we reconstructed a genome-scale constraint-based metabolic network model of Shewanella loihica PV-4, an important electricigen, based on its genomic functional annotations, reaction databases and published metabolic network models of seven microorganisms. The resulting network model iGX790 consists of 902 reactions (including 71 exchange reactions), 798 metabolites and 790 genes, covering the main pathways such as carbon metabolism, energy metabolism, amino acid metabolism, nucleic acid metabolism and lipid metabolism. Using the model, we simulated the growth rate, the maximal synthetic rate of ATP, the flux variability analysis of metabolic network, gene deletion and so on to examine the metabolism of S. loihica PV-4.

R. Tamakloe

Proton Exchange Membrane Fuel Cell • 2018

Microbial fuel cells (MFCs) are comparatively new technique of simultaneously generating electricity from bio-waste while degrading the organic waste. The use of microbes to generate electricity is an uninterrupted process in MFCs since the bacteria replicate and continue to produce power indefinitely as long as there is enough food source to nurture the bacteria. Besides, MFCs have the potential to produce hydrogen for fuel cells, desalinate sea water, and provide sustainable energy sources for remote areas. Factors like type of electrodes used in the cells, partitioning of cells, oxygen complement and configurations are important factors that affect the performance of MFCs. The fabrication of microbial fuel cells of different configurations and the relationship between the factors affecting the efficiency of single chambered (SC-MFCs) and double chambered (DC-MFCs) will be presented. The experimental data on observations made on the effects of these materials on the MFCs characteristics, electricity generation and wastewater treatment have also been included. The main aim of this study is to find out whether a nonconventional inexpensive clay could be used as an ion-exchange medium alternative to the conventional expensive PEM in the fabrication of MFCs. The results obtained on power generation, current density, open circuit voltage, etc., clearly show that PEM-less MFCs can be used as practical devices for sustainable energy generation.

Xia Zhang, Hongpei Zhang, Chuan Wang et al.

Annals of Microbiology • 2020

Purpose Sediment microbial fuel cell (SMFC) is a promising bioremediation technology in which microbes play an important role. Electricigens as the bio-catalysts have effect on pollution control and electricity generation. It is of great significance to screen the microorganisms with the ability of generating electricity. Methods The SMFC anode biofilm was used as microbiological source to study the feasibility of electricigens with iron-reducing property for eutrophication water treatment. Preliminarily, we isolated 20 facultative anaerobic pure bacteria and evaluated their cyclic voltammogram (CV) through the three-electrode system and electrochemical workstation. The power generation performance of strains was verified by air-cathode microbial fuel cells (AC-MFCs) under different single carbon sources. Result According to its morphological, physiological, and biochemical characteristics, along with phylogenetic analysis, the two strains (SMFC-7 and SMFC-17) with electrical characteristics were identified as Bacillus cereus . Compared with SMFC-7, SMFC-17 exhibited efficient NH 4 + -N and NO 3 − -N removal and PO 4 3− -P accumulation from eutrophic solution with a removal rate of 79.91 ± 6.34% and 81.26 ± 1.11% and accumulation rate of 57.68 ± 4.36%, respectively. Conclusion The isolated bacteria SMFC-17 showed a good performance in eutrophic solution, and it might be a useful biocatalyst to enable the industrialized application of SMFC in eutrophic water treatment.

R. Jinisha, J. Jerlin Regin, J. Maheswaran

IOP Conference Series: Materials Science and Engineering • 2020

The principle of generating electrical energy using biomass forms the basis of Microbial Fuel Cells (MFCs). This new technology not only produces electricity but also cleans up the waste. Based on the number of chamber units, MFCs are mainly divided into single chamber (SCMFC) and double chamber (DCMFC). This paper reviews particularly about SCMFC. The fundamental components of SCMFC like anode and cathode and the various microbes used in the fuel cell are explained in this review. This paper details about the materials used for the synthesis of anode and cathode. Also, the applicability of SCMFC for the purification of synthetic and real wastewater is discussed.

