Emma Martínez‐Alonso, Sonia Pena-Perez, Sandra Serrano et al.

Scientific Reports • 2019

Glaciers are populated by a large number of microorganisms including bacteria, archaea and microeukaryotes. Several factors such as solar radiation, nutrient availability and water content greatly determine the diversity and abundance of these microbial populations, the type of metabolism and the biogeochemical cycles. Three ecosystems can be differentiated in glaciers: supraglacial, subglacial and englacial ecosystems. Firstly, the supraglacial ecosystem, sunlit and oxygenated, is predominantly populated by photoautotrophic microorganisms. Secondly, the subglacial ecosystem contains a majority of chemoautotrophs that are fed on the mineral salts of the rocks and basal soil. Lastly, the englacial ecosystem is the least studied and the one that contains the smallest number of microorganisms. However, these unknown englacial microorganisms establish a food web and appear to have an active metabolism. In order to study their metabolic potentials, samples of englacial ice were taken from an Antarctic glacier. Microorganisms were analyzed by a polyphasic approach that combines a set of -omic techniques: 16S rRNA sequencing, culturomics and metaproteomics. This combination provides key information about diversity and functions of microbial populations, especially in rare habitats. Several whole essential proteins and enzymes related to metabolism and energy production, recombination and translation were found that demonstrate the existence of cellular activity at subzero temperatures. In this way it is shown that the englacial microorganisms are not quiescent, but that they maintain an active metabolism and play an important role in the glacial microbial community.

Xiaodong Zhao, Xiaojing Li, Yue Li et al.

Biotechnology for Biofuels • 2019

Soil MFCs possess advantages for the elimination of antibiotics and ARGs with sevenfold to eightfold higher electricity generation than that of the control treatment. Compared with sulphonamides, the enhancement removal of tetracycline is higher, while both potential ARG propagation risk is reduced in soil MFCs. This study firstly synchronously reveals the relationships among bacteria, fungi and archaea and with ARGs and MGE genes in soil bioelectrochemical systems.

Laxmi Parwani, Medha Bhatt, Jaspreet Singh

Brazilian Archives of Biology and Technology • 2021

HIGHLIGHTS Illustration of various important fields of biotechnology where cyanobacterial exopolysaccharides are potentially useful. Discussion of research gaps and new opportunities to make the biomaterial suitable for industrial uses.

Rubén Martínez Moreno, Elia Judith Martínez Torres, Adrián Escapa et al.

Fermentation • 2018

Anaerobic digestion and bioelectrochemical systems have great potential to recover energy from waste streams and help overcome common hurdles associated with this process, as integrated technologies. In this study, the benefit of integrating an electrogen-enriched bioanode in a batch anaerobic digester was explored under ambient temperature conditions associated with organic overloading and reactor acidity. An increase in CH4 production was observed in the electrode-containing reactors (0.56 L CH4 kgVS−1 h−1) in comparison with the conventional anaerobic digester (0.14 L CH4 kgVS−1 h−1) during the initial stages of operation. In addition, the mere presence of electrodes operating in open circuit mode resulted in a delay in volatile fatty acid (VFA) build-up. This seems to be associated with the enhancement in VFA consumption due to biomass proliferation on the electrode surface, rather than on electrochemical activity.

Yilin Dong, Dongyu Xu, Jie Zhang et al.

Journal of Hazardous Materials • 2022

Ahmed I. Osman, Zhi Ying Lai, Mohamed Farghali et al.

Environmental Chemistry Letters • 2023

Abstract The current energy crisis, depletion of fossil fuels, and global climate change have made it imperative to find alternative sources of energy that are both economically sustainable and environmentally friendly. Here we review various pathways for converting biomass into bioenergy and biochar and their applications in producing electricity, biodiesel, and biohydrogen. Biomass can be converted into biofuels using different methods, including biochemical and thermochemical conversion methods. Determining which approach is best relies on the type of biomass involved, the desired final product, and whether or not it is economically sustainable. Biochemical conversion methods are currently the most widely used for producing biofuels from biomass, accounting for approximately 80% of all biofuels produced worldwide. Ethanol and biodiesel are the most prevalent biofuels produced via biochemical conversion processes. Thermochemical conversion is less used than biochemical conversion, accounting for approximately 20% of biofuels produced worldwide. Bio-oil and syngas, commonly manufactured from wood chips, agricultural waste, and municipal solid waste, are the major biofuels produced by thermochemical conversion. Biofuels produced from biomass have the potential to displace up to 27% of the world's transportation fuel by 2050, which could result in a reduction in greenhouse gas emissions by up to 3.7 billion metric tons per year. Biochar from biomass can yield high biodiesel, ranging from 32.8% to 97.75%, and can also serve as an anode, cathode, and catalyst in microbial fuel cells with a maximum power density of 4346 mW/m 2 . Biochar also plays a role in catalytic methane decomposition and dry methane reforming, with hydrogen conversion rates ranging from 13.4% to 95.7%. Biochar can also increase hydrogen yield by up to 220.3%.

Mohamed A.S. Abdel-Razek, Ahmed M. Abozeid, Mahmoud Eltholth et al.

