Microbial Biofuel Cells Research Articles

Electrochemical Biosensors for Express Analysis of the Integral Toxicity of Polymer Materials.

Biosensors based on an oxygen electrode, a mediator electrode, and a mediator microbial biofuel cell (MFC) using the bacteria Gluconobacter oxydans B-1280 were formed and tested to determine the integral toxicity. G. oxydans bacteria exhibited high sensitivity to the toxic effects of phenol, 2,4-dinitrophenol, salicylic and trichloroacetic acid, and a number of heavy metal ions. The system "G. oxydans bacteria-ferrocene-graphite-paste electrode" was superior in sensitivity to biosensors formed using an oxygen electrode and MFC, in particular regarding heavy metal ions (EC50 of Cr3+, Mn2+, and Cd2+ was 0.8 mg/dm3, 0.3 mg/dm3 and 1.6 mg/dm3, respectively). It was determined that the period of stable functioning of electrochemical systems during measurements was reduced by half (from 30 to 15 days) due to changes in the enzyme system of microbial cells when exposed to toxicants. Samples of the products made from polymeric materials were analyzed using developed biosensor systems and standard biotesting methods based on inhibiting the growth of duckweed Lemna minor, reducing the motility of bull sperm, and quenching the luminescence of the commercial test system "Ecolum". The developed bioelectrocatalytic systems were comparable in sensitivity to commercial biosensors, which made it possible to correlate the results and identify, by all methods, a highly toxic sample containing diphenylmethane-4,4'-diisocyanate according to GC-MS data.

Microbial Biofuel Cells: Fundamental Principles, Development and Recent Obstacles.

This review focuses on the development of microbial biofuel cells to demonstrate how similar principles apply to the development of bioelectronic devices. The low specificity of microorganism-based amperometric biosensors can be exploited in designing microbial biofuel cells, enabling them to consume a broader range of chemical fuels. Charge transfer efficiency is among the most challenging and critical issues while developing biofuel cells. Nanomaterials and particular redox mediators are exploited to facilitate charge transfer between biomaterials and biofuel cell electrodes. The application of conductive polymers (CPs) can improve the efficiency of biofuel cells while CPs are well-suitable for the immobilization of enzymes, and in some specific circumstances, CPs can facilitate charge transfer. Moreover, biocompatibility is an important issue during the development of implantable biofuel cells. Therefore, biocompatibility-related aspects of conducting polymers with microorganisms are discussed in this review. Ways to modify cell-wall/membrane and to improve charge transfer efficiency and suitability for biofuel cell design are outlined.

Stimulation of Muscle Cells Using a Microbial Fuel Cell

Today there are a lot of areas where the use of soft robotics is necessary. Nowadays the main task in this field is to find a device that sets a soft robot in motion. In this work we propose the prototype of a mechanism that works by stimulating muscle cells and can act as an actuator. The possibility of using low-power biofuel elements as a battery for the actuator is also investigated. A microbial biofuel cell is selected as the most suitable for this field of application. During assembly of the biofuel cell, the materials of the electrodes and biofilms are explored, and the voltages produced by the cell are measured. In addition, we develop and assemble a board that generates a pulse-width-modulation (PWM) signal to stimulate muscle cells with a pulse which has certain characteristics. The attained results make clear the fact that a low-power energy source such as a biofuel cell can be successfully used to stimulate muscle cells in the development of soft robots.

On a Promising Electrode Material for Microbial Biofuel Cells Based on Natural Polymers

A production technology for conductive materials with different morphologies is developed: flat (films) and porous (sponges) composites suitable for use as the anode of a biofuel cell. Chitosan is used as a polymer matrix, and carbon-black particles with an average size of aggregates of 17 μm act as a conductive component. The morphological, electrically conductive, and mechanical characteristics of the composites are studied. Based on the functional characteristics, the optimum concentration of the filler in the composite materials for their use as the electrode of a microbial biofuel cell is 5 wt %.

