K. S. Wani, B. Mir

International Journal of Geotechnical Engineering • 2019

ABSTRACT Concern over environmental effects of dredging, disposal and the increasing unavailability of suitable disposal sites, has put pressure on engineers to improve dredged soils which are weak, have low bearing capacity and undergo excessive settlements over time. This study deals with improvement of such soils generated by dredging of the flood spill channel of River Jhelum, passing through world-renowned wetland, Hokersar. A recent introduction to the ground improvement techniques that utilizes microbes is known as microbial geo-technology. Both natural processes and laboratory investigations have shown that microorganisms can be used to improve the mechanical properties of soil. In this study, dredged soil is treated with microbes (Bacillus Subtilis) at different optical densities (1 and 1.3) and then supplemented with cementing agent solution of urea and calcium chloride at different molarities (0.25M and 1M). The samples are treated for a period of 48 h and then tested for shear strength. Curing for a period of 7 and 28 days is done in a temperature-controlled chamber (25–28°C). With increasing the optical density and molarity of cementing solution there is an increase in calcium carbonate precipitate which increases the strength parameters, the results are in-turn supported by SEM and XRD analysis. Treated dredged soil can be utilized in bulk as a resource for various engineering applications for eco-friendly and sustainable development of the environment.

Zeyu Zhang, Zheng Fan, Guoliang Zhang et al.

BioResources • 2021

In recent years, microbial degradation technology has shown broad potential in the fields of agriculture, industry, and environmental protection. However, in practical applications the technology still encounters many problems, such as low bacterial survivability during dynamic operations, the need to remove bacterial liquid, and low tolerance in high-toxic environments, among other issues. Immobilization technology has been developed to overcome such limitations. Microbial strains have been prepared for a specific range of activities utilizing self-fixation or exosome fixation. Immobilization can significantly improve strain density, toxicity tolerance, and bacterial liquid removal. This review first presents the advantages and disadvantages of the current microbial immobilization technologies and then summarizes the properties and characteristics of various carrier materials. The review focuses on how biomass-derived materials have been used as the carriers in new microbial immobilization technologies. The excellent biocompatibility, unique physical structure, and diversified modification methods of biomass-derived materials have shown excellent prospects in the field of microbial immobilization. Finally, microbial immobilization technologies’ potential applications in agriculture, industry, and environmental applications are considered.

Jiasheng Lu, Wenfang Peng, Y. Lv et al.

Industrial & Engineering Chemistry Research • 2020

Due to the heavy metabolic burden and low efficiency of microbial pure cultures during the biotechnological process for biochemicals production, researchers have focused on microbial cocultivation ...

Yasmine Kebbi, A. Muhammad, A. Sant’Ana et al.

Comprehensive Reviews in Food Science and Food Safety • 2020

Conventional technologies for the inactivation of microorganisms in food products have their limitations, especially changes in quality attributes that have led to quality deterioration, low consumer acceptance, impact on the environment, and potential health hazards (carcinogens). Ultraviolet (UV) light is an emerging promising nonthermal technology employed for microbial inactivation in water, liquid, and solid food products to curtail the limitations above. This review provides an insight into UV light-emitting diodes (UV-LEDs)' potential as an alternative to the traditional UV lamps for microbial inactivation in liquid and solid media. Also, the mechanisms of inactivation of lone and combined UVA-, UVB-, and UVC-LEDs were discussed. The strategies utilized to improve the efficacy between the UV-LED treatments at various wavelengths were summarized. Combining different UV-LEDs treatments at different wavelengths have a synergistic effect and suppression of microbial cell reactivation. The UV-LED-based advanced oxidation processes (AOPs) also have high germicidal action against numerous microorganisms and are efficient for the degradation of micropollutants. Among the UV-LEDs discussed, UVC-LED has the most antimicrobial effect with the most efficient micropollutants decomposition with regards to UV-LED-based AOPs. This review has provided vital information for future application, development, and customization of UV-LED systems that can meet the food and water safety requirements and energy efficiency.

N. Singhal, Manish Kumar, P. Kanaujia et al.

Frontiers in Microbiology • 2015

Currently microorganisms are best identified using 16S rRNA and 18S rRNA gene sequencing. However, in recent years matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has emerged as a potential tool for microbial identification and diagnosis. During the MALDI-TOF MS process, microbes are identified using either intact cells or cell extracts. The process is rapid, sensitive, and economical in terms of both labor and costs involved. The technology has been readily imbibed by microbiologists who have reported usage of MALDI-TOF MS for a number of purposes like, microbial identification and strain typing, epidemiological studies, detection of biological warfare agents, detection of water- and food-borne pathogens, detection of antibiotic resistance and detection of blood and urinary tract pathogens etc. The limitation of the technology is that identification of new isolates is possible only if the spectral database contains peptide mass fingerprints of the type strains of specific genera/species/subspecies/strains. This review provides an overview of the status and recent applications of mass spectrometry for microbial identification. It also explores the usefulness of this exciting new technology for diagnosis of diseases caused by bacteria, viruses, and fungi.

S. Dave, Asha B. Sodha, D. Tipre

Journal of Bacteriology & Mycology: Open Access • 2018

Rapid urbanization, industrialization, and population growth have resulted in increased demand of electronic and electrical gadgets. With fast technological advancement and development, due to the demand of people, industries are now manufacturing novel, superior and smart electronic and electrical equipments (EEEs) at an alarming rate. More and more EEEs products are produced purchased, used and discarded resulting in the generation of huge amount of waste electronic and electrical equipments (WEEEs).1 The electronic waste (e-Waste) normally consist of small and large equipment such as LED lamps, cell phones, smart mobile phones, superior televisions, refrigerators, printers, driers, temperature exchangers as well as advance computing devices.2 Due to the fast advancement in technology and tremendous market growth most of these electronic and electric material have very short life span, which resulted in the fastest accumulation in e-Waste.3 Broadly, the end of life electrical and electronic equipments without intent of reuse is considered as e-Waste. As per the information available in literature in 2014, about 41.8 million tons of e-Waste generated globally and as per the estimation e-Waste is growing at the rate of 4-5% annually, which leads to about 49.8 million tons of e-Waste generation in 2018.4 The large amounts of complex and diverse e-Waste generated have adverse impact on environment as well as human being, if they are not properly managed. Unfortunately there is no proper system to collect, store, transport, treat, and disposal of e-Waste. Thus, it has become major issue of concern for the industries, government and non-government organization and even for the public to protect the environment from the hazardous effect of improperly managed e-Waste.5 Most of us know that e-Waste has been accumulated since many years, but their devastating environmental effects is realized recently, which has created keen awareness in the scientific community as well as in common people throughout the world and it has forced concerned peoples for their proper treatment. E-Waste has been accumulated since many years; contain several hazardous organic pollutant as well as considerable amount of base, precious and rare earth metals.6 The core component of all electronic and many electrical equipment is printed circuit boards (PCBs), which is used for smooth, fast and convenient functioning of small to large electronic devices. PCBs contain several metals as well as various organic pollutants. Thus, it cannot be dumped as landfill or incinerated. However, incineration and land filling are the common method adapted for e-Waste management, which leads to the release of toxic gases in atmosphere and highly harmful metals in soil and ground waters. These pollutants will accumulate and transport in plant systems, which ultimately reach to animals and human.7,8 Due to this awareness e-Waste management has become a vital and significant field of research throughout the world. The current chapter mainly focus on bio-treatment of PCBs with special reference to extraction of metals from waste PCBs by using microbial technology. Types of microorganisms involved in the metal solubilisation process and major mechanisms of metal extractions are illustrated.

