Utilization of Nanomaterials as Anode Modifiers for Improving Microbial Fuel Cells Performance

Microbial fuel cells(MFCs)are an attractive innovation at the nexus of energy and water security for the future.MFC utilizes electrochemically active microorganisms to oxidize biodegradable substrates and generate bioelectricity in a single step.The material of the anode plays a vital role in increasing the MFC’s power output.The anode in MFC can be upgraded using nanomaterials providing benefits of exceptional physicochemical properties.The nanomaterials in anode gives a high surface area,improved electron transfer promotes electroactive biofilm.Enhanced power output in terms of Direct current(DC)can be obtained as the consequence of improved microbe-electrode interaction.However,several limitations like complex synthesis and degeneration of property do exist in the development of nanomaterial-based anode.The present review discusses different renewable nanomaterial applied in the anode to recover bioelectricity in MFC.Carbon nanomaterials have emerged in the past decade as promising materials for anode construction.Composite materials have also demonstrated the capacity to become potential anode materials of choice.Application of a few transition metal oxides have been explored for efficient extracellular electron transport(EET)from microbes to the anode.

A Comprehensive Review on Oxygen Reduction Reaction in Microbial Fuel Cells

The focus of microbial fuel cell research in recent years has been on the development of materials,microbes,and transfer of charges in the system,resulting in a substantial improvement in current density and improved power generation.The cathode is generally recognized as the limiting factor due to its high-distance proton transfer,slow oxygen reduction reaction(ORR),and expensive materials.The heterogeneous reaction determines power gen-eration in MFC.This comprehensive review describes-recent advancements in the development of cathode mate-rials and catalysts associated with ORR.The recent studies indicated the utilization of different metal oxides,the ferrite-based catalyst to overcome this bottleneck.These studies conclude that some cathode materials,in parti-cular,graphene-based conductive polymer composites with non-precious metal catalysts provide substantial ben-efits for sustainable development in the field of MFCs.Furthermore,it also highlights the potentiality to replace the conventional platinum air cathode for the large-scale production of the next generation of MFCs.It was evi-dent from the experiments that cathode catalyst needs to be blended with conductive carbon materials to make cathode conductive and efficient for ORR.This review discusses various antifouling strategies for cathode biofoul-ing and its effect on the MFC performance.Moreover,it also depicts cost estimations of various catalysts essential for further scale-up of MFC technology.

Delineating the role of phytocompounds against anti-bacterial drug resistance–An update

Antibacterial resistance developed by bacteria due to the unlimited use of antibiotics has posed a challenge for human civilization.This kind of problem is not limited to India only,but it is a global concern.Nowadays,many treatments and medicines for bacterial diseases have been developed.However,they possess some drawbacks.Therefore,the alternative medicine has been used to target the drug resistant mechanisms and such medicines have less side effects which is becoming necessary.Natural products have traditionally or historically been of importance for the development of antibacterial agents and are also known to overcome bacterial drug resistance by directly targeting the drug resistance mechanisms in bacteria.In recent years,researchers have also focused on new drug discovery from plant-based research.They have looked on various phytocompounds as antibacterial agents.In the current review,we report various classes of secondary metabolites such as phenolic compounds,flavonoids,alkaloids,saponins,terpenes,quinones,and some essential oils that have been used as an antibacterial agent.In addition,we also discuss several mechanisms behind bacterial multi-drug resistance that are used during bacterial pathogenesis.

Synthesis, Characterization and Remedial Action of Biogenic Silver Nanoparticles and Chitosan-Silver Nanoparticles against Bacterial Pathogens

Custard apple is a dry land fruit.Its leaves exhibit different pharmacological activities.In the present study,both silver(Ag)nanoparticles and chitosan-coated Ag(Chi-Ag)nanoparticles were fabricated using the aqueous leaf extract of the custard apple plant.During preliminary phytochemical analysis,various types of phytocompounds were found in the aqueous leaf extract of the same plant.Next,both nanoparticles were physiochemically characterized.FTIR analysis exhibited the fingerprint vibrational peaks of active bioactive compounds in plant extract,Ag nanoparticles,and Chi-Ag nanoparticles.UV/Visible spectral analysis revealed the highest absorbance peak at 419 nm,indicating the presence of Ag nanoparticles.XRD analysis presented the face-centered cubic(FCC)structure of both prepared nanomaterials.Further,the average crystalline size of both Ag nanoparticles and Chi-Ag nanoparticles was calculated to be 23 and 74 nm,respectively.FESEM analysis showed the spherical and cubical shapes of Ag nanoparticles and Chi-Ag nanoparticles,respectively.EDS analysis indicated a peak around 3.29 keV,conforming to the binding energies of Ag ions.The biogenic nanomaterial also showed strong antibacterial activity against all tested bacterial pathogens.

Epigenetic regulation−The guardian of cellular homeostasis and lineage commitment

Stem cells constitute the source of cells that replenishes the worn out or damaged cells in our tissue and enable the tissue to carry out the destined function.Tissue-specific stem cells are compartmentalized in a niche,which keeps the stem cells under quiescent condition.Thus,understanding the molecular events driving the successful differentiation of stem cells into several lineages is essential for its better manipulation of human applications.Given the developmental aspects of the cell,the cellular function is greatly dependent on the epigenomics signature that in turn governs the expression profile of the cell.The stable inheritance of the epigenome is crucial for the development,modulation,and maintenance of the cell and its complex tissue-specific function.Emerging evidence suggesting that stem cell chromatin comprises a specialized state in which self-renewing genes and its downstream lineage-specific genes are kept paralleled poised for activation.Thus,the epigenetic regulatory network and pathway dictate lineage commitment and differentiation.It mainly modifies the chromatin landscape to facilitate euchromatin and heterochromatin architecture,which in turn alters the accessibility of transcription factors to the gene loci.DNA methylation and histone marks are the two widely studied epigenetic modifications regulating the transcriptome profile of a specific lineage.Abnormalities in the epigenetic landscape lead to diseases or disorders.Here,we emphasize the prominence of the epigenetic network and its regulation in normal tissue functioning and in the diseased state.Furthermore,we highlighted the emerging role of epigenetic modifiers in lineage differentiation and epigenetic markers as novel druggable targets for cancer therapy.

Biosurfactant-assisted phytoremediation of potentially toxic elements in soil:Green technology for meeting the United Nations Sustainable Development Goals

Biosurfactants are biomolecules produced by microorganisms, low in toxicity, biodegradable, and relatively easy to synthesize using renewable waste substrates. Biosurfactants are of great importance with a wide and versatile range of applications, including the bioremediation of contaminated sites. Plants may accumulate soil potentially toxic elements(PTEs), and the accumulation efficacy may be further enhanced by the biosurfactants produced by rhizospheric microorganisms. Occasionally, the growth of bacteria slows down in adverse conditions, such as highly contaminated soils with PTEs. In this context,the plant's phytoextraction capacity could be improved by the addition of metal-tolerant bacteria that produce biosurfactants. Several sources, categories,and bioavailability of PTEs in soil are reported in this article, with the focus on the cost-effective and sustainable soil remediation technologies, where biosurfactants are used as a remediation method. How rhizobacterial biosurfactants can improve PTE recovery capabilities of plants is discussed, and the molecular mechanisms in bacterial genomes that support the production of important biosurfactants are listed. The status and cost of commercial biosurfactant production in the international market are also presented.