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Zhuang X, Wang S, Wu S. Electron Transfer in the Biogeochemical Sulfur Cycle. Life (Basel) 2024; 14:591. [PMID: 38792612 PMCID: PMC11123123 DOI: 10.3390/life14050591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 04/30/2024] [Accepted: 05/02/2024] [Indexed: 05/26/2024] Open
Abstract
Microorganisms are key players in the global biogeochemical sulfur cycle. Among them, some have garnered particular attention due to their electrical activity and ability to perform extracellular electron transfer. A growing body of research has highlighted their extensive phylogenetic and metabolic diversity, revealing their crucial roles in ecological processes. In this review, we delve into the electron transfer process between sulfate-reducing bacteria and anaerobic alkane-oxidizing archaea, which facilitates growth within syntrophic communities. Furthermore, we review the phenomenon of long-distance electron transfer and potential extracellular electron transfer in multicellular filamentous sulfur-oxidizing bacteria. These bacteria, with their vast application prospects and ecological significance, play a pivotal role in various ecological processes. Subsequently, we discuss the important role of the pili/cytochrome for electron transfer and presented cutting-edge approaches for exploring and studying electroactive microorganisms. This review provides a comprehensive overview of electroactive microorganisms participating in the biogeochemical sulfur cycle. By examining their electron transfer mechanisms, and the potential ecological and applied implications, we offer novel insights into microbial sulfur metabolism, thereby advancing applications in the development of sustainable bioelectronics materials and bioremediation technologies.
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Affiliation(s)
- Xuliang Zhuang
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; (X.Z.); (S.W.)
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources (TPESER), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Shijie Wang
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; (X.Z.); (S.W.)
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shanghua Wu
- Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; (X.Z.); (S.W.)
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
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2
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Sandfeld T, Grøn LV, Munoz L, Meyer RL, Koren K, Philips J. Considerations on the use of microsensors to profile dissolved H2 concentrations in microbial electrochemical reactors. PLoS One 2024; 19:e0293734. [PMID: 38241241 PMCID: PMC10798470 DOI: 10.1371/journal.pone.0293734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 10/18/2023] [Indexed: 01/21/2024] Open
Abstract
Measuring the distribution and dynamics of H2 in microbial electrochemical reactors is valuable to gain insights into the processes behind novel bioelectrochemical technologies, such as microbial electrosynthesis. Here, a microsensor method to measure and profile dissolved H2 concentrations in standard H-cell reactors is described. Graphite cathodes were oriented horizontally to enable the use of a motorized microprofiling system and a stereomicroscope was used to place the H2 microsensor precisely on the cathode surface. Profiling was performed towards the gas-liquid interface, while preserving the electric connections and flushing the headspace (to maintain anoxic conditions) and under strict temperature control (to overcome the temperature sensitivity of the microsensors). This method was tested by profiling six reactors, with and without inoculation of the acetogen Sporomusa ovata, at three different time points. H2 accumulated over time in the abiotic controls, while S. ovata maintained low H2 concentrations throughout the liquid phase (< 4 μM) during the whole experimental period. These results demonstrate that this setup generated insightful H2 profiles. However, various limitations of this microsensor method were identified, as headspace flushing lowered the dissolved H2 concentrations over time. Moreover, microsensors can likely not accurately measure H2 in the immediate vicinity of the solid cathode, because the solids cathode surface obstructs H2 diffusion into the microsensor. Finally, the reactors had to be discarded after microsensor profiling. Interested users should bear these considerations in mind when applying microsensors to characterize microbial electrochemical reactors.
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Affiliation(s)
| | - Louise Vinther Grøn
- Department of Biological and Chemical Engineering, Aarhus University, Aarhus, Denmark
| | - Laura Munoz
- Department of Biological and Chemical Engineering, Aarhus University, Aarhus, Denmark
| | - Rikke Louise Meyer
- Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark
| | - Klaus Koren
- Department of Biology, Aarhus University, Aarhus, Denmark
| | - Jo Philips
- Department of Biological and Chemical Engineering, Aarhus University, Aarhus, Denmark
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3
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Yee MO, Ottosen LDM, Rotaru A. Electrical current disrupts the electron transfer in defined consortia. Microb Biotechnol 2024; 17:e14373. [PMID: 38070192 PMCID: PMC10832552 DOI: 10.1111/1751-7915.14373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 11/03/2023] [Accepted: 11/05/2023] [Indexed: 02/03/2024] Open
Abstract
Improving methane production through electrical current application to anaerobic digesters has garnered interest in optimizing such microbial electrochemical technologies, with claims suggesting direct interspecies electron transfer (DIET) at the cathode enhances methane yield. However, previous studies with mixed microbial communities only reported interspecies interactions based on species co-occurrence at the cathode, lacking insight into how a poised cathode influences well-defined DIET-based partnerships. To address this, we investigated the impact of continuous and discontinuous exposure to a poised cathode (-0.7 V vs. standard hydrogen electrode) on a defined consortium of Geobacter metallireducens and Methanosarcina barkeri, known for their DIET capabilities. The physiology of DIET consortia exposed to electrical current was compared to that of unexposed consortia. In current-exposed incubations, overall metabolic activity and cell numbers for both partners declined. The consortium, receiving electrons from the poised cathode, accumulated acetate and hydrogen, with only 32% of the recovered electrons allocated to methane production. Discontinuous exposure intensified these detrimental effects. Conversely, unexposed control reactors efficiently converted ethanol to methane, transiently accumulating acetate and recovering 88% of electrons in methane. Our results demonstrate the overall detrimental effect of electrochemical stimulation on a DIET consortium. Besides, the data indicate that the presence of an alternative electron donor (cathode) hinders efficient electron retrieval by the methanogen from Geobacter, and induces catabolic repression of oxidative metabolism in Geobacter. This study emphasizes understanding specific DIET-based interactions to enhance methane production during electrical stimulation, providing insights for optimizing tailored interspecies partnerships in microbial electrochemical technologies.
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Affiliation(s)
- Mon Oo Yee
- Nordcee, Department of BiologyUniversity of Southern DenmarkOdenseDenmark
- Nature EnergyOdenseDenmark
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Rumora A, Hopkins L, Yim K, Baykus MF, Martinez L, Jimenez L. Detection and Characterization of Electrogenic Bacteria from Soils. BIOTECH 2023; 12:65. [PMID: 38131677 PMCID: PMC10871078 DOI: 10.3390/biotech12040065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 11/21/2023] [Accepted: 11/28/2023] [Indexed: 12/23/2023] Open
Abstract
Soil microbial fuel cells (SMFCs) are bioelectrical devices powered by the oxidation of organic and inorganic compounds due to microbial activity. Seven soils were randomly selected from Bergen Community College or areas nearby, located in the state of New Jersey, USA, were used to screen for the presence of electrogenic bacteria. SMFCs were incubated at 35-37 °C. Electricity generation and electrogenic bacteria were determined using an application developed for cellular phones. Of the seven samples, five generated electricity and enriched electrogenic bacteria. Average electrical output for the seven SMFCs was 155 microwatts with the start-up time ranging from 1 to 11 days. The highest output and electrogenic bacterial numbers were found with SMFC-B1 with 143 microwatts and 2.99 × 109 electrogenic bacteria after 15 days. Optimal electrical output and electrogenic bacterial numbers ranged from 1 to 21 days. Microbial DNA was extracted from the top and bottom of the anode of SMFC-B1 using the ZR Soil Microbe DNA MiniPrep Protocol followed by PCR amplification of 16S rRNA V3-V4 region. Next-generation sequencing of 16S rRNA genes generated an average of 58 k sequences. BLAST analysis of the anode bacterial community in SMFC-B1 demonstrated that the predominant bacterial phylum was Bacillota of the class Clostridia (50%). However, bacteria belonging to the phylum Pseudomonadota (15%) such as Magnetospirillum sp. and Methylocaldum gracile were also part of the predominant electrogenic bacterial community in the anode. Unidentified uncultured bacteria accounted for 35% of the predominant bacterial community. Bioelectrical devices such as MFCs provide sustainable and clean alternatives to future applications for electricity generation, waste treatment, and biosensors.
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Affiliation(s)
| | | | | | | | | | - Luis Jimenez
- Biology and Horticulture Department, Bergen Community College, 400 Paramus Road, Paramus, NJ 07652, USA; (A.R.); (K.Y.); (L.M.)