K. Zhang, C. Tang, Ningjun Jiang et al.

Environmental Earth Sciences • 2023

The microbial‑induced carbonate precipitation (MICP), as an emerging biomineralization technology mediated by specific bacteria, has been a popular research focus for scientists and engineers through the previous two decades as an interdisciplinary approach. It provides cutting-edge solutions for various engineering problems emerging in the context of frequent and intense human activities. This paper is aimed at reviewing the fundaments and engineering applications of the MICP technology through existing studies, covering realistic need in geotechnical engineering, construction materials, hydraulic engineering, geological engineering, and environmental engineering. It adds a new perspective on the feasibility and difficulty for field practice. Analysis and discussion within different parts are generally carried out based on specific considerations in each field. MICP may bring comprehensive improvement of static and dynamic characteristics of geomaterials, thus enhancing their bearing capacity and resisting liquefication. It helps produce eco-friendly and durable building materials. MICP is a promising and cost-efficient technology in preserving water resources and subsurface fluid leakage. Piping, internal erosion and surface erosion could also be addressed by this technology. MICP has been proved suitable for stabilizing soils and shows promise in dealing with problematic soils like bentonite and expansive soils. It is also envisaged that this technology may be used to mitigate against impacts of geological hazards such as liquefaction associated with earthquakes. Moreover, global environment issues including fugitive dust, contaminated soil and climate change problems are assumed to be palliated or even removed via the positive effects of this technology. Bioaugmentation, biostimulation, and enzymatic approach are three feasible paths for MICP. Decision makers should choose a compatible, efficient and economical way among them and develop an on-site solution based on engineering conditions. To further decrease the cost and energy consumption of the MICP technology, it is reasonable to make full use of industrial by-products or wastes and non-sterilized media. The prospective direction of this technology is to make construction more intelligent without human intervention, such as autogenous healing. To reach this destination, MICP could be coupled with other techniques like encapsulation and ductile fibers. MICP is undoubtfully a mainstream engineering technology for the future, while ecological balance, environmental impact and industrial applicability should still be cautiously treated in its real practice.

R. Overbeek, R. Olson, G. Pusch et al.

Nucleic Acids Research • 2013

In 2004, the SEED (http://pubseed.theseed.org/) was created to provide consistent and accurate genome annotations across thousands of genomes and as a platform for discovering and developing de novo annotations. The SEED is a constantly updated integration of genomic data with a genome database, web front end, API and server scripts. It is used by many scientists for predicting gene functions and discovering new pathways. In addition to being a powerful database for bioinformatics research, the SEED also houses subsystems (collections of functionally related protein families) and their derived FIGfams (protein families), which represent the core of the RAST annotation engine (http://rast.nmpdr.org/). When a new genome is submitted to RAST, genes are called and their annotations are made by comparison to the FIGfam collection. If the genome is made public, it is then housed within the SEED and its proteins populate the FIGfam collection. This annotation cycle has proven to be a robust and scalable solution to the problem of annotating the exponentially increasing number of genomes. To date, >12 000 users worldwide have annotated >60 000 distinct genomes using RAST. Here we describe the interconnectedness of the SEED database and RAST, the RAST annotation pipeline and updates to both resources.

G. Hong, Xie Yuebo, Sarfraz Hashim et al.

Water • 2018

Contrary to the constraints in time, investment, and management of the traditional technology for waste water treatment, this paper seeks to propose a more advanced, reliable, and affordable new technology to restore urban polluted rivers to pristine quality levels. The paper also presents new ideas on the selection and use of microbial agents to improve the efficiency of pollution removal. It presents the successful implementation of microbial technology (MT) on Chengnan River, which was heavily polluted before MT implementation. Without artificial aeration, sediment dredging, or complete sewage interception, we directly sprayed a previously configured HP-RPe-3 Microbial Agent into the water body and sediment. We considered the feasibility of MT for treating polluted urban rivers from the perspective of several water quality indices evaluation methods. After the treatment, the concentration of dissolved oxygen (DO) reached 5.0 mg/L, the removal rates of ammonia nitrogen (NH3-N) and chemical oxygen demand (COD) reached 20% and 38% respectively, and the average degradation rate of total phosphorus (TP) along river was close to 15%. Also, the Nemerow Index of the river was reduced from 2.7 to 1.9. The Fuzzy Comprehensive Index shows a tendency for improvement from Inferior Grade V to a better grade (approximately Grade III). The color of the river water changed, from black or dark green, to its original color. The results indicate that the bioremediation technology of directly adding microbial agents mainly aimed for the degradation of NH3-N can preliminarily eliminate the black-odor phenomenon of urban rivers, and improve their water quality. It is expected that the MT application, and the concept of how to select the corresponding microbial agents according to main pollutants, can be widely accepted and applied to similar cases.

Faming Zhang, Weihong Wang, Y. Nie et al.

