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

<p>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. </p>

Jittiwut Suwatthikul, Rangsarit Vanijjirattikhan, Unpong Supakchukul et al.

Journal of Disaster Research • 2021

<jats:p>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.</jats:p>

J.L. Watson, P.G. Williams

Program • 1982

<jats:p>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.</jats:p>

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

Applied Mechanics and Materials • 0

<jats:p>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.</jats:p>

Ariel Ma, Jian Yu, William Uspal

Energies • 0

<jats:p>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.</jats:p>

Chiudo Ehirim, Ogbonna F. Joel

Advanced Materials Research • 0

<jats:p>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.</jats:p>

Dr. R. Mohanapriya Et al.

INFORMATION TECHNOLOGY IN INDUSTRY • 0

<jats:p>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.</jats:p>

Robin Dahlheim, William J. Pike

Journal of Petroleum Technology • 2012

<jats:p>Technology Update</jats:p> <jats:p>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.</jats:p> <jats:p>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&amp;M University petroleum engineering department, and Dixie Electric Cooperative.</jats:p> <jats:p>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:</jats:p> <jats:p>Demonstrate the ability to produce electricity from waste heat in the produced water.</jats:p> <jats:p>Show that producing electricity from produced water does not interfere with normal well operations.</jats:p> <jats:p>Demonstrate how small oil and gas producers might increase their profitability by adding an income stream from power generation.</jats:p> <jats:p>Determine the economic viability of generating electricity from waste heat in the produced water.</jats:p> <jats:p>Determine whether the kWh output of electricity from the produced water has practical applications.</jats:p> <jats:p>Identify the environmental impact of generating fuel-free, emission-free electricity from waste heat in the produced water.</jats:p> <jats:p>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.</jats:p>

Manfred Lenzen

Energies • 0

<jats:p>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.</jats:p>

Derek R. Lovley

Environmental Microbiology Reports • 2011

<jats:title>Summary</jats:title><jats:p>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.</jats:p>

Silvia Bonardi, Rosario Pitino

Italian Journal of Food Safety • 0

<jats:p>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.</jats:p>

Ismail Raheel, Asmaa N. Mohammed, Asmaa Abdrabo Mohamed

Current Microbiology • 2023

<jats:title>Abstract</jats:title><jats:p>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 <jats:italic>Bacillus subtilis</jats:italic>, 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 (<jats:italic>sed</jats:italic> and <jats:italic>seb</jats:italic>), resistance genes (<jats:italic>mecA</jats:italic> and <jats:italic>blaZ</jats:italic>), and biofilm-associated genes (<jats:italic>icaA</jats:italic> and <jats:italic>fnbA</jats:italic>) in the isolated bacteria. The susceptibility patterns of the bacterial isolates to bacteriocins were assessed using an agar well-diffusion assay. <jats:italic>S. aureus</jats:italic> was significantly more capable of producing biofilms than coagulase-negative <jats:italic>Staphylococcus</jats:italic> isolates. <jats:italic>S. ubris</jats:italic> was the strongest biofilm producer among the <jats:italic>Streptococcus</jats:italic> species. The sensitivity profiles of the <jats:italic>Staphylococcus</jats:italic> spp. (<jats:italic>S. aureus</jats:italic> and coagulase-negative <jats:italic>Staphylococcus</jats:italic>) and their biofilm producers to bacteriocins were significantly higher (100% and 90%, respectively) at the same concentration. Bacteriocins had a lethal effect on <jats:italic>Staphylococci</jats:italic>, <jats:italic>Streptococci</jats:italic>, 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.</jats:p>