Bacterial community structure of electrogenic biofilm developed on modified graphite anode in microbial fuel cell

Formation of electrogenic microbial biofilm on the electrode is critical for harvesting electrical power from wastewater in microbial biofuel cells (MFCs). Although the knowledge of bacterial community structures in the biofilm is vital for the rational design of MFC electrodes, an in-depth study on the subject is still awaiting. Herein, we attempt to address this issue by creating electrogenic biofilm on modified graphite anodes assembled in an air–cathode MFC. The modification was performed with reduced graphene oxide (rGO), polyaniline (PANI), and carbon nanotube (CNTs) separately. To accelerate the growth of the biofilm, soybean-potato composite (plant) powder was blended with these conductive materials during the fabrication of the anodes. The MFC fabricated with PANI-based anode delivered the current density of 324.2 mA cm−2, followed by CNTs (248.75 mA cm−2), rGO (193 mA cm−2), and blank (without coating) (151 mA cm−2) graphite electrodes. Likewise, the PANI-based anode supported a robust biofilm growth containing maximum bacterial cell densities with diverse shapes and sizes of the cells and broad metabolic functionality. The alpha diversity of the biofilm developed over the anode coated with PANI was the loftiest operational taxonomic unit (2058 OUT) and Shannon index (7.56), as disclosed from the high-throughput 16S rRNA sequence analysis. Further, within these taxonomic units, exoelectrogenic phyla comprising Proteobacteria, Firmicutes, and Bacteroidetes were maximum with their corresponding level (%) 45.5, 36.2, and 9.8. The relative abundance of Gammaproteobacteria, Clostridia, and Bacilli at the class level, while Pseudomonas, Clostridium, Enterococcus, and Bifidobacterium at the genus level were comparatively higher in the PANI-based anode.

Assessment of Rhizobium anhuiense Bacteria as a Potential Biocatalyst for Microbial Biofuel Cell Design.

The development of microbial fuel cells based on electro-catalytic processes is among the novel topics, which are recently emerging in the sustainable development of energetic systems. Microbial fuel cells have emerged as unique biocatalytic systems, which transform the chemical energy accumulated in renewable organic fuels and at the same time reduce pollution from hazardous organic compounds. However, not all microorganisms involved in metabolic/catalytic processes generate sufficient redox potential. In this research, we have assessed the applicability of the microorganism Rhizobium anhuiense as a catalyst suitable for the design of microbial fuel cells. To improve the charge transfer, several redox mediators were tested, namely menadione, riboflavin, and 9,10-phenanthrenequinone (PQ). The best performance was determined for a Rhizobium anhuiense-based bio-anode mediated by menadione with a 0.385 mV open circuit potential and 5.5 μW/cm2 maximal power density at 0.35 mV, which generated 50 μA/cm2 anode current at the same potential.

Microbial Electrochemical-based Biofuel Cell System for Remediation of Oil Contaminated Soil

With the growing problem of oil seepage from gas stations around the world, remediation of oil-contaminated soils is receiving increased attention. Microbial electrochemical techniques have been shown to remove hydrocarbons from soil. Microbial fuel cells (MFC) show a strong potential to immobilize and dissipate contaminants using microorganisms. In this context, this review briefly introduces the conventional methods for remediation of petroleum soil contamination, focusing on the effects of different factors and configurations on the effectiveness of MFC remediation. Compared to traditional remediation methods, applying MFC to petroleum leaks in gas stations has better environmental and economic benefits. It does not require the application of chemicals or ex situ remediation of the soil, which largely reduces the cost and does not cause secondary pollution to the surrounding environment such as soil or atmosphere. In the long term, this technology has a good potential to enhance the remediation effect by changing the applied electric field, soil texture, and petroleum degrading bacteria. In addition, making soil MFC simultaneously achieve combined remediation of petroleum hydrocarbons and other contaminants remains to be studied. Finally, this paper emphasizes that there are few practical applications about MFC site remediation and there is a need to conduct site tests with large scale. If the pilot-scale tests are similar to the laboratory-scale treatment results, the technology will gain more popularity.