Microbial Biotechnology • 2023

Health and wellbeing are important components of the United Nations Sustainable Development Goals. Research on microbiota and human health is a burning question in achieving these goals. Global use of antibiotics and other drugs, the prevalence of the ultraprocessed foods in the Western diet, drastic changes in lifestyle and industrial development continue to damage both environmental and human microbiota (Marchesi et al., 2016). Numerous studies have shown that human microbiota plays an important role in disease profiles, from infections, inflammation, malnutrition to cancer, providing a new dimension for understanding medicine and life science. The recognition of the importance of the microbiome in health and disease, particularly in inflammation and immune function, has become one of the most significant scientific breakthroughs in the past decade. Targeting the human microbiome for diagnosis and treatment of diseases has led to a series of groundbreaking technologies, especially in microbiome sequencing, multiomics integration, and faecal microbiota transplantation (FMT), which are changing clinical practice. From the perspective of using microbial cells to treat diseases, probiotics and FMT are at two extremes. FMT being the most effective clinical technology fundamentally proves the importance of the microbiome in human health and disease. An analysis of global FMT clinical reports in the 10 years since the term ‘fecal microbiota transplantation’ was defined in 2011, FMT has been used to treat 85 diseases related to microbiome dysbiosis, which can be collectively referred to as microbiota dysbiosisrelated diseases (Wang et al., 2022). These diseases are related to dysbiosis and can be treated by microbiome reconstruction. In recent years, new technologies derived from FMT have emerged, mainly including washed microbiota transplantation (WMT) based on medical devices approved in China (Lu et al., 2022; Wang et al., 2022), faecal liquid enemas as drug approved in the United States (Khanna et al., 2022) and purified spores from faeces as drug approved in the United States (Feuerstadt et al., 2022). This rapidly increasing clinical evidence has broken through the boundaries of classical digestive system diseases, highlighting the transformative role of microbiometargeted technologies. Developing microbiomebased therapeutics is the driving force moving clinical medicine forward. How can we maximize the use of human microbiome to diagnose and treat individual diseases and promote human health? In fact, the number of patients who actually benefited from emerging microbiome technologies was far from the theoretical number of beneficiaries. If these microbiome technologies are allowed to develop freely according to the current form and promoted and developed according to the rules of technical commercialization, the entire field will face bottleneck constraints. The use of technical thinking, utilitarian behaviour and commercial activities may result in medical unfairness due to high costs. Additionally, excessive reliance on technology can lead to ethical and moral issues, which can create obstacles for the development of the field. To solve these bottleneck problems and avoid these potential traps, a scientific framework higher than the technology itself is needed to achieve sustainable development goals. However, in the existing clinical medicine discipline classification system, there is no discipline that can cover the above medical needs. Solving the emerging microbiomebased clinical medical problems is an important action to transform our world and achieve sustainable development goals. After Faming Zhang received the invitation from Juan Luis Ramos, the editor of Microbial Biotechnology in 2023 for contributing an article which highlights the potential contributions of microbes to achieving sustainable development goals in clinical medicine, the authors of this article prepared for this and held a dialogue and discussion on the theme of ‘From Microbial Technology to Microbiota Medicine: Sustainable Development Goals’ at the China Gut Conference (China National Convention Center, Beijing) on May 21, 2023 and then revised and formed this article. Received: 7 June 2023 | Accepted: 3 July 2023

Jenny M. Booth, Marco Fusi, Ramona Marasco et al.

Microbial Biotechnology • 2023

<jats:title>Abstract</jats:title><jats:p>Globally, soils and sediments are affected by the bioturbation activities of benthic species. The consequences of these activities are particularly impactful in intertidal sediment, which is generally anoxic and nutrient‐poor. Mangrove intertidal sediments are of particular interest because, as the most productive forests and one of the most important stores of blue carbon, they provide global‐scale ecosystem services. The mangrove sediment microbiome is fundamental for ecosystem functioning, influencing the efficiency of nutrient cycling and the abundance and distribution of key biological elements. Redox reactions in bioturbated sediment can be extremely complex, with one reaction creating a cascade effect on the succession of respiration pathways. This facilitates the overlap of different respiratory metabolisms important in the element cycles of the mangrove sediment, including carbon, nitrogen, sulphur and iron cycles, among others. Considering that all ecological functions and services provided by mangrove environments involve microorganisms, this work reviews the microbial roles in nutrient cycling in relation to bioturbation by animals and plants, the main mangrove ecosystem engineers. We highlight the diversity of bioturbating organisms and explore the diversity, dynamics and functions of the sediment microbiome, considering both the impacts of bioturbation. Finally, we review the growing evidence that bioturbation, through altering the sediment microbiome and environment, determining a ‘halo effect’, can ameliorate conditions for plant growth, highlighting the potential of the mangrove microbiome as a nature‐based solution to sustain mangrove development and support the role of this ecosystem to deliver essential ecological services.</jats:p>

Judith Naamala, Donald L. Smith

Frontiers in Microbiology • 0

<jats:p>Sustainable agriculture remains a focus for many researchers, in an effort to minimize environmental degradation and climate change. The use of plant growth promoting microorganisms (PGPM) is a hopeful approach for enhancing plant growth and yield. However, the technology faces a number of challenges, especially inconsistencies in the field. The discovery, that microbial derived compounds can independently enhance plant growth, could be a step toward minimizing shortfalls related to PGPM technology. This has led many researchers to engage in research activities involving such compounds. So far, the findings are promising as compounds have been reported to enhance plant growth under stressed and non-stressed conditions in a wide range of plant species. This review compiles current knowledge on microbial derived compounds, taking a reader through a summarized protocol of their isolation and identification, their relevance in present agricultural trends, current use and limitations, with a view to giving the reader a picture of where the technology has come from, and an insight into where it could head, with some suggestions regarding the probable best ways forward.</jats:p>

Gregory L. Cote, Jeffrey A. Ahlgren

Kirk-Othmer Encyclopedia of Chemical Technology • 0

<jats:title>Abstract</jats:title><jats:p>Cote, Gregory L. and Ahlgren, Jeffrey A. (U.S. Dept. of Agriculture). Microbial polysaccharides are complex carbohydrate polymers produced by a variety of microorganisms. Those of commercial interest are generally produced extracellularly in substantial quantities. Commercial applications can be based on specific structural features or on physical properties. Applications based on physical properties include use as water‐soluble thickeners, gelling agents, and emulsion stabilizers. Applications based on specific structural features include the use of bacterial capsular antigens as vaccines, and the use of polysaccharides as metal complexants. Economically, the most important microbial polysaccharides are xanthan gum, dextran, and gellan. Others, such as pullulan, curdlan, and scleroglucan, are used less in the United States, but significant quantities are used overseas. Other microbial polysaccharides that show promise are bacterial cellulose, emulsan, liposan, levan, and succinoglucan. β‐<jats:sc>D</jats:sc>‐Glucans and sulfated polysaccharides are of interest as immunomodulators. Vol. 16, pp. 578–611, 372 refs. to November 1993.</jats:p>

, Gabriele Berg, et al.