Rabia Saleem, Safia Ahmed

• 0

<jats:title>Abstract</jats:title><jats:p>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<jats:italic>Bacillus subtilis</jats:italic>U1,<jats:italic>Achromobacter xylosoxidans</jats:italic>G1,<jats:italic>Bacillus subtilis</jats:italic>Q2,<jats:italic>Stenotrophomonas maltophilia</jats:italic>U3 and<jats:italic>Alcaligenes faecalis</jats:italic>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<jats:italic>Achromobacter xylosoxidans</jats:italic>G1 and<jats:italic>Alcaligenes faecalis</jats:italic>S3, pH 6 in<jats:italic>Bacillus subtilis</jats:italic>U1, pH 8 in<jats:italic>Stenotrophomonas maltophilia</jats:italic>U3, pH 6-8 in<jats:italic>Bacillus subtilis</jats:italic>Q2. Best glutaminase production was obtained at 37°C by<jats:italic>Bacillus subtilis</jats:italic>U1and<jats:italic>Bacillus subtilis</jats:italic>Q2, 30°C for<jats:italic>Achromobacter xylosoxidans</jats:italic>G1,<jats:italic>Stenotrophomonas maltophilia</jats:italic>U3 and 25°C by<jats:italic>Alcaligenes faecalis</jats:italic>S3. The carbon sources put fluctuated effects on activity of enzyme in such a way that glucose was the best carbon source for<jats:italic>Bacillus subtilis</jats:italic>U1and<jats:italic>Bacillus subtilis</jats:italic>Q2, Sorbitol for<jats:italic>Achromobacter xylosoxidans</jats:italic>G1 and<jats:italic>Alcaligenes faecalis</jats:italic>S3 while xylose was the best for<jats:italic>Stenotrophomonas maltophilia</jats:italic>U3. Yeast extract and Trypton were among good nitrogen sources for<jats:italic>Achromobacter xylosoxidans</jats:italic>G1 and of<jats:italic>Bacillus subtilis</jats:italic>U1 respectively. Glutamine was the best inducer for<jats:italic>Bacillus subtilis</jats:italic>Q2,<jats:italic>Alcaligenes faecalis</jats:italic>S3 and<jats:italic>Stenotrophomonas maltophilia</jats:italic>U3, while lysine for<jats:italic>Achromobacter xylosoxidans</jats:italic>G1 and glycine act as good inducer in case of<jats:italic>Bacillus subtilis</jats:italic>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.</jats:p>

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

Current Organocatalysis • 2022

<jats:sec> <jats:title>Background:</jats:title> <jats:p>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.</jats:p> </jats:sec> <jats:sec> <jats:title>Aim:</jats:title> <jats:p>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.</jats:p> </jats:sec> <jats:sec> <jats:title>Methods:</jats:title> <jats:p>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.</jats:p> </jats:sec> <jats:sec> <jats:title>Results:</jats:title> <jats:p>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.</jats:p> </jats:sec> <jats:sec> <jats:title>Conclusion:</jats:title> <jats:p>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.</jats:p> </jats:sec>

Farzane Kargar, Mojtaba Mortazavi, Mahmood Maleki et al.

Current Proteomics • 2021

<jats:sec> <jats:title>Aims:</jats:title> <jats:p>The purpose of this study was to screen the bacteria producing cellulase enzymes and their bioinformatics studies.</jats:p> </jats:sec> <jats:sec> <jats:title>Background:</jats:title> <jats:p>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.</jats:p> </jats:sec> <jats:sec> <jats:title>Objective:</jats:title> <jats:p>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.</jats:p> </jats:sec> <jats:sec> <jats:title>Methods:</jats:title> <jats:p>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.</jats:p> </jats:sec> <jats:sec> <jats:title>Result:</jats:title> <jats:p>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.</jats:p> </jats:sec> <jats:sec> <jats:title>Conclusion:</jats:title> <jats:p>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.</jats:p> </jats:sec>

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.

