Anurag Yadav, Kusum Yadav

SVOA Microbiology • 2024

As eco-friendly alternative to chemical fertilizers, biofertilizers have gained significance in the quest for sustainable farming. While challenges exist, such as regulatory hurdles and technical complexities, the opportunities in this field are substantial. Understanding rhizosphere engineering can enhance biofertilizers' efficiency, ensuring they provide maximum crop benefits. Genetic engineering of bioinoculants offers a pathway to tailor biofertilizers to specific crop needs, potentially increasing their effectiveness. Multi-trait, multi-strain, and multi-nutrient microbial formulations have the potential to revolutionize the biofertilizer market, allowing for customized solutions that address a range of agricultural needs. These innovations are complemented by market dynamics and the integration of nanotechnology, which can further enhance biofertilizer performance and reach. Such opportunities indicate a bright future for biofertilizer commercialization, where sustainable agriculture can benefit from advanced formulations with an improved understanding of soil-plant interactions. Biofertilizers' prospects are promising, offering a more sustainable and environmentally friendly approach to nourishing the world's growing population.

Pema Lhamo, S. Behera, B. Mahanty

Biotechnology Journal • 2021

Microbial polyhydroxyalkanoates (PHAs) produced using renewable resources could be the best alternative for conventional plastics. Despite their incredible potential, commercial production of PHAs remains very low. Nevertheless, sincere attempts have been made by researchers to improve the yield and economic viability of PHA production by utilizing low‐cost agricultural or industrial wastes. In this context, the use of efficient microbial culture or consortia, adoption of experimental design to trace ideal growth conditions, nutritional requirements, and intervention of metabolic engineering tools have gained significant attention.

Hari Koneru, Safiatou Bamba, Aksel Bell et al.

Frontiers in Microbiology • 2025

Microalgae are increasingly recognized for their potential in wastewater treatment and the sustainable production of feedstock for fuel, feed, food, and other bioproducts. Like conventional agricultural systems, algal cultivation involves complex microbial communities. However, despite their pivotal role in cultivation outcomes, especially at the commodity-scale, the critical interactions between microalgae and their microbiomes are often overlooked. Here we synthesize current knowledge on the taxonomic diversity, ecological roles, and biotechnological potential of algal microbiomes, with a focus on their interactions with algal hosts through nutrient exchange, growth modulation, pathogen defense, and environmental conditioning. We also examine how environmental factors such as nutrient availability, salinity, and temperature influence these interactions. Advances in microbiome engineering, including synthetic biology and ecological approaches, offer opportunities to enhance beneficial algal-microbiome interactions, thereby improving growth, resilience, and yield. These advancements could lead to more sustainable and economically viable microalgae cultivation, with far-reaching implications for environmental management and biotechnological innovation. By addressing key economic and environmental barriers, microbiome engineering holds transformative potential to revolutionize large-scale algae cultivation and provide sustainable solutions to global challenges.

Di Min, Lei Cheng, Feng Zhang et al.

Environmental Science & Technology • 2017

Dissimilatory metal reducing bacteria (DMRB) are capable of extracellular electron transfer (EET) to insoluble metal oxides, which are used as external electron acceptors by DMRB for their anaerobic respiration. The EET process has important contribution to environmental remediation mineral cycling, and bioelectrochemical systems. However, the low EET efficiency remains to be one of the major bottlenecks for its practical applications for pollutant degradation. In this work, Shewanella oneidensis MR-1, a model DMRB, was used to examine the feasibility of enhancing the EET and its biodegradation capacity through genetic engineering. A flavin biosynthesis gene cluster ribD-ribC-ribBA-ribE and metal-reducing conduit biosynthesis gene cluster mtrC-mtrA-mtrB were coexpressed in S. oneidensis MR-1. Compared to the control strain, the engineered strain was found to exhibit an improved EET capacity in microbial fuel cells and potentiostat-controlled electrochemical cells, with an increase in maximum current density by approximate 110% and 87%, respectively. The electrochemical impedance spectroscopy (EIS) analysis showed that the current increase correlated with the lower interfacial charge-transfer resistance of the engineered strain. Meanwhile, a three times more rapid removal rate of methyl orange by the engineered strain confirmed the improvement of its EET and biodegradation ability. Our results demonstrate that coupling of improved synthesis of mediators and metal-reducing conduits could be an efficient strategy to enhance EET in S. oneidensis MR-1, which is essential to the applications of DMRB for environmental remediation, wastewater treatment, and bioenergy recovery from wastes.

M. Angelaalincy, R. Navanietha Krishnaraj, Ganeshan Shakambari et al.

Frontiers in Energy Research • 2018

Microbial fuel cells (MFCs) are emerging as a promising future technology for a wide range of applications such as bioremediation, desalination, production of biofuels/value-added products in addition to sustainable electricity generation. Electroactive (EA) biofilms are the key players in any bioelectrochemical systems including MFCs. They are involved in the catalyzing oxidation/reduction reactions as well as mediating the electron transfer at electrode-electrolyte interfaces. Low power output of the MFCs remains a major limitation in MFCs and biofilm engineering is an ideal option for improving the rates of microbial electrocatalysis. Herein, we critically address the biofilm formation mechanisms in electroactive microorganisms, strategies for improving the biofilm formation leading to improved electrocatalytic rates for applications in bioelectrochemical systems.