Burleigh Dodds Series in Agricultural Science • 2021

<jats:p>Plant-associated microorganisms are involved in important functions related to growth, performance and health of their hosts. Understanding their modes of action is important for the development and application of microbial bioprotectants and biostimulants. Recent studies have revealed manifold plant-microbe as well as pathogen-microbe interactions, which form the basis of understanding beneficial effects of plant-associated microorganisms. Microbiome research has contributed to our understanding of the modes of action of various plant-associated microorganisms. This chapter summarizes current knowledge about beneficial plant-microbe interactions, discusses recent insights into the functioning of the plant microbiome and beneficial plant-microbe networks. It shows that the use of microorganisms and the exploitation of beneficial plant–microbe interactions offer promising and environmentally-friendly strategies to achieve sustainable agriculture on a global scale.</jats:p>

Sinje Neukirchen, Filipa L. Sousa

Microbial Genomics • 2021

<jats:p>Current methods in comparative genomic analyses for metabolic potential prediction of proteins involved in, or associated with the Dsr (dissimilatory sulphite reductase)-dependent dissimilatory sulphur metabolism are both time-intensive and computationally challenging, especially when considering metagenomic data. We developed DiSCo, a Dsr-dependent dissimilatory sulphur metabolism classification tool, which automatically identifies and classifies the protein type from sequence data. It takes user-supplied protein sequences and lists the identified proteins and their classification in terms of protein family and predicted type. It can also extract the sequence data from user-input to serve as basis for additional downstream analyses. DiSCo provides the metabolic functional prediction of proteins involved in Dsr-dependent dissimilatory sulphur metabolism with high levels of accuracy in a fast manner. We ran DiSCo against a dataset composed of over 190 thousand (meta)genomic records and efficiently mapped Dsr-dependent dissimilatory sulphur proteins in 1798 lineages across both prokaryotic domains. This allowed the identification of new micro-organisms belonging to Thaumarchaeota and Spirochaetes lineages with the metabolic potential to use the Dsr-pathway for energy conservation. DiSCo is implemented in Perl 5 and freely available under the GNU GPLv3 at <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="https://github.com/Genome-Evolution-and-Ecology-Group-GEEG/DiSCo" xlink:type="simple">https://github.com/Genome-Evolution-and-Ecology-Group-GEEG/DiSCo.</jats:ext-link> </jats:p>

M. Azari, A. V. Le, M. Lübken et al.

Water Science and Technology • 2018

<jats:title>Abstract</jats:title><jats:p>A mathematical model for a granular biofilm reactor for leachate treatment was validated by long-term measured data to investigate the mechanisms and drivers influencing biological nitrogen removal and microbial consortia dynamics. The proposed model, based on Activated Sludge Model (ASM1), included anaerobic ammonium oxidation (anammox), nitrifying and heterotrophic denitrifying bacteria which can attach and grow on granular activated carbon (GAC) particles. Two kinetic descriptions for the model were proposed: with and without soluble microbial products (SMP) and extracellular polymeric substance (EPS). The model accuracy was checked using recorded total inorganic nitrogen concentrations in the effluent and estimated relative abundance of active bacteria using quantitative fluorescence in-situ hybridization (qFISH). Results suggested that the model with EPS kinetics fits better for the relative abundance of anammox bacteria and nitrifying bacteria compared to the model without EPS. The model with EPS and SMP confirms that the growth and existence of heterotrophs in anammox biofilm systems slightly increased due to including the kinetics of SMP production in the model. During the one-year simulation period, the fractions of autotrophs and EPS in the biomass were almost stable but the fraction of heterotrophs decreased which is correlated with the reduction in nitrogen surface loading on the biofilm.</jats:p>

Panu Pimviriyakul, Thanyaporn Wongnate, Ruchanok Tinikul et al.

Microbial Biotechnology • 2020

<jats:title>Summary</jats:title><jats:p>Halogenated aromatics are used widely in various industrial, agricultural and household applications. However, due to their stability, most of these compounds persist for a long time, leading to accumulation in the environment. Biological degradation of halogenated aromatics provides sustainable, low‐cost and environmentally friendly technologies for removing these toxicants from the environment. This minireview discusses the molecular mechanisms of the enzymatic reactions for degrading halogenated aromatics which naturally occur in various microorganisms. In general, the biodegradation process (especially for aerobic degradation) can be divided into three main steps: upper, middle and lower metabolic pathways which successively convert the toxic halogenated aromatics to common metabolites in cells. The most difficult step in the degradation of halogenated aromatics is the dehalogenation step in the middle pathway. Although a variety of enzymes are involved in the degradation of halogenated aromatics, these various pathways all share the common feature of eventually generating metabolites for utilizing in the energy‐producing metabolic pathways in cells. An in‐depth understanding of how microbes employ various enzymes in biodegradation can lead to the development of new biotechnologies <jats:italic>via</jats:italic> enzyme/cell/metabolic engineering or synthetic biology for sustainable biodegradation processes.</jats:p>

Z. Ren, L. M. Steinberg, J. M. Regan

Water Science and Technology • 2008

<jats:p>Converting biodegradable materials into electricity, microbial fuel cells (MFCs) present a promising technology for renewable energy production in specific applications. Unlike typical soluble substrates that have been used as electron donors in MFC studies, cellulose is unique because it requires a microbial consortium that can metabolize both an insoluble electron donor (cellulose) and electron acceptor (electrode). In this study, electricity generation and the microbial ecology of cellulose-fed MFCs were analyzed using a defined co-culture of Clostridium cellulolyticum and Geobacter sulfurreducens. Fluorescent in situ hybridization and quantitative PCR showed that when particulate MN301 cellulose was used as sole substrate, most Clostridium cells were found adhered to cellulose particles in suspension, while most Geobacter cells were attached to the electrode. By comparison, both bacteria resided in suspension and biofilm samples when soluble carboxymethyl cellulose was used. This distinct function-related distribution of the bacteria suggests an opportunity to optimize reactor operation by settling cellulose and decanting supernatant to extend cellulose hydrolysis and improve cellulose-electricity conversion.</jats:p>

Thomas Maskow, Richard Kemp, Friederike Buchholz et al.

Microbial Biotechnology • 2010

<jats:title>Summary</jats:title><jats:p>The exploitation of microorganisms in natural or technological systems calls for monitoring tools that reflect their metabolic activity in real time and, if necessary, are flexible enough for field application. The Gibbs energy dissipation of assimilated substrates or photons often in the form of heat is a general feature of life processes and thus, in principle, available to monitor and control microbial dynamics. Furthermore, the combination of measured heat fluxes with material fluxes allows the application of Hess' law to either prove expected growth stoichiometries and kinetics or identify and estimate unexpected side reactions. The combination of calorimetry with respirometry is theoretically suited for the quantification of the degree of coupling between catabolic and anabolic reactions. New calorimeter developments overcome the weaknesses of conventional devices, which hitherto limited the full exploitation of this powerful analytical tool. Calorimetric systems can be integrated easily into natural and technological systems of interest. They are potentially suited for high‐throughput measurements and are robust enough for field deployment. This review explains what information calorimetric analyses provide; it introduces newly emerging calorimetric techniques and it exemplifies the application of calorimetry in different fields of microbial research.</jats:p>