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Yadav S, Sadhotra C, Patil SA. Retracted: The bidirectional extracellular electron transfer process aids iron cycling by Geoalkalibacter halelectricus in a highly saline-alkaline condition. Appl Environ Microbiol 2023:e0060923. [PMID: 37681980 DOI: 10.1128/aem.00609-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 07/16/2023] [Indexed: 09/09/2023] Open
Abstract
Bidirectional extracellular electron transfer (EET) is crucial to upholding microbial metabolism with insoluble electron acceptors or donors in anoxic environments. Investigating bidirectional EET-capable microorganisms is desired to understand the cell-cell and microbe-mineral interactions and their role in mineral cycling besides leveraging their energy generation and conversion, biosensing, and bio-battery applications. Here, we report on iron cycling by haloalkaliphilic Geoalkalibacter halelectricus via bidirectional EET under haloalkaline conditions. It efficiently reduces Fe3+ oxide (Fe2O3) to Fe0 at a 0.75 ± 0.08 mM/mgprotein/d rate linked to acetate oxidation via outward EET and oxidizes Fe0 to Fe3+ at a 0.24 ± 0.03 mM/mgprotein/d rate via inward EET to reduce fumarate. Bioelectrochemical cultivation confirmed its outward and inward EET capabilities. It produced 895 ± 23 µA/cm2 current by linking acetate oxidation to anode reduction via outward EET and reduced fumarate by drawing electrons from the cathode (‒2.5 ± 0.3 µA/cm2) via inward EET. The cyclic voltammograms of G. halelectricus biofilms revealed redox moieties with different formal potentials, suggesting the involvement of different membrane components in bidirectional EET. The cyclic voltammetry and GC-MS analysis of the cell-free spent medium revealed the lack of soluble redox mediators, suggesting direct electron transfer by G. halelecctricus in achieving bidirectional EET. By reporting on the first haloalkaliphilic bacterium capable of oxidizing and reducing insoluble Fe0 and Fe3+ oxide, respectively, this study advances the limited understanding of the metabolic capabilities of extremophiles to respire on insoluble electron acceptors or donors via bidirectional EET and invokes the possible role of G. halelectricus in iron cycling in barely studied haloalkaline environments. IMPORTANCE Bidirectional extracellular electron transfer (EET) appears to be a key microbial metabolic process in anoxic environments that are depleted in soluble electron donor and acceptor molecules. Though it is an ecologically important and applied microbial phenomenon, it has been reported with a few microorganisms, mostly from nonextreme environments. Moreover, direct electron transfer-based bidirectional EET is studied for very few microorganisms with electrodes in engineered systems and barely with the natural insoluble electron acceptor and donor molecules in anoxic conditions. This study advances the understanding of extremophilic microbial taxa capable of bidirectional EET and its role in barely investigated Fe cycling in highly saline-alkaline environments. It also offers research opportunities for understanding the membrane components involved in the bidirectional EET of G. halelectricus. The high rate of Fe3+ oxide reduction activity by G. halelectricus suggests its possible use as a biocatalyst in the anaerobic iron bioleaching process under neutral-alkaline pH conditions.
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Affiliation(s)
- Sukrampal Yadav
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali (IISER Mohali) , Knowledge City, Punjab, India
| | - Chetan Sadhotra
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali (IISER Mohali) , Knowledge City, Punjab, India
| | - Sunil A Patil
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali (IISER Mohali) , Knowledge City, Punjab, India
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Zhang B, Shi S, Tang R, Qiao C, Yang M, You Z, Shao S, Wu D, Yu H, Zhang J, Cao Y, Li F, Song H. Recent advances in enrichment, isolation, and bio-electrochemical activity evaluation of exoelectrogenic microorganisms. Biotechnol Adv 2023; 66:108175. [PMID: 37187358 DOI: 10.1016/j.biotechadv.2023.108175] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 05/10/2023] [Accepted: 05/10/2023] [Indexed: 05/17/2023]
Abstract
Exoelectrogenic microorganisms (EEMs) catalyzed the conversion of chemical energy to electrical energy via extracellular electron transfer (EET) mechanisms, which underlay diverse bio-electrochemical systems (BES) applications in clean energy development, environment and health monitoring, wearable/implantable devices powering, and sustainable chemicals production, thereby attracting increasing attentions from academic and industrial communities in the recent decades. However, knowledge of EEMs is still in its infancy as only ~100 EEMs of bacteria, archaea, and eukaryotes have been identified, motivating the screening and capture of new EEMs. This review presents a systematic summarization on EEM screening technologies in terms of enrichment, isolation, and bio-electrochemical activity evaluation. We first generalize the distribution characteristics of known EEMs, which provide a basis for EEM screening. Then, we summarize EET mechanisms and the principles underlying various technological approaches to the enrichment, isolation, and bio-electrochemical activity of EEMs, in which a comprehensive analysis of the applicability, accuracy, and efficiency of each technology is reviewed. Finally, we provide a future perspective on EEM screening and bio-electrochemical activity evaluation by focusing on (i) novel EET mechanisms for developing the next-generation EEM screening technologies, and (ii) integration of meta-omics approaches and bioinformatics analyses to explore nonculturable EEMs. This review promotes the development of advanced technologies to capture new EEMs.
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Affiliation(s)
- Baocai Zhang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Sicheng Shi
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Rui Tang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Chunxiao Qiao
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Meiyi Yang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Zixuan You
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Shulin Shao
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Deguang Wu
- Department of Brewing Engineering, Moutai Institute, Luban Ave, Renhuai 564507, Guizhou, PR China
| | - Huan Yu
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Junqi Zhang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Yingxiu Cao
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Feng Li
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
| | - Hao Song
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China; Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
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7
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Wang Z, Lin H, Zhang M, Yu W, Zhu C, Wang P, Huang Y, Lv F, Bai H, Wang S. Water-soluble conjugated polymers for bioelectronic systems. MATERIALS HORIZONS 2023; 10:1210-1233. [PMID: 36752220 DOI: 10.1039/d2mh01520j] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Bioelectronics is an interdisciplinary field of research that aims to establish a synergy between electronics and biology. Contributing to a deeper understanding of bioelectronic processes and the built bioelectronic systems, a variety of new phenomena, mechanisms and concepts have been derived in the field of biology, medicine, energy, artificial intelligence science, etc. Organic semiconductors can promote the applications of bioelectronics in improving original performance and creating new features for organisms due to their excellent photoelectric and electrical properties. Recently, water-soluble conjugated polymers (WSCPs) have been employed as a class of ideal interface materials to regulate bioelectronic processes between biological systems and electronic systems, relying on their satisfying ionic conductivity, water-solubility, good biocompatibility and the additional mechanical and electrical properties. In this review, we summarize the prominent contributions of WSCPs in the aspect of the regulation of bioelectronic processes and highlight the latest advances in WSCPs for bioelectronic applications, involving biosynthetic systems, photosynthetic systems, biophotovoltaic systems, and bioelectronic devices. The challenges and outlooks of WSCPs in designing high-performance bioelectronic systems are also discussed.
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Affiliation(s)
- Zenghao Wang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
- College of Chemistry, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Hongrui Lin
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
- College of Chemistry, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Miaomiao Zhang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
| | - Wen Yu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
- College of Chemistry, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Chuanwei Zhu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
- College of Chemistry, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Pengcheng Wang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
| | - Yiming Huang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
| | - Fengting Lv
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
| | - Haotian Bai
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
| | - Shu Wang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
- College of Chemistry, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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Alberto García Mogollón C, Carlos Quintero Díaz J, Omar Gil Posada J. Production of acetone, butanol, and ethanol by electro-fermentation with Clostridium saccharoperbutylacetonicum N1-4. Bioelectrochemistry 2023; 152:108414. [PMID: 36940584 DOI: 10.1016/j.bioelechem.2023.108414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 03/09/2023] [Accepted: 03/10/2023] [Indexed: 03/17/2023]
Abstract
This manuscript describes the effect of altering the extracellular redox potential during the production of acetone, butanol, and ethanol on a dual chamber H-type microbial fuel cell by fermenting glucose with Clostridium saccharoperbutylacetonicum N1-4. Extracellular redox potential modification was achieved by either supplementing the microbial broth with the redox agent NADH or by poising the cathode potential at -600 mV vs. Ag/AgCl. The addition of NADH was found to foment the production of acetone via fermentation of glucose. The addition of 200 mM of NADH to the catholyte rendered the highest production of acetone (2.4 g L-1), thus outperforming the production of acetone by conventional fermentation means (control treatment) by a factor of 2.2. The experimental evidence gathered here, indicates that cathodic electro-fermentation of glucose favors the production of butanol. When poising the cathode potential at -600 mV vs Ag/AgCl (electro-fermentation), the largest production of butanol was achieved (5.8 g L-1), outperforming the control treatment by a factor of 1.5. The production of ABE solvents and the electrochemical measurements demonstrate the electroactive properties of C. saccharoperbutylacetonicum N1-4 and illustrates the usefulness of bio-electrochemical systems to improve conventional fermentative processes.