E. Hellequin, C. Monard, M. Chorin et al.

Scientific Reports • 2020

Agriculture is changing to rely on agroecological practices that take into account biodiversity, and the ecological processes occurring in soils. The use of agricultural biostimulants has emerged as a valid alternative to chemicals to indirectly sustain plant growth and productivity. Certain BS have been shown to select and stimulate plant beneficial soil microorganisms. However, there is a lack of knowledge on the effects and way of action of the biostimulants operating on soil functioning as well as on the extent and dynamic of these effects. In this study we aimed to decipher the way of action of a seaweed and amino-acids based biostimulant intended to be applied on soil crop residues to increase their microbial mineralization and the further release of nutrients. By setting-up a two-phase experiment (soil plant-growing and soil incubation), our objectives were to (1) determine the effects of the soil biostimulant over time on the active soil bacteria and fungi and the consequences on the organic carbon mineralization in bare soils, and (2) assess the biostimulant effects on soil microorganisms relatively to plant legacy effects in planted soils. We demonstrated that the soil biostimulant had a delayed effect on the active soil microorganisms and activated both plant growth promoting bacteria and saprophytes microorganisms at the medium-term of 49 days. However, the changes in the abundances of active microbial decomposers were not associated to a higher mineralization rate of organic carbon derived from soil and/or litter. The present study assessed the biostimulant beneficial effect on active soil microbial communities as similar as or even higher than the legacy effects of either A. thaliana or T. aestivum plants. We specifically showed that the biostimulant increased the active fungal richness to a higher extent than observed in soils that previously grew the two plants tested.

Andrea Trevisiol, Aiman S. Saab, U. Winkler et al.

eLife • 2017

In several neurodegenerative diseases and myelin disorders, the degeneration profiles of myelinated axons are compatible with underlying energy deficits. However, it is presently impossible to measure selectively axonal ATP levels in the electrically active nervous system. We combined transgenic expression of an ATP-sensor in neurons of mice with confocal FRET imaging and electrophysiological recordings of acutely isolated optic nerves. This allowed us to monitor dynamic changes and activity-dependent axonal ATP homeostasis at the cellular level and in real time. We find that changes in ATP levels correlate well with compound action potentials. However, this correlation is disrupted when metabolism of lactate is inhibited, suggesting that axonal glycolysis products are not sufficient to maintain mitochondrial energy metabolism of electrically active axons. The combined monitoring of cellular ATP and electrical activity is a novel tool to study neuronal and glial energy metabolism in normal physiology and in models of neurodegenerative disorders. DOI: http://dx.doi.org/10.7554/eLife.24241.001

R. Kirkegaard, S. McIlroy, J. M. Kristensen et al.

• 2017

Anaerobic digestion is widely applied to treat organic waste at wastewater treatment plants. Characterisation of the underlying microbiology represents a source of information to develop strategies for improved operation. To this end, we investigated the microbial community composition of thirty-two full-scale digesters over a six-year period using 16S rRNA gene amplicon sequencing. Sampling of the sludge fed into these systems revealed that several of the most abundant populations were likely inactive and immigrating with the influent. This observation indicates that a failure to consider immigration will interfere with correlation analysis and give an inaccurate picture of the active microbial community. Furthermore, several abundant OTUs could not be classified to genus level with commonly applied taxonomies, making inference of their function unreliable. As such, the existing MiDAS taxonomy was updated to include these abundant phylotypes. The communities of individual plants surveyed were remarkably similar – with only 300 OTUs representing 80% of the total reads across all plants, and 15% of these identified as likely inactive immigrating microbes. By identifying the abundant and active taxa in anaerobic digestion, this study paves the way for targeted characterisation of the process important organisms towards an in-depth understanding of the microbial ecology of these biotechnologically important systems.

Sarah D. Ditchek, Kristen L. Corbosiero, R. Fovell et al.

Monthly Weather Review • 2019

While the frequency and structure of Atlantic basin tropical cyclone diurnal cooling and warming pulses have recently been explored, how often diurnal pulses are associated with deep convection was left unanswered. Here, storm-relative, GridSat-B1, 6-h IR brightness temperature difference fields were supplemented with World Wide Lightning Location Network (WWLLN) data to answer that question. Electrically active, long-lived cooling and warming pulses were defined objectively by determining critical thresholds for the lightning flash density, areal coverage, and longevity within each pulse. Pulses with lightning occurred 61% of the time, with persistently electrically active pulses (≥9 h, ACT) occurring on 38% of pulse days and quasi–electrically active pulses (3–6 h, QUASI) occurring on 23% of pulse days. Electrically inactive pulses (<3 h, INACT) occurred 39% of the time. ACT pulse days had more pulses located right-of-shear, the preferred quadrant for outer-rainband lightning activity, and were associated with more favorable environmental conditions than INACT pulse days. Cooling pulses were more likely to occur in lower-shear environments while warming pulses were more likely to occur in high-shear environments. Finally, while the propagation speeds of ACT and INACT cooling pulses and ACT warming pulses did lend support to the recent gravity wave and tropical squall-line explanations of diurnal pulses, the INACT warming pulses did not and should be studied further.