Slovenian Veterinary Research • 2019

The presence of organophosphate pesticides and heavy metals in water are known to be toxic to aquatic organisms. Bioremediation makes use of naturally-occurring organisms to remove pollutants from the environment. This study explored the potential of using a consortium of microalgae and cyanobacteria (Chlorella vulgaris, Scenedesmus quadricuda and Spirulina platensis) to remove the organophosphate pesticide malathion and the heavy metals cadmium, nickel and lead from water samples taken from varying combinations of urban wastewater and agricultural drainage water in Egypt. The fastest algal growth observed in this study was in a treatment containing the microorganismal consortium, malathion and heavy metals cultured in water samples taken from agriculture drainage and urban wastewater. Microalgae in this study were able to remove malathion from samples of wastewater with up to 99% efficacy and were able to bioaccumulate nickel at up to 95% efficacy. Moreover, microalgae demonstrated the ability to uptake lead and cadmium at up to 89% and 88% efficacy respectively. The results from this study suggest that a consortium of Chlorella vulgaris, Scenedesmus quadricuda and Spirulina platensis can be effective in remediating the pesticide malathion and the heavy metals cadmium, lead and nickel from wastewater.

Emilio D’Ugo, Arghya Mukherjee, Marco Resitano et al.

Journal of Hazardous Materials • 2025

Isolating microorganisms from oil spill-contaminated environments is essential for advancing bioremediation strategies and discovering novel bioprocesses for hydrocarbon degradation. In this study, we report the isolation of a novel strain, Rhodococcus erythropolis LP27217, from Pertusillo Lake (Italy) on february 2017. Water samples were collected during an oil spill event and microbial community was previously characterized using 16S rRNA gene-targeted metagenomic analysis and functional prediction. The Rhodococcus genus was identified as the dominant member of this microbiome, and functional predictive analyses guided the isolation of the R. erythropolis LP27217 strain under various growth conditions, including the presence of hydrocarbons and in Liquid Microbial Fuel Cell (L-MFC) systems. This strain exhibits a versatile hydrocarbon-degrading and transforming metabolism, effectively addressing pollutants such as crude oil, polycyclic aromatic hydrocarbons (PAHs), and dibenzothiophene (DBT), even under psychrophilic conditions. Additionally, R. erythropolis LP27217 demonstrated the ability to produce lipopeptide biosurfactants and lipophilic polymers, with the latter being associated with the formation of an electrogenic hydrocarbonoclastic biofilm at the anoxic oil-water interface. Overall, this study demonstrated that R. erythropolis LP27217 is a promising candidate for sustainable applications, including in situ bioremediation of oil spills in lake ecosystems and the biosynthesis of innovative polymers and biosurfactants for biotechnological and environmental purposes. Furthermore, its ability to operate across oxic and hypoxic conditions, at the oil-water interface and within the water column, highlights a novel microbial mechanism with significant ecological and industrial potential.

T. Srinivasa Kumar, Rahul Baghel, Satya Eswari Jujjavarapu

Water Air & Soil Pollution • 2025

Mustapha Omenesa Idris, Nur Asshifa Md Noh, Mohamad Nasir Mohamad Ibrahim et al.

Biomass Conversion and Biorefinery • 2024

Sulman Shafeeq, Wang Xiao-da, Heinrich Lünsdorf et al.

Microorganisms • 2020

: Enterobacter ludwigii is a fermentative Gram-negative environmental species and accidental human pathogen that belongs to the Enterobacter cloacae complex with the general characteristics of the genus Enterobacter. The clinical isolate E. ludwigii CEB04 was derived from a urinary tract catheter of an individual not suffering from catheter-associated urinary tract infection. The draft genome sequence of the high biofilm forming E. ludwigii CEB04 was determined by PacBio sequencing. The chromosome of E. ludwigii CEB04 is comprised of one contig of 4,892,375 bps containing 4596 predicted protein-coding genes and 120 noncoding RNAs. E. ludwigii CEB04 harbors several antimicrobial resistance markers and has an extended cyclic-di-GMP signaling network compared to Escherichia coli K-12.

Nesrine Saidi, Benjamin Erable, Sirine Saadaoui et al.

Frontiers in Energy Research • 2022

This study investigated for the first time the performance of microbial halotolerant bioanodes designed from two Tunisian Hypersaline Sediments (THS) for simultaneous electrostimulated biodegradation of synthetic fruit packaging wastewater containing thiabendazole (TBZ), and recovery of an anodic current signal. Halotolerant bioanodes formation has been conducted on 6 cm 2 carbon felt electrodes polarized at −0.1V vs Saturated Calomel Electrode (SCE), inoculated with 80% (v:v) of synthetic wastewater containing 50 ppm of irradiated or not irradiated TBZ and 20% (v:v) of THS for a period of 7 days. Microbial bioanodes, and the corresponding anolytes, i.e., synthetic wastewater, were studied comparatively by electrochemical, microscopic, spectroscopic, molecular and microbial ecology tools. Despite the low maximum current densities recorded in the 50 ppm TBZ runs (3.66 mA/m 2 ), more than 80% of the TBZ was degraded when non-irradiated TBZ (nTBZ) was used as the sole carbon energy by the microorganisms. Nevertheless, the degradation in the presence of irradiated TBZ (iTBZ) was greatly reduced by increasing the irradiation dose with maximum current density of 0.95 mA/m 2 and a degradation rate less than 50% of iTBZ. In addition, chemical changes were observed in TBZ as a result of gamma irradiation and bioelectrochemical degradation. FT-IR and UV-Vis techniques confirmed the degradation of TBZ structural bonds producing novel functional groups. Culture-dependent approach and 16S ribosomal RNA sequencing demonstrated that bacterial community of halotolerant bioanodes formed with nTBZ were dominated by Proteobacteria (75%) and Firmicutes (25%) . At species level, enrichment of Halomonas smyrnensis , Halomonas halophila , Halomonas salina , Halomonasor ganivorans and Halomonas koreensis on carbon felt electrodes were correlated with maximal current production and nTBZ degradation. As a result, THS halotolerant bacteria, and specifically those from Chott El Djerid (CJ) site certainly have well established application for the electrostimulated microbial biodegradation of fungicide in the real fruit and vegetable processing industries.