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Affiliation(s)
| | - Juan Carlos Quintero Díaz
- Grupo de Bioprocesos, Departamento de Ingeniería Química, Universidad de Antioquia, Medellín, Colombia
| | - Jorge Omar Gil Posada
- Grupo de Bioprocesos, Departamento de Ingeniería Química, Universidad de Antioquia, Medellín, Colombia.
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9
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Surti P, Kailasa SK, Mungray AK. Enhancement of electrode properties using carbon dots functionalized magnetite nanoparticles for azo dye decolorization in microbial fuel cell. CHEMOSPHERE 2023; 313:137601. [PMID: 36565763 DOI: 10.1016/j.chemosphere.2022.137601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 11/25/2022] [Accepted: 12/17/2022] [Indexed: 06/17/2023]
Abstract
Technology integration of nanomaterials with microbial fuel cell (MFC) have led to simultaneous degradation of recalcitrant dyes and energy extraction from textile wastewater. Limited electron transfer capacity and hydrophobicity of electrode are the bottlenecks for enhancing the performance of MFC. Nanomaterials can provide surface functionalities for electron transfers and serve as catalyst for pollutant degradation. In this paper, magnetite nanoparticles functionalized with carbon dots (Fe3O4@CDs) were used to enhance the electron transfer capacity of the electrodes due to numerous surface-active functional groups of CDs and the reversible redox reaction of Fe2+/Fe3+. Polydopamine (PDA) was used as binder to coat Fe3O4@CDs onto the surface of carbon felt (CF) electrodes in a sono-chemical reaction, favoring to form biocompatible electrodes. Charge transfer resistance of Fe3O4@CDs@PDA-CF was 5.02Ω as compared to 293.34Ω of unmodified CF. Fe3O4@CDs@PDA-CF installed MFC could achieve almost 98% dye degradation efficiency within 48 h and 18.30 mW m-2 power output as compared to 77% dye degradation and 0.34 mW m-2 power output by unmodified CF electrode MFC. Moreover, metagenomic analysis of microbial consortia developed in Fe3O4@CDs@PDA-CF MFC showed enrichment of electrogenic and dye degrading microbial communities of Achromobacter. Delftia, Geobacter and Pseudomonas.
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Affiliation(s)
- Parini Surti
- Department of Chemistry, Sardar Vallabhbhai National Institute of Technology, Surat, 395007, Gujarat, India
| | - Suresh Kumar Kailasa
- Department of Chemistry, Sardar Vallabhbhai National Institute of Technology, Surat, 395007, Gujarat, India
| | - Arvind Kumar Mungray
- Department of Chemical Engineering, Sardar Vallabhbhai National Institute of Technology, Surat, 395 007, Gujarat, India.
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In situ electrosynthetic bacterial growth using electricity generated by a deep-sea hydrothermal vent. THE ISME JOURNAL 2023; 17:12-20. [PMID: 36151459 PMCID: PMC9751133 DOI: 10.1038/s41396-022-01316-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 08/28/2022] [Accepted: 09/01/2022] [Indexed: 11/08/2022]
Abstract
Electroautotrophic microorganisms have attracted great attention since they exhibit a new type of primary production. Here, in situ electrochemical cultivation was conducted using the naturally occurring electromotive forces at a deep-sea hydrothermal vent. The voltage and current generation originating from the resulting microbial activity was observed for 12 days of deployment, with fluctuation in response to tidal cycles. A novel bacterium belonging to the genus Thiomicrorhabdus dominated the microbial community specifically enriched on the cathode. Metagenomic analysis provided the draft genome of the bacterium and the gene repertoire indicated that the bacterium has the potential for thio-autotrophic growth, which is a typical physiological feature of the members of the genus, while the bacterium had a unique gene cluster encoding multi-heme cytochrome c proteins responsible for extracellular electron transfer. Herein, we propose this bacterium as a new species, specifically enriched during electricity generation, as 'Candidatus Thiomicrorhabdus electrophagus'. This finding suggests the natural occurrence of electrosynthetic microbial populations using the geoelectricity in deep-sea hydrothermal environments.
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Alvarado KA, García Martínez JB, Brown MM, Christodoulou X, Bryson S, Denkenberger DC. Food production in space from CO2 using microbial electrosynthesis. Bioelectrochemistry 2022; 149:108320. [DOI: 10.1016/j.bioelechem.2022.108320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 10/30/2022] [Accepted: 11/04/2022] [Indexed: 11/13/2022]
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12
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Yadav S, Singh R, Sundharam SS, Chaudhary S, Krishnamurthi S, Patil SA. Geoalkalibacter halelectricus SAP-1 sp. nov. possessing extracellular electron transfer and mineral-reducing capabilities from a haloalkaline environment. Environ Microbiol 2022; 24:5066-5081. [PMID: 36066180 DOI: 10.1111/1462-2920.16200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 09/03/2022] [Indexed: 11/29/2022]
Abstract
The extracellular electron transfer (EET)-capable electroactive microorganisms (EAMs) play crucial roles in mineral cycling and interspecies electron transfer in different environments and are used as biocatalysts in microbial electrochemical technologies. Studying EAMs from extreme environments is desired to advance the electromicrobiology discipline, understanding their unique metabolic traits with implications to extreme microbiology, and develop specific bioelectrochemical applications. Here, we present a novel haloalkaliphilic bacterium named Geoalkalibacter halelectricus SAP-1, isolated from a microbial electroactive biofilm enriched from the haloalkaline lake sediments. It is a rod-shaped Gram-negative heterotrophic anaerobe that uses various carbon and energy sources and respires on soluble and insoluble terminal electron acceptors. Besides 16S-rRNA and whole-genome-based phylogeny, the GGDC values of 21.7 %, ANI of 78.5, and 2.77 % genomic DNA GC content difference with the closest validly named species Geoalkalibacter ferrihydriticus (DSM 17813T ) confirmed its novelty. When grown with the solid-state electrode as the only electron acceptor, it produced 460±23 μA/cm2 bioelectrocatalytic current, thereby confirming its electroactivity. Further electrochemical analysis revealed the presence of membrane redox components with high formal potentials, putatively involved in the direct mode of EET. These are distinct from EET components reported for any known electroactive microorganisms, including well-studied Geobacter spp., Shewanella spp. and Desulfuromonas acetexigens. Further the capabilities of G. halelectricus SAP-1 to respire soluble as well insoluble electron acceptors including fumarate, SO4 2- , Fe3+ , and Mn4+ suggests its role in cycling these elements in haloalkaline environments. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Sukrampal Yadav
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali (IISER Mohali), Knowledge City, Sector 81, SAS Nagar, Punjab, India
| | - Ramandeep Singh
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali (IISER Mohali), Knowledge City, Sector 81, SAS Nagar, Punjab, India
| | - Shiva S Sundharam
- Microbial Types Culture Collection & Gene Bank (MTCC), CSIR-Institute of Microbial Technology, Sector 39A, Chandigarh, India
| | - Srishti Chaudhary
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali (IISER Mohali), Knowledge City, Sector 81, SAS Nagar, Punjab, India
| | - Srinivasan Krishnamurthi
- Microbial Types Culture Collection & Gene Bank (MTCC), CSIR-Institute of Microbial Technology, Sector 39A, Chandigarh, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Sunil A Patil
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali (IISER Mohali), Knowledge City, Sector 81, SAS Nagar, Punjab, India
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13
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Choi S. Electrogenic Bacteria Promise New Opportunities for Powering, Sensing, and Synthesizing. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2107902. [PMID: 35119203 DOI: 10.1002/smll.202107902] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/06/2022] [Indexed: 06/14/2023]
Abstract
Considerable research efforts into the promises of electrogenic bacteria and the commercial opportunities they present are attempting to identify potential feasible applications. Metabolic electrons from the bacteria enable electricity generation sufficient to power portable or small-scale applications, while the quantifiable electric signal in a miniaturized device platform can be sensitive enough to monitor and respond to changes in environmental conditions. Nanomaterials produced by the electrogenic bacteria can offer an innovative bottom-up biosynthetic approach to synergize bacterial electron transfer and create an effective coupling at the cell-electrode interface. Furthermore, electrogenic bacteria can revolutionize the field of bioelectronics by effectively interfacing electronics with microbes through extracellular electron transfer. Here, these new directions for the electrogenic bacteria and their recent integration with micro- and nanosystems are comprehensively discussed with specific attention toward distinct applications in the field of powering, sensing, and synthesizing. Furthermore, challenges of individual applications and strategies toward potential solutions are provided to offer valuable guidelines for practical implementation. Finally, the perspective and view on how the use of electrogenic bacteria can hold immeasurable promise for the development of future electronics and their applications are presented.
