Evaluation of a Yeast-Polypyrrole Biocomposite Used in Microbial Fuel Cells

New insights on the decolorization of waste flows by Saccharomyces cerevisiae strain - A systematic review

One of the common causes of water pollution is the presence of toxic dye-based effluents, which can pose a serious threat to the ecosystem and human health. The application of Saccharomyces cerevisiae (S. cerevisiae) for wastewater decolorization has been widely investigated due to their efficient removal and eco-friendly treatments. This review attempts to create an awareness of different forms and methods of using Saccharomyces cerevisiae (S. cerevisiae) for wastewater decolorization through a systematic approach. Overall, some suggestions on classification of dyes and related environmental/health problems, and treatment methods are discussed. Besides, the mechanisms of dye removal by S. cerevisiae including biosorption, bioaccumulation, and biodegradation and cell immobilization methods such as adsorption, covalent binding, encapsulation, entrapment, and self-aggregation are discussed. This review would help to inspire the exploration of more creative methods for applications and modification of S. cerevisiae and its further practical applications.

Novel Conductive Polymer Composite PEDOT:PSS/Bovine Serum Albumin for Microbial Bioelectrochemical Devices

A novel conductive composite based on PEDOT:PSS, BSA, and Nafion for effective immobilization of acetic acid bacteria on graphite electrodes as part of biosensors and microbial fuel cells has been proposed. It is shown that individual components in the composite do not have a significant negative effect on the catalytic activity of microorganisms during prolonged contact. The values of heterogeneous electron transport constants in the presence of two types of water-soluble mediators were calculated. The use of the composite as part of a microbial biosensor resulted in an electrode operating for more than 140 days. Additional modification of carbon electrodes with nanomaterial allowed to increase the sensitivity to glucose from 1.48 to 2.81 μA × mM-1 × cm-2 without affecting the affinity of bacterial enzyme complexes to the substrate. Cells in the presented composite, as part of a microbial fuel cell based on electrodes from thermally expanded graphite, retained the ability to generate electricity for more than 120 days using glucose solution as well as vegetable extract solutions as carbon sources. The obtained data expand the understanding of the composition of possible matrices for the immobilization of Gluconobacter bacteria and may be useful in the development of biosensors and biofuel cells.

Conductive Polymers and Their Nanocomposites: Application Features in Biosensors and Biofuel Cells

Conductive polymers and their composites are excellent materials for coupling biological materials and electrodes in bioelectrochemical systems. It is assumed that their relevance and introduction to the field of bioelectrochemical devices will only grow due to their tunable conductivity, easy modification, and biocompatibility. This review analyzes the main trends and trends in the development of the methodology for the application of conductive polymers and their use in biosensors and biofuel elements, as well as describes their future prospects. Approaches to the synthesis of such materials and the peculiarities of obtaining their nanocomposites are presented. Special emphasis is placed on the features of the interfaces of such materials with biological objects.

Bioelectricity Production from Microbial Fuel Cell (MFC) Using Lysinibacillus xylanilyticus Strain nbpp1 as a Biocatalyst

Microbial fuel cells (MFCs) function by using microorganisms to decompose the substrate at the anode, producing electrons and protons. These charges are then transported to the cathode, where electricity is generated. Previous studies have shown their promising probabilities for practical applications. MFCs are praised for their ability to address energy shortages and environmental pollution simultaneously. They have the potential to generate electricity directly from organic substances, reducing energy losses that occur during intermediate conversion steps. The main challenge lies in transitioning these technologies from the laboratory setting to practical systems that can be implemented on a large scale for bioenergy production along with various engineering hurdles. This study focused on investigating the power production potential of a soil-isolated bacterial strain taxonomically classified as Lysinibacillus xylanilyticus nbpp1, which is a relatively new addition to the extensive range of biocatalysts known for their ability to generate electricity. The study analyzed the electrochemical performance of an H-type MFC setup. LB broth was used as the substrate, while aluminum and graphite served as electrode materials. Other parameters, such as Coulombic efficiency, internal resistance, and electrode corrosion rate, were also measured. The MFC produced a high open circuit voltage of 1127 mV and achieved a maximum power density of 6.71 mW/cm² at a current density of 11.14 mA/cm². The MFC setup successfully powered LED lamps when connected in a joint circuit, showcasing its potential for practical applications. These findings suggest the promising high electrochemical performance of the MFC system in terms of electricity generation using the specified conditions.