Yaoben Lin, Yanmei Ye, Shuchang Liu et al.

International Journal of Environmental Research and Public Health • 2022

Farmland consolidation is an effective tool to improve farmland infrastructures, soil quality, and sustain a healthy farmland ecosystem and rural population, generating contributions to food security and regional sustainable development. Previous studies showed that farmland consolidation regulates soil physical and chemical properties. Soil microorganisms also play an important role in soil health and crop performance; however, few studies reported how farmland consolidation influence soil microecology. Here, we used DNA sequencing technology to compare bacterial community structure in farmlands with and without consolidation. DNA sequencing technology is the most advanced technology used to obtain biological information in the world, and it has been widely used in the research of soil micro-ecological environment. In September 2018, we collected soil samples in Jiashan County, Zhejiang Province, China, and used DNA sequence technology to compare the bacterial community structure in farmlands with and without consolidation. Our results found that (1) farmland consolidation had significant impacts on soil microbial characteristics, which were mainly manifested as changes in microbial biomass, microbial diversity and community structure. Farmland consolidation can increase the relative abundance of the three dominant bacteria phyla and the three fungal dominant phyla, but it also negatively affects the relative abundance of the six dominant bacteria phyla and the three fungal dominant phyla. (2) Farmland consolidation had an indirect impact on soil bacterial community structure by adjusting the soil physical and chemical properties. (3) The impact of heavy metals on bacterial community structure varied significantly under different levels of heavy metal pollution in farmland consolidation areas. There were 6, 3, 3, and 5 bacterial genera that had significant correlations with heavy metal content in cultivated land with low pollution, light pollution, medium pollution, and heavy pollution, respectively. The number of heavy metal-tolerant bacteria in the soil generally increased first and then decreased under heavy metal polluted conditions. Our study untangled the relationship between varied farmland consolidation strategies and bacteria through soil physcicochemical properties and metal pollution conditions. Our results can guide farmland consolidation strategies and sustain soil health and ecological balance in agriculture.

О. М. Мороз, S. О. Hnatush, H. V. Yavorska et al.

Regulatory Mechanisms in Biosystems • 2022

In the process of anaerobic respiration, sulfate reducing bacteria, besides sulfates, can use other electron acceptors: nitrates, nitrites, oxidized forms of heavy metals, in particular, hexavalent chromium, which are harmful for organisms. Selection of pollutant-resistant stains of this kind of bacteria isolated from technogenically altered ecotopes, capable of reductive transformation of various nature pollutants, is an especially relevant task for the creation of new effective remediation biotechnologies. The purpose of this work was to investigate the regularities of usage of sulfate, nitrate or nitrite ions by bacteria of the Desulfovibrio genus, isolated from Yavorivske Lake, at conditions of simultaneous presence in the medium of another electron acceptor – Cr(VI), to establish a succession of electron acceptors’ reduction by investigated sulfidogenic bacteria and to evaluate the efficiency of their possible application in technologies of complex purification of the environment from metal, sulfur and nitrogen compounds. Bacteria were grown under anaerobic conditions for 10 days in Kravtsov-Sorokin medium without Mohr’s salt. To study the efficiency of sulfate, nitrate, or nitrite ions’ reduction at simultaneous presence in the medium of Cr(VI), bacteria were sown in media with Na2SO4×10H2O, NaNO3, NaNO2 or K2Cr2O7 to final SO42–, NO3–, NO2– or Cr(VI) concentration in the medium of 3.47 (concentration of SO42– in medium of standard composition) or 1.74, 3.47, 5.21, 6.94, 10.41 mM. Biomass was determined turbidimetrically, and the concentrations of sulfate, nitrate, nitrite, ammonium ions, hydrogen sulfide, Cr(VI), Cr(ІІІ) in cultural liquid were determined by spectrophotometric method. It has been established that Cr(VI) inhibits the biomass accumulation, sulfate ions’ reduction and hydrogen sulfide production by Desulfovibrio sp. after simultaneous introduction into the medium of 3.47 mM SO42– and 1.74–10.41 mM Cr(VI). In the medium with the same initial content (3.47 mM) of SO42– and Cr(VI), bacteria reduced 2.1–2.3 times more Cr(VI) than sulfate ions with Cr(III) production at concentrations up to 2.2 times higher than hydrogen sulfide. It has been shown that K2Cr2O7 inhibits the biomass accumulation, the nitrate ions reduction and the ammonium ions production by bacteria after simultaneous addition into the medium of 3.47 mM NO3– and 1.74–10.41 mM Cr(VI) or 1.74–10.41 mM NO3– and 3.47 mM Cr(VI). In the medium with the same initial content (3.47 mM) of NO3– and Cr(VI) bacteria reduced 1.1–1.3 times more nitrate ions than Cr(VI) with the production of ammonium ions at concentrations up to 1.3 times higher than that of Cr(III). It has been established that K2Cr2O7 inhibits the biomass accumulation, the nitrite ions’ reduction and the ammonium ions’ production by bacteria after simultaneous addition into the medium of 3.47 mM NO2– and 1.74–10.41 mM Cr(VI) or 1.74–10.41 mM NO2– and 3.47 mM Cr(VI). In the medium with the same initial content (3.47 mM) NO2– and Cr(VI) the reduction of Cr(VI) by bacteria practically did not differ from the reduction of nitrite ions (was only slightly lower – up to 1.1 times), almost the same concentrations of trivalent chromium and ammonium ions in the cultural liquid were detected. The processes of nitrate and nitride reduction, carried out by bacteria of Desulfovibrio genus, were revealed to be less sensitive to the negative influence of sodium dichromate, as compared with the process of sulfate ions’ reduction, which in the medium with 3.47 mM SO42– and 1.74–10.41 mM Cr(VІ) decreased by 3.2–4.6 times as compared with this process in the medium with only Na2SO4×10H2O. The investigated strains of bacteria are adapted to high concentrations of toxic pollutants (up to 10.41 mM) and therefore are promising for application in technologies of complex environment purification from hexavalent chromium, sulfur and nitrogen compounds.