M. Moradi, Rahim Molaei, Seyedeh Alaleh Kousheh et al.

Critical Reviews in Food Science and Nutrition • 2021

Abstract Nanotechnology is rapidly becoming a commercial reality for application in food packaging. In particular, the incorporation of nanoparticles into packaging materials is being used to increase the shelf life and safety of foods. Carbon dots (C-dots) have a diverse range of potential applications in food packaging. They can be synthesized from environmentally friendly sources such as microorganisms, food by-products, and waste streams, or they may be generated in foods during normal processing operations, such as cooking. These processes often produce nitrogen- and sulfur-rich heteroatom-doped C-dots, which are beneficial for certain applications. The incorporation of C-dots into food packaging materials can improve their mechanical, barrier, and preservative properties. Indeed, C-dots have been used as antioxidant, antimicrobial, photoluminescent, and UV-light blocker additives in food packaging materials to reduce the chemical deterioration and inhibit the growth of pathogenic and spoilage microorganisms in foods. This article reviews recent progress on the synthesis of C-dots from microorganisms and food by-products of animal origin. It then highlights their potential application for the development of active and intelligent food packaging materials. Finally, a discussion of current challenges and future trends is given.

Joao Barbosa, Diego Lozano-Soldevilla, A. Compte

PLOS Biology • 2021

Persistently active neurons during mnemonic periods have been regarded as the mechanism underlying working memory maintenance. Alternatively, neuronal networks could instead store memories in fast synaptic changes, thus avoiding the biological cost of maintaining an active code through persistent neuronal firing. Such “activity-silent” codes have been proposed for specific conditions in which memories are maintained in a nonprioritized state, as for unattended but still relevant short-term memories. A hallmark of this “activity-silent” code is that these memories can be reactivated from silent, synaptic traces. Evidence for “activity-silent” working memory storage has come from human electroencephalography (EEG), in particular from the emergence of decodability (EEG reactivations) induced by visual impulses (termed pinging) during otherwise “silent” periods. Here, we reanalyze EEG data from such pinging studies. We find that the originally reported absence of memory decoding reflects weak statistical power, as decoding is possible based on more powered analyses or reanalysis using alpha power instead of raw voltage. This reveals that visual pinging EEG “reactivations” occur in the presence of an electrically active, not silent, code for unattended memories in these data. This crucial change in the evidence provided by this dataset prompts a reinterpretation of the mechanisms of EEG reactivations. We provide 2 possible explanations backed by computational models, and we discuss the relationship with TMS-induced EEG reactivations.

Yuhan Mu, Wei Su, Yingchun Mu et al.

Frontiers in Microbiology • 2020

Panxian ham, a traditional Chinese dry-cured ham, is protected by national geographical indication. Similar to other fermented foods, the microbial population of dry-cured ham is pivotal to taste and flavor formation. This study aimed to establish the relationship between microorganisms and metabolites during the spontaneous fermentation of Panxian ham. Multivariate analysis based on metabolomics data revealed that continuous metabolic changes occurred during the entire fermentation process, with the most significant changes occurring in the initial stage of ripening. Thirty-one significantly different metabolites (SDMs) were identified as discriminant factor, and pathway analysis suggested that these metabolites were involved in 30 pathways, including alanine, aspartate, and glutamate metabolism; glycine, serine, and threonine metabolism; and arginine and proline metabolism. Microbial community analysis using the Illumina MiSeq platform indicated that the bacterial community was more complex than the fungal community, and their succession regulation differed during processing. At the genus level, 11 bacteria and five fungi were identified as core microbes, of which Staphylococcus was the dominant bacteria and Debaryomyces and Aspergillus were the dominant fungi. Further, statistical redundancy analysis (RDA) indicated that Staphylococcus, Debaryomyces, and Chromohalobacter promoted the production of amino and fatty acids; Cobetia and Aspergillus were associated with sugar metabolism, and Kushneria, Penicillium, and Yamadazyma were closely related with organic acids. These findings provide fundamental knowledge regarding the metabolically active microorganisms in Panxian ham, helping industrial processors to develop effective strategies for standardizing quality parameters.