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Affiliation(s)
- Seokheun Choi
- Bioelectronics & Microsystems Laboratory, Department of Electrical & Computer Engineering, State University of New York at Binghamton, Binghamton, NY, 13902, USA
- Center for Research in Advanced Sensing Technologies & Environmental Sustainability, State University of New York at Binghamton, Binghamton, NY, 13902, USA
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14
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Singh R, Chaudhary S, Yadav S, Patil SA. Protocol for bioelectrochemical enrichment, cultivation, and characterization of extreme electroactive microorganisms. STAR Protoc 2022; 3:101114. [PMID: 35118426 PMCID: PMC8792420 DOI: 10.1016/j.xpro.2021.101114] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Electroactive microorganisms (EAMs) are a group of microbes that can access solid extracellular electron donors or acceptors via extracellular electron transfer processes. EAMs are useful in developing various microbial electrochemical technologies. This protocol describes the use of bioelectrochemical systems (BESs) to enrich EAMs at the cathode from an extreme haloalkaline habitat. It also provides information for a detailed characterization of enriched cathodic biofilms via various cross-disciplinary techniques, including electrochemical, analytical, microscopic, and gene sequencing techniques. For complete details on the use and execution of this protocol, please refer to Chaudhary et al. (2021). Detailed protocol for the electrochemical enrichment of extreme microorganisms Useful for cultivating different microbes at cathode of bioelectrochemical systems Protocols for characterizing electrotrophic biofilm and metabolic products provided These include electrochemical, analytical, microscopic, and gene sequencing techniques
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Affiliation(s)
- Ramandeep Singh
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali (IISER Mohali), Knowledge City, Sector 81, SAS Nagar, 140306 Punjab, India
| | - Srishti Chaudhary
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali (IISER Mohali), Knowledge City, Sector 81, SAS Nagar, 140306 Punjab, India
| | - Sukrampal Yadav
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali (IISER Mohali), Knowledge City, Sector 81, SAS Nagar, 140306 Punjab, India
| | - Sunil A Patil
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali (IISER Mohali), Knowledge City, Sector 81, SAS Nagar, 140306 Punjab, India
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15
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Paquete CM, Rosenbaum MA, Bañeras L, Rotaru AE, Puig S. Let's chat: Communication between electroactive microorganisms. BIORESOURCE TECHNOLOGY 2022; 347:126705. [PMID: 35065228 DOI: 10.1016/j.biortech.2022.126705] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 01/07/2022] [Accepted: 01/08/2022] [Indexed: 06/14/2023]
Abstract
Electroactive microorganisms can exchange electrons with other cells or conductive interfaces in their extracellular environment. This property opens the way to a broad range of practical biotechnological applications, from manufacturing sustainable chemicals via electrosynthesis, to bioenergy, bioelectronics or improved, low-energy demanding wastewater treatments. Besides, electroactive microorganisms play key roles in environmental bioremediation, significantly impacting process efficiencies. This review highlights our present knowledge on microbial interactions promoting the communication between electroactive microorganisms in a biofilm on an electrode in bioelectrochemical systems (BES). Furthermore, the immediate knowledge gaps that must be closed to develop novel technologies will also be acknowledged.
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Affiliation(s)
- Catarina M Paquete
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-156 Oeiras, Portugal
| | - Miriam A Rosenbaum
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute, Beutenbergstrasse 11a, Jena, Germany; Faculty of Biological Sciences, Friedrich Schiller University, Jena, Germany
| | - Lluís Bañeras
- Group of Molecular Microbial Ecology, Institute of Aquatic Ecology, University of Girona, C/ Maria Aurèlia Capmany, 40, E-17003 Girona, Spain
| | - Amelia-Elena Rotaru
- Faculty of Natural Sciences, Department of Biology, University of Southern Denmark, Odense, Denmark
| | - Sebastià Puig
- LEQUiA, Institute of the Environment, University of Girona, Carrer Maria Aurelia Capmany, 69, E-17003 Girona, Spain.
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16
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Thapa BS, Kim T, Pandit S, Song YE, Afsharian YP, Rahimnejad M, Kim JR, Oh SE. Overview of electroactive microorganisms and electron transfer mechanisms in microbial electrochemistry. BIORESOURCE TECHNOLOGY 2022; 347:126579. [PMID: 34921921 DOI: 10.1016/j.biortech.2021.126579] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/10/2021] [Accepted: 12/11/2021] [Indexed: 06/14/2023]
Abstract
Electroactive microorganisms acting as microbial electrocatalysts have intrinsic metabolisms that mediate a redox potential difference between solid electrodes and microbes, leading to spontaneous electron transfer to the electrode (exo-electron transfer) or electron uptake from the electrode (endo-electron transfer). These microbes biochemically convert various organic and/or inorganic compounds to electricity and/or biochemicals in bioelectrochemical systems (BESs) such as microbial fuel cells (MFCs) and microbial electrosynthesis cells (MECs). For the past two decades, intense studies have converged to clarify electron transfer mechanisms of electroactive microbes in BESs, which thereby have led to improved bioelectrochemical performance. Also, many novel exoelectrogenic eukaryotes as well as prokaryotes with electroactive properties are being continuously discovered. This review presents an overview of electroactive microorganisms (bacteria, microalgae and fungi) and their exo- and endo-electron transfer mechanisms in BESs for optimizing and advancing bioelectrochemical techniques.
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Affiliation(s)
- Bhim Sen Thapa
- Department of Biological Environment, Kangwon National University, Chuncheon, Gangwondo 24341, Republic of Korea
| | - Taeyoung Kim
- Department of Environmental Engineering, Chosun University, Gwangju 61452, Republic of Korea
| | - Soumya Pandit
- Department of Life Sciences, School of Basic Sciences and Research, Sharda University, Greater Noida 201306, India
| | - Young Eun Song
- Advanced Biofuel and Bioproducts Process Development Unit, Lawrence Berkeley National Laboratory, Emeryville, CA 94608, USA
| | - Yasamin Pesaran Afsharian
- Biofuel and Renewable Energy Research Center, Chemical Engineering Department, Babol Noshirvani University of Technology, Babol, Iran
| | - Mostafa Rahimnejad
- Biofuel and Renewable Energy Research Center, Chemical Engineering Department, Babol Noshirvani University of Technology, Babol, Iran
| | - Jung Rae Kim
- School of Chemical Engineering, Pusan National University, Busan 46241, Republic of Korea
| | - Sang-Eun Oh
- Department of Biological Environment, Kangwon National University, Chuncheon, Gangwondo 24341, Republic of Korea.