Peter Bossier, Julie Ekasari

Microbial Biotechnology • 2017

<jats:title>Summary</jats:title><jats:p>Biofloc technology (BFT) application offers benefits in improving aquaculture production that could contribute to the achievement of sustainable development goals. This technology could result in higher productivity with less impact to the environment. Furthermore, biofloc systems may be developed and performed in integration with other food production, thus promoting productive integrated systems, aiming at producing more food and feed from the same area of land with fewer input. The biofloc technology is still in its infant stage. A lot more research is needed to optimise the system (in relation to operational parameters) e.g. in relation to nutrient recycling, MAMP production, immunological effects. In addition research findings will need to be communicated to farmers as the implementation of biofloc technology will require upgrading their skills.</jats:p>

Willy Verstraete, Jo De Vrieze

Microbial Biotechnology • 2017

<jats:title>Summary</jats:title><jats:p>Several needs in the context of the water–energy–food nexus will become more prominent in the next decades. It is crucial to delineate these challenges and to find opportunities for innovative microbial technologies in the framework of sustainability and climate change. Here, we focus on four key issues, that is the imbalance in the nitrogen cycle, the diffuse emission of methane, the necessity for carbon capture and the deterioration of freshwater reserves. We suggest a set of microbial technologies to deal with each of these issues, such as (i) the production of microbial protein as food and feed, (ii) the control of methanogenic archaea and better use of methanotrophic consortia, (iii) the avoidance of nitrification and (iv) the upgrading of CO<jats:sub>2</jats:sub> to microbial bioproducts. The central message is that instead of using crude methods to exploit microorganisms for degradations, the potentials of the microbiomes should be used to create processes and products that fit the demands of the cyclic market economy.</jats:p>

Kenneth Timmis, John E. Hallsworth

Microbial Biotechnology • 2024

<jats:title>Abstract</jats:title><jats:p>Microbial technologies constitute a huge and unique potential for confronting major humanitarian and biosphere challenges, especially in the realms of sustainability and providing basic goods and services where they are needed and particularly in low‐resource settings. These technologies are evolving rapidly. Powerful approaches are being developed to create novel products, processes, and circular economies, including new prophylactics and therapies in healthcare, bioelectric systems, and whole‐cell understanding of metabolism that provides novel insights into mechanisms and how they can be utilised for applications. The modulation of microbiomes promises to create important applications and mitigate problems in a number of spheres. Collectively, microbial technologies save millions of lives each year and have the potential, through increased deployment, to save many more. They help restore environmental health, improve soil fertility, enable regenerative agriculture, reduce biodiversity losses, reduce pollution, and mitigate polluted environments. Many microbial technologies may be considered to be ‘healing’ technologies – healing of humans, of other members of the biosphere, and of the environment. This is the <jats:italic>Age of Microbial Technology</jats:italic>. However, the current exploitation of microbial technologies in the service of humanity and planetary health is woefully inadequate and this failing unnecessarily costs many lives and biosphere deterioration. Microbiologists – the practitioners of these healing technologies – have a special, preordained responsibility to promote and increase their deployment for the good of humanity and the planet. To do this effectively – <jats:italic>to actually make a difference</jats:italic> – microbiologists will need to partner with key enablers and gatekeepers, players such as other scientists with essential complementary skills like bioengineering and bioinformatics, politicians, financiers, and captains of industry, international organisations, and the general public. Orchestration and coordination of the establishment and functioning of effective partnerships will best be accomplished by learned societies, their academies, and the international umbrella organisations of learned societies. Effective dedication of players to the tasks at hand will require unstinting support from employers, particularly the heads of institutes of higher education and of research establishments. Humanity and the biosphere are currently facing challenges to their survival not experienced for millennia. Effectively confronting these challenges is existential, and microbiologists and their learned societies have pivotal roles to play: <jats:italic>they must step up and act now</jats:italic>.</jats:p>

Lawrence P. Wackett

Microbial Biotechnology • 2008

<jats:title>Summary</jats:title><jats:p>The production of biofuels via microbial biotechnology is a very active field of research. A range of fuel molecule types are currently under consideration: alcohols, ethers, esters, isoprenes, alkenes and alkanes. At the present, the major alcohol biofuel is ethanol. The ethanol fermentation is an old technology. Ongoing efforts aim to increase yield and energy efficiency of ethanol production from biomass. <jats:italic>n</jats:italic>‐Butanol, another microbial fermentation product, is potentially superior to ethanol as a fuel but suffers from low yield and unwanted side‐products currently. In general, biodiesel fuels consist of fatty acid methyl esters in which the carbon derives from plants, not microbes. A new biodiesel product, called microdiesel, can be generated in engineered bacterial cells that condense ethanol with fatty acids. Perhaps the best fuel type to generate from biomass would be biohydrocarbons. Microbes are known to produce hydrocarbons such as isoprenes, long‐chain alkenes and alkanes. The biochemical mechanisms of microbial hydrocarbon biosynthesis are currently under study. Hydrocarbons and minimally oxygenated molecules may also be produced by hybrid chemical and biological processes. A broad interest in novel fuel molecules is also driving the development of new bioinformatics tools to facilitate biofuels research.</jats:p>

Jing Kang, B. Hao, Yutong Li et al.

Energies • 2022

LVDC buildings use a low-voltage direct current (LVDC) distribution system for energy transmission and integrate photovoltaic (PV), battery energy storage (BES) and the utility grid as building energy resources. This technology can reduce energy loss in conversion to a certain extent and increase renewable energy compared with traditional AC distribution systems. Under the national goal of carbon peaking and carbon neutrality, LVDC buildings have been proven to be a new approach to energy conservation and emission reductions, and have been applied in engineering in China. However, the construction methods and integrated technologies of those projects are not clear, and technical barriers and policy constraints for the engineering application of LVDC buildings are not systematically discussed yet. This paper presents the latest study of LVDC building engineering applications the advantages and drawbacks of LVDC development in China. First, relevant policies and standards which support the development of LVDC building industries are summarized. More than 60 practical LVDC projects are investigated, and the application characteristics and the technology status of building types, and their capacity and design methods, etc., are analyzed. The attitudes of stakeholders toward LVDC buildings are surveyed to determine the policy direction according to the demands of this technology, with reference to building practitioners who intend to engage in LVDC projects.