Yuanyuan Pan, Ying Wang, Wen-bo Hao et al.

Microbiology Spectrum • 2022

There is an urgent need for discovering the diversity and functions of the active microbial community in solid-state fermentation, especially in the pit of Chinese distilled liquor fermentation. Although the genetic composition of the microbial community has been clarified frequently by DNA-based sequencing, the composition and functions of the active microbial community have not been systematically revealed so far. ABSTRACT The microbial community in the fermented pit determines the quantity and quality of light-flavor liquor. Genetic diversity and the potential functions of the microbial community are often analyzed by DNA-based omics sequencing. However, the features of the active microbial community have not been systematically studied. Here, metatranscriptomic analysis was performed to elucidate the active microbial composition, drivers, and their functions in light-flavor liquor fermentation. Bacterial genera, Lactobacillus, Streptococcus, Pediococcus, Thermotoga, and Faecalibacterium, and fungal genera, Saccharomyces, Talaromyces, Aspergillus, Clavispora, Rhizophagus, Cyberlindnera, and Wickerhamomyces, were the dominant active microorganisms during the fermentation process. Additionally, they dominated the three-stage fermentation successively. Redundancy analysis showed that pH, ethanol, moisture, and starch were the main driving forces of microbial succession. Among the genes for the respective carbohydrate-active enzyme families, those for the glycoside hydrolase family 23, the glycosyltransferase family 2, the carbohydrate-binding module family 50, the polysaccharide lyase family 4, the auxiliary activity family 1, and the carbohydrate esterase family 9 showed the highest expression level. Additionally, the highly expressed enzymes and their contributed microorganisms were found in the key KEGG pathways, including carbohydrate metabolism, energy metabolism, lipid metabolism, and amino acid metabolism. Based on these data, a functional model of carbohydrate hydrolysis, ethanol production, and flavor generation were proposed. Taken together, Saccharomyces, Lactobacillus, Wickerhamomyces, Pediococcus, Candida, and Faecalibacterium were suggested as the core active microorganisms. Overall, our findings provide new insights into the composition, drivers, and functions of the active microorganisms, which is crucial for improving the quality of light-flavor liquor. IMPORTANCE There is an urgent need for discovering the diversity and functions of the active microbial community in solid-state fermentation, especially in the pit of Chinese distilled liquor fermentation. Although the genetic composition of the microbial community has been clarified frequently by DNA-based sequencing, the composition and functions of the active microbial community have not been systematically revealed so far. Therefore, analysis of RNA-based data is crucial for discovering the functional microbial community. In this study, we employed metatranscriptomic analysis to elucidate the active microbial composition, successive drivers, and their functions in light-flavor liquor fermentation. The strategy can be broadly useful for discovering the active microbial community and exploring their functions in other types of flavor distilled liquor or other ecosystems. This study provides new insights into the understanding of the active microbial community composition and its functions.

N. Fur, M. Belanche, C. Martinella et al.

IEEE Transactions on Nuclear Science • 2023

Deep-level transient spectroscopy (DLTS) and minority carrier transient spectroscopy (MCTS) are used to investigate electrically active defects in commercial silicon carbide (SiC) Schottky power diodes after heavy-ion microbeam irradiation at different voltages. The DLTS and MCTS spectra of pristine samples are analyzed and compared to devices showing or not signatures of single event leakage current (SELC) degradation. An additional peak labeled “C” with an activation energy of 0.17 eV below the conduction band edge is observed in the DLTS spectra of a sample degraded with SELC.