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17
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Kuchenbuch A, Frank R, Ramos JV, Jahnke HG, Harnisch F. Electrochemical Microwell Plate to Study Electroactive Microorganisms in Parallel and Real-Time. Front Bioeng Biotechnol 2022; 9:821734. [PMID: 35242754 PMCID: PMC8887713 DOI: 10.3389/fbioe.2021.821734] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 12/28/2021] [Indexed: 11/26/2022] Open
Abstract
Microbial resource mining of electroactive microorganism (EAM) is currently methodically hampered due to unavailable electrochemical screening tools. Here, we introduce an electrochemical microwell plate (ec-MP) composed of a 96 electrochemical deepwell plate and a recently developed 96-channel multipotentiostat. Using the ec-MP we investigated the electrochemical and metabolic properties of the EAM models Shewanella oneidensis and Geobacter sulfurreducens with acetate and lactate as electron donor combined with an individual genetic analysis of each well. Electrochemical cultivation of pure cultures achieved maximum current densities (jmax) and coulombic efficiencies (CE) that were well in line with literature data. The co-cultivation of S. oneidensis and G. sulfurreducens led to an increased current density of jmax of 88.57 ± 14.04 µA cm−2 (lactate) and jmax of 99.36 ± 19.12 µA cm−2 (lactate and acetate). Further, a decreased time period of reaching jmax and biphasic current production was revealed and the microbial electrochemical performance could be linked to the shift in the relative abundance.
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Affiliation(s)
- Anne Kuchenbuch
- Department of Environmental Microbiology, UFZ—Helmholtz-Centre for Environmental Research GmbH, Leipzig, Germany
| | - Ronny Frank
- Centre for Biotechnology and Biomedicine, Molecular Biological-Biochemical Processing Technology, Leipzig University, Leipzig, Germany
| | - José Vazquez Ramos
- Centre for Biotechnology and Biomedicine, Molecular Biological-Biochemical Processing Technology, Leipzig University, Leipzig, Germany
| | - Heinz-Georg Jahnke
- Centre for Biotechnology and Biomedicine, Molecular Biological-Biochemical Processing Technology, Leipzig University, Leipzig, Germany
| | - Falk Harnisch
- Department of Environmental Microbiology, UFZ—Helmholtz-Centre for Environmental Research GmbH, Leipzig, Germany
- *Correspondence: Falk Harnisch,
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18
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ACETONE-BUTYL FERMENTATION PECULIARITIES OF THE BUTANOL STRAINS -PRODUCER. BIOTECHNOLOGIA ACTA 2022. [DOI: 10.15407/biotech15.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The aim of this review was to generalize and analyze the features of acetone-butyl fermentation as a type of butyric acid fermentation in the process of obtaining butanol as an alternative biofuel. Methods. The methods of analysis and generalization of analytical information and literature sources were used in the review. The results were obtained using the following methods such as microbiological (morphological properties of strains), chromatographic (determination of solvent concentration), spectrophotometric (determination of bacterial concentration), and molecular genetic (phylogenetic analysis of strains). Results. The process of acetone-butyl fermentation was analyzed, the main producer strains were considered, the features of the relationship between alcohol formation and sporulation were described, the possibility of butanol obtaining from synthesis gas was shown, and the features of the industrial production of butanol were considered. Conclusions. The features of the mechanism of acetone-butyl fermentation (the relationships between alcohol formation and sporulation, the duration of the acid-forming and alcohol-forming stages during batch fermentation depending on the change in the concentration of H2, CO, partial pressure, organic acids and mineral additives) and obtaining an enrichment culture during the production of butanol as an alternative fuel were shown. The possibility of using synthesis gas as a substrate for reducing atmospheric emissions during the fermentation process was shown. The direction of increasing the productivity of butanol-producing strains to create a competitive industrial biofuel technology was proposed.
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19
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Lovley DR. Electrotrophy: Other microbial species, iron, and electrodes as electron donors for microbial respirations. BIORESOURCE TECHNOLOGY 2022; 345:126553. [PMID: 34906705 DOI: 10.1016/j.biortech.2021.126553] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/06/2021] [Accepted: 12/08/2021] [Indexed: 06/14/2023]
Abstract
Electrotrophy, the growth of microbes on extracellular electron donors, drives important biogeochemical cycles and has practical applications. Studies of Fe(II)-based electrotrophy have provided foundational cytochrome-based mechanistic models for electron transport into cells. Direct electron uptake from other microbial species, Fe(0), or cathodes is of intense interest due to its potential roles in the production and anaerobic oxidation of methane, corrosion, and bioelectrochemical technologies. Other cells or Fe(0) can serve as the sole electron donor supporting the growth of several Geobacter and methanogen strains that are unable to use H2 as an electron donor, providing strong evidence for electrotrophy. Additional evidence for electrotrophy in Geobacter strains and Methanosarcina acetivorans is a requirement for outer-surface c-type cytochromes. However, in most instances claims for electrotrophy in anaerobes are based on indirect inference and the possibility that H2 is actually the electron donor supporting growth has not been rigorously excluded.
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Affiliation(s)
- Derek R Lovley
- Electrobiomaterials Institute, Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang 110819, China; Department of Microbiology and Institute for Applied Life Sciences (IALS), University of Massachusetts, Amherst, MA, USA.
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20
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Valorisation of CO2 into Value-Added Products via Microbial Electrosynthesis (MES) and Electro-Fermentation Technology. FERMENTATION-BASEL 2021. [DOI: 10.3390/fermentation7040291] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Microbial electrocatalysis reckons on microbes as catalysts for reactions occurring at electrodes. Microbial fuel cells and microbial electrolysis cells are well-known in this context; both prefer the oxidation of organic and inorganic matter for producing electricity. Notably, the synthesis of high energy-density chemicals (fuels) or their precursors by microorganisms using bio-cathode to yield electrical energy is called Microbial Electrosynthesis (MES), giving an exceptionally appealing novel way for producing beneficial products from electricity and wastewater. This review accentuates the concept, importance and opportunities of MES, as an emerging discipline at the nexus of microbiology and electrochemistry. Production of organic compounds from MES is considered as an effective technique for the generation of various beneficial reduced end-products (like acetate and butyrate) as well as in reducing the load of CO2 from the atmosphere to mitigate the harmful effect of greenhouse gases in global warming. Although MES is still an emerging technology, this method is not thoroughly known. The authors have focused on MES, as it is the next transformative, viable alternative technology to decrease the repercussions of surplus carbon dioxide in the environment along with conserving energy.
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21
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Using Oxidative Electrodes to Enrich Novel Members in the Desulfobulbaceae Family from Intertidal Sediments. Microorganisms 2021; 9:microorganisms9112329. [PMID: 34835454 PMCID: PMC8618199 DOI: 10.3390/microorganisms9112329] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 10/21/2021] [Accepted: 11/08/2021] [Indexed: 01/04/2023] Open
Abstract
Members in the family of Desulfobulbaceae may be influential in various anaerobic microbial communities, including those in anoxic aquatic sediments and water columns, and within wastewater treatment facilities and bioelectrochemical systems (BESs) such as microbial fuel cells (MFCs). However, the diversity and roles of the Desulfobulbaceae in these communities have received little attention, and large portions of this family remain uncultured. Here we expand on findings from an earlier study (Li, Reimers, and Alleau, 2020) to more fully characterize Desulfobulbaceae that became prevalent in biofilms on oxidative electrodes of bioelectrochemical reactors. After incubations, DNA extraction, microbial community analyses, and microscopic examination, we found that a group of uncultured Desulfobulbaceae were greatly enriched on electrode surfaces. These Desulfobulbaceae appeared to form filaments with morphological features ascribed to cable bacteria, but the majority were taxonomically distinct from recognized cable bacteria genera. Thus, the present study provides new information about a group of Desulfobulbaceae that can exhibit filamentous morphologies and respire on the oxidative electrodes. While the phylogeny of cable bacteria is still being defined and updated, further enriching these members can contribute to the overall understanding of cable bacteria and may also lead to identification of successful isolation strategies.
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22
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McCuskey SR, Chatsirisupachai J, Zeglio E, Parlak O, Panoy P, Herland A, Bazan GC, Nguyen TQ. Current Progress of Interfacing Organic Semiconducting Materials with Bacteria. Chem Rev 2021; 122:4791-4825. [PMID: 34714064 DOI: 10.1021/acs.chemrev.1c00487] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Microbial bioelectronics require interfacing microorganisms with electrodes. The resulting abiotic/biotic platforms provide the basis of a range of technologies, including energy conversion and diagnostic assays. Organic semiconductors (OSCs) provide a unique strategy to modulate the interfaces between microbial systems and external electrodes, thereby improving the performance of these incipient technologies. In this review, we explore recent progress in the field on how OSCs, and related materials capable of charge transport, are being used within the context of microbial systems, and more specifically bacteria. We begin by examining the electrochemical communication modes in bacteria and the biological basis for charge transport. Different types of synthetic organic materials that have been designed and synthesized for interfacing and interrogating bacteria are discussed next, followed by the most commonly used characterization techniques for evaluating transport in microbial, synthetic, and hybrid systems. A range of applications is subsequently examined, including biological sensors and energy conversion systems. The review concludes by summarizing what has been accomplished so far and suggests future design approaches for OSC bioelectronics materials and technologies that hybridize characteristic properties of microbial and OSC systems.