Nofan Hadi Ahmad, A. Rusdiansyah, A. Wikarta

2019 Asia Pacific Conference on Research in Industrial and Systems Engineering (APCoRISE) • 2019

Electric motors are one of the achievements of technology that is qualified, both in terms of development of science and socio-economic aspects. Electric motors are promising products as an alternative mode of transportation for people by utilizing electricity as an energy source. To ensure the reliability and sustainability of these products in order to enter the automotive industry market and avoid negative sentiments in the form of consumers' concerns to recharge when they run out of electricity in the middle of their journey, it is proposed for the establishment of Battery Exchange Station (BES) in several locations in order to meet the availability of electrical energy supply in the form of batteries that are ready to use. Through the battery swapping method, electric motor users will exchange batteries that will run out with a new battery that has been charged 100% (fully charged). This causes the supplier is responsible for distributing the electric battery so that a model is needed to minimize distribution costs while maintaining inventory levels at the customer. The inventory routing problem model by considering stochastic demand and recharging time on BES is designed to solve that vendor problem related to the distribution of electric batteries. This problem is approached by the Traveling Salesman Problem (TSP) to determine the delivery route with a minimum total distance and modeled with the Markov Chain to determine scheduling related to its replenishment. The result revealed that cost of transportation will be minimum by TSP and cost of distribution (replenishment unit and truck dispatching) will be minimum by Modified Markov Chain Model.

S. Nagar, Vishu Gupta, R. Kumar et al.

2019 8th International Conference on Power Systems (ICPS) • 2019

Developing countries like INDIA mainly depends on conventional sources to meet the energy demand because of cheaper price. To meet the sustainable development goals every country is reducing their carbon footprint, this is possible when the energy generation can be shifted from conventional to renewable. As the energy demand is increasing, to meet the demand the penetration of renewable energy mainly photo voltaic panel (PV) is increasing exponentially on residential and commercial sites as they are eco-friendly in nature. However, the existing power plants are running on fossil fuel which are creating air pollution and burning the fossil fuel in huge amount. In this paper, a mathematical model is proposed of residential buildings which are integrated with PV and Battery Energy Storage (BES). Proposed model is a problem with maximizing the revenue from BES and minimizing the electricity bill of residential buildings in 2 different modes of operation. As indicated by the results, the electricity bill is reduced by using BES and PV.

D. Pant, Anoop Singh, G. V. Bogaert et al.

RSC Adv. • 2012

Bioelectrochemical systems (BESs) are unique systems capable of converting the chemical energy of organic waste including low-strength wastewaters and lignocellulosic biomass into electricity or hydrogen/chemical products in microbial fuel cells (MFCs) or microbial electrolysis cells (MECs) respectively, or other products formed at the cathode by an electrochemical reduction process. As compared to conventional fuel cells, BESs operate under relatively mild conditions, use a wide variety of organic substrates and mostly do not use expensive precious metals as catalysts. The recently discovered use of BES for product synthesis via microbial electrosynthesis have greatly expanded the horizon for these systems. Newer concepts in application as well as development of alternative materials for electrodes, separators, and catalysts, along with innovative designs have made BESs very promising technologies. This article discusses the recent developments that have been made in BESs so far, with an emphasis on their various applications beyond electricity generation, resulting performances and current limitations.

Yaru Chen, Lixia Fang, X. Ying et al.

Advanced Biology • 2022

Shewanella oneidensis MR‐1, as a model electroactive microorganism (EAM) for extracellular electron transfer (EET) study, plays a key role in advancing practical applications of bio‐electrochemical systems (BES). Efficient genome‐level manipulation tools are vital to promote EET efficiency; thus, a powerful and rapid base editing toolbox in S. oneidensis MR‐1 is developed. Firstly a CRISPR/dCas9‐AID base editor that shows a relatively narrow editing window restricted to the “−20 to −16” range upstream of the protospacer adjacent motif (PAM) is constructed. Cas9 is also confined by its native PAM requirement, NGG. Then to expand the editable scope, the sgRNA and the Cas‐protein to broaden the editing window to “−22 to −9” upstream of the PAM are engineered, and the PAM field to NNN is opened up. Consequently, the coverage of the editable gene is expanded from 89% to nearly 100% in S. oneidensis MR‐1. This whole genome‐scale cytidine deaminase‐based base editing toolbox (WGcBE) is applied to regulate the cell length and the biofilm morphology, which enhances the EET efficiency by 6.7‐fold. WGcBE enables an efficient deactivation of genes with full genome coverage, which would contribute to the in‐depth and multi‐faceted EET study in Shewanella.

Chunmei Chen, Pu Zheng, Peng-cheng Chen et al.

Biotechnology for Biofuels and Bioproducts • 2023

The production of bio-succinic acid (SA) from renewable feedstocks is a promising and sustainable approach to mitigating the high carbon emissions associated with the current energy crisis. Actinobacillus succinogenes was recognized as one of the most promising SA producers; however, lack of genetic background and the scarcity of genetic manipulation tools hinder the improvement in A. succinogenes by metabolic engineering. Here, for the first time, we successfully developed a series of A. succinogenes base editors (BEs) mediated by the fusion of Cas9 nickase and deaminase, including CBE, ABE, Td-GABE, and Td-CBE. Among these, ABE and Td-CBE based on a fusion of Cas9 nickase and TadA-8e variant ( Escherichia coli TadA) can efficiently convert A to G and C to T, respectively, with editing efficiencies of up to 100%. We also investigated the multiplex base editing of ABE and Td-CBE, and the results showed that the editing efficiency of ABE reached 100% for six sites and 10% editing efficiency of Td-CBE for two sites. In addition, cytosine base editors were applied to inactivate hypothetical sugar and SA transporters of A. succinogenes . We found that the inactivation of Asuc_0914 encoding sucrose-specific IIBC subunit enhanced SA production, while the inactivation of hypothetical SA transporters Asuc_0715 and Asuc_0716 significantly reduced SA production. Therefore, the tools have great application potential in the metabolic engineering of A. succinogenes .

Marek Haššo, Jiří Kudr, Jan Zítka et al.

Microchimica Acta • 2024

The introduced work represents an implementation of the automatic benchtop electrochemical station (BES) as an effective tool for the possibilities of high-throughput preparation of modified sensor/biosensors, speeding up the development of the analytical method, and automation of the analytical procedure for the determination of paracetamol (PAR) and dopamine (DOP) as target analytes. Within the preparation of gold nanoparticles modified screen-printed carbon electrode (AuNPs-SPCE) by electrodeposition, the deposition potential EDEP, the deposition time tDEP, and the concentration of HAuCl4 were optimized and their influence was monitored on 1 mM [Ru(NH3)6]3+/2+ redox probe and 50 μM DOP. The morphology of the AuNPs-SPCE prepared at various modification conditions was observed by SEM. The analytical performance of the AuNPs-SPCE prepared at different modification conditions was evaluated by a construction of the calibration curves of DOP and PAR. SPCE and AuNPs-SPCE at modification condition providing the best sensitivity to PAR and DOP, were successfully used to determine PAR and DOP in tap water by “spike-recovery” approach. The BES yields better reproducibility of the preparation of AuNPs-SPCE (RSD = 3.0%) in comparison with the case when AuNPs-SPCE was prepared manually by highly skilled laboratory operator (RSD = 7.0%). Graphical abstract Supplementary Information The online version contains supplementary material available at 10.1007/s00604-024-06454-6.