Bethany A. Frew, A. Christy

2006 Portland, Oregon, July 9-12, 2006 • 2006

Microbial fuel cells, in which microorganisms catalyze the transfer of electrons released from the oxidation of organic compounds onto an electrode, are a promising biotechnological approach for harvesting energy in the form of electricity from certain wastes. The purpose of this study was to determine if landfill leachate is a productive source of substrate and microbes for generating electricity in microbial fuel cells. Research methods included filling the anodic chambers of multiple fuel cells with landfill leachate. The cathodic chambers were filled with a buffer solution of KH2PO4 and were separated from the anodic chambers by a proton exchange membrane (NafionTM). Graphite plates were used as the electrodes in both chambers. Findings from this study show that microorganisms in landfill leachate are electrochemically active, and thus, landfill leachate can be an effective source of bio-electricity. Further results indicate that these electricity-producing microbes reside on the graphite anode, as opposed to being suspended throughout the leachate fluid. Experiments indicated that the leachate may lack enough carbon constituents (or food sources) to support long-term electrical generation. The addition of 10 mL of a 0.4% soluble sugar mixture (0.1% each of glucose, cellobiose, maltose, and xylose) provided enough food source for the microorganisms in the leachate to generate electrical voltage that was nearly three times the amount produced without the sugar mixture (0.120 volts). Furthermore, this maximum voltage generation (0.450 volts) continued for nearly two weeks, over twice the length of generation for the leachate without sugar. Additionally, leachate Chemical Oxygen Demand (COD) levels were reduced in initial tests after fuel cell electrical generation was complete, indicating that microbial fuel cells are potentially effective in treating landfill leachate. A cost analysis of a conceptual large scale design indicated that MFC technology is not mature enough to justify the implementation of this design based on economics alone. However, as energy costs continue to rise and MFC power production is maximized, MFC implementation could become more feasible.

G. Bhargavi, V. Venu, S. Renganathan

IOP Conference Series: Materials Science and Engineering • 2018

Microbial Fuel Cells (MFCs) are the promising devices which can produce electricity by anaerobic fermentation of organic / inorganic matter from easily metabolized biomass to complex wastewater using microbes as biocatalysts. MFC technology has been found as a potential technology for electricity generation and concomitant wastewater treatment. However, the high cost of the components and low efficiency are barricading the commercialization of MFC when compared with other energy generating systems. The performance of an MFC is largely relying on the reactor design and electrode materials. On the way to improve the efficiency of an MFC, tremendous exercises have been carried out to explore new electrode materials and reactor designs in recent decades. The current review is excogitated to amass the progress in design and electrode materials, which could bolster further investigations on MFCs to improve their performance, mitigate the cost and successful implementation of technology in field applications as well.

J. Kassongo, C. Togo

African Journal of Biotechnology • 2011

Various methods are available for the recycling and treatment of cheese whey with the objective of enhancing sustainable manufacturing. Currently, an increasing interest is on the anaerobic bioremediation of whey with the added benefit of generating electricity in microbial fuel cells (MFCs). Since microorganisms are the biocatalysts in MFCs, their initial density plays a paramount role both towards electricity generation and bioremediation. Hence, this study was aimed at evaluating the effects of anode enrichment with microorganisms on power generation. Anodes were enriched with microorganisms inherent to whey for periods of 30 and 90 days before their application in wheypowered MFCs. At the termination of reactor cycles, the one-month-old pre-incubated anodes had 0.13% coulombic efficiency (e cb ), 88.3% total chemical oxygen demand (tCOD) removal efficiency and maximum power density (P d ) was 29.1 ± 4.9 W/m 2 , whereas the three-month-old pre-incubated anode had e cb = 80.9 and 92.8%, tCOD removal and maximum P d was 1800 ± 120 W/m 2 . Two non-acclimated anodes used as control in separate setups exhibited 0.17% coulombic efficiency, 71.6% tCOD removal and maximum P d of 30.9 ± 4.2 W//m 2 . Microscopy analyses revealed different morphologies on anode surfaces depending on the length of the enrichment periods and further molecular analyses of electrode communities indicated up to 92% identity to various species from the Lactobacillus genus. This study established that, an initial acclimation step ahead of MFC setups significantly improved the performance of reactors utilising live cheese whey as fuel. Key words : Cheese whey, microbial fuel cell, enrichment, alternative energy, bioelectricity, bioremediation.

pAbu Hashem Titon Ch, M. Salimullahp

Journal of Bioprocessing & Biotechniques • 2018

Microbial Fuel Cell (MFC) is a device in which microorganisms consume organic compounds as nutrient source and discharge electrons to the electrode, thereby generating electricity. In this study, double chamber MFCs and multiple chambers MFCs were constructed for the generation of electricity from microorganisms present in organic waste samples. Samples were collected from organic wastes from local garbage dumping area in wetland and electricity was generated by the oxidation of endogenous microbes present in samples. Electricity production was gradually increased with growth of organisms, which was decreased after time interval due to depletion of organic matter. A steady state for electricity generation was maintained by adding external glucose. In total, 44 bacteria were isolated from the anodic biofilm. The electrogenic activity of each isolate was observed using artificial wastewater (without organic matter) as substrate. A significant generation of electricity (Maximum 5.78 V and 5.03 mA in multiple chambers MFC) was attained connecting multiple chambers containing MFCs and able to lid light. Microbial diversity on anodic biofilm was observed by scanning electron microscope (SEM) image analysis. Characterization of anodic biofilm bacterial community suggested that 54.54% of electrogenic bacterial community belonged to Enterobacteriaceae family. In addition, the non-fermentative genera Pseudomonas, Moraxella, Vibrio, Burkholderia, Escherichia, Enterobacter, Photobacterium, Obesumbacterium, Sphingomonas and Raoultella also played an important role. MFC, a renewable method for electricity generation from biodegradable compounds without emission of carbon dioxide, is crucial for sustainable in electricity production in countries like Bangladesh as an environment friendly approach.