A. Ayol, L. Peixoto, T. Keskin et al.

International Journal of Environmental Research and Public Health • 2021

Microbial C1 gas conversion technologies have developed into a potentially promising technology for converting waste gases (CO2, CO) into chemicals, fuels, and other materials. However, the mass transfer constraint of these poorly soluble substrates to microorganisms is an important challenge to maximize the efficiencies of the processes. These technologies have attracted significant scientific interest in recent years, and many reactor designs have been explored. Syngas fermentation and hydrogenotrophic methanation use molecular hydrogen as an electron donor. Furthermore, the sequestration of CO2 and the generation of valuable chemicals through the application of a biocathode in bioelectrochemical cells have been evaluated for their great potential to contribute to sustainability. Through a process termed microbial chain elongation, the product portfolio from C1 gas conversion may be expanded further by carefully driving microorganisms to perform acetogenesis, solventogenesis, and reverse β-oxidation. The purpose of this review is to provide an overview of the various kinds of bioreactors that are employed in these microbial C1 conversion processes.

Oluwadamilola Oluwatoyin Hazzan, Biyi Zhao, Yong Xiao

Applied Sciences • 2023

Extracellular electron transfer (EET) is a biological mechanism that plays a crucial role in various bioelectrochemical systems (BESs) and has substantial implications for renewable energy production. By utilizing the metabolic capacities of exoelectrogens, BESs offer a viable and environmentally friendly approach to electricity generation and chemical production; however, the diminished effectiveness of EET remains a hindrance to their optimal application in practical contexts. This paper examines the various strategies that have the potential to be employed to enhance the efficiency of EET systems and explores the potential for the integration of BESs technology with contemporary technologies, resulting in the development of an enhanced and sustainable system. It also examines how quorum sensing, electrode modifications, electron shuttles, and mediators can aid in improving EET performance. Many technological innovations, such as additive manufacturing, the science of nanotechnology, the technique of genetic engineering, computational intelligence, and other combinations of technologies that can be used to augment the efficacy of BESs are also discussed. Our findings will help readers understand how BESs, though an evolving technology, can play an important role in addressing our environmental concerns. Technical constraints are identified, and future directions in the field of EET are suggested.

Yan Tian, Jing Wu, Dandan Liang et al.

Environmental Science & Technology • 2023

Bioelectrochemical-based biogas upgrading is a promising technology for the storage of renewable energy and reduction of the global greenhouse gas emissions. Understanding the electron transfer behavior between the electrodes and biofilm is crucial for the development of this technology. Herein, the electron transfer pathway of the biofilm and its catalytic capability that responded to the cathode potential during the electromethanogenesis process were investigated. The result suggested that the dominant electron transfer pathway shifted from a direct (DET) to indirect (IDET) way when decreasing the cathode potential from -0.8 V (Bio-0.8 V) to -1.0 V (Bio-1.0 V) referred to Ag/AgCl. More IDET-related redox substances and high content of hydrogenotrophic methanogens (91.9%) were observed at Bio-1.0 V, while more DET-related redox substances and methanogens (82.3%) were detected at Bio-0.8 V. H2, as an important electron mediator, contributed to the electromethanogenesis up to 72.9% of total CH4 yield at Bio-1.0 V but only ∼17.3% at Bio-0.8 V. Much higher biogas upgrading performance in terms of CH4 production rate, final CH4 content, and carbon conversion rate was obtained with Bio-1.0 V. This study provides insight into the electron transfer pathway in the mixed culture constructed biofilm for biogas upgrading.

Nils Rohbohm, Tianran Sun, Ramiro Blasco-Gómez et al.

bioRxiv (Cold Spring Harbor Laboratory) • 2023

Microbial electrosynthesis is an emerging biosynthesis technology that produces value-added chemicals and fuels and, at the same time, reduces the environmental carbon footprint. However, constraints, such as low current densities and high inner resistance, disfavor this technology for industrial-scale purposes. The cathode performance has been strongly improved in recent years, while the anode performance has not been given enough attention despite its importance in closing the electric circuit. For traditional water electrolysis, O2 is produced at the anode, which is toxic to the anaerobic autotrophs that engage in microbial electrosynthesis. To overcome O2 toxicity in conventional microbial electrosynthesis, the anode and the cathode chamber have been separated by an ion-exchange membrane to avoid contact between the microbes and O2. However, ion-exchange membranes increase the maintenance costs and compromise the production efficiency by introducing an additional internal resistance. Furthermore, O2 is inevitably transferred to the catholyte due to diffusion and electro-osmotic fluxes that occur within the membrane. Here, we proved the concept of integrating carbon oxidation with sacrificial anodes and microbes to simultaneously inhibit the O2 evolution reaction (OER) and circumvent membrane application, which allows microbial electrosynthesis to proceed in a single chamber. The carbon-based anodes performed carbon oxidation as the alternative reaction to the OER. This enables microbial electrosynthesis to be performed with cell voltages as low as 1.8-2.1 V at 10 A·m-2. We utilized Methanothermobacter thermautotrophicus ΔH in a single-chamber Bioelectrochemical system (BES) with the best performing carbon-based anode (i.e., activated-carbon anode with soluble iron) to achieve a maximum cathode-geometric CH4 production rate of 27.3 L·m-2·d-1, which is equal to a volumetric methane production rate of 0.11 L·L-1·d-1 in our BES, at a coulombic efficiency of 99.4%. In this study, Methanothermobacter thermautotrophicus ΔH was majorly limited by sulfur that inhibited electromethanogenesis. However, this proof-of-concept study allows microbial electrosynthesis to be performed more energy-efficiently and can be immediately utilized for research purposes in microbial electrosynthesis.

Shen Wang, Xinglei Zhuang, W. Dong et al.