Cristina Decano-Valentin, In-bok Lee, U. Yeo et al.

Agronomy • 2021

A substantial reduction in the environmental impacts related to the construction and operation of agricultural buildings is needed to adapt to the continuing development of agriculture. The life cycle assessment (LCA) is a methodology used to quantify the environmental impact of different processes involved in the production and therefore has been increasingly applied to assess the environmental burden. However, most LCA-related research studies have focused on the overall environmental impact of the entire system without considering the energy load of the agricultural buildings. By integrating the LCA tool with other design tools such as the building energy simulation (BES), the identification of environmental hotspots and the mitigation options become possible during the design process. Thus, the objective of the paper was to identify the current integration approaches used to combine BES and LCA results to assess the environmental impact of different heating systems such as absorption heat pump (AHP) using energy from thermal effluent, electricity-powered heat pump and kerosene-powered boilers used in a conventional multi-span Korean greenhouse. The assessment result revealed that the environmental impact caused using a kerosene-powered boiler is largest in terms of the acidification potential (AP), global warming potential (GWP) and Eutrophication Potential (EP) of 1.15 × 100 kg SO2-eq, 1.13 × 102 kg CO2-eq and 1.62 × 10−1 kg PO4-eq, respectively. Detailed analysis of the result showed that the main contributor for greenhouse gas emission was caused by the type, amount and source of energy used to heat the greenhouse, which contributed to a maximum of 86.59% for case 1, 96.69% for case 2 and a maximum of 96.47% for case 3, depending on the type of greenhouse gas being considered.

Dan Liu, Yanjiao Cui, Zilong Zhao et al.

BMC Genomics • 2021

Background BES/BZR family genes have vital roles in plant growth, development, and adaptation to environmental stimuli. However, they have not yet been characterized and systematically analyzed in wheat and foxtail millet. Results In the current study, five common and two unique BES/BZR genes were identified by genome-wide analysis in wheat and foxtail millet, respectively. These genes were unevenly distributed on 14 and five chromosomes of wheat and foxtail millet, respectively, and clustered in two subgroups in a phylogenetic analysis. The BES/BZR gene family members in each subgroup contained similar conserved motifs. Investigation of cis -acting elements and expression profile analysis revealed that the BES/BZR genes were predominantly expressed in leaf tissues of wheat and foxtail millet seedlings and responded to brassinosteroid, abscisic acid, and NaCl treatments. Conclusions Our results provide a basis for future studies on the function and molecular mechanisms of the BES/BZR gene family in wheat, foxtail millet, and other plants.

Ndongmo Fotsa Nicaire, P. Steve, N. Salomé et al.

International Journal of Photoenergy • 2021

The global demand for renewable energy is growing, and one of the proposed solutions to this energy crisis is the use of photovoltaic systems. So far, they are a reliable solution, as they are nonpolluting and can be used almost anywhere on the planet. However, the design and development of more efficient photovoltaic cells and modules require an accurate extraction of their intrinsic parameters. Up to date, metaheuristic algorithms have proven to be the best methods to obtain accurate values of these intrinsic parameters. Hence, to extract these parameters reliably and accurately, this paper presents an optimization method based on the principle of bald eagle search (BES) during fish hunting. This search is divided into three steps: in the first stage (space selection), the eagle selects the space with the largest number of prey; in the second stage (space search), the eagle moves into the selected space to search for prey; in the third stage (dive), the eagle swings from the best position identified in the second stage and determines the best point to hunt. Thus, we used the proposed BES algorithm to determine the parameters of the single-diode model (SDM), the double-diode model (DDM), and the PV modules. This algorithm converges very quickly and gives a root mean square error (RMSE) of 9.8602 e − 04   for the single-diode model and 9.8248 e − 4 for the dual-diode model. The results obtained show that the proposed algorithm is more efficient than the other methods available in the literature, in terms of the better accuracy of the results obtained. The good harmony of the I-V and P-V characteristic curve of the calculated parameters with that of the measured data from a PV module/cell data sheet proves that the proposed BES should be used among the methods provided in the literature for the identification of PV solar cell parameters.

Amaia Lejarazu-Larrañaga, Juan Manuel Ortiz, Serena Molina et al.

Membranes • 0

<jats:p>The present work shows a methodology for the preparation of membranes with a high affinity for nitrates. For this purpose, a polymeric mixture containing an anion exchange resin was extended on a recycled pressure filtration membrane used as mechanical support. Different ion exchange resins were tested. The influence in ion fractionation of (i) the type of ion exchange resin, (ii) the use of a recycled membrane as support and (iii) the operating current density during the separation process were studied. Results revealed that the employed anion exchange resin could tune up the transport numbers of the anions in the membrane and enhance the transport of nitrates over sulfates. The use of the recycled filtration membrane as support further increased the transport of nitrates in detriment of sulfates in nitrate-selective membranes. Moreover, it considerably improved the mechanical stability of the membranes. Lowering the operational current density also boosted ion fractionation. In addition, the use of recycled membranes as support in membrane preparation is presented as an alternative management route of discarded reverse osmosis membranes, coupling with the challenging management of waste generated by the desalination industry. These membranes could be used for nitrate recovery from wastewater or for nitrate separation from groundwater.</jats:p>

Ana María Sánchez de la Nava, Felipe Atienza, Javier Bermejo et al.

American Journal of Physiology-Heart and Circulatory Physiology • 2021

<jats:p>Although atrial fibrillation (AF) is the most common cardiac arrhythmia, its early identification, diagnosis, and treatment is still challenging. Due to its heterogeneous mechanisms and risk factors, targeting an individualized treatment of AF demands a large amount of patient data to identify specific patterns. Artificial intelligence (AI) algorithms are particularly well suited for treating high-dimensional data, predicting outcomes, and eventually, optimizing strategies for patient management. The analysis of large patient samples combining different sources of information such as blood biomarkers, electrical signals, and medical images opens a new paradigm for improving diagnostic algorithms. In this review, we summarize suitable AI techniques for this purpose. In particular, we describe potential applications for understanding the structural and functional bases of the disease, as well as for improving early noninvasive diagnosis, developing more efficient therapies, and predicting long-term clinical outcomes of patients with AF.</jats:p>

Muhammad Muddasar, R. Liaquat, A. Abdullah et al.