M. Yee, Joerg S. Deutzmann, A. Spormann et al.

Nanotechnology • 2020

Electromicrobiology is an emerging field investigating and exploiting the interaction of microorganisms with insoluble electron donors or acceptors. Some of the most recently categorized electroactive microorganisms became of interest to sustainable bioengineering practices. However, laboratories worldwide typically maintain electroactive microorganisms on soluble substrates, which often leads to a decrease or loss of the ability to effectively exchange electrons with solid electrode surfaces. In order to develop future sustainable technologies, we cannot rely solely on existing lab-isolates. Therefore, we must develop isolation strategies for environmental strains with electroactive properties superior to strains in culture collections. In this article, we provide an overview of the studies that isolated or enriched electroactive microorganisms from the environment using an anode as the sole electron acceptor (electricity-generating microorganisms) or a cathode as the sole electron donor (electricity-consuming microorganisms). Next, we recommend a selective strategy for the isolation of electroactive microorganisms. Furthermore, we provide a practical guide for setting up electrochemical reactors and highlight crucial electrochemical techniques to determine electroactivity and the mode of electron transfer in novel organisms.

R. Darmawan, S. Juliastuti, N. Hendrianie et al.

Trends in Sciences • 2022

Mud contains little organic matter but has the potential for microbial electricigens (electrogenic) (4.5 - 6.6 mV) this is because the mud comes from bursts from below the earth's surface containing magma and hydrothermal fluids. Therefore, this study aims to learn the addition of Sidoarjo mud (a source of microbes as a biocatalyst) and molasses into microbial fuel cells technology for external resistance variations in generating bioelectricity. Referring to this goal, variations in molasses (2.5, 5.0 and 10 % w/w) and external resistance (1, 10, 100, 1,000 and 5,100 kΩ) were carried out. The stages in this study include starter preparation by assembling MFCs using carbon electrodes connected to electronic devices. Furthermore, the mixture of mud and molasses was put into the MFCs by immersing the anode while the cathode was on top of the mud. After that, measuring the electricity potential (voltage and power density) on various external resistances and molasses. The optimum results for the electric voltage and the best power density were obtained when using an external resistance of 1 kΩ and adding 2.5 % molasses with, respectively 210.25 mV/m2 and 38.91 mW/m2 (electric current 51.75 mA/m2). Based on the results of the SEM-EDX analysis for carbon electrodes, it was found that there was a change in composition from before the process to 9 weeks of running time, where the previous carbon content was 97.27 to 0.67 %. In addition, there were other contents such as sulfur, silica, ferrum, phosphorus and other elements caused by bacterial metabolism in biochemical degradation of organic components. HIGHLIGHTS Utilization of Sidoarjo mud is as a source of microbes (biocatalyst) in microbial fuel cells to produce bioelectricity The organic material used as a substrate comes from Sidoarjo mud and sugar factory waste in the form of molasses The addition of external resistance to microbial fuel cell technology has the potential to increase the number of microbes in the system during the process GRAPHICAL ABSTRACT 

S. Yamamoto, Kei-ichiro Suzuki, Y. Araki et al.

Microbes and Environments • 2014

The relationship between the bacterial communities in anolyte and anode biofilms and the electrochemical properties of microbial fuel cells (MFCs) was investigated when a complex organic waste-decomposing solution was continuously supplied to MFCs as an electron donor. The current density increased gradually and was maintained at approximately 100 to 150 mA m−2. Polarization curve analyses revealed that the maximum power density was 7.4 W m−3 with an internal resistance of 110 Ω. Bacterial community structures in the organic waste-decomposing solution and MFCs differed from each other. Clonal analyses targeting 16S rRNA genes indicated that bacterial communities in the biofilms on MFCs developed to specific communities dominated by novel Geobacter. Multidimensional scaling analyses based on DGGE profiles revealed that bacterial communities in the organic waste-decomposing solution fluctuated and had no dynamic equilibrium. Bacterial communities on the anolyte in MFCs had a dynamic equilibrium with fluctuations, while those of the biofilm converged to the Geobacter-dominated structure. These bacterial community dynamics of MFCs differed from those of control-MFCs under open circuit conditions. These results suggested that bacterial communities in the anolyte and biofilm have a gentle symbiotic system through electron flow, which resulted in the advance of current density from complex organic waste.