Recent Advances in Energy Harvesting from the Human Body for Biomedical Applications

Energy harvesters serve as continuous and long-lasting sources of energy that can be integrated into wearable and implantable sensors and biomedical devices. This review paper presents the current progress, the challenges, the advantages, the disadvantages and the future trends of energy harvesters which can harvest energy from various sources from the human body. The most used types of energy are chemical; thermal and biomechanical and each group is represented by several nano-generators. Chemical energy can be harvested with a help of microbial and enzymatic biofuel cells, thermal energy is collected via thermal and pyroelectric nano-generators, biomechanical energy can be scavenged with piezoelectric and triboelectric materials, electromagnetic and electrostatic generators and photovoltaic effect allows scavenging of light energy. Their operating principles, power ratings, features, materials, and designs are presented. There are different ways of extracting the maximum energy and current trends and approaches in nanogenerator designs are discussed. The ever-growing interest in this field is linked to a larger role of wearable electronics in the future. Possible directions of future development are outlined; and practical biomedical applications of energy harvesters for glucose sensors, oximeters and pacemakers are presented. Based on the increasingly accumulated literature, there are continuous promising improvements which are anticipated to lead to portable and implantable devices without the requirement for batteries.

A facile technique to develop conductive paper based bioelectrodes for microbial fuel cell applications

Electronic devices with multifunctional capabilities is forever an attractive area with diverse scope including towards developing solutions to sustainable energy technology. Microbial biofuel cells (MiBFCs) are one such sustainable energy technology based electronic device which can not only harvest energy, but can perform biosensing leading to bioremediation. However, low energy yield, costly fabrication procedures and bulky devices are some of the limitations of such MiBFCs. In this work, for the first time a simple vacuum filtration fabrication technique is used for making thin and conductive electrodes with homogeneous CNT solution for MiBFC application. The fully paper-based MiBFC is integrated into a compact micro device with 3D printed components which adds novelty to the work. The MiBFC is capable of maintaining a stable open circuit voltage of 410 mV for more than 1 h and can deliver a maximum power density of 192 μW/cm2 which is reasonably high for such paper-based MiBFCs operating with micro-volume of substrate. This device will help in developing more freestanding power sources for instant diagnostics and data transfer.

Gold nanoparticle-based biofuel cell catalytic efficiency reliance on medium pH

Over the past several decades, biology, chemistry, and medicine took advantage of gold nanoparticles (AuNPs) for their fascinating characteristics. Today these nanomaterials can be synthesized in various methods from biosynthesis, when particles are made by microbial culture, to physical. Using the fast scan cyclic voltammetry, AuNPs can be electrodeposited from chloroauric acid (HAuCl4) directly onto the surface of a graphite electrode. This method provides high reproducibility and allows to control the size of the nanoparticles (from 4 to 75 nm) and electrode coverage by changing HAuCl4 concentration, scan speed, and a number of applied cycles. Gold nanoparticles are known to express comparable catalytic activity to natural enzymes such as glucose oxidase or horseradish peroxidase. Despite the advantages over natural enzymes, inorganic enzyme mimicking catalysts exhibit limited catalytical efficiency and selectivity. To increase efficiency, we used low size AuNPs which increase reactivity; the lack of selectivity in a biofuel cell is advantageous since AuNPs can reduce/oxidize several substrates in the medium. Biofuel cell based on AuNP’s has a superior life span, as the main active part of the system is inorganic, and thus it is not affected by oxygen stress, where typical microbial biofuel cells are struggling. The observed catalytic activity had a minimal dependency on temperature change. pH was changed from 4 to 10 with the smallest synthesized AuNPs. However, pH has an impact on the reaction speed. Results showed that biofuel cell is suitable for raw wastewater as it usually deviates from pH 7, and usable current can be generated.