International Journal of Energy Research • 2021

The microbial electrolysis cell (MEC) is an emerging technology for bioenergy production using organic wastewater. Normally, a preassimilated bio‐anode is utilized by the MEC to break down the organic content, but the formation and assimilation of microbial community at the anode surface is a time‐consuming process. This study utilized a novel unassimilated Ni‐foam anode for the first time in solar‐powered MEC for bioenergy production. Synthetic dairy manure wastewater (SDMW) was used both as substrate and an inoculum in the solar‐powered tubular MEC. The impacts of the exposed surface area of the bio‐anode on bioenergy production were evaluated by utilizing two different separation techniques (rate‐limited bio‐anode – MEC and fully exposed bio‐anode ‐ MEC). The former technique achieves a maximum methane production rate of 30.35 ± 0.03 mL/L, 14.2% more than that achieved by the later mentioned technique (26.4 ± 0.05 mL/L). Hydrogen production was approximately 800 ± 5 mm3 in both experimentations. The maximum generated current in the rate limited bio‐anode – MEC was 35.5 mA. Scanning electron microscope images confirmed the formation of rod‐shaped along with round‐shaped microbial communities on the anode surface, and, interestingly, round‐shaped bacteria were also grown on the cathode surface. The bioenergy (H2 and CH4) produced using SDMW within first 13 days of operation, along with the formation of a microbial community, was a significant success in this area and has opened up many research opportunities for producing instant bioenergy from organic waste.

Abudukeremu Kadier, Pratiksha Jain, Bin Lai et al.

Biofuel Research Journal • 2020

The degradation of waste organics through microbial electrolysis cell (MEC) generates hydrogen (H2) gas in an economically efficient way. MEC is known as the advanced concept of the microbial fuel cell (MFC) but requires a minor amount of supplementary electrical energy to produce H2 in the cathode microenvironment. Different bio/processes could be integrated to generate additional energy from the substrate used in MECs, which would make the whole process more sustainable. On the other hand, the energy required to drive the MEC mechanism could be harvested from renewable energy sources. These integrations could advance the efficiency and economic feasibility of the whole process. The present review critically discusses all the integrations investigated to date with MECs such as MFCs, anaerobic digestion, microbial desalination cells, membrane bioreactors, solar energy harvesting systems, etc. Energy generating non-biological and eco-friendly processes (such as dye-sensitized solar cells and thermoelectric microconverters) which could also be integrated with MECs, are also presented and reviewed. Achieving a comprehensive understanding about MEC integration could help with developing advanced biorefineries towards more sustainable energy management. Finally, the challenges related to the scaling up of these processes are also scrutinized with the aim to identify the practical hurdles faced in the MEC processes.

Bu Qing, Md Tabish Noori, Booki Min

Environmental Science and Pollution Research • 2025

Microbial electrolysis cells (MEC) can produce hydrogen (H2) at a low energy expense, but the H2 production rate is often limited by poor microbe-electrode interaction. This study aimed to enhance the interaction of microbes with a cathode electrode modified with an iron-sulfide (FeS) catalyst in MECs to achieve an efficient H2 evolution reaction (HER) and to investigate performance at different substrate concentrations, ranging from 1 to 3 g/L of glucose. The electrochemical analysis revealed FeS, a highly active catalyst for HER, surpassing the performance of a 10% platinum (Pt-C)-modified cathode. At 2 g/L glucose, MECs with a FeS-modified cathode (MEC-FeS) produced H2 at the highest yield of 7.01 mol H2/mol glucose, and the H2 production rate was 1.96 ± 0.09 m3/m3·d. The control operations of MEC with a pristine cathode and dark fermentation resulted in a reduced H2 yield of 5.83 ± 0.49 mol H2/mol glucose and 2.12 ± 0.12 mol H2/mol glucose, respectively. Moreover, the MEC-FeS achieved a high energy efficiency of 78 ± 5% compared to the MEC without catalyst (60 ± 5%) and the dark fermentation (24 ± 1%). This study suggests that utilizing FeS as a cathode catalyst in MECs can ensure high-rate hydrogen generation with optimal substrate concentration, paving the way for efficient upscaling and field application.

Aditya Amrut Pawar, Anandakrishnan Karthic, Sangmin Lee et al.

Environmental Engineering Research • 0

<jats:p>Anaerobic digestion is a traditional method of producing methane-containing biogas by utilizing the methanogenic conversion of organic matter like agricultural waste and animal excreta. Recently, the application of microbial electrolysis cell (MECs) technology to a traditional anaerobic digestion system has been extensively studied to find new opportunities in increasing wastewater treatability and methane yield and producing valuable chemicals. The finding that both anodic and cathodic bacteria can synthesize methane has led to the efforts of optimizing multiple aspects like microbial species, formation of biofilms, substrate sources and electrode surface for higher production of the combustible compound. MECs are very fascinating because of its ability to uptake a wide variety of raw materials including untreated wastewater (and its microbial content as biocatalysts). Extensive work in this field has established different systems of MECs for hydrogen production and biodegradation of organic compounds. This review is dedicated to explaining the operating principles and mechanism of the MECs for electromethanogenesis using different biochemical pathways. Emphasis on single- and double-chambered MECs along with reactor components is provided for a comprehensive description of the technology. Methane production using hydrogen evolution reaction and nanocatalysts has also been discussed.</jats:p>

Yuan Xu, Yangyue Jiang, Yingwen Chen et al.

Water Environment Research • 2014

<jats:title>ABSTRACT: </jats:title><jats:p>The broad application of microbial electrolysis cells (MECs) requires a system characterized by low cost and high operational sustainability. Biocathode MECs, which only require bacteria as the cathode catalysts, can satisfy these demands and have attracted considerable attention in recent years. In this study, we have examined biocathode alternatives to the typical platinum cathode in a single‐chamber, membrane‐free MEC. This biocathode MEC has been used for simultaneous hydrogen production and wastewater treatment. The results showed that hydrogen production rates increased in response to an increase in voltage. At an applied voltage of 0.9 V, the biocathode MEC achieved a hydrogen production rate of 0.39 m<jats:sup>3</jats:sup> m<jats:sup>−3</jats:sup> d<jats:sup>−1</jats:sup>, with a current density of 134 Am<jats:sup>−3</jats:sup>, chemical oxygen demand (COD) removal of 90%, a coulombic efficiency of 63%, a cathodic hydrogen recovery of 37%, and an energy efficiency based on an electricity input of 67%. The biocathode demonstrated sufficient electrocatalytic activity and achieved a performance level comparable to that of the platinum cathode. Moreover, the substrate that was used to simulate wastewater in this study was efficiently treated by the MEC.</jats:p>