B. Priya, V. Priyadharshini, V. Sandhiya et al.

Telecommunications and Radio Engineering • 2023

Currently, due to increased population and development of industries, the demand for electrical energy is increased. To measure the energy consumption of electrical appliances in a building, a nonintrusive load monitoring (NILM) method is used, in which the energy meter is installed with only a main supply. This method will identify loads that are currently active and provide a detailed accounting of energy consumption of loads. The proposed automatic electricity bill generation system uses the NILM method to measure energy consumption and to periodically provide information about the number of electricity units consumed along with the bill amount. By knowing the consumption of their household appliances, consumers can save energy by controlling their use. Existing billing systems generate electricity bills door-to-door at the end of two months using manual calculation but do not provide periodic billing information. Hence, there can be reading errors, and no energy savings are guaranteed. To overcome these issues the proposed system is designed to provide continuous monitoring of power consumption using the ACS712 current sensor and the corresponding amount calculated by the Arduino board. This system allows users to know exact electricity units consumed and bill amount. Hence, the chance of bill tampering is avoided in the proposed system. Periodically, it alerts consumers through LEDs and GSM messages so that they can manage their power consumption and add support for money management.

Jittiwut Suwatthikul, Rangsarit Vanijjirattikhan, Unpong Supakchukul et al.

Journal of Disaster Research • 2021

More than 4,000 dams are constructed in Thailand for several purposes, including water supply, flood control, irrigation, and hydropower generation. Among these dams, 14 large dams are operated by the Electricity Generating Authority of Thailand (EGAT). As a dam operator, EGAT is committed to ensuring dam safety by regularly conducting dam inspections and maintenance. This paper presents the development and practical applications of the Dam Safety Remote Monitoring System (DS-RMS). The objective of DS-RMS is to enhance the EGAT’s implementation of its dam safety program in terms of dam monitoring by instrumentation to satisfy international recommendations. DS-RMS consists of five subsystems: Dam Behavior, Reservoir Operation, Earthquake Monitoring, Expert System and Public Communication. DS-RMS has been deployed at 14 large EGAT-operated dams across the country since 2016. Results show that the novel features of DS-RMS enable faster and more reliable dam safety monitoring and evaluation processes.

J.L. Watson, P.G. Williams

Program • 1982

Discusses one application of a commercially available computer software package suitable for scientific and technical information storage and retrieval. Source documents, mode of input, indexing technique and thesaurus control are described. The various forms of output which are generated and the services available to users are explained. These services include retrospective searching of the database, and provision of printed indexes and personalised current awareness.

S. Bharathi, G. Balaji, V.A. Saravanan et al.

Applied Mechanics and Materials • 2011

A method for generating electricity using high wind pressure generated by fast moving vehicles channeling the induced wind in the direction of the wind turbine; converting the energy of the wind into mechanical energy by using wind turbine; and converting the mechanical energy into electrical energy by using a generating device and can be used for applications.

Ariel Ma, Jian Yu, William Uspal

Energies • 2021

Natural evaporation has recently come under consideration as a viable source of renewable energy. Demonstrations of the validity of the concept have been reported for devices incorporating carbon-based nanocomposite materials. In this study, we investigated the possibility of using polymer thin films to generate electricity from natural evaporation. We considered a polymeric system based on polyvinylidene fluoride (PVDF). Porous PVDF films were created by incorporating a variety of nanocomposite materials into the polymer structure through a simple mixing procedure. Three nanocomposite materials were considered: carbon nanotubes, graphene oxide, and silica. The evaporation-induced electricity generation was confirmed experimentally under various ambient conditions. Among the nanocomposite materials considered, mesoporous silica (SBA-15) was found to outperform the other two materials in terms of open-circuit voltage, and graphene oxide generated the highest short-circuit current. It was found that the nanocomposite material content in the PVDF film plays an important role: on the one hand, if particles are too few in number, the number of channels will be insufficient to support a strong capillary flow; on the other hand, an excessive number of particles will suppress the flow due to excessive water absorption underneath the surface. We show that the device can be modeled as a simple circuit powered by a current source with excellent agreement between the theoretical predictions and experimental data.

Chiudo Ehirim, Ogbonna F. Joel

Advanced Materials Research • 2013

The aim of this study was to estimate the electricity generating potential of three (3) dumpsites in specified locations of Obio/Akpor LGA of Rivers State, Nigeria using the Columbia Landfill Gas Model Version 1 developed for the United States Environmental Protection Agency Landfill Methane Outreach Programme (LMOP) as well as determine using the LMOP Landfill Gas Energy Benefits Calculator, the environmental/energy benefits of landfill gas to energy projects at the sites. The study involved literature review of waste management practice in the State, selection of study sites, consultation with relevant regulatory bodies in the State, field visits, waste burden quantification as well as data analysis. The findings from the study showed that two dumpsites have the potential to generate 0.5MW whilst the third dumpsite could generate 0.3MW of electricity if a comprehensive landfill gas collection system is installed in year 2015. Landfill gas energy projects of these sizes can provide power for about 500 homes. With rapid population growth in Port-Harcourt City and a corresponding increase in municipal waste generation, it is imperative to develop efficient landfill gas (LFG) to energy projects at landfills and dumpsites. This will not only reduce greenhouse gas emissions but improve local air quality, and control environmental pollution. The projects will also provide economic benefits to the community and the energy end user.