María Lucila Hernández-Macedo, Jorge A. López, Katlin Ivon Barrios Eguiluz et al.

Revista Peruana de Biología • 2020

The various industrial sectors, as well as livestock and agricultural activities, are increasing the production of inputs to meet the demand of the worldwide demographic explosion, making a challenge the clean maintenance of water, soil, and air. Therefore, the search for solutions for a pollutant-free environment without compromising economic development has become extremely important. Thereby, biotechnological studies in order to solve environmental issues have been gaining extensive attention through the coupling of technology procedures to biological systems as sustainable solutions to remediate contaminated areas. In this sense, this review covers topics such as the role of Omics era in microbial environmental biotechnology for pollution control as well as the microbial fuel cell use in energy production. Moreover, phytoremediation and the perspective of applying chemical methods are approached as environmentally friendly tools for the pollutant control to improve remediation processes.

C. Li, Zhenyi Chen, Tao Li et al.

Journal of Electroanalytical Chemistry • 2025

Junlin Huang, Chih‐Hung Wu, Fuying Li et al.

Materials • 2024

The usage time of air-cathode microbial fuel cells (MFCs) is significantly influenced by the moisture content within the proton exchange membrane (PEM). Therefore, enhancing the water retention capability of the PEM by applying a hydrophobic polymer coating to its surface has extended the PEM's usage time by three times and increased MFCs' operational duration by 66%. Moreover, the hydrophobic nature of the polymer coating reduces contamination on the PEM and prevents anode liquid from permeating into the air cathode. Towards the end of MFC operation, the internal resistance of the MFC is reduced by 45%. The polymer coating effectively maintained the oxygen reduction reaction activity in the cathode. The polymer coating's ability to restrict oxygen transmembrane diffusion is demonstrated by experimental data showing a significant decrease in oxygen diffusion coefficient due to its presence. The degradation efficiency of the chemical oxygen demand from 16% to 35% increased by a factor of one.

Institut Teknologi Sepuluh Nopember, Simpliste Dusabe, Sri Rachmania Juliastuti et al.

Journal of Sustainability Science and Management • 2023

The complex organic-rich nature and nutrients of food waste (FW) can be converted into bioelectricity.This research investigated the hydrolysis of FW by three types of microorganisms, the produced electricity and the removed pollutants using a Single Chamber Microbial Fuel Cell (SC-MFC).FW was first diluted with water at different ratios (ᴡ/ν) of 2:1, 1:1 and 1:2 and blended, then, hydrolysed by Aspergillus aculeatus, Aspergillus oryzae, and Candida rugosa.DNS reagent was used to analyse glucose production.The hydrolysate was mixed with Sidoarjo mud since it contains electricigen bacteria and fed to SC-MFC for direct electricity generation.In addition, Shewanella oneidensis MR-1 was used in this study as it is one of the electrogenic bacteria with high productivity.Experiments revealed that the highest glucose reading obtained was 11.36 g/L by mixing all the fungi with a concentration ratio of (ᴡ/ν) 2:1.The highest power density of 8515.35 mW/m 2 , 78.38% of Biochemical Oxygen Demand (BOD 5 ) removal and 84.87% of Chemical Oxygen Demand (COD) removal was also obtained by mixing all the fungi with a concentration ratio (ᴡ/ν) of 2:1.Therefore, this study indicates that fungal hydrolysis may be used as an alternative pretreatment to conventional FW utilisation in MFC for bioelectricity production.

Ibrahim Yusuf, Amina Sharu

BioTechnologia • 2022

One of the major pollutants generated from guinea fowl farms and slaughterhouses is guinea fowl feather (GFF) wastes. Chicken feathers are an important substrate for removing aqueous pollutants due to their structural characteristics, but the application of GFFs for such purposes has not been elucidated. This study was carried out to determine the potential of raw as well as chemically and physically pretreated GFFs in the bioremediation of copper (Cu) and zinc (Zn) from aqueous solutions and the subsequent biodegradation of Cu- and Zn-laden GFFs using free and immobilized heavy-metal-tolerant bacteria. Using atomic adsorption spectrometry, the ability of treated and untreated GFFs to adsorb Cu and Zn was determined, and the generated heavy-metal-laden GFFs were degraded using Pseudochrobactrum sp. IY-BUK1. The results revealed that under optimized conditions, acetone and autoclave pretreatment enhanced Cu and Zn removal by 40% within 6 h when compared with raw GFFs. Similarly, complete biodegradation of Cu- and Zn-laden GFFs was achieved at pH 8, with 2% inoculum size, and at 25°C using IY-BUK1 in 7 days. Upon optimization of physical and nutritional conditions, using one factor at a time and response surface methodology, the maximum keratinase activity was achieved at 30°C, with 3% inoculum size and 3.5% polluted GFF concentration in 3 h. The degradation and keratinase activity were further enhanced by 50% by the immobilization of Pseudochrobactrum sp. IY-BUK1 cells compared with free cells. Thus, GFFs can act as good biosorbents, and together with IY-BUK1, the use of GFFs can be an alternative approach to dispose of GFFs, thus preventing environmental pollution via bioremediation.