Haoran Liu, Hongmiao Tian, Duorui Wang et al.

Science Advances • 2023

Perching-and-takeoff robot can effectively economize onboard power and achieve long endurance. However, dynamic perching on moving targets for a perching-and-takeoff robot is still challenging due to less autonomy to dynamically land, tremendous impact during landing, and weak contact adaptability to perching surfaces. Here, a self-sensing, impact-resistant, and contact-adaptable perching-and-takeoff robot based on all-in-one electrically active smart adhesives is proposed to reversibly perch on moving/static dry/wet surfaces and economize onboard energy. Thereinto, attachment structures with discrete pillars have contact adaptability on different dry/wet surfaces, stable adhesion, and anti-rebound; sandwich-like artificial muscles lower weight, enhance damping, simplify control, and achieve fast adhesion switching (on-off ratio approaching ∞ in several seconds); and the flexible pressure (0.204% per kilopascal)–and–deformation (force resolution, <2.5 millinewton) sensor enables the robot’s autonomy. Thus, the perching-and-takeoff robot equipped with electrically active smart adhesives exhibits tremendous advantages of soft materials over their rigid counterparts and promising application prospect of dynamic perching on moving targets.

Attila Tókos, Monica Jipa, V. Marinescu et al.

Electrotehnica, Electronica, Automatica • 2021

A system for electromagnetic stimulation of microorganisms' activity from the active sludge of wastewater treatment plants was developed and preliminarily tested. Through electrochemical, gravimetric, XRD, and SEM-EDAX measurements, it was found that austenitic stainless steel 18/8 presents good stability to AC polarization in wastewater. Preliminary determinations performed through the dielectric spectroscopy technique indicated that the activated sludge's microbial flora is sensitive to 50 ± 0.1 Hz. The stimulation system developed and put into service on the biological aerobic treatment bioreactor consists of a pair of polarizing electrodes, made of perforated 18/8 stainless steel sheet, electrically connected to a power supply, which at 50 Hz is capable of debiting adjustable voltages between 5 and 24 Vrms at a maximum current of 5 A. Preliminary in situ measurements showed that following the stimulation of the microorganisms from the sludge suspension, as a result of an applied electromagnetic field of approximately 4.5 V/m at 50 Hz, the metabolism of residues is accelerated substantially (organic residues determined by oxygen demand decrease by about 42 %, nitrogen/ammonium content by about 44% and total phosphorus by about 50 % which results in an increase in free oxygen concentration by about 71 %).

C. Pablos, J. Marugán, R. van Grieken et al.

Molecules • 2017

TiO2 photocatalysis is considered as an alternative to conventional disinfection processes for the inactivation of waterborne microorganisms. The efficiency of photocatalysis is limited by charge carrier recombination rates. When the photocatalyst is immobilized on an electrically conducting support, one may assist charge separation by the application of an external electrical bias. The aim of this work was to study electrochemically assisted photocatalysis with nitrogen doped titania photoanodes under visible and UV-visible irradiation for the inactivation of Escherichia coli. Aligned TiO2 nanotubes were synthesized (TiO2-NT) by anodizing Ti foil. Nanoparticulate titania films were made on Ti foil by electrophoretic coating (P25 TiO2). N-doped titania nanotubes and N,F co-doped titania films were also prepared with the aim of extending the active spectrum into the visible. Electrochemically assisted photocatalysis gave higher disinfection efficiency in comparison to photocatalysis (electrode at open circuit) for all materials tested. It is proposed that electrostatic attraction of negatively charged bacteria to the positively biased photoanodes leads to the enhancement observed. The N-doped TiO2 nanotube electrode gave the most efficient electrochemically assisted photocatalytic inactivation of bacteria under UV-Vis irradiation but no inactivation of bacteria was observed under visible only irradiation. The visible light photocurrent was only a fraction (2%) of the UV response.