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Affiliation(s)
- Samantha R McCuskey
- Department of Chemistry, National University of Singapore, Singapore 119077, Singapore
| | - Jirat Chatsirisupachai
- Center for Polymers and Organic Solids & Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States.,Department of Materials Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Wangchan, Rayong 21210, Thailand
| | - Erica Zeglio
- Division of Micro and Nanosystems, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, Stockholm 17177, Sweden
| | - Onur Parlak
- Dermatology and Venereology Division, Department of Medicine(Solna), Karolinska Institute, Stockholm 17177, Sweden.,AIMES Center of Integrated Medical and Engineering Sciences, Department of Neuroscience, Karolinska Institute, Stockholm 17177, Sweden
| | - Patchareepond Panoy
- Center for Polymers and Organic Solids & Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States.,Department of Materials Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Wangchan, Rayong 21210, Thailand
| | - Anna Herland
- Division of Micro and Nanosystems, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, Stockholm 17177, Sweden.,AIMES Center of Integrated Medical and Engineering Sciences, Department of Neuroscience, Karolinska Institute, Stockholm 17177, Sweden
| | - Guillermo C Bazan
- Department of Chemistry, National University of Singapore, Singapore 119077, Singapore
| | - Thuc-Quyen Nguyen
- Center for Polymers and Organic Solids & Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
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23
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Lovley DR, Holmes DE. Electromicrobiology: the ecophysiology of phylogenetically diverse electroactive microorganisms. Nat Rev Microbiol 2021; 20:5-19. [PMID: 34316046 DOI: 10.1038/s41579-021-00597-6] [Citation(s) in RCA: 156] [Impact Index Per Article: 52.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/16/2021] [Indexed: 02/03/2023]
Abstract
Electroactive microorganisms markedly affect many environments in which they establish outer-surface electrical contacts with other cells and minerals or reduce soluble extracellular redox-active molecules such as flavins and humic substances. A growing body of research emphasizes their broad phylogenetic diversity and shows that these microorganisms have key roles in multiple biogeochemical cycles, as well as the microbiome of the gut, anaerobic waste digesters and metal corrosion. Diverse bacteria and archaea have independently evolved cytochrome-based strategies for electron exchange between the outer cell surface and the cell interior, but cytochrome-free mechanisms are also prevalent. Electrically conductive protein filaments, soluble electron shuttles and non-biological conductive materials can substantially extend the electronic reach of microorganisms beyond the surface of the cell. The growing appreciation of the diversity of electroactive microorganisms and their unique electronic capabilities is leading to a broad range of applications.
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Affiliation(s)
- Derek R Lovley
- Electrobiomaterials Institute, Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang, China. .,Department of Microbiology, University of Massachusetts, Amherst, MA, USA. .,Institute for Applied Life Sciences (IALS), University of Massachusetts, Amherst, MA, USA.
| | - Dawn E Holmes
- Department of Microbiology, University of Massachusetts, Amherst, MA, USA.,Institute for Applied Life Sciences (IALS), University of Massachusetts, Amherst, MA, USA.,Department of Physical and Biological Sciences, Western New England University, Springfield, MA, USA
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24
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In Situ Electrochemical Characterization of a Microbial Fuel Cell Biocathode Running on Wastewater. Catalysts 2021. [DOI: 10.3390/catal11070839] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The electrochemical features of microbial fuel cells’ biocathodes, running on wastewater, were evaluated by cyclic voltammetry. Ex situ and in situ electrochemical assays were performed and the redox processes associated with the presence of microorganisms and/or biofilms were attained. Different controls using sterile media (abiotic cathode microbial fuel cell) and membranes covering the electrodes were performed to evaluate the source of the electrochemistry response (surface biofilms vs. biotic electrolyte). The bacteria presence, in particular when biofilms are allowed to develop, was related with the enhanced active redox processes associated with an improved catalytic activity, namely for oxygen reduction, when compared with the results attained for an abiotic microbial fuel cell cathode. The microbial main composition was also attained and is in agreement with other reported studies. The current study aims contributing to the establishment of the advantages of using biocathodes rather than abiotic, whose conditions are frequently harder to control and to contribute to a better understanding of the bioelectrochemical processes occurring on the biotic chambers and the electrode surfaces.
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25
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Nath D, Das S, Ghangrekar MM. High throughput techniques for the rapid identification of electroactive microorganisms. CHEMOSPHERE 2021; 285:131489. [PMID: 34265713 DOI: 10.1016/j.chemosphere.2021.131489] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 06/20/2021] [Accepted: 07/06/2021] [Indexed: 02/08/2023]
Abstract
Electroactive microorganisms (EAM), capable of executing extracellular electron transfer (EET) in/out of a cell, are employed in microbial electrochemical technologies (MET) and bioelectronics for harnessing electricity from wastewater, bioremediation and as biosensors. Thus, investigation on EAM is becoming a topic of interest for multidisciplinary areas, such as environmental science, energy and health sectors. Though, EAM are widespread in three domains of life, nevertheless, only a few hundred EAM have been identified so far and hence, the rapid identification of EAM is imperative. In this review, the techniques that are developed for the direct identification of EAM, such as azo dye and WO3 based techniques, dielectrophoresis, potentiostatic/galvanometric techniques, and other indirect methods, such as spectroscopy and molecular biology techniques, are highlighted with a special focus on time required for the detection of these EAM. The bottlenecks for identifying EAM and the knowledge gaps based on the present investigations are also discussed. Thus, this review is intended to encourage researchers for devolving high-throughput techniques for identifying EAM with more accuracy, while consuming less time.
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Affiliation(s)
- Dibyojyoty Nath
- School of Environmental Science & Engineering, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India
| | - Sovik Das
- Department of Civil Engineering, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India
| | - M M Ghangrekar
- School of Environmental Science & Engineering, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India; Department of Civil Engineering, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India.
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26
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Electrochemical enrichment of haloalkaliphilic nitrate-reducing microbial biofilm at the cathode of bioelectrochemical systems. iScience 2021; 24:102682. [PMID: 34195563 PMCID: PMC8233197 DOI: 10.1016/j.isci.2021.102682] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 01/25/2021] [Accepted: 05/31/2021] [Indexed: 12/01/2022] Open
Abstract
Electrotrophic microorganisms have not been well studied in extreme environments. Here, we report on the nitrate-reducing cathodic microbial biofilm from a haloalkaline environment. The biofilm enriched via electrochemical approach under 9.5 pH and 20 g NaCl/L salinity conditions achieved −43.5±7.2μA/cm2 current density and 49.5±13.2%nitrate reduction efficiency via partial and complete denitrification. Voltammetric characterization of the biocathodes revealed a redox center with −0.294±0.003V (vs. Ag/AgCl) formal potential putatively involved in the electron uptake process. The lack of soluble redox mediators and hydrogen-driven nitrate reduction suggests direct-contact cathodic electron uptake by the nitrate-reducing microorganisms in the enriched biofilm. 16S-rRNA amplicon sequencing of the cathodic biofilm revealed the presence of unreported Pseudomonas, Natronococcus, and Pseudoalteromonas spp. at 31.45%,11.82%, and 9.69% relative sequence abundances, respectively. The enriched nitrate-reducing microorganisms also reduced nitrate efficiently using soluble electron donors found in the lake sediments, thereby suggesting their role in N-cycling in such environments. Enrichment of haloalkaliphilic nitrate-reducing microbial biofilm at the cathode Cathodic reduction current corresponded to the nitrate reduction process Pseudomonas, Natronococcus, and Pseudoalteromonas spp. enriched in the cathodic biofilm Enriched culture reduced nitrate efficiently with soluble electron donor sources
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Guo Y, Aoyagi T, Hori T. Comparative insights into genome signatures of ferric iron oxide- and anode-stimulated Desulfuromonas spp. strains. BMC Genomics 2021; 22:475. [PMID: 34171987 PMCID: PMC8235581 DOI: 10.1186/s12864-021-07809-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 06/15/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Halotolerant Fe (III) oxide reducers affiliated in the family Desulfuromonadaceae are ubiquitous and drive the carbon, nitrogen, sulfur and metal cycles in marine subsurface sediment. Due to their possible application in bioremediation and bioelectrochemical engineering, some of phylogenetically close Desulfuromonas spp. strains have been isolated through enrichment with crystalline Fe (III) oxide and anode. The strains isolated using electron acceptors with distinct redox potentials may have different abilities, for instance, of extracellular electron transport, surface recognition and colonization. The objective of this study was to identify the different genomic signatures between the crystalline Fe (III) oxide-stimulated strain AOP6 and the anode-stimulated strains WTL and DDH964 by comparative genome analysis. RESULTS The AOP6 genome possessed the flagellar biosynthesis gene cluster, as well as diverse and abundant genes involved in chemotaxis sensory systems and c-type cytochromes capable of reduction of electron acceptors with low redox potentials. The WTL and DDH964 genomes lacked the flagellar biosynthesis cluster and exhibited a massive expansion of transposable gene elements that might mediate genome rearrangement, while they were deficient in some of the chemotaxis and cytochrome genes and included the genes for oxygen resistance. CONCLUSIONS Our results revealed the genomic signatures distinctive for the ferric iron oxide- and anode-stimulated Desulfuromonas spp. strains. These findings highlighted the different metabolic abilities, such as extracellular electron transfer and environmental stress resistance, of these phylogenetically close bacterial strains, casting light on genome evolution of the subsurface Fe (III) oxide reducers.
