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Woo SG, Averesch NJH, Berliner AJ, Deutzmann JS, Pane VE, Chatterjee S, Criddle CS. Isolation and characterization of a Halomonas species for non-axenic growth-associated production of bio-polyesters from sustainable feedstocks. Appl Environ Microbiol 2024; 90:e0060324. [PMID: 39058034 PMCID: PMC11338360 DOI: 10.1128/aem.00603-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Accepted: 06/20/2024] [Indexed: 07/28/2024] Open
Abstract
Biodegradable plastics are urgently needed to replace petroleum-derived polymeric materials and prevent their accumulation in the environment. To this end, we isolated and characterized a halophilic and alkaliphilic bacterium from the Great Salt Lake in Utah. The isolate was identified as a Halomonas species and designated "CUBES01." Full-genome sequencing and genomic reconstruction revealed the unique genetic traits and metabolic capabilities of the strain, including the common polyhydroxyalkanoate (PHA) biosynthesis pathway. Fluorescence staining identified intracellular polyester granules that accumulated predominantly during the strain's exponential growth, a feature rarely found among natural PHA producers. CUBES01 was found to metabolize a range of renewable carbon feedstocks, including glucosamine and acetyl-glucosamine, as well as sucrose, glucose, fructose, and further glycerol, propionate, and acetate. Depending on the substrate, the strain accumulated up to ~60% of its biomass (dry wt/wt) in poly(3-hydroxybutyrate), while reaching a doubling time of 1.7 h at 30°C and an optimum osmolarity of 1 M sodium chloride and a pH of 8.8. The physiological preferences of the strain may not only enable long-term aseptic cultivation but also facilitate the release of intracellular products through osmolysis. The development of a minimal medium also allowed the estimation of maximum polyhydroxybutyrate production rates, which were projected to exceed 5 g/h. Finally, also, the genetic tractability of the strain was assessed in conjugation experiments: two orthogonal plasmid vectors were stable in the heterologous host, thereby opening the possibility of genetic engineering through the introduction of foreign genes. IMPORTANCE The urgent need for renewable replacements for synthetic materials may be addressed through microbial biotechnology. To simplify the large-scale implementation of such bio-processes, robust cell factories that can utilize sustainable and widely available feedstocks are pivotal. To this end, non-axenic growth-associated production could reduce operational costs and enhance biomass productivity, thereby improving commercial competitiveness. Another major cost factor is downstream processing, especially in the case of intracellular products, such as bio-polyesters. Simplified cell-lysis strategies could also further improve economic viability.
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Affiliation(s)
- Sung-Geun Woo
- Center for the
Utilization of Biological Engineering in Space
(CUBES), Berkeley,
California, USA
- Department of Civil
and Environmental Engineering, Stanford
University, Stanford,
California, USA
| | - Nils J. H. Averesch
- Center for the
Utilization of Biological Engineering in Space
(CUBES), Berkeley,
California, USA
- Department of Civil
and Environmental Engineering, Stanford
University, Stanford,
California, USA
| | - Aaron J. Berliner
- Center for the
Utilization of Biological Engineering in Space
(CUBES), Berkeley,
California, USA
- Department of
Bioengineering, University of
California, Berkeley,
California, USA
| | - Joerg S. Deutzmann
- Department of Civil
and Environmental Engineering, Stanford
University, Stanford,
California, USA
| | - Vince E. Pane
- Center for the
Utilization of Biological Engineering in Space
(CUBES), Berkeley,
California, USA
- Department of
Chemistry, Stanford University,
Stanford, California,
USA
| | - Sulogna Chatterjee
- Center for the
Utilization of Biological Engineering in Space
(CUBES), Berkeley,
California, USA
- Department of Civil
and Environmental Engineering, Stanford
University, Stanford,
California, USA
| | - Craig S. Criddle
- Center for the
Utilization of Biological Engineering in Space
(CUBES), Berkeley,
California, USA
- Department of Civil
and Environmental Engineering, Stanford
University, Stanford,
California, USA
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Wu J, Zhuang X, Zhao R, Wang Y. Insights into the biocorrosion of Q235A steel influenced by the electron transfer process between iron and methanogenic microbiota. ENVIRONMENTAL RESEARCH 2024; 261:119765. [PMID: 39134113 DOI: 10.1016/j.envres.2024.119765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2024] [Revised: 08/01/2024] [Accepted: 08/07/2024] [Indexed: 08/15/2024]
Abstract
Anaerobic microbiologically influenced corrosion (MIC) of Fe (0) metals causes great harm to the environment and economy, which depends on the key electron transfer process between anaerobic microorganisms and Fe (0) metals. However, the key electron transfer process in microbiota dominating MIC remains unclear, especially for methanogenic microbiota wildly distributed in the environment. Herein, three different methanogenic microbiota (Methanothrix, Methanospirillum, and Methanobacterium) were acclimated to systematically investigate electron transfer pathways on corroding Q235A steel coupons. Results indicated that microbiota dominated by Methanothrix, Methanospirillum, or Methanobacterium accelerated the steel corrosion mainly through direct electron transfer (DET) pathway, H2 mediated electron transfer (HMET) pathway, and combined DET and HMET pathways, respectively. Compared with Methanospirillum dominant microbiota, Methanothrix or Methanobacterium dominant microbiota caused more methane production, higher weight loss, corrosion pits with larger areas, higher corrosion depth, and smaller corrosion pits density. Such results reflected that the DET process between microbiota and Fe (0) metals decided the biocorrosion degree and behavior of Fe (0) metals. This study insightfully elucidates the mechanisms of methanogenic microbiota on corroding steels, in turn providing new insights for anti-corrosion motives.