Fermentation • 2023

Bioelectrochemical systems (BESs) are an emerging technology for wastewater treatment and resource recovery. These systems facilitate electron transfer between microorganisms and electrodes, enabling their application in various fields, such as electricity production, bioremediation, biosensors, and biocatalysis. However, electrode biofilms, which play a critical role in BESs, face several challenges (e.g., a long acclimation period, low attached biomass, high electron transfer resistance, and poor tolerance and stability) that limit the development of this technology. Quorum sensing (QS) is a communication method among microorganisms that can enhance the performance of BESs by regulating electrode biofilms. QS regulation can positively impact electrode biofilms by enhancing extracellular electron transfer (EET), biofilm formation, cellular activity, the secretion of extracellular polymeric substances (EPS), and the construction of microbial community. In this paper, the characteristics of anode electrogenic biofilms and cathode electrotrophic biofilms in BESs, EET mechanisms, and the main factors affecting biofilm formation were summarized. Additionally, QS regulation mechanisms for biofilm formation, strategies for enhancing and inhibiting QS, and the application of QS regulation for electrode biofilms in BESs were systematically reviewed and discussed. This paper provides valuable background information and insights for future research and development of BES platforms based on QS regulation of electrode biofilms.

Yan Tian, Dandan Liang, Da Li et al.

Environmental Science & Technology • 2023

The metal-based current collector has been adopted as an essential component of cathodes for electron delivery in microbial electrosynthesis (MES) cells, while the effect of its corrosion on biofilm development and electromethanogenesis activity was overlooked. In this study, the corrosion of the Fe-based current collector was identified to in situ decorate cathode naturally which substantially boosted the performance of CO2 electromethanogenesis in terms of taking over two-thirds less time starting up MES and increasing the CH4 production rate by 3.5 times. Despite the low concentration of Fe (0.13 at%), the electrochemical analysis indicated that it was possible for these Fe deposits to act as electron shuttles and catalysts for H2 production to benefit methanogenesis. The Fe aggregates weakened the dependence of methanogens on electroactive bacteria (EABs) to conduct methanogenesis via interspecies electron transfer as the proportion of EABs on Bio FeCF (with Fe current collector, where CF is carbon felt) was only 25.5% of that on Bio CF (without Fe current collector). On the contrary, the abundance of genes encoding the proteins to uptake extracellular electrons of methanogens on Bio FeCF was 2.3 times higher than that on Bio CF. The enhanced energy transfer maintained high amounts of methanogens and live microorganisms. This study comprehensively explored the multiple roles of Fe-based current collectors in enhancing CO2 electromethanogenesis.

Qun Xue, Zhihui Chen, Wenjing Xie et al.

Molecules • 2024

Bioelectrochemical systems (BESs) are an innovative technology for the efficient degradation of antibiotics. Shewanella oneidensis (S. oneidensis) MR-1 plays a pivotal role in degrading sulfamethoxazole (SMX) in BESs. Our study investigated the effect of BES conditions on SMX degradation, focusing on microbial activity. The results revealed that BESs operating with a 0.05 M electrolyte concentration and 2 mA/cm2 current density outperformed electrolysis cells (ECs). Additionally, higher electrolyte concentrations and elevated current density reduced SMX degradation efficiency. The presence of nutrients had minimal effect on the growth of S. oneidensis MR-1 in BESs; it indicates that S. oneidensis MR-1 can degrade SMX without nutrients in a short period of time. We also highlighted the significance of mass transfer between the cathode and anode. Limiting mass transfer at a 10 cm electrode distance enhanced S. oneidensis MR-1 activity and BES performance. In summary, this study reveals the complex interaction of factors affecting the efficiency of BES degradation of antibiotics and provides support for environmental pollution control.

Mengqian Lu, Shirley Chan, Sofia Babanova et al.

Biotechnology and Bioengineering • 2017

ABSTRACT Extracellular electron transfer (EET) is a mechanism that enables microbes to respire solid‐phase electron acceptors. These EET reactions most often occur in the absence of oxygen, since oxygen can act as a competitive electron acceptor for many facultative microbes. However, for Shewanella oneidensis MR‐1, oxygen may increase biomass development, which could result in an overall increase in EET activity. Here, we studied the effect of oxygen on S. oneidensis MR‐1 EET rates using bioelectrochemical systems (BESs). We utilized optically accessible BESs to monitor real‐time biomass growth, and studied the per‐cell EET rate as a function of oxygen and riboflavin concentrations in BESs of different design and operational conditions. Our results show that oxygen exposure promotes biomass development on the electrode, but significantly impairs per‐cell EET rates even though current production does not always decrease with oxygen exposure. Additionally, our results indicated that oxygen can affect the role of riboflavin in EET. Under anaerobic conditions, both current density and per‐cell EET rate increase with the riboflavin concentration. However, as the dissolved oxygen (DO) value increased to 0.42 mg/L, riboflavin showed very limited enhancement on per‐cell EET rate and current generation. Since it is known that oxygen can promote flavins secretion in S. oneidensis , the role of riboflavin may change under anaerobic and aerobic conditions. Biotechnol. Bioeng. 2017;114: 96–105. © 2016 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc.