Microbial fuel cells: Technologically advanced devices and approach for sustainable/renewable energy development

• The paper focuses on sustainable energy generation from waste treatment approaches. • MFCs design influences the quantity of electricity, hydrogen and alcoholic fuel. • Wastewater treatments via MFCs discuss the reduction of COD and pollutant values. • Modified components in MFCs find enhanced bioenergy without purification. There is a huge quantity of energy needs/demands for multiple developmental and domestic activities in the modern era. And in this context, consumption of more non-renewable energy is reported and created many problems or issues (availability of fossil fuel stocks in the future period, causes a huge quantity of toxic gases or particles or climatic change effects) at the global level. And only sustainable or renewable fuel development can provide alternate fuel, and we report from various biological agents processes, including microbial biofuel cell applications for future energy needs only. These will not cause any interference in natural resources or services. Microbial biofuel cells utilize the living cell to produce bioelectricity via bioelectrochemical system. It can drive electricity or other energy generation currents via lived cell interaction. Microbial fuel cells (MFCs) and enzymatic biofuel cells, with their advancement in design, can improve sustainable bio-energy production by proving an efficient conversion system compared to chemical fuels into electric power. Different types of MFCs operation are reported in wastewater treatment with biogas, biohydrogen and other biofuel/energy generation. Later, biogas can convert into electric power. Hybrid microbial biofuel cell utility with photochemical reaction is found for electricity generation. Recent research and development in microbial biofuel design and its application will emphasize bioenergy for the future.

An Approach to Bio Battery and Its Scope in Future

Abstract: An electrical signal can induce a biological reaction; the reverse in is also true in most of the cases and in this way biological processes can be used to generate electricity for powering electrical equipment. Even though the Bio fuel cells have been known for almost a century since the first microbial BFC(Bio fuel cells) was demonstrated in 1912,the first enzyme-based bio-fuel cell was reported only in 1964 using glucose oxidize (GOx) as the anodic catalyst and glucose as the bio-fuel. a type of battery that uses energy sources such as carbohydrates, amino acids and enzymes from a variety of sources. anode consists of sugar-digesting enzymes and mediator, and the cathode composes of oxygen reducing enzymes and mediator. The mediators in this case are Vitamin K3 for the anode and potassium ferricyanide for the cathode. When sugar is added to the mixture, the anode garners the electrons and hydrogen ions. When the battery generates power, the protons travel to the cathode through the electrolyte to combine with the oxygen to produce water. Since the biocatalysts (enzymes) are very selective catalytically, the miniaturized bio-fuel cell could in principle be fabricated as a membrane-less fuel cell. Keywords: Bio-fuel Cells, Biocatalyst, Glucose Oxides, Enzymes.

Research Progress and Prospects of Nanozyme-Based Glucose Biofuel Cells.

The appearance and evolution of biofuel cells can be categorized into three groups: microbial biofuel cells (MBFCs), enzymatic biofuel cells (EBFCs), and enzyme-like nanomaterial (nanozyme)-based biofuel cells (NBFCs). MBFCs can produce electricity from waste; however, they have significantly low power output as well as difficulty in controlling electron transfer and microbial growth. EBFCs are more productive in generating electricity with the assistance of natural enzymes, but their vulnerability under diverse environmental conditions has critically hindered practical applications. In contrast, because of the intrinsic advantages of nanozymes, such as high stability and robustness even in harsh conditions, low synthesis cost through facile scale-up, and tunable catalytic activity, NBFCs have attracted attention, particularly for developing wearable and implantable devices to generate electricity from glucose in the physiological fluids of plants, animals, and humans. In this review, recent studies on NBFCs, including the synthetic strategies and catalytic activities of metal and metal oxide-based nanozymes, the mechanism of electricity generation from glucose, and representative studies are reviewed and discussed. Current challenges and prospects for the utilization of nanozymes in glucose biofuel cells are also discussed.

From Microorganism-Based Amperometric Biosensors towards Microbial Fuel Cells.