Dr. R. Mohanapriya Et al.

INFORMATION TECHNOLOGY IN INDUSTRY • 2021

Walking is the most common movement in human life. When a person walks, he distributes energy to the road surface in the form of impact, vibrations, sound etc, due to the transfer his weight on the road exterior, through foot falls on the ground during a every steps. This energy Can be tapped and transformed in the practical form such as in electrical form. In order to develop a procedure to connect footstep energy, we are developing a footstep electricity generating device. This device, if embedded in the footpath can varying foot impact energy into electrical energy. The working principle, when a pedestrian step on the upper plate of the device, the plate will dip down to some extent due to the weight of the pedestrian. The descendant movement of the plate results in sturdiness of the piezoelectric materials fitted in the device to produce electrical energy the device was worked by persons walking over to it. However, if there is determined movement of pedestrians over the device, a large amount power will be a formed in this research a prototype of the power producing tiles is developed and studied under varying loading environments to inspect the feasibility of the technology.

Robin Dahlheim, William J. Pike

Journal of Petroleum Technology • 2012

Technology Update There are 823,000 oil and gas wells in the United States that coproduce hot water with their hydrocarbon output. This equates to approximately 25 billion bbl of water annually that could be used as fuel to produce up to 3 GW of clean electrical power. Not only would electricity generated from produced water add much needed electrical power, the life of many of these wells also would be extended and additional oil and gas produced. A recent project funded by the National Energy Technology Laboratory of the United States Department of Energy conducted field demonstrations to determine the potential of generating electricity from hot produced water. Participants included Gulf Coast Green Energy (GCGE), ElectraTherm, Den-bury Resources, the Southern Methodist University (SMU) Geothermal Laboratory, the Texas A&M University petroleum engineering department, and Dixie Electric Cooperative. The primary goal of the project was to prove the feasibility of interfacing the ElectraTherm Green Machine, a waste heat-to-power generator, with a producing oil or gas well. The project’s subsidiary goals were as follows: Demonstrate the ability to produce electricity from waste heat in the produced water. Show that producing electricity from produced water does not interfere with normal well operations. Demonstrate how small oil and gas producers might increase their profitability by adding an income stream from power generation. Determine the economic viability of generating electricity from waste heat in the produced water. Determine whether the kWh output of electricity from the produced water has practical applications. Identify the environmental impact of generating fuel-free, emission-free electricity from waste heat in the produced water. It was important to hold a field trial to determine the extent of known factors that could not be identified or quantified in laboratory and bench scale runs. In addition, a field trial was necessary to identify potential corrective measures for new equipment designs and future produced water projects. The site chosen was a producing oil well, Denbury’s Summerland No. 2 well, near Laurel, Mississippi. In production for 5 years, the well has a high water cut and high produced water temperature. The well produces 100 BOPD and 4,000 BWPD from a depth of 9,500 ft with an electric submersible pump. The temperature of the produced water exiting the “knockout” tank at 120 gal/min is 204°F. The site has an ambient temperature range of 60°F to 105°F.

Manfred Lenzen

Energies • 2010

Electricity is perhaps the most versatile energy carrier in modern economies, and it is therefore fundamentally linked to human and economic development. Electricity growth has outpaced that of any other fuel, leading to ever-increasing shares in the overall mix. This trend is expected to continue throughout the following decades, as large—especially rural—segments of the world population in developing countries start to climb the “energy ladder” and become connected to power grids. Electricity therefore deserves particular attention with regard to its contribution to global greenhouse gas emissions, which is reflected in the ongoing development of low-carbon technologies for power generation. The focus of this updated review of electricity-generating technologies is twofold: (a) to provide more technical information than is usually found in global assessments on critical technical aspects, such as variability of wind power, and (b) to capture the most recent findings from the international literature. This report covers eight technologies. Seven of these are generating technologies: hydro-, nuclear, wind, photovoltaic, concentrating solar, geothermal and biomass power. The remaining technology is carbon capture and storage. This selection is fairly representative for technologies that are important in terms of their potential capacity to contribute to a low-carbon world economy.