Laura Rago, Juan A Baeza, Albert Guisasola

Journal of Chemical Technology & Biotechnology • 2017

ABSTRACT BACKGROUND Microbial electrochemical systems ( MXCs ) are an emerging technology aiming at recovering energy contained in wastewaters either as electrical energy in microbial fuel cells ( MFCs ) or as hydrogen in microbial electrolysis cells ( MECs ). Successful results have been reported with readily biodegradable substrates, but the performance with real complex substrates needs to be evaluated to bridge the gap between lab‐ and full‐scale. This work aims at studying bioelectrochemical hydrogen production using real cheese whey as sole substrate. RESULTS A microbial consortium able to consume cheese whey to produce electricity or H 2 was developed. Cheese whey was fermented mainly by lactic acid bacteria ( Enterococcus genus) and exoelectrogenic activity was performed by Geobacter sp. The coulombic efficiency was 49 ± 8% in the MFC fed only with cheese whey, which is higher than most previous values reported for MFCs fed with dairy products. Good results for H 2 production in MEC (0.8 L H2 L − 1 REACTOR d −1 ) were also obtained. CONCLUSION The high potentiality of cheese whey as carbon source for bioelectrochemical systems is demonstrated in this study. The populations involved were determined by advanced microbial tools. The efficient selection of a syntrophic consortium to produce H 2 directly from cheese whey in a single‐chamber MEC was demonstrated. © 2016 Society of Chemical Industry

Dong-Mei Piao, Young-Chae Song, Gyung-Geun Oh et al.

Energies • 2019

The bioelectrochemical conversion of coal to methane was investigated in an anaerobic batch reactor containing yeast extract and activated carbon. In anaerobic degradation of coal, yeast extract was a good stimulant for the growth of anaerobic microorganisms, and activated carbon played a positive role. An electrostatic field of 0.67 V/cm significantly improved methane production from coal by promoting direct and mediated interspecies electron transfers between exoelectrogenic bacteria and electrotrophic methanogenic archaea. However, the accumulation of coal degradation intermediates gradually repressed the conversion of coal to methane, and the methane yield of coal was only 31.2 mL/g lignite, indicating that the intermediates were not completely converted to methane. By supplementing yeast extract and seed sludge into the anaerobic reactor, the intermediate residue could be further converted to methane under an electrostatic field of 0.67 V/cm, and the total methane yield of coal increased to 98.0 mL/g lignite. The repression of the intermediates to the conversion of coal to methane was a kind of irreversible substrate inhibition. The irreversible substrate inhibition in the conversion of coal to methane could be attenuated under the electrostatic field of 0.67 V/cm by ensuring sufficient biomass through biostimulation or bioaugmentation.

E. M. Sander, B. Virdis, S. Freguia

Water Science and Technology • 2017

Abstract Addition of an external carbon source is usually necessary to guarantee a sufficiently high C/N ratio and enable denitrification in wastewater treatment plants (WWTPs). Alternatively, denitrification processes using autotrophic microorganisms have been proposed i.e., with the use of H2 as electron donor or with the use of cathodic denitrification in bioelectrochemical systems (BES), in which electrons are transferred directly to a denitrifying biofilm. The aim of this work was to investigate and demonstrate the feasibility of applying an easy-to-operate BES as a polishing mechanism for treated secondary clarified effluent from a municipal WWTP, containing low levels of organic matter, buffer capacity and low concentrations of remaining nitrate. In the proposed system, nitrogen removal rates (0.018–0.121 Kg N m−3 d−1) increased with the nitrogen loading rates, suggesting that biofilm kinetics were not rate limiting. The lowest energy consumption for denitrification was 12.7 kWh Kg N−1, equivalent to 0.021 kWh m−3 and could be further reduced by 14% by adding recirculation circuits within both the anode and cathode.

Gyung-Geun Oh, Young-Chae Song, Byung-Uk Bae et al.

Processes • 2020

The bioelectrochemical methane production from acetate as a non-fermentable substrate, glucose as a fermentable substrate, and their mixture were investigated in an anaerobic sequential batch reactor exposed to an electric field. The electric field enriched the bulk solution with exoelectrogenic bacteria (EEB) and electrotrophic methanogenic archaea, and promoted direct interspecies electron transfer (DIET) for methane production. However, bioelectrochemical methane production was dependent on the substrate characteristics. For acetate as the substrate, the main electron transfer pathway for methane production was DIET, which significantly improved methane yield up to 305.1 mL/g chemical oxygen demand removed (CODr), 77.3% higher than that in control without the electric field. For glucose, substrate competition between EEB and fermenting bacteria reduced the contribution of DIET to methane production, resulting in the methane yield of 288.0 mL/g CODr, slightly lower than that of acetate. In the mixture of acetate and glucose, the contribution of DIET to methane production was less than that of the single substrate, acetate or glucose, due to the increase in the electron equivalent for microbial growth. The findings provide a better understanding of electron transfer pathways, biomass growth, and electron transfer losses depending on the properties of substrates in bioelectrochemical methane production.

Ganesan V. Murugesu, Saifulnizam Abd. Khalid, Hussain Shareef

ASEANA: Science and Education Journal • 2022

Microbial fuel cell (MFC) has become new technology in the energy harvesting system. MFC uses the electrolysis concept to convert chemical energy directly into electrical energy. Even though the research in MFC was conducted for the last 60 years, this technology is still not available for commercial use. One of the main drawbacks of this issue could be the involvement of electronics practitioners in the development of electronic control systems. So, to investigate this statement, the authors decide to conduct a bibliometric analysis of MFC research trends for the last 60 years to clarify. This bibliometric analysis is conducted based on five main databases with an accumulation of 15,462 document titles and 108,381 keywords. First, the analysis was done based on the Journal title to analyze the researcher's background and the second analysis was done based on MFC's subject area. Each analysis shows that the MFCs research trend is less focused by electronic practitioners. Authors suggest that more electronic background researchers and the subject area should be concentrated to optimize the power generation from MFC.