Acceptor properties of "carbon nanotubes-redox-active polymer based on bovine serum albumin modified with ferrocenecarboxaldehyde" composite for creating a BOD biosensor with Blastobotrys adeninivorans BKM Y-2677 yeast

The possibility of using a composite material based on bovine serum albumin (BSA) covalently bonded with ferrocenecarboxaldehyde and containing carbon nanotubes (CNT) for the immobilization of Blastobotrys adeninivorans BKM Y-2677 (B. adeninivorans) yeast is discussed. The optimal ratio of ferrocenecarboxaldehyde to BSA for the redox-active polymer synthesis is 1:2, since the heterogeneous electron transfer constant is 0.45 ± 0.01 s-1. When carbon nanotubes (CNTs) are added to this polymer, the heterogeneous electron transfer constant increases: at a CNT specific density of 2.5 µg/mm2, it reaches a maximum value of 0.55 ± 0.01 s-1. The addition of CNTs into the conducting system leads to increasing of the rate constant of interaction redox species with B. adeninivorans yeast by an order: the rate constant of interaction between B. adeninivorans yeast and electroactive particles in a redox-active polymer is 0.056 ± 0.005 dm3/g × s and in a composite material based on CNTs is 0.51 ± 0.02 dm3/g × s. The yeast specific density at the electrode of 0.1 mg/mm2 and electrolyte pH of 6.2 was chosen as the working value for the receptor system operation. Immobilized in a composite material, yeast oxidizes a wider range of substrates compared with a similar receptor element based on the ferrocene mediator. The biosensors formed on the basis of hybrid polymers have a high sensitivity with a lower limit of determined concentrations of 1.5 mg/dm3 with an assay time of 5 min and a high correlation (R = 0.9945) with the results of the standard method for determining biochemical oxygen demand (BOD) in nine real surface water samples of the Tula region.

The Role of Fungal Fuel Cells in Energy Production and the Removal of Pollutants from Wastewater

Pure water, i.e., a sign of life, continuously circulates and is contaminated by different discharges. This emerging environmental problem has been attracting the attention of scientists searching for methods for the treatment of wastewater contaminated by multiple recalcitrant compounds. Various physical and chemical methods are used to degrade contaminants from water bodies. Traditional methods have certain limitations and complexities for bioenergy production, which motivates the search for new ways of sustainable bioenergy production and wastewater treatment. Biological strategies have opened new avenues to the treatment of wastewater using oxidoreductase enzymes for the degradation of pollutants. Fungal-based fuel cells (FFCs), with their catalysts, have gained considerable attention among scientists worldwide. They are a new, ecofriendly, and alternative approach to nonchemical methods due to easy handling. FFCs are efficiently used in wastewater treatment and the production of electricity for power generation. This article also highlights the construction of fungal catalytic cells and the enzymatic performance of different fungal species in energy production and the treatment of wastewater.

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.

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.

Recent Literature Review of Significance of Polypyrrole and Its Biocomposites in Adsorption of Dyes from Aqueous Solution

The usage of dyes has been tremendously augmented due to industrialization and human’s intrinsic fascination with colors. Owing to their excessive usage in industries like textiles, food, cosmetics, paints, printing etc., it is indisputably a contributing factor in aquatic pollution. Dyes effluents have emerged as a burgeoning challenge. Owing to issues such as toxicity, mutagenicity, and disturbed photosynthesis associated with dye contamination, it is crucial to look for an explication to deal with this challenge. Polypyrrole-based biocomposites have been reported as good adsorbents for textile wastewater treatment. In the last decade, numerous studies have stated the effective removal of dyes via Polypyrrole-based biocomposites. This review concentrates on the implication of different Polypyrrole-based biocomposites for decontamination of dyes and synthesis methods, characteristics, and mechanism of dyes degradation by these biocomposites from wastewater.

Biomass-Derived Carbon Anode for High-Performance Microbial Fuel Cells

: Although microbial fuel cells (MFCs) have been developed over the past decade, they still have a low power production bottleneck for practical engineering due to the ineffective interfacial bioelectrochemical reaction between exoelectrogens and anode surfaces using traditional carbonaceous materials. Constructing anodes from biomass is an effective strategy to tackle the current challenges and improve the efficiency of MFCs. The advantage features of these materials come from the well-decorated aspect with an enriched functional group, the turbostratic nature, and porous structure, which is important to promote the electrocatalytic behavior of anodes in MFCs. In this review article, the three designs of biomass-derived carbon anodes based on their final products (i.e., biomass-derived nanocomposite carbons for anode surface modification, biomass-derived free-standing three-dimensional carbon anodes, and biomass-derived carbons for hybrid structured anodes) are highlighted. Next, the most frequently obtained carbon anode morphologies, characterizations, and the carbonization processes of biomass-derived MFC anodes were systematically reviewed. To conclude, the drawbacks and prospects for biomass-derived carbon anodes are suggested.

Microbe-Based Sensor for Long-Term Detection of Urine Glucose

The development of a reusable and low-cost urine glucose sensor can benefit the screening and control of diabetes mellitus. This study focused on the feasibility of employing microbial fuel cells (MFC) as a selective glucose sensor for continuous monitoring of glucose levels in human urine. Using MFC technology, a novel cylinder sensor (CS) was developed. It had a quick response time (100 s), a large detection range (0.3-5 mM), and excellent accuracy. More importantly, the CS could last for up to 5 months. The selectivity of the CS was validated by both synthetic and actual diabetes-negative urine samples. It was found that the CS's selectivity could be significantly enhanced by adjusting the concentration of the culture's organic matter. The CS results were comparable to those of a commercial glucose meter (recovery ranged from 93.6% to 127.9%) when the diabetes-positive urine samples were tested. Due to the multiple advantages of high stability, low cost, and high sensitivity over urine test strips, the CS provides a novel and reliable approach for continuous monitoring of urine glucose, which will benefit diabetes assessment and control.