Derek R. Lovley

Environmental Microbiology Reports • 2011

Summary The discovery of electrotrophs, microorganisms that can directly accept electrons from electrodes for the reduction of terminal electron acceptors, has spurred the investigation of a wide range of potential applications. To date, only a handful of pure cultures have been shown to be capable of electrotrophy, but this process has also been inferred in many studies with undefined consortia. Potential electron acceptors include: carbon dioxide, nitrate, metals, chlorinated compounds, organic acids, protons and oxygen. Direct electron transfer from electrodes to cells has many advantages over indirect electrical stimulation of microbial metabolism via electron shuttles or hydrogen production. Supplying electrons with electrodes for the bioremediation of chlorinated compounds, nitrate or toxic metals may be preferable to adding organic electron donors or hydrogen to the subsurface or bioreactors. The most transformative application of electrotrophy may be microbial electrosynthesis in which carbon dioxide and water are converted to multi‐carbon organic compounds that are released extracellularly. Coupling photovoltaic technology with microbial electrosynthesis represents a novel photosynthesis strategy that avoids many of the drawbacks of biomass‐based strategies for the production of transportation fuels and other organic chemicals. The mechanisms for direct electron transfer from electrodes to microorganisms warrant further investigation in order to optimize envisioned applications.

Silvia Bonardi, Rosario Pitino

Italian Journal of Food Safety • 2019

Antimicrobial resistance is an increasing global health problem and one of the major concerns for economic impacts worldwide. Recently, resistance against carbapenems (doripenem, ertapenem, imipenem, meropenem), which are critically important antimicrobials for human cares, poses a great risk all over the world. Carbapenemases are β-lactamases belonging to different Ambler classes (A, B, D) and encoded by both chromosomal and plasmidic genes. They hydrolyze a broad variety of β-lactams, including carbapenems, cephalosporins, penicillins and aztreonam. Despite several studies in human patients and hospital settings have been performed in European countries, the role of livestock animals, wild animals and the terrestrial and aquatic environment in the maintenance and transmission of carbapenemase- producing bacteria has been poorly investigated. The present review focuses on the carbapenemase-producing bacteria detected in pigs, cattle, poultry, fish, mollusks, wild birds and wild mammals in Europe as well as in non-European countries, investigating the genetic mechanisms for their transmission among food-producing animals and wildlife. To shed light on the important role of the environment in the maintenance and genetic exchange of resistance determinants between environmental and pathogenic bacteria, studies on aquatic sources (rivers, lakes, as well as wastewater treatment plants) are described.

Ismail Raheel, Asmaa N. Mohammed, Asmaa Abdrabo Mohamed

Current Microbiology • 2023

Abstract Using an alternative bio-product is one of the most promising ways to control bovine mastitis and avoid new intra-mammary infections. The aims of this study were to ascertain the prevalence of biofilm-forming bacteria responsible for causing clinical mastitis in dairy herds and to assess the effectiveness of bacteriocins, produced by Bacillus subtilis , in controlling the growth of these bacteria in the milk of animals. A total of 150 milk samples were collected from cows and buffalos suffering from mastitis and the etiological agents were isolated and identified by the VITEK-2-COMPACT-SYSTEM®. Additionally, the capability of the bacterial isolates to produce biofilms was determined. RT-PCR was used to detect enterotoxin-producing genes ( sed and seb ), resistance genes ( mecA and blaZ ), and biofilm-associated genes ( icaA and fnbA ) in the isolated bacteria. The susceptibility patterns of the bacterial isolates to bacteriocins were assessed using an agar well-diffusion assay. S. aureus was significantly more capable of producing biofilms than coagulase-negative Staphylococcus isolates. S. ubris was the strongest biofilm producer among the Streptococcus species. The sensitivity profiles of the Staphylococcus spp. ( S. aureus and coagulase-negative Staphylococcus ) and their biofilm producers to bacteriocins were significantly higher (100% and 90%, respectively) at the same concentration. Bacteriocins had a lethal effect on Staphylococci , Streptococci , and biofilm development at a dose of 250 µg/mL. In dairy farms, bacteriocins are a viable alternative treatment for the prevention and control of bovine clinical mastitis.