This review focuses on the overview of microbial amperometric biosensors and microbial biofuel cells (MFC) and shows how very similar principles are applied for the design of both types of these bioelectronics-based devices. Most microorganism-based amperometric biosensors show poor specificity, but this drawback can be exploited in the design of microbial biofuel cells because this enables them to consume wider range of chemical fuels. The efficiency of the charge transfer is among the most challenging and critical issues during the development of any kind of biofuel cell. In most cases, particular redox mediators and nanomaterials are applied for the facilitation of charge transfer from applied biomaterials towards biofuel cell electrodes. Some improvements in charge transfer efficiency can be achieved by the application of conducting polymers (CPs), which can be used for the immobilization of enzymes and in some particular cases even for the facilitation of charge transfer. In this review, charge transfer pathways and mechanisms, which are suitable for the design of biosensors and in biofuel cells, are discussed. Modification methods of the cell-wall/membrane by conducting polymers in order to enhance charge transfer efficiency of microorganisms, which can be potentially applied in the design of microbial biofuel cells, are outlined. The biocompatibility-related aspects of conducting polymers with microorganisms are summarized.

Yeast-based microbial biofuel cell mediated by 9,10-phenantrenequinone

Microbial fuel cells can be efficiently used for simultaneous cleaning of wastewater and generation of electricity. This research demonstrates the applicability of Baker yeast cells in the design of microbial biofuel cells. The applicability the 9,10-phenantrenequinone (PQ) as a redox mediator in the design of yeast-based microbial cell (MFC) for the improvement of charge transfer through the yeast cell membrane and cell wall towards the electrode was evaluated. The viability of bakers' yeast and pure Saccharomyces cerevisiae cell strains was investigated by evaluating the growth velocity of cells in the presence of a different concentration of PQ in solution. The growth curves of bakers' yeast showed that they were more resistant to PQ. Electrochemical measurements were performed with PQ as a redox mediator, which was (i) dissolved in solution and (ii) adsorbed on a graphite electrode. Differently modified graphite electrodes (namely: (i) non-modified, (ii) yeast-modified, (iii) modified by PQ and yeast) were evaluated. The modified electrodes were evaluated as anodes of MFC. The dependence of potential on external resistance and generated power of MFC was evaluated. Maximal open circuit potential was 178 mV at 7.8 mM of glucose and 23 mM of potassium ferricyanide. Maximal power of BFC calculated at the same conditions was registered at 56 mV, and it reached 22.2 mW/m2 (at 30 mM of glucose). The application of PQ as a redox mediator for yeast-based MFC improves electron transfer through the yeast cell membrane and cell wall towards electrode without any noticeable decrease of yeast cell viability.

Performance Of Inherent Electrogens In Benthic Sediment Mud At Different Ph Conditions In Microbial Fuel Cell

Comparative measurement of electricity produced by inherent eletrogens in benthic mud that were maintained at different operating pH using microbial fuel cell was studied. A two-chamber microbial fuel cell model with proton exchange membrane was adopted for this study applying electrogene sourced from benthic mud collected from local lake and pond in Ontario. The objective of this study is to investigate the effects of different pH of 6, 7 and 8 maintained within the anode cell in a microbial biofuel cell (MFC) containing microbial communities found in a benthic mud medium over 192 hours. The outcomes of the study demonstrated that in acidic conditions, there was an initial decrease in output whereas an alkaline condition allowed for the acclimatization and eventual increase of electric current and microbial activity of the study period. MFC operated at pH 7 generated consistently higher electric power during the study duration exhibiting ideal conditions for the inherent exoelectrogenic bacteria. On average 249.8 mV of electricity were measured from the MFC with pH 7. The average current density calculated to be 9.76 (±2.02) X 10-5 µA/cm2 . The average power density during the study period was calculated to be 2.49 (± 0.77) X 10-5 µW/cm2

Towards Microorganism-Based Biofuel Cells: The Viability of Saccharomyces cerevisiae Modified by Multiwalled Carbon Nanotubes