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Affiliation(s)
- Jianping Wu
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiamen, China
| | - Xiao Zhuang
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiamen, China
| | - Ruixiang Zhao
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiamen, China
| | - Yuanpeng Wang
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiamen, China.
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3
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Day LA, Carlson HK, Fonseca DR, Arkin AP, Price MN, Deutschbauer AM, Costa KC. High-throughput genetics enables identification of nutrient utilization and accessory energy metabolism genes in a model methanogen. mBio 2024:e0078124. [PMID: 39120137 DOI: 10.1128/mbio.00781-24] [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: 03/14/2024] [Accepted: 07/08/2024] [Indexed: 08/10/2024] Open
Abstract
Archaea are widespread in the environment and play fundamental roles in diverse ecosystems; however, characterization of their unique biology requires advanced tools. This is particularly challenging when characterizing gene function. Here, we generate randomly barcoded transposon libraries in the model methanogenic archaeon Methanococcus maripaludis and use high-throughput growth methods to conduct fitness assays (RB-TnSeq) across over 100 unique growth conditions. Using our approach, we identified new genes involved in nutrient utilization and response to oxidative stress. We identified novel genes for the usage of diverse nitrogen sources in M. maripaludis including a putative regulator of alanine deamination and molybdate transporters important for nitrogen fixation. Furthermore, leveraging the fitness data, we inferred that M. maripaludis can utilize additional nitrogen sources including ʟ-glutamine, ᴅ-glucuronamide, and adenosine. Under autotrophic growth conditions, we identified a gene encoding a domain of unknown function (DUF166) that is important for fitness and hypothesize that it has an accessory role in carbon dioxide assimilation. Finally, comparing fitness costs of oxygen versus sulfite stress, we identified a previously uncharacterized class of dissimilatory sulfite reductase-like proteins (Dsr-LP; group IIId) that is important during growth in the presence of sulfite. When overexpressed, Dsr-LP conferred sulfite resistance and enabled use of sulfite as the sole sulfur source. The high-throughput approach employed here allowed for generation of a large-scale data set that can be used as a resource to further understand gene function and metabolism in the archaeal domain.IMPORTANCEArchaea are widespread in the environment, yet basic aspects of their biology remain underexplored. To address this, we apply randomly barcoded transposon libraries (RB-TnSeq) to the model archaeon Methanococcus maripaludis. RB-TnSeq coupled with high-throughput growth assays across over 100 unique conditions identified roles for previously uncharacterized genes, including several encoding proteins with domains of unknown function (DUFs). We also expand on our understanding of carbon and nitrogen metabolism and characterize a group IIId dissimilatory sulfite reductase-like protein as a functional sulfite reductase. This data set encompasses a wide range of additional conditions including stress, nitrogen fixation, amino acid supplementation, and autotrophy, thus providing an extensive data set for the archaeal community to mine for characterizing additional genes of unknown function.