Lina Maja Marie Krenz, Sandra Grebenteuch, Kathleen Zocher et al.

Biomass Conversion and Biorefinery • 2023

Abstract From harvesting to consumption of the faba bean ( Vicia faba ), different plant residues such as stems, leaves, pods, and seed husks remain as by-products. The harvest residues constitute about 50% (w/w) of the whole aboveground biomass, while the empty pods and the seed husks account for 11% and 6% (w/w) on average, respectively. Due to the environmental and dietary benefits, the global production of faba beans is most likely to increase in the future. Concomitantly, the amounts of by-products will rise as well. So far, mainly the harvest residues have been widely studied, whereas the pods and husks have received less consideration. Therefore, the aim of this review was to provide an overview of the composition of the faba bean plant residues and to illustrate their potential of being used as feedstock in food, feed, or even non-food applications. This literature survey clearly reveals that all the residual materials of faba beans contain valuable compounds and might be suitable for a multitude of different applications. The residual material should thus not be disposed of but further valorized in order to exploit the full potential of the biomass.

A.N.Z. Alshehri

International Journal of Current Microbiology and Applied Sciences • 2017

In this investigation on Anaerobic Sulfate Respiration Bacteria (ASRB), it is reported that the obligate anaerobic microorganism, Desulfuromonas acetoxidans are capable of producing nano scale bacterial appendages for facilitating extracellular electron transfer. The nanowires were resistive and electrically conductive (1.88 × 10–8 Ω•m and 7.32 S•m–1). They also permitted the ASRB to colonize the surface of the solid or insoluble electron acceptors, thereby making it possible for extracellular electron transfer to take place to the insoluble electrode in the MFC directly and without the need of mediators for electron shuttling. The maximum power density reached was 7.9 Wm-3, and nanowire production was stimulated whilst insoluble electron acceptors were present for cellular respiration to occur. The results suggest D. acetoxidans initiates the production of conductive nanowires in case of limited availability of a soluble electron acceptor (SO42-) for ASRB as an alternative means for facilitating electron transfer to the insoluble electron acceptors.

Yuning Yang, Lei Chen, Yufeng Jiang et al.

Water Science & Technology Water Supply • 2020

Abstract The biological reduction process of Fe(III) not only strongly affects the circulation of C, N, O, P and other elements in the environment, but also plays an important role in the transformation and degradation of organic and inorganic pollutants. Most Fe(III) oxides existing in nature have low bioavailability due to their poor solubility or strongly crystalline form with stable chemical properties. Addition of a substance having redox activity can form an electron shuttle cycle between Fe(III) oxide and the microorganism, which can not only enhance the bioavailability of Fe(III) and accelerate electron transfer, but also improve the removal efficiency of contaminants. This paper compares and analyzes several common redox active substances, for their promoting effect and limiting factors of Fe(III) bioavailability. Moreover, the mechanism by which the electron shuttle promotes the bioavailability of Fe(III) oxide is discussed. This review demonstrates that the electron shuttle promotes the Fe(III) bioreaction process for the degradation and removal of heavy metals, polycyclic aromatic hydrocarbons, azo dyes and other pollutants, which is of great environmental significance.

Tianming Chen, Chao Zou, Jingjing Pan et al.

Processes • 2022

Microbial fuel cells (MFCs) are promising technologies, aiming at treating different types of industrial and domestic wastewater. In recent years, more and more publications focusing on wastewater treatment have been published. Based on the retrieval of publications from Web of Science Core Collection database, the new emerging trends of microbial fuel cells in wastewater treatment was evaluated with a scientometric analysis method from 1995 to 2020. All publications downloaded from (WOS) were screened by inclusion criteria, and 2233 publications were obtained for further analysis. Document co-citation and burst detection of MFCs in wastewater treatment were analyzed and visualized by software of CiteSpace. Our study indicated that “Environmental Science” is the most popular discipline, while the journal of Bioresource Technology published the greatest quantity of articles in the field of MFCs applied wastewater treatment. China and the Chinese Academy of Science are the most productive country and institution, respectively. “Azo dye” has become the new research topic, which indicates the application area and the development of MFCs. The performance of MFCs for wastewater treatment has been widely discussed. The findings of this study may ameliorate the researcher in seizing the frontier of MFCs in wastewater treatment.

Lianbin Cao, Mingguo Lu, Mengrui Zhao et al.

Frontiers in Microbiology • 2023

A facultative exoelectrogen, Cellulomonas fimi strain Clb-11, was isolated from polluted river water. This strain could generate electricity in microbial fuel cells (MFCs) with carboxymethyl cellulose (CMC) as the carbon source, and the maximum output power density was 12.17 ± 2.74 mW·m -2 . In addition, Clb-11 could secrete extracellular chromate reductase or extracellular electron mediator to reduce Cr(VI) to Cr(III). When the Cr(VI) concentration was less than 0.5 mM in Luria-Bertani (LB) medium, Cr(VI) could be completely reduced by Clb-11. However, the Clb-11 cells swelled significantly in the presence of Cr(VI). We employed transcriptome sequencing analysis to identify genes involved in different Cr(VI) stress responses in Clb-11. The results indicate that 99 genes were continuously upregulated while 78 genes were continuously downregulated as the Cr(VI) concentration increased in the growth medium. These genes were mostly associated with DNA replication and repair, biosynthesis of secondary metabolites, ABC transporters, amino sugar and nucleotide sugar metabolism, and carbon metabolism. The swelling of Clb-11 cells might have been related to the upregulation of the genes atoB , INO1 , dhaM , dhal , dhak , and bccA , which encode acetyl-CoA C-acetyltransferase, myo-inositol-1-phosphate synthase, phosphoenolpyruvate-glycerone phosphotransferase, and acetyl-CoA/propionyl-CoA carboxylase, respectively. Interestingly, the genes cydA and cydB related to electron transport were continuously downregulated as the Cr(VI) concentration increased. Our results provide clues to the molecular mechanism of Cr(VI) reduction by microorganisms in MFCs systems.