Rabia Saleem, Safia Ahmed

bioRxiv (Cold Spring Harbor Laboratory) • 2020

Abstract Being a significant protein L-glutaminases discovers potential applications in various divisions running from nourishment industry to restorative and cure. It is generally disseminated in microbes, actinomycetes, yeast and organisms. Glutaminase is the principal enzyme that changes glutamine to glutamate. The samples were gathered from soil of Taxila, Wah Cantt and Quetta, Pakistan for the isolation of glutaminase producing bacteria. After primary screening, subordinate screening was done which includes multiple testification such as purification, observation of morphological characters and biochemical testing of bacterial strains along with 16S rRNA sequence homology testing. Five bacterial strains were selected showing glutaminase positive test in screening, enzyme production via fermentation and enzymatic and protein assays. Taxonomical characterization of the isolates identified them as Bacillus subtilis U1, Achromobacter xylosoxidans G1, Bacillus subtilis Q2, Stenotrophomonas maltophilia U3 and Alcaligenes faecalis S3. The optimization of different effectors such as incubation time, inducers, carbon source, pH, and nitrogen source were also put under consideration. There was slight difference among incubation of bacterial culture, overall, 36 hours of incubation time was the best for glutaminase production by all the strains. Optimal pH was around 9 in Achromobacter xylosoxidans G1 and Alcaligenes faecalis S3, pH 6 in Bacillus subtilis U1, pH 8 in Stenotrophomonas maltophilia U3, pH 6-8 in Bacillus subtilis Q2. Best glutaminase production was obtained at 37°C by Bacillus subtilis U1and Bacillus subtilis Q2, 30°C for Achromobacter xylosoxidans G1, Stenotrophomonas maltophilia U3 and 25°C by Alcaligenes faecalis S3. The carbon sources put fluctuated effects on activity of enzyme in such a way that glucose was the best carbon source for Bacillus subtilis U1and Bacillus subtilis Q2, Sorbitol for Achromobacter xylosoxidans G1 and Alcaligenes faecalis S3 while xylose was the best for Stenotrophomonas maltophilia U3. Yeast extract and Trypton were among good nitrogen sources for Achromobacter xylosoxidans G1 and of Bacillus subtilis U1 respectively. Glutamine was the best inducer for Bacillus subtilis Q2, Alcaligenes faecalis S3 and Stenotrophomonas maltophilia U3, while lysine for Achromobacter xylosoxidans G1 and glycine act as good inducer in case of Bacillus subtilis U1. After implementation of optimal conditions microbial L-glutaminase production can be achieved and the bacterial isolates have a great potential for production of glutaminase enzyme and their applications.

M. Amin Mir, Mohammad Waqar Ashraf, Altaf Hussain et al.

Current Organocatalysis • 2022

Background: Soil is an ultimate source of all types of nutrients, which have both biological and non-biological importance. Studies are being carried out to isolate the various type of micro- organism from soil which has much more importance. So in the present study, amylase-producing bacteria have been isolated from various soil samples. Aim: The isolation, identification, and estimation of various microbial strains for α-amylase enzyme production and then the inhibition of the growth of these microbial stains. Methods: The bacterial strains were isolated and then identified by various microbiological methods, including Gram’s staining method followed by several biochemical methods such as litmus test, Gelatin test and Urea agar media, and by viable cells. Results: Altogether, three microbial strains were identified from the soil samples in the concerned study. The concerned strains include- Shigella, Proteus and Bacillus, respectively. The concerned microbial strains were then analyzed for the amount of amylase enzyme, and it had been found that Bacillus sp produce much more amount of amylase followed by Shigella sp, and lesser amylase enzyme- producing activity was found in Proteus sp. The isolated bacteria were then analysed for inhibition of their growth by water and ethanolic extracts of Cuminum cyminuni. Among the extracts, it had been found that water extracts exhibited more inhibiting capacity than ethanolic extracts. The study also revealed that among the bacterial strains, the Shigella sp got much more affected by the concerned plant extracts followed by Proteus sp and the least inhibition was observed against the Bacillus sp. Conclusion: As per the above study, it is being concluded that - three amylase-producing bacteria viz Shigella, proteus, bacillus sp were isolated from the soil samples. These isolated microbial strains could be used for the decomposition of cholesterol levels in humans in addition to other microbial activity. These isolated bacterial could sometimes be averse, so their growth could be stopped by various biological and chemical substances like Gentamicin and by various Plant extracts viz, Cuminum cyminuni Plant.

Farzane Kargar, Mojtaba Mortazavi, Mahmood Maleki et al.