M. Post, S. Levenberg, D. Kaplan et al.

Nature Food • 2020

Cellular agriculture is an emerging branch of biotechnology that aims to address issues associated with the environmental impact, animal welfare and sustainability challenges of conventional animal farming for meat production. Cultured meat can be produced by applying current cell culture practices and biomanufacturing methods and utilizing mammalian cell lines and cell and gene therapy products to generate tissue or nutritional proteins for human consumption. However, significant improvements and modifications are needed for the process to be cost efficient and robust enough to be brought to production at scale for food supply. Here, we review the scientific and social challenges in transforming cultured meat into a viable commercial option, covering aspects from cell selection and medium optimization to biomaterials, tissue engineering, regulation and consumer acceptance. Producing meat without the drawbacks of conventional animal agriculture would greatly contribute to future food and nutrition security. This Review Article covers biological, technological, regulatory and consumer acceptance challenges in this developing field of biotechnology.

Árpád Takács, T. Haidegger

Buildings • 2022

The United Nations has long put on the discussion agenda the sustainability challenges of urbanization, which have both direct and indirect effects on future regulation strategies. Undoubtedly, most initiatives target better quality of life, improved access to services & goods and environment protection. As commercial aerial urban transportation may become a feasible research goal in the near future, the connection possibilities between cities and regions scale up. It is expected that the growing number of vertical takeoff & landing vehicles used for passenger and goods transportation will change the infrastructure of the cities, and will have a significant effect on the cityscapes as well. In addition to the widely discussed regulatory and safety issues, the introduction of elevated traffic also raises environmental concerns, which influences the existing and required service and control infrastructure, and thus significantly affects sustainability. This paper provides narrated overview of the most common aspects of safety, licensing and regulations for passenger vertical takeoff & landing vehicles, and highlights the most important aspects of infrastructure planning, design and operation, which should be taken into account to maintain and efficiently operate this new way of transportation, leading to a sustainable urban air mobility ecosystem.

Paul W. O'Toole, Max Paoli

Microbial Biotechnology • 2017

Summary Complex communities of microbes live on and in plants, humans and other animals. These communities are collectively referred to as the microbiota or microbiome. Plants and animals evolved to co‐exist with these microbes. In mammals, particular kinds of alteration of the microbiome (dysbiosis) are associated with loss of health, most likely due to loss of microbial metabolites, signalling molecules, or regulators of host pathways. Modern life‐style diseases such as Inflammatory Bowel Disease ( IBD ), Irritable Bowel Syndrome ( IBS ), type 2 diabetes, obesity and metabolic syndrome have been linked to dysbiosis. These multifactorial diseases involve multiple risk factors and triggers, depletion of certain gut microbiota species being one of them. Live Biotherapeutics operate by restoring microbial products or activities in affected subjects. They are being developed as adjuncts, alternatives or new treatment options for diseases that affect a growing proportion of global citizens.

Ian M. Head, Neil D. Gray

Microbial Biotechnology • 2016

Summary This roadmap examines the future of microbiology research and technology in fossil fuel energy recovery. Globally, the human population will be reliant on fossil fuels for energy and chemical feedstocks for at least the medium term. Microbiology is already important in many areas relevant to both upstream and downstream activities in the oil industry. However, the discipline has struggled for recognition in a world dominated by geophysicists and engineers despite widely known but still poorly understood microbially mediated processes e.g. reservoir biodegradation, reservoir souring and control, microbial enhanced oil recovery. The role of microbiology is even less understood in developing industries such as shale gas recovery by fracking or carbon capture by geological storage. In the future, innovative biotechnologies may offer new routes to reduced emissions pathways especially when applied to the vast unconventional heavy oil resources formed, paradoxically, from microbial activities in the geological past. However, despite this potential, recent low oil prices may make industry funding hard to come by and recruitment of microbiologists by the oil and gas industry may not be a high priority. With regards to public funded research and the imperative for cheap secure energy for economic growth in a growing world population, there are signs of inherent conflicts between policies aimed at a low carbon future using renewable technologies and policies which encourage technologies which maximize recovery from our conventional and unconventional fossil fuel assets.

Zhou Fang, Sichao Cheng, Hui Wang et al.

RSC Advances • 2017

Microbial fuel cells (MFCs) were embedded into constructed wetlands to form microbial fuel cell coupled constructed wetlands (CW-MFCs) and were used for simultaneous azo dye wastewater treatment and bioelectricity generation.

Hemma Philamore, I. Ieropoulos, A. Stinchcombe et al.

Soft Robotics • 2016

Abstract A significant goal of robotics is to develop autonomous machines, capable of independent and collective operation free from human assistance. To operate with complete autonomy robots must be capable of independent movement and total energy self-sufficiency. We present the design of a soft robotic mouth and artificial stomach for aquatic robots that will allow them to feed on biomatter in their surrounding environment. The robot is powered by electrical energy generated through bacterial respiration within a microbial fuel cell (MFC) stomach, and harvested using state-of-the-art voltage step-up electronics. Through innovative exploitation of compliant, biomimetic actuation, the soft robotic feeding mechanism enables the connection of multiple MFC stomachs in series configuration in an aquatic environment, previously a significant challenge. We investigate how a similar soft robotic feeding mechanism could be driven by electroactive polymer artificial muscles from the same bioenergy supply. This wo...

J. Aguzzi, C. Costa, M. Calisti et al.

Sensors • 2021

Mechatronic and soft robotics are taking inspiration from the animal kingdom to create new high-performance robots. Here, we focused on marine biomimetic research and used innovative bibliographic statistics tools, to highlight established and emerging knowledge domains. A total of 6980 scientific publications retrieved from the Scopus database (1950–2020), evidencing a sharp research increase in 2003–2004. Clustering analysis of countries collaborations showed two major Asian-North America and European clusters. Three significant areas appeared: (i) energy provision, whose advancement mainly relies on microbial fuel cells, (ii) biomaterials for not yet fully operational soft-robotic solutions; and finally (iii), design and control, chiefly oriented to locomotor designs. In this scenario, marine biomimicking robotics still lacks solutions for the long-lasting energy provision, which presently hinders operation autonomy. In the research environment, identifying natural processes by which living organisms obtain energy is thus urgent to sustain energy-demanding tasks while, at the same time, the natural designs must increasingly inform to optimize energy consumption.