Jinfeng Hu, Longjun Xu, Qi Jing et al.

Kemija u industriji • 2017

The effect of cathode type on contaminant removal efficiency and electricity production in disposing leachate was investigated in a self-assembled microbial fuel cell (MFC). When the landfill leachate was treated with the chemical-cathode MFC (CMFC) and aerobic bio-cathode MFC (ABMFC), the maximum output voltages were 699.0 mV and 459.4 mV, the maximum output powers were 197.7 mW m -3 and 147.6 mW m -3 , and the internal resistances were 900 and 700 , respectively. After running the MFCs for 45 days, the COD removal ratios of CMFC and ABMFC were 56.5 % and 64.3 %, the Coulombic efficiencies were 14.3 % and 17.1 %, and the ammonia nitrogen removal ratios were 53.8 % and 58.1 %, respectively.

S. V. Diakiv, S. О. Hnatush, O. М. Moroz et al.

Studia Biologica • 2016

Sulfur reducing bacteria from coal pits waste heaps of Chervonograd minig region were isolated and their seasonal number changes were established. Sulfur reducing bacteria number increases during cold season both at the end of vegetation season, depending on gangue humidity as well as on substrate temperature. The forty sulfur reducing bacteria isolates were selected. According to the highest biomass acumulation and hydrogen sulfide production for the following identification two strains were chosen. The morpho-physiological characteristics of isolated strains SV 30 and SV 35 were investigated. In accordance with obtained data, we assumed isolated strain SV 30 to be identified as genus Desulfuromusa , meanwhile SV 35 – Geobacter . After the seventh day of cultivation, the highest sulfur reducing activity of both strains was observed. Due to the metabolization ability of wide range of pollutants isolated sulfur reducing bacteria are perspective for application in environmental remediation technologies with biological methods.

Roberta Pastorelli, Alessandro Casagli, Filippo Rocchi et al.

Applied Sciences • 2024

This study addresses the need for a comprehensive understanding of digestate and biochar in mitigating climate change and improving soil health, crucial for sustainable agriculture within the circular bioeconomy framework. Through a mesocosm experiment, soil was amended with digestates from pilot-scale reactors and two concentrations of biochar produced by pyrolysis of digested sewage sludge and waste wood. The Germination Index (GI) assay assessed phytotoxicity on Lactuca sativa and Triticum aestivum seeds. Greenhouse gas emissions (CO2, CH4, N2O) measurements, soil characteristics analyses, and the study of microbial community structure enriched the study’s depth. The GI assay revealed diverse responses among by-products, dilution rates, and plant types, highlighting the potential phyto-stimulatory effects of digestate and biochar water-extracts. While digestate proved to be effective as fertilizer, concerns arose regarding microbial contamination. Biochar application reduced Clostridiaceae presence in soil but unexpectedly increased N2O emissions at higher concentrations, emphasizing the need for further research on biochar’s role in mitigating microbial impacts. CO2 emissions increased with digestate application but decreased with a 10% biochar concentration, aligning with control levels. CH4 uptake decreased with digestate and high biochar concentrations. The study underscores the importance of tailored approaches considering biochar composition and dosage to optimize soil greenhouse gas fluxes and microbial communities.

Muriel González-Muñoz, Xochitl Dominguez‐Benetton, Jorge Domínguez‐Maldonado et al.

Energies • 2018

Halotolerant bioanodes are considered an attractive alternative in microbial electrochemical systems, as they can operate under higher conductive electrolytes, in comparison with traditional wastewater and freshwater bioanodes. The dependency between energetic performance and polarization potential has been addressed in several works; however the vast majority discusses its effect when wastewater or freshwater inocula are employed, and fewer reports focus on inocula from highly-saline environments. Moreover, the effect of the polarization potential on current production is not fully understood. To determine if the polarization potential has a significant effect on current production, eight bioanodes were grown by chronoamperometry at positive and negative potentials relative to the reference electrode (+0.34 V/SHE and −0.16 V/SHE), in a three-electrode set-up employing sediments from a hyperhaline coastal lagoon. The maximum current density obtained was the same, despite the differences in the applied potential. Our findings indicate that even if differences in organic matter removal and coulombic efficiency are obtained, the polarization potential had no statistically significant effect on overall current density production.

Stephen Taylor, Laura Jaliff, George Wells et al.

The Science of The Total Environment • 2024

Haikun Zhang, Manman Cheng, Yan Li et al.

Water • 2023

In recent years, quinoid redox mediators (QRMs) have attracted increasing attention because of their key role in wastewater biotreatment. Previous studies have shown that the anaerobic respiration of many bacteria could be coupled to the reduction and reoxidation of quinone groups. Thus, QRMs are widely involved in the microbial transformation of various organic and inorganic substances. To date, few reviews have focused on the involvement of quinoid compounds in environmental pollution biotreatment processes. In this paper, we review the different types of QRMs that interact closely with microorganisms, the characteristics of those QRMs, the involvement of QRMs during the biotransformation of recalcitrant organic pollutants, heavy metal ions and metallic oxides, and their enhancement on microbial fuel cells. Finally, the future research focus and application prospects with regard to different types of QRMs are proposed. This study can improve our understanding of QRM-mediated environmental pollution biotreatment processes and provide fundamental guidance on what kinds of QRMs are practical for engineering applications.