Current Proteomics • 2021

Aims: The purpose of this study was to screen the bacteria producing cellulase enzymes and their bioinformatics studies. Background: Cellulose is a long-chain polymer of glucose that hydrolyzes by cellulases to glucose molecules. In order to design the new biotechnological applications, some strategies have been used as increasing the efficiency of enzyme production, generating cost-effective enzymes, producing stable enzymes and identification of new strains. Objective: On the other hand, some bacteria special features have made them suitable candidates for the identification of the new source of enzymes. In this regard, some native strains of bacteria were screened. Methods: These bacteria were grown on a culture containing the liquid M9 media containing CMC to ensure the synthesis of cellulase. The formation of a clear area in the culture medium indicated decomposition of cellulose. In the following, the DNA of these bacteria were extracted and their 16S rDNA genes were amplified. Result: The results show that nine samples were able to synthesize cellulase. In following, these strains were identified using 16S rDNA. The results show that these screened bacteria belonged to the Bacillus sp., Alcaligenes sp., Alcaligenes sp., and Enterobacter sp. Conclusion: The enzyme activity analysis shows that the Bacillus toyonensis, Bacillus sp. strain XA15-411 Bacillus cereus have produced the maximum yield of cellulases. However, these amounts of enzyme production in these samples are not proportional to their growth rate. As the bacterial growth chart within 4 consecutive days shows that the Alcaligenes sp. Bacillus cereus, Bacillus toyonensis, Bacillus sp. strain XA15-411 have a maximum growth rate. The study of the phylogenetic tree also shows that Bacillus species are more abundant in the production of cellulase enzyme. These bioinformatics analyses show that the Bacillus species have different evolutionary relationships and evolved in different evolutionary time. However, for maximum cellulase production by this bacteria, some information as optimum temperature, optimum pH, carbon and nitrogen sources are needed for the ideal formulation of media composition. The cellulase production is closely controlled in microorganisms and the cellulase yields appear to depend on a variety of factors. However, the further studies are needed for cloning, purification and application of these new microbial cellulases in the different commercial fields as in food, detergent, and pharmaceutical, paper, textile industries and also various chemical industries. However, these novel enzymes can be further engineered through rational design or using random mutagenesis techniques.

Т. Sidorova, А.М. Asaturova, A. Homyak

Sel'skokhozyaistvennaya Biologiya • 2018

t The use of nonpathogenic soil bacteria living in association with the roots of higher plants enhances the adaptive potential of the hosts, stimulates their growth and serves as a promising alternative to chemical 2015). The bacterium Bacillus subtilis is recognized as a powerful biocontrol tool because of suppression of a wide range of phytopathogens due to the ability to produce a variety of secondary metabolites of different chemical e.g. cyclic lipopeptides, polypeptides, proteins and nonpeptidic 2005). Information 2006). Proteins, lipopeptides, polysaccharides and other compounds associated with the B. subtilis cell wall can trigger the protective mechanism of the plant, that is, act as elicitors (M. Ongena et al., 2007). Thus, research aimed at studying biologically active metabolites of B. subtilis , which possess the properties of biopesticides or inducers of plant resistance to diseases, opens new prospects for the development of environmentally friendly technologies for protection against

David J. F. Walker, R. Adhikari, D. Holmes et al.

The ISME Journal • 2017

The possibility that bacteria other than Geobacter species might contain genes for electrically conductive pili (e-pili) was investigated by heterologously expressing pilin genes of interest in Geobacter sulfurreducens. Strains of G. sulfurreducens producing high current densities, which are only possible with e-pili, were obtained with pilin genes from Flexistipes sinusarabici, Calditerrivibrio nitroreducens and Desulfurivibrio alkaliphilus. The conductance of pili from these strains was comparable to native G. sulfurreducens e-pili. The e-pili derived from C. nitroreducens, and D. alkaliphilus pilin genes are the first examples of relatively long (>100 amino acids) pilin monomers assembling into e-pili. The pilin gene from Candidatus Desulfofervidus auxilii did not yield e-pili, suggesting that the hypothesis that this sulfate reducer wires itself with e-pili to methane-oxidizing archaea to enable anaerobic methane oxidation should be reevaluated. A high density of aromatic amino acids and a lack of substantial aromatic-free gaps along the length of long pilins may be important characteristics leading to e-pili. This study demonstrates a simple method to screen pilin genes from difficult-to-culture microorganisms for their potential to yield e-pili; reveals new sources for biologically based electronic materials; and suggests that a wide phylogenetic diversity of microorganisms may use e-pili for extracellular electron exchange.

M. Bok, Yunwoo Lee, Daehoon Park et al.

Nanoscale • 2018

In this study, a combined system of microneedles and a triboelectric nanogenerator (TENG) has been developed for drug delivery. A triboelectric device, which converts mechanical energy into alternating current (AC), was chosen to replace the electrophoresis (EP) effect. To directly generate triboelectricity from salmon deoxyribonucleic acid (SDNA)-based microneedles, a triboelectric series of SDNA film and chargeable polymers (polyimide and Teflon) was studied. The electrical output of the two charged polymers was compared to find a material that could be highly charged with SDNA. The electrical output was also compared as a function of the concentration of a drug embedded in the SDNA film, and the results confirmed that drug intercalation affected the carrier diffusion. The mechanical strength of the microneedles was assessed by histological analysis of their penetration into porcine cadaver skin. Furthermore, the output voltage of a system incorporating microneedles and TENG in cadaver skin, and in vitro drug release into gelatin were evaluated to examine potential application as an electrically active drug delivery system. The electrical output voltage of this system was ∼95 V. The mechanism of triboelectric perturbation to the skin has also been discussed. The system developed in this work is a new, facile approach toward effective drug delivery that replaces the existing EP method and expands the application of TENGs.