Anwar Elhadad, Yang Gao, Seokheun Choi

Advanced Materials Technologies • 2024

Aquatic mobile robots are gaining attention for their potential to revolutionize marine monitoring and exploration within the Ocean Internet of Things. A significant challenge for these untethered robots, especially in remote areas, is achieving energy autonomy. This work presents an innovative self‐sustaining energy system for compact aquatic robots, inspired by biological digestion. Utilizing microbial fuel cell (MFC) technology, organic materials found in aquatic environments are converted into electricity through catalytic redox reactions. To extend the MFC's lifespan, spore‐forming Bacillus subtilis is used as the anodic biocatalyst, leveraging its ability to endure harsh conditions and reactivate in favorable environments, thus enhancing the MFC's longevity. To ensure a steady supply of organic substrates for microbial viability, a biomimetic Janus membrane with asymmetric surface wettability is integrated, enabling selective substrate intake. Additionally, stability mechanisms inspired by water striders allow the robot to move efficiently across water surfaces. The robot mimics the water strider's movement using a motor powered by microbial metabolism, fueled by organic nutrients via the Janus membrane. This study demonstrates the feasibility of using natural processes for technological advancement, setting new benchmarks in the design of autonomous systems.

Ripel Chakma, M. K. Hossain, P. Paramasivam et al.

Global Challenges • 2025

Microbial fuel cell (MFC), a clean and promising technology that has the potential to tackle both environmental degradation and the global energy crisis, receives tremendous attention from researchers over recent years. The performance of each system component, including the membrane and electrode utilized in MFCs, has a great effect on the efficiency of converting chemical energy found in organic waste to power generation through bacterial metabolism. The MFCs have diverse applications that are growing day by day in developed countries. This review discusses recently available various potential applications including wastewater treatment, biohydrogen production, hazardous waste removal, generation of bioelectricity, robotics, biosensors, etc. There are still several challenges (e.g., system complexity, economic, commercialization, and other operational factors) for large‐scale practical applications, particularly for relatively low power output and delayed start‐up time, which is also reported in this review article. Moreover, the operational factors (e.g., electrode materials, proton exchange system, substrate, electron transfer mechanism, pH, temperature, external resistance, and shear stress and feed rate) that affect the performance of MFCs, are discussed in detail. To resolve these issues, optimizations of various parameters are also presented. In the previously published studies, this paper indicates that MFCs have demonstrated power densities ranging from 2.44 to 3.31 W m−2, with Coulombic efficiencies reaching up to 55.6% under optimized conditions. It is also reported that MFCs have achieved the removal efficiency of chemical oxygen demand (COD), total organic carbon (TOC), and antibiotics up to 93.7%, 70%, and 98%, respectively. Finally, this paper highlights the future perspective of MFCs for full‐scale applications.

M. Halim, M. Ibrahim, Md Rasel Molla et al.

2019 1st International Conference on Advances in Science, Engineering and Robotics Technology (ICASERT) • 2019

Demand of energy is increasing in the whole part of the world, it is estimated that in near future a significant energy crisis will be occurred. Furthermore, fossil fuels play a noticeable role for environmental pollutions. So, an alternative clean and environmental amiable renewable energy source is the most significant demand for the modern scientists. Bio-fuel cell especially microbial fuel cell can partially eliminate this crisis by producing electricity from biodegradable waste. Considering this aspect we produced double chamber MFCs where Zinc and copper plates are used as anode and cathode materials. In this study urine and fish waste mixed waste water are used as a source of substrate, aerobic bacteria helps to decompose it, in anode chamber where oxygen amplifies the reduction reaction in cathode chamber. To find out the effects of urine and fish waste on the performance of voltage, current and power we used digital multimeter and Hantek 365A data logger. Urine mixed waste water gives the maximum voltage 1.02 V, current 1.67 mA and power 1.7034 mW, whereas, for fish mixed waste water these values were 0.968 V, 1.365 mA and 1.3213 mW respectively. The whole operation we done batch wise, initial pH 8 and cell volume was 5 liter.

Sheikh Shehab Uddin, Kazi Shoffiuddin Roni, F. Kabir et al.

2019 International Conference on Robotics,Electrical and Signal Processing Techniques (ICREST) • 2019

This research paper analyzes the performance of Microbial Fuel Cell (MFC) under aerobic condition for drain sludge, tannery sludge and Turag sludge. Starch of boiled rice was applied as source of carbohydrates for the growth of bacteria. Saltbridge was used as the membrane. Water was placed in cathode chamber as electron acceptor. A total number of three experiments were carried out throughout the research and all of them were observed for seven days. A fixed amount of sludge (0.5L), substrate (0.5L) and water (1L) was used. Analysis of the MFCs constructed during this research work is based on the obtained current density and power density from each experiment across different loads. In this study 220.77 mV was measured as highest voltage across while 12.23 mA/m2 and 2.7 mW/m2 were recorded as maximum current density and power density respectively for Turag sludge.