Rosa María Martínez‐Espinosa

Sustainability • 2021

Water scarcity and sustainability are main current concerns affecting billions of people worldwide. Apart from policies designed to guarantee water supply, technologies and procedures have been developed to optimize the uses of water and water recycling as well as to minimize water scarcity. Among these technologies, those based on the use of bioinspired fibres, membranes, nanomaterials, liquid-liquid extraction methods using ionic liquids or approaches involving plants or microbes have been successfully carried out. One of the main problems associated with most of these technologies is the high cost of their implementation and maintenance. Consequently, other cheaper strategies have been explored, such as the use of shade covers. The objective of this work is to summarize the most recent findings on the use of shade covers (suspended shade cloth covers and shade objects) on water reservoirs, mainly agricultural water reservoirs (AWRs). Reflections on the investment-benefit relationship of this technological proposal are also herein discussed. Apart from traditional shade cloth clover, more recently, other covers like shade balls/squares/hexagons (shady objects) have also been proposed as promising approaches to save water and keep its quality. However, the manufacturing of shady objects, mainly made of polyethylene plastic, results in: (i) high cost (high energy cost and use of raw materials like crude oil and natural gas); (ii) significant production of residues, and (iii) visual environmental pollution. The main conclusion reached from this review is that the controversy over the use of shade covers continues in the spotlight of scientists, water managers, and related companies; although this approach saves water and prevents water quality deterioration, a large number of recalcitrant residues are produced, not only during their production, but also when they must be replaced due to deterioration.

Xiaoyan Qi, Huangwei Cai, Xiaolei Wang et al.

Engineering Microbiology • 2024

Microbial fuel cells (MFCs) employing Pseudomonas putida B6-2 (ATCC BAA-2545) as an exoelectrogen have been developed to harness energy from various conventional substrates, such as acetate, lactate, glucose, and fructose. Owing to its metabolic versatility, P. putida B6-2 demonstrates adaptable growth rates on diverse, cost-effective carbon sources within MFCs, exhibiting distinct energy production characteristics. Notably, the anode chamber's pH rises with carboxylates' (acetate and lactate) consumption and decreases with carbohydrates' (glucose and fructose) utilization. The MFC utilizing fructose as a substrate achieved the highest power density at 411 mW m -2 . Initial analysis revealed that P. putida B6-2 forms biofilms covered with nanowires, contributing to bioelectricity generation. These microbial nanowires are likely key players in direct extracellular electron transport through physical contact. This study established a robust foundation for producing valuable compounds and bioenergy from common substrates in bioelectrochemical systems (BESs) utilizing P. putida as an exoelectrogen.

Ping Wu, Yingdong Fu, Tony Vancov et al.

Biochar • 2024

Abstract Biochar, produced from the thermochemical conversion of biomass waste, has various applications owing to its broad utility and advantageous properties. This study employs a scientometric approach to comprehensively assess the advancements in biochar application from 2022 to 2023. Utilizing 13,357 bibliographic records sourced from the Web of Science Core Collection with the search term “biochar”, the analysis focuses on authorship, national contributions, and keyword trends. Findings demonstrate a continual rise in annual publications since 2009, albeit with a moderated growth rate in 2023. China leads in publication outputs, followed by USA and India, with Hailong Wang emerging as a prominent figure in biochar research. Keyword co-occurrence analyses identify key research themes such as biochar’s role in climate change mitigation, easing salinity and drought stress, immobilizing toxic metals, degrading organic pollutants, serving as additives in anaerobic digestion, and functioning as electrodes in microbial fuel cells. Among these, biochar’s application for global climate change mitigation gains significant attention, while its utilization as electrodes in microbial fuel cells emerges as a promising research frontier, indicating the growing need for sustainable energy sources. The study also outlines critical research gaps and future priorities for enhancing biochar application. Overall, it highlights the diverse applicability of biochar and offers valuable insight into research progression and forthcoming directions in biochar studies. Graphical Abstract

Jing Guo, Jianping Cheng, Jiaquan Wang et al.

Processes • 2021

A rectangular double chamber with trivalent arsenic as the electron donor of the biological anode was constructed by microbial fuel cells (MFC), and the feasibility of the MFC simultaneous degradation of trivalent arsenic and nitrate was studied. Experimental results show that the co-matrix-coupled MFC reactor oxidizes trivalent arsenic in an anode chamber and degrades nitrate in the cathode chamber. The removal rate of trivalent arsenic is about 63.35%, and the degradation rate of nitrate is about 55.95% during the complete and stable operation period. MFC can continuously output electric energy, and the maximum output voltage is 388 mV. We compared and analyzed the main functional microflora of biofilm microorganisms in an anode chamber. In the long-term arsenic-polluted environment, the activity of Acinetobacter, Pseudomonas bacteria with arsenic resistance, was improved. It is inferred that a fraction of trivalent arsenic was oxidized to pentavalent arsenic by electrode-attached microorganisms. While remaining trivalent, arsenic was taken up by the suspended bacterial biomass and converted into stable arsenide. The results of this study have theoretical reference value for the expansion of the MFC application scope.

Yunbin Jiang, Wenting Hu, Kailou Liu et al.