This research aimed to evaluate the toxic effect of multi-walled carbon nanotubes (MW-CNTs) on yeast cells in order to apply MW-CNTs for possible improvement of the efficiency of microbial biofuel cells. The SEM and XRD analysis suggested that here used MW-CNTs are in the range of 10–25 nm in diameter and their structure was confirmed by Raman spectroscopy. In this study, we evaluated the viability of the yeast Saccharomyces cerevisiae cells, affected by MW-CNTs, by cell count, culture optical density and atomic force microscopy. The yeast cells were exposed towards MW-CNTs (of 2, 50, 100 μg/mL concentrations in water-based solution) for 24 h. A mathematical model was applied for the evaluation of relative growth and relative death rates of yeast cells. We calculated that both of the rates are two times higher in the case if yeasts were treated by 50, 100 μg/mL of MW-CNTs containing solution, comparing to that treated by 0 and 2 μg/mL c of MW-CNTs containing solution. It was determined that the MW-CNTs have some observable effect upon the incubation of the yeast cells. The viability of yeast has decreased together with MW-CNTs concentration only after 5 h of the treatment. Therefore, we predict that the MW-CNTs can be applied for the modification of yeast cells in order to improve electrical charge transfer through the yeast cell membrane and/or the cell wall.

Nanorods of cerium oxide as an improved electrocatalyst for enhanced oxygen reduction in single-chambered microbial biofuel cells

This paper reports the synthesis and utilization of cerium oxide (CeO2) nanorods as a cathode catalyst and a potential, low-cost replacement of platinum for microbial biofuel cells (MBFCs). The nanorod electrocatalyst had exhibited significant improvements over Pt nanoparticles in terms of forward and backward onset potentials and peak current densities, electronic conductivity, charge transfer resistance, stability in 0.1 M phosphate buffer solution, and cost. It had also demonstrated a more stable forward peak current density at the 100th steady cycle, as well as, higher current density values up to 7,200 s. In addition, the synthesized CeO2 nanorods also produced ∼103 times higher exchange current density over the synthesized Pt nanoparticles. Furthermore, in a single-chamber MBFC, the CeO2 nanorods exhibited higher open circuit voltage (+0.80 V after 14 days), and output current (3613 mAm−2 at +0.3 V) and power (1084 mWm−2) densities in comparison to Pt nanoparticles.

Membraneless microbial biofuel cell for municipal waste water treatment

Microbial biofuel cell is the promising technology that gives possibilities to generate electricity by degradation of organic contaminations. Thus, this technology became very perspective for municipal waste water treatment to minimize energy consumption of waste water treatment plants. The main limitations of microbial biofuel cell application are related with high cost of membranes and electrodes materials. Absence of membrane and application of cheap materials with low conductivity and low surface area usually leads to decreasing of power output. In this paper we present membraneless microbial fuel cell (MFC) with cheap conductive electrodes that can be applied in future for waste water treatment. Gluconobacter Oxydans VKM V-1280 strain from All-Russian Collection of Microorganisms was used as biocatalyzer for anode. Graphite was applied as electrode material. Immobilization was provided by using mixture of poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and poly (ethyleneglycol) diglycidyl ether (PEGDE). Experiments were provided by using synthetic analog of municipal waste water. No additional chemical mediator was applied. Power output was 1.43 mcW/sm2. Electrodes were stable during biofuel cell (BFC) operation. Thus, it was demonstrated that it is possible to apply membraneless MFC for municipal waste water treatment.

Escherichia Coli Fed Paper-Based Microfluidic Microbial Fuel Cell With MWCNT Composed Bucky Paper Bioelectrodes.

This paper demonstrates a simple-in-struct- ure, cost-effective, and environment-friendly Microfluidic Paper-based Analytical Device for Microbial Biofuel Cell ( μ PAD-MBFC). It consists of a microchannel with biofuel cell (Escherichia.Coli) and an oxidant (aerated tap water) flowing co-parallelly over Multiwalled Carbon Nanotube (MWCNT)-based Bucky Paper (BP) electrodes using a self-capillary and co-laminar flow mechanism. The electrochemical studies, such as open circuit potential (OCP) and polarization were evaluated using a potentiostat. Various volumetric bacterial studies were also carried out to find out the best suitable optimal bacterial volume. Subsequently, the morphological and detailed element composition study of electrode surface was performed using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) techniques. This well-designed portable μ PAD-MBFC yields a maximum power density of 4 [Formula: see text]/cm2 ( [Formula: see text]/cm2) at 0.405 V over [Formula: see text] of culture and leveraging to its long-lasting potential to operate miniaturized microelectronics sensors and portable devices.