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Affiliation(s)
- Yong Guo
- Environmental Management Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki, 305-8569, Japan
| | - Tomo Aoyagi
- Environmental Management Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki, 305-8569, Japan
| | - Tomoyuki Hori
- Environmental Management Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki, 305-8569, Japan.
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Vassilev I, Averesch NJH, Ledezma P, Kokko M. Anodic electro-fermentation: Empowering anaerobic production processes via anodic respiration. Biotechnol Adv 2021; 48:107728. [PMID: 33705913 DOI: 10.1016/j.biotechadv.2021.107728] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 01/31/2021] [Accepted: 03/03/2021] [Indexed: 11/24/2022]
Abstract
In nature as well as in industrial microbiology, all microorganisms need to achieve redox balance. Their redox state and energy conservation highly depend on the availability of a terminal electron acceptor, for example oxygen in aerobic production processes. Under anaerobic conditions in the absence of an electron acceptor, redox balance is achieved via the production of reduced carbon-compounds (fermentation). An alternative strategy to artificially stabilize microbial redox and energy state is the use of anodic electro-fermentation (AEF). This emerging biotechnology empowers respiration under anaerobic conditions using the anode of a bioelectrochemical system as an undepletable terminal electron acceptor. Electrochemical control of redox metabolism and energy conservation via AEF can steer the carbon metabolism towards a product of interest and avoid the need for continuous and cost-inefficient supply of oxygen as well as the production of mixed reduced by-products, as is the case in aerobic production and fermentation processes, respectively. The great challenge for AEF is to establish efficient extracellular electron transfer (EET) from the microbe to the anode and link it to central carbon metabolism to enhance the synthesis of a target product. This article reviews the advantages and challenges of AEF, EET mechanisms, microbial energy gain, and discusses the rational choice of substrate-product couple as well as the choice of microbial catalyst. Besides, it discusses the potential of the industrial model-organism Bacillus subtilis as a promising candidate for AEF, which has not been yet considered for such an application. This prospective review contributes to a better understanding of how industrial microbiology can benefit from AEF and analyses key-factors required to successfully implement AEF processes. Overall, this work aims to advance the young research field especially by critically revisiting the fundamental aspects of AEF.
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Affiliation(s)
- Igor Vassilev
- Faculty of Engineering and Natural Sciences, Tampere University, Tampere, Finland.
| | - Nils J H Averesch
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, United States.
| | - Pablo Ledezma
- Advanced Water Management Centre, The University of Queensland, Brisbane, QLD, Australia.
| | - Marika Kokko
- Faculty of Engineering and Natural Sciences, Tampere University, Tampere, Finland.
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Lekbach Y, Liu T, Li Y, Moradi M, Dou W, Xu D, Smith JA, Lovley DR. Microbial corrosion of metals: The corrosion microbiome. Adv Microb Physiol 2021; 78:317-390. [PMID: 34147188 DOI: 10.1016/bs.ampbs.2021.01.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Microbially catalyzed corrosion of metals is a substantial economic concern. Aerobic microbes primarily enhance Fe0 oxidation through indirect mechanisms and their impact appears to be limited compared to anaerobic microbes. Several anaerobic mechanisms are known to accelerate Fe0 oxidation. Microbes can consume H2 abiotically generated from the oxidation of Fe0. Microbial H2 removal makes continued Fe0 oxidation more thermodynamically favorable. Extracellular hydrogenases further accelerate Fe0 oxidation. Organic electron shuttles such as flavins, phenazines, and possibly humic substances may replace H2 as the electron carrier between Fe0 and cells. Direct Fe0-to-microbe electron transfer is also possible. Which of these anaerobic mechanisms predominates in model pure culture isolates is typically poorly documented because of a lack of functional genetic studies. Microbial mechanisms for Fe0 oxidation may also apply to some other metals. An ultimate goal of microbial metal corrosion research is to develop molecular tools to diagnose the occurrence, mechanisms, and rates of metal corrosion to guide the implementation of the most effective mitigation strategies. A systems biology approach that includes innovative isolation and characterization methods, as well as functional genomic investigations, will be required in order to identify the diagnostic features to be gleaned from meta-omic analysis of corroding materials. A better understanding of microbial metal corrosion mechanisms is expected to lead to new corrosion mitigation strategies. The understanding of the corrosion microbiome is clearly in its infancy, but interdisciplinary electrochemical, microbiological, and molecular tools are available to make rapid progress in this field.
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Affiliation(s)
- Yassir Lekbach
- Shenyang National Laboratory for Materials Science, Northeastern University, Shenyang, China; Electrobiomaterials Institute, Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang, China
| | - Tao Liu
- College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai, China
| | - Yingchao Li
- Beijing Key Laboratory of Failure, Corrosion and Protection of Oil/Gas Facility Materials, College of New Energy and Materials, China University of Petroleum-Beijing, Beijing, China
| | - Masoumeh Moradi
- Shenyang National Laboratory for Materials Science, Northeastern University, Shenyang, China; Electrobiomaterials Institute, Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang, China
| | - Wenwen Dou
- Institute of Marine Science and Technology, Shandong University, Qingdao, China
| | - Dake Xu
- Shenyang National Laboratory for Materials Science, Northeastern University, Shenyang, China; Electrobiomaterials Institute, Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang, China.
| | - Jessica A Smith
- Department of Biomolecular Sciences, Central Connecticut State University, New Britain, CT, United States
| | - Derek R Lovley
- Electrobiomaterials Institute, Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang, China; Department of Microbiology, University of Massachusetts, Amherst, MA, United States.
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Gaffney EM, Simoska O, Minteer SD. The Use of Electroactive Halophilic Bacteria for Improvements and Advancements in Environmental High Saline Biosensing. BIOSENSORS-BASEL 2021; 11:bios11020048. [PMID: 33673343 PMCID: PMC7917972 DOI: 10.3390/bios11020048] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/08/2021] [Accepted: 02/09/2021] [Indexed: 01/20/2023]
Abstract
Halophilic bacteria are remarkable organisms that have evolved strategies to survive in high saline concentrations. These bacteria offer many advances for microbial-based biotechnologies and are commonly used for industrial processes such as compatible solute synthesis, biofuel production, and other microbial processes that occur in high saline environments. Using halophilic bacteria in electrochemical systems offers enhanced stability and applications in extreme environments where common electroactive microorganisms would not survive. Incorporating halophilic bacteria into microbial fuel cells has become of particular interest for renewable energy generation and self-powered biosensing since many wastewaters can contain fluctuating and high saline concentrations. In this perspective, we highlight the evolutionary mechanisms of halophilic microorganisms, review their application in microbial electrochemical sensing, and offer future perspectives and directions in using halophilic electroactive microorganisms for high saline biosensing.