Soil Ecology Letters • 2023

Wengang Li, Fang Chen, Rong Zhong et al.

Frontiers in Microbiology • 2022

It is widely believed that biochar plays an essential role in sequestrating pollutants. The impacts of biochar on microbial growth, and consequently on the environmental fate of pollutants, however, remains poorly understood. In this study, wheat-straw-derived biochar was used to investigate how biochar amendment affected Shewanella oneidensis MR-1 growth and roxarsone transformation in water under anaerobic conditions. Three biochar with different physicochemical properties were used to mediate the roxarsone degradation. The results showed that the degradation rate of roxarsone could be accelerated by the increase of biochar pyrolysis temperature. From the characterization of biochar, the total specific surface area, micropore surface area and micropore volume of biochar increase, but the average pore diameter decreases as the pyrolysis temperature increases. Through infrared spectroscopy analysis, it was found that as the pyrolysis temperature increases, the degree of condensation of biochar increases, thereby increasing the pollutant removal rate. From the changes of the relative concentration of MR-1 and its secreted extracellular polymer content, the growth promotion ability of biochar also increases as the pyrolysis temperature increases. These results suggest that wheat-straw-derived biochar may be an important agent for activating microbial growth and can be used to accelerate the transformation of roxarsone, which could be a novel strategy for roxarsone remediation.

Lílian Lefol Nani Guarieiro, Jeancarlo Pereira dos Anjos, Luciana da Silva et al.

Journal of the Brazilian Chemical Society • 2022

Green hydrogen is a fuel capable of promoting sustainable energy development and is gaining attention in the current global energy transition framework. The global shift toward decarbonization has triggered a substantial boost in the hydrogen industry. This study presents an overview of the current status of hydrogen production, regulation of the green hydrogen segment, hydrogen storage, distribution, and transportation, and final use and application. We also critically discuss the viability of adopting green hydrogen in terms of possible economic and environmental impacts as well as the main challenges and opportunities it represents for the Chemical Sciences.

Lei Zhou, Tuoxian Tang, Dandan Deng et al.

Polish Journal of Microbiology • 2024

Electricigens decompose organic matter and convert stored chemical energy into electrical energy through extracellular electron transfer. They are significant biocatalysts for microbial fuel cells with practical applications in green energy generation, effluent treatment, and bioremediation. A facultative anaerobic electrogenic strain SQ-1 is isolated from sludge in a biotechnology factory. The strain SQ-1 is a close relative of Klebsiella variicola . Multilayered biofilms form on the surface of a carbon electrode after the isolated bacteria are inoculated into a microbial fuel cell device. This strain produces high current densities of 625 μA cm -2 by using acetate as the carbon source in a three-electrode configuration. The electricity generation performance is also analyzed in a dual-chamber microbial fuel cell. It reaches a maximum power density of 560 mW m -2 when the corresponding output voltage is 0.59 V. The facultative strain SQ-1 utilizes hydrous ferric oxide as an electron acceptor to perform extracellular electricigenic respiration in anaerobic conditions. Since facultative strains possess better properties than anaerobic strains, Klebsiella sp. SQ-1 may be a promising exoelectrogenic strain for applications in microbial electrochemistry.

Rosen Ivanov, Petia Genova

Bulgarian Portal for Open Science • 2023

ABSTRACT. Sediment microbial fuel cells (SMFCs) are bio-electrochemical systems in which the anode is placed in the anaerobic sediment and the cathode is immersed in the surface layer of water. Natural exoelectrogenic bacteria decompose organic compounds in sediment, producing electrons and protons. The electrons reach the cathode through an external electrical circuit, while the protons pass through the soil layer, which acts as a kind of membrane. Oxygen is in many cases the preferred electron acceptor due to its presence in the cathode region and its high potential. Heavy metal ions and other compounds can also be reduced on the cathode, which will increase the energy generated. Based on the above characteristics, SMFCs would be suitable for application as biosensors for monitoring water pollution with heavy metals. In the present study, the possibility of application of SMFCs as biosensors for water pollution with copper has been studied. A high correlation was found between the concentration of copper ions in the range 0,1 – 100 mg/L and the voltage generated by SMFC. The constructed SMFC based biosensor showed wider detection limits for copper compared to other authors' studies as the coefficient of determination reached 0,9911. Native exoelectrogenic bacteria were represented mainly by Geobacter, Clostridium, Anaeromixobacter and Bacillus.

Kriti Akansha, Tanvir Kaur, Ashok K. Yadav et al.

Journal of Applied Biology & Biotechnology • 2022

An array of industrial dyes most often azo dyes (-N=N-) deployed for different staining purposes, consequently impacting the environment significantly. The increasing pace of dye production often produces enormous wastewater from textile processing. After processing steps, dyes concentration remains left in expelled wastewater, consequently causing water pollution, and triggers negative toxicological impacts. However, remediation or decolorization is necessitating minimizing its negative consequences. Improper treatment of dye-containing waste waters triggers pollution of soil, water bodies, and so on. Numerous biological, physical, and chemical approaches for dye degradation and wastewater decolorization have been established. However, the high cost and practical feasibility of such methodologies remain obstacles in dye-containing wastewater. Microbial-assisted remediation is predominantly resilient to transforming dye compounds and reducing toxicity from water matrices in the ability to cope and provide cost-effective and efficient solutions. To cover the literature gap, and highlighting recent update information on dye remediation, we outlined different azo dyes, and their remediation deploying different physicochemical and microbial-mediated systems. In addition, recent advances in dye degradation, together with concluding remarks and future perspectives, have been pointed out.