Qing-zhu Luo, Aimin An, Minmin Wang

Proceedings of the 2019 4th International Conference on Robotics, Control and Automation • 2019

Microbial Fuel Cell (MFC) is efficient and clean power supply equipment, but serious nonlinearities exist when the MFC runs, so, how to guarantee its output voltage to reach the setting curve quickly and smoothly is a significant topic. To manipulate the feeding flow is an effective way to achieve this goal; especially the satisfactory results can be received through manipulating anode feeding flow. The working point in the MFC running process is linearized in the localized region to obtain the equivalent state space description using the model reference adaptive control algorithm in this study, so the output voltage of MFC can be effectively controlled. Simulation results indicate that the model reference adaptive control algorithm can quickly and smoothly control the voltage output of MFC's voltage tracking reference model. MFC has better performance in rapidity and accuracy after using the algorithm. This is of great significance for MFC to provide stable energy supply for the external load.

Upal Barua Joy, Mohammed Moin Uddin, Nayeem Uddin Ahmed Khan et al.

2023 3rd International Conference on Robotics, Electrical and Signal Processing Techniques (ICREST) • 2023

Microbial Fuel Cell (MFC) uses bio-electrochemical process to generate electricity. It is considered as a new approach in renewable energy generation. However, due to low output voltage and current, supplying power to loads from MFC is quite challenging. Research so far done on MFC mainly focused on material analysis, creating new designs, bacterial activity in MFC and so on. But very few attempts have been done on delivering power to loads from MFC. In this research, using waste water as input, three Double chamber MFCs and two single chamber membrane-less MFCs have been constructed using Aluminum as anode and Copper as cathode. Constructed MFCs were connected in series which generated maximum 2.6 V. The MFC combination could light up a small Light Emitting Diode (LED).

John Greenman, Arjuna Mendis, Jiseon You et al.

Frontiers in Robotics and AI • 2021

On the roadmap to building completely autonomous artificial bio-robots, all major aspects of robotic functions, namely, energy generation, processing, sensing, and actuation, need to be self-sustainable and function in the biological realm. Microbial Fuel Cells (MFCs) provide a platform technology for achieving this goal. In a series of experiments, we demonstrate that MFCs can be used as living, autonomous sensors in robotics. In this work, we focus on thermal sensing that is akin to thermoreceptors in mammalian entities. We therefore designed and tested an MFC-based thermosensor system for utilization within artificial bio-robots such as EcoBots. In open-loop sensor characterization, with a controlled load resistance and feed rate, the MFC thermoreceptor was able to detect stimuli of 1 min directed from a distance of 10 cm causing a temperature rise of ∼1°C at the thermoreceptor. The thermoreceptor responded to continuous stimuli with a minimum interval of 384 s. In a practical demonstration, a mobile robot was fitted with two artificial thermosensors, as environmental thermal detectors for thermotactic application, mimicking thermotaxis in biology. In closed-loop applications, continuous thermal stimuli were detected at a minimum time interval of 160 s, without the need for complete thermoreceptor recovery. This enabled the robot to detect thermal stimuli and steer away from a warmer thermal source within the rise of 1°C. We envision that the thermosensor can be used for future applications in robotics, including as a potential sensor mechanism for maintaining thermal homeostasis.

Michail-Antisthenis Tsompanas, Jiseon You, Hemma Philamore et al.

Frontiers in Robotics and AI • 2021

The development of biodegradable soft robotics requires an appropriate eco-friendly source of energy. The use of Microbial Fuel Cells (MFCs) is suggested as they can be designed completely from soft materials with little or no negative effects to the environment. Nonetheless, their responsiveness and functionality is not strictly defined as in other conventional technologies, i.e. lithium batteries. Consequently, the use of artificial intelligence methods in their control techniques is highly recommended. The use of neural networks, namely a nonlinear autoregressive network with exogenous inputs was employed to predict the electrical output of an MFC, given its previous outputs and feeding volumes. Thus, predicting MFC outputs as a time series, enables accurate determination of feeding intervals and quantities required for sustenance that can be incorporated in the behavioural repertoire of a soft robot.

Zhongcheng Lei, Hong Zhou, Wenshan Hu et al.

IEEE Transactions on Power Systems • 2024

Power systems are a crucial infrastructure to ensure a sustainable supply of electricity and are thus important for industrial, commercial and domestic consumption. As an interactive and visualizing enabling technology, the digital twin can be effectively applied to the training and education of students and operators in power systems. This article discusses a web-based communication system of power systems (CSPS) constructed with digital twin technologies, and provides a digital replica of the communication system and process as well as the remote monitoring and control of the physical system, the detailed design and implementation of which are presented. The functionalities and uses of the digital twin CSPS are also provided. To illustrate the effectiveness of the proposed digital twin CSPS, a case study with optical fiber line fault detection that emulates a real scenario is conducted, which includes remote control-based digital twin interactions and visualization.

J. K. Wallace, S. Rider, E. Serabyn et al.

Optics Express • 2015

Recent advances in digital technologies, such as high-speed computers and large-format digital imagers, have led to a burgeoning interest in the science and engineering of digital holographic microscopy (DHM). Here we report on a novel off-axis DHM, based on a twin-beam optical design, which avoids the limitations of prior systems, and provides many advantages, including compactness, intrinsic stability, robustness against misalignment, ease of use, and cost. These advantages are traded for a physically constrained sample volume, as well as a fixed fringe spacing. The first trade is not overly restrictive for most applications, and the latter provides for a pre-set assembly alignment that optimizes the spatial frequency sampling. Moreover, our new design supports use in both routine laboratory settings as well as extreme environments without any sacrifice in performance, enabling ready observation of microbial species in the field. The instrument design is presented in detail here, along with a demonstration of bacterial video imaging at sub-micrometer resolution at temperatures down to -15 °C.