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Rotaru AE, Yee MO, Musat F. Microbes trading electricity in consortia of environmental and biotechnological significance. Curr Opin Biotechnol 2021; 67:119-129. [PMID: 33540362 DOI: 10.1016/j.copbio.2021.01.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 01/15/2021] [Accepted: 01/19/2021] [Indexed: 02/08/2023]
Abstract
Favorable interspecies associations prevail in natural microbial assemblages. Some of these favorable associations are co-metabolic dependent partnerships in which extracellular electrons are exchanged between species. For such electron exchange to occur, the cells must exhibit electroactive interfaces and get involved in direct cell-to-cell contact (Direct Interspecies Electron Transfer/DIET) or use available conductive mineral grains from their environment (Conductive-particle-mediated Interspecies Electron Transfer/CIET). This review will highlight recent discoveries and knowledge gaps regarding DIET and CIET interspecies associations in artificial co-cultures and consortia from natural and man-made environments and emphasize approaches to validate DIET and CIET. Additionally, we acknowledge the initiation of a movement towards applying electric syntrophies in biotechnology, bioremediation and geoengineering for natural attenuation of toxic compounds. Next, we have highlighted the urgent research needs that must be met to develop such technologies.
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Affiliation(s)
| | - Mon Oo Yee
- Lawrence Berkley National Laboratories, Cyclotron Rd. 1, Berkeley, CA, United States
| | - Florin Musat
- Helmholtz Center for Environmental Research, Permoserstraße 15, Leipzig, Germany
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Yin Q, Gu M, Wu G. Inhibition mitigation of methanogenesis processes by conductive materials: A critical review. BIORESOURCE TECHNOLOGY 2020; 317:123977. [PMID: 32799079 DOI: 10.1016/j.biortech.2020.123977] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/02/2020] [Accepted: 08/04/2020] [Indexed: 06/11/2023]
Abstract
Methanogenesis can be promoted by the addition of conductive materials. Although stimulating effects of conductive materials on methane (CH4) production has been extensively reported, the crucial roles on recovering methanogenic activities under inhibitory conditions have not been systematically discussed. This critical review presents the current findings on the effects of conductive materials in methanogenic systems under volatile fatty acids (VFAs), ammonia, sulfate, and nano-cytotoxicity stressed conditions. Conductive materials induce fast VFAs degradation, avoiding VFAs accumulation during anaerobic digestion. Under high ammonia concentrations, conductive materials may ensure sufficient energy conservation for methanogens to maintain intracellular pH and proton balance. When encountering the competition of sulfate-reducing bacteria, conductive materials can benefit electron competitive capability of methanogens, recovering CH4 production activity. Conductive nanomaterials stimulate the excretion of extracellular polymeric substances, which can prevent cells from nano-cytotoxicity. Future perspectives about unraveling mitigation mechanisms induced by conductive materials in methanogenesis processes are further discussed.
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Affiliation(s)
- Qidong Yin
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong, China
| | - Mengqi Gu
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong, China
| | - Guangxue Wu
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong, China.
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Hao DC, Li XJ, Xiao PG, Wang LF. The Utility of Electrochemical Systems in Microbial Degradation of Polycyclic Aromatic Hydrocarbons: Discourse, Diversity and Design. Front Microbiol 2020; 11:557400. [PMID: 33193139 PMCID: PMC7644954 DOI: 10.3389/fmicb.2020.557400] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 09/25/2020] [Indexed: 12/27/2022] Open
Abstract
Polycyclic aromatic hydrocarbons (PAHs), especially high molecular weight PAHs, are carcinogenic and mutagenic organic compounds that are difficult to degrade. Microbial remediation is a popular method for the PAH removal in diverse environments and yet it is limited by the lack of electron acceptors. An emerging solution is to use the microbial electrochemical system, in which the solid anode is used as an inexhaustible electron acceptor and the microbial activity is stimulated by biocurrent in situ to ensure the PAH removal and avoid the defects of bioremediation. Based on the extensive investigation of recent literatures, this paper summarizes and comments on the research progress of PAH removal by the microbial electrochemical system of diversified design, enhanced measures and functional microorganisms. First, the bioelectrochemical degradation of PAHs is reviewed in separate and mixed PAH degradation, and the removal performance of PAHs in different system configurations is compared with the anode modification, the enhancement of substrate and electron transfer, the addition of chemical reagents, and the combination with phytoremediation. Second, the key functional microbiota including PAH degrading microbes and exoelectrogens are overviewed as well as the reduced microbes without competitive advantage. Finally, the typical representations of electrochemical activity especially the internal resistance, power density and current density of systems and influence factors are reviewed with the correlation analysis between PAH removal and energy generation. Presently, most studies focused on the anode modification in the bioelectrochemical degradation of PAHs and actually more attentions need to be paid to enhance the mass transfer and thus larger remediation radius, and other smart designs are also proposed, especially that the combined use of phytoremediation could be an eco-friendly and sustainable approach. Additionally, exoelectrogens and PAH degraders are partially overlapping, but the exact functional mechanisms of interaction network are still elusive, which could be revealed with the aid of advanced bioinformatics technology. In order to optimize the efficacy of functional community, more advanced techniques such as omics technology, photoelectrocatalysis and nanotechnology should be considered in the future research to improve the energy generation and PAH biodegradation rate simultaneously.
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Affiliation(s)
- Da-Cheng Hao
- School of Environmental and Chemical Engineering, Dalian Jiaotong University, Dalian, China
| | - Xiao-Jing Li
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs/Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, MARA/Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin, China
| | - Pei-Gen Xiao
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Beijing, China
| | - Lian-Feng Wang
- School of Environmental and Chemical Engineering, Dalian Jiaotong University, Dalian, China
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Microbial electroactive biofilms dominated by Geoalkalibacter spp. from a highly saline-alkaline environment. NPJ Biofilms Microbiomes 2020; 6:38. [PMID: 33051461 PMCID: PMC7555509 DOI: 10.1038/s41522-020-00147-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 09/11/2020] [Indexed: 11/08/2022] Open
Abstract
Understanding of the extreme microorganisms that possess extracellular electron transfer (EET) capabilities is pivotal to advance electromicrobiology discipline and to develop niche-specific microbial electrochemistry-driven biotechnologies. Here, we report on the microbial electroactive biofilms (EABs) possessing the outward EET capabilities from a haloalkaline environment of the Lonar lake. We used the electrochemical cultivation approach to enrich haloalkaliphilic EABs under 9.5 pH and 20 g/L salinity conditions. The electrodes controlled at 0.2 V vs. Ag/AgCl yielded the best-performing biofilms in terms of maximum bioelectrocatalytic current densities of 548 ± 23 and 437 ± 17 µA/cm2 with acetate and lactate substrates, respectively. Electrochemical characterization of biofilms revealed the presence of two putative redox-active moieties with the mean formal potentials of 0.183 and 0.333 V vs. Ag/AgCl, which represent the highest values reported to date for the EABs. 16S-rRNA amplicon sequencing of EABs revealed the dominance of unknown Geoalkalibacter sp. at ~80% abundance. Further investigations on the haloalkaliphilic EABs possessing EET components with high formal potentials might offer interesting research prospects in electromicrobiology.
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Abstract
Since the observation of direct interspecies electron transfer (DIET) in anaerobic mixed cultures in 2010s, the topic “DIET-stimulation” has been the main route to enhance the performance of anaerobic digestion (AD) under harsh conditions, such as high organic loading rate (OLR) and the toxicants’ presence. In this review article, we tried to answer three main questions: (i) What are the merits and strategies for DIET stimulation? (ii) What are the consequences of stimulation? (iii) What is the mechanism of action behind the impact of this stimulation? Therefore, we introduced DIET history and recent relevant findings with a focus on the theoretical advantages. Then, we reviewed the most recent articles by categorizing how DIET reaction was stimulated by adding conductive material (CM) and/or applying external voltage (EV). The emphasis was made on the enhanced performance (yield and/or production rate), CM type, applied EV, and mechanism of action for each stimulation strategy. In addition, we explained DIET-caused changes in microbial community structure. Finally, future perspectives and practical limitations/chances were explored in detail. We expect this review article will provide a better understanding for DIET pathway in AD and encourage further research development in a right direction.
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