C. Hayward, Harriet Whiley, N. J. Ashbolt

Current Opinion in Infectious Diseases • 2025

PURPOSE OF REVIEW This review examines the interplay between biological and anthropogenic factors in the development and persistence of antimicrobial resistance (AMR) within building plumbing systems, which is of particular concern in high risk setting such as healthcare facilities. The review highlights the role of biofilms and amoeba as reservoirs for AMR and explores how engineering and design decisions, governance structures, and cleaning protocols influence microbial resistance dynamics. RECENT FINDINGS Biofilms provide a protective environment that facilitates horizontal gene transfer and enhances bacterial resistance to disinfection. Amoeba-hosted bacteria can evade standard cleaning practices, further promoting AMR persistence. Emerging technologies, such as digital twin modelling, offer new opportunities to optimize risk mitigation strategies. However, more consideration is needed to be given to design or management decision that may have unintended consequences, such as unintended design outcomes, such as increased biofilm growth from tap mixers and low-flow fixtures, and ineffective cleaning protocols, which can inadvertently worsen AMR. SUMMARY Effectively managing AMR in plumbing systems requires a multidisciplinary approach that integrates microbiology, engineering, and policy. Data driven risk assessments can identify high-risk areas that may require design changes but also can enable targeted cleaning strategies, reducing reliance on widespread disinfection that may drive resistance. Future policies must consider system-wide implications to prevent unintended consequences. By addressing both biological and anthropogenic drivers, we can develop sustainable solutions to mitigate AMR risks in healthcare and beyond.

Fatemeh Sarshartehrani, Anthony Lee, Mohamed Azab et al.

2024 IEEE 15th Annual Ubiquitous Computing, Electronics & Mobile Communication Conference (UEMCON) • 2024

Critical infrastructures, such as water treatment plants (WTPs) and communication networks, are vital to our daily lives, providing essential resources. As these infrastructures increasingly rely on computer systems and internet networks, conducting cybersecurity training on expensive, real-world equipment becomes impractical due to the risk of operational interruptions. To address this challenge, we present a Digital Twin training platform that simulates three key cybersecurity concepts: Input Manipulation, Output Manipulation, and Denial of Service attacks, within the context of WTPs. These concepts are mapped to four critical functions: water level, chlorine level, water temperature, and the microbial water purification process. This paper primarily focuses on the design and development of the VR component of our digital twin platform, as well as the integration process with our hardware testbed. Initial investigations demonstrated significant potential for the experiential learning platform, serving as an effective tool for educating users about cybersecurity issues in mission-critical facilities such as WTPs.

Bichar Dip Shrestha Gurung, Manish Rayamajhi, Naina Maharjan et al.

bioRxiv (Cold Spring Harbor Laboratory) • 2025

Urban wastewater microbiomes are complex and temporally dynamic, offering valuable insight into community-scale microbial ecology and potential public health trends. However, existing wastewater-based studies often remain descriptive, lacking tools for predictive modeling. In this study, we introduce a digital twin framework that forecasts microbial abundance trajectories in urban wastewater using an interpretable generative model, Q-net. Trained on a 30-week longitudinal metagenomic dataset from seven wastewater treatment plants, the model captures temporal microbial dynamics with high fidelity (R2>0.97 for key taxa; R2=0.998 at the final timepoint). Beyond accurate forecasting, Q-net provides transparent model structure through conditional inference trees and enables simulation of realistic microbial trends under hypothetical scenarios. This work demonstrates the potential of digital twins to move wastewater microbiome studies from static snapshots to dynamic, predictive systems, with broad implications for environmental monitoring and microbial ecosystem modeling.

Jianye Xia, Dongjiao Long, Min Chen et al.

PubMed • 2025

As a strategic emerging industry, biomanufacturing faces core challenges in achieving precise optimization and efficient scale-up of fermentation processes. This review focuses on two critical aspects of fermentation-real-time sensing and intelligent control-and systematically summarizes the advancements in online monitoring technologies, artificial intelligence (AI)-driven optimization strategies, and digital twin applications. First, online monitoring technologies, ranging from conventional parameters (e.g., temperature, pH, and dissolved oxygen) to advanced sensing systems (e.g., online viable cell sensors, spectroscopy, and exhaust gas analysis), provide a data foundation for real-time microbial metabolic state characterization. Second, conventional static control relying on expert experience is evolving toward AI-driven dynamic optimization. The integration of machine learning technologies (e.g., artificial neural networks and support vector machines) and genetic algorithms significantly enhances the regulation efficiency of feeding strategies and process parameters. Finally, digital twin technology, integrating real-time sensing data with multi-scale models (e.g., cellular metabolic kinetics and reactor hydrodynamics), offers a novel paradigm for lifecycle optimization and rational scale-up of fermentation. Future advancements in closed-loop control systems based on intelligent sensing and digital twin are expected to accelerate the industrialization of innovative achievements in synthetic biology and drive biomanufacturing toward higher efficiency, intelligence, and sustainability.

Daniel Ayala-Ruiz, A. Atoche, E. Ruiz-Ibarra et al.

Wireless Communications and Mobile Computing • 2019

Long power wide area networks (LPWAN) systems play an important role in monitoring environmental conditions for smart cities applications. With the development of Internet of Things (IoT), wireless sensor networks (WSN), and energy harvesting devices, ultra-low power sensor nodes (SNs) are able to collect and monitor the information for environmental protection, urban planning, and risk prevention. This paper presents a WSN of self-powered IoT SNs energetically autonomous using Plant Microbial Fuel Cells (PMFCs). An energy harvesting device has been adapted with the PMFC to enable a batteryless operation of the SN providing power supply to the sensor network. The low-power communication feature of the SN network is used to monitor the environmental data with a dynamic power management strategy successfully designed for the PMFC-based LoRa sensor node. Environmental data of ozone (O3) and carbon dioxide (CO2) are monitored in real time through a web application providing IoT cloud services with security and privacy protocols.