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Affiliation(s)
- Leslie A Day
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, Minnesota, USA
| | - Hans K Carlson
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Dallas R Fonseca
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, Minnesota, USA
| | - Adam P Arkin
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Department of Bioengineering, University of California, Berkeley, California, USA
| | - Morgan N Price
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Adam M Deutschbauer
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- Plant and Microbial Biology Department, University of California, Berkeley, California, USA
| | - Kyle C Costa
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, Minnesota, USA
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4
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Palacios PA, Philips J, Bentien A, Kofoed MVW. Relevance of extracellular electron uptake mechanisms for electromethanogenesis applications. Biotechnol Adv 2024; 73:108369. [PMID: 38685440 DOI: 10.1016/j.biotechadv.2024.108369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 02/21/2024] [Accepted: 04/24/2024] [Indexed: 05/02/2024]
Abstract
Electromethanogenesis has emerged as a biological branch of Power-to-X technologies that implements methanogenic microorganisms, as an alternative to chemical Power-to-X, to convert electrical power from renewable sources, and CO2 into methane. Unlike biomethanation processes where CO2 is converted via exogenously added hydrogen, electromethanogenesis occurs in a bioelectrochemical set-up that combines electrodes and microorganisms. Thereby, mixed, or pure methanogenic cultures catalyze the reduction of CO2 to methane via reducing equivalents supplied by a cathode. Recent advances in electromethanogenesis have been driven by interdisciplinary research at the intersection of microbiology, electrochemistry, and engineering. Integrating the knowledge acquired from these areas is essential to address the specific challenges presented by this relatively young biotechnology, which include electron transfer limitations, low energy and product efficiencies, and reactor design to enable upscaling. This review approaches electromethanogenesis from a multidisciplinary perspective, putting emphasis on the extracellular electron uptake mechanisms that methanogens use to obtain energy from cathodes, since understanding these mechanisms is key to optimize the electrochemical conditions for the development of these systems. This work summarizes the direct and indirect extracellular electron uptake mechanisms that have been elucidated to date in methanogens, along with the ones that remain unsolved. As the study of microbial corrosion, a similar bioelectrochemical process with Fe0 as electron source, has contributed to elucidate different mechanisms on how methanogens use solid electron donors, insights from both fields, biocorrosion and electromethanogenesis, are combined. Based on the repertoire of mechanisms and their potential to convert CO2 to methane, we conclude that for future applications, electromethanogenesis should focus on the indirect mechanism with H2 as intermediary. By summarizing and linking the general aspects and challenges of this process, we hope that this review serves as a guide for researchers working on electromethanogenesis in different areas of expertise to overcome the current limitations and continue with the optimization of this promising interdisciplinary technology.
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Affiliation(s)
- Paola Andrea Palacios
- Department of Biological and Chemical Engineering, Aarhus University, Gustav Wieds Vej 10C, 8200 Aarhus, Denmark.
| | - Jo Philips
- Department of Biological and Chemical Engineering, Aarhus University, Gustav Wieds Vej 10C, 8200 Aarhus, Denmark
| | - Anders Bentien
- Department of Biological and Chemical Engineering, Aarhus University, Aabogade 40, Aarhus N, 8200 Aarhus, Denmark
| | - Michael Vedel Wegener Kofoed
- Department of Biological and Chemical Engineering, Aarhus University, Gustav Wieds Vej 10C, 8200 Aarhus, Denmark
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5
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Li Y, Cao M, Gupta VK, Wang Y. Metabolic engineering strategies to enable microbial electrosynthesis utilization of CO 2: recent progress and challenges. Crit Rev Biotechnol 2024; 44:352-372. [PMID: 36775662 DOI: 10.1080/07388551.2023.2167065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 10/17/2022] [Accepted: 12/08/2022] [Indexed: 02/14/2023]
Abstract
Microbial electrosynthesis (MES) is a promising technology that mainly utilizes microbial cells to convert CO2 into value-added chemicals using electrons provided by the cathode. However, the low electron transfer rate is a solid bottleneck hindering the further application of MES. Thus, as an effective strategy, genetic tools play a key role in MES for enhancing the electron transfer rate and diversity of production. We describe a set of genetic strategies based on fundamental characteristics and current successes and discuss their functional mechanisms in driving microbial electrocatalytic reactions to fully comprehend the roles and uses of genetic tools in MES. This paper also analyzes the process of nanomaterial application in extracellular electron transfer (EET). It provides a technique that combines nanomaterials and genetic tools to increase MES efficiency, because nanoparticles have a role in the production of functional genes in EET although genetic tools can subvert MES, it still has issues with difficult transformation and low expression levels. Genetic tools remain one of the most promising future strategies for advancing the MES process despite these challenges.
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Affiliation(s)
- Yixin Li
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Key Laboratory for Chemical Biology of Fujian Province, Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, China
| | - Mingfeng Cao
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Key Laboratory for Chemical Biology of Fujian Province, Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, China
- Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen, China
| | - Vijai Kumar Gupta
- Biorefining and Advanced Materials Research Center, SRUC, Edinburgh, UK
| | - Yuanpeng Wang
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Key Laboratory for Chemical Biology of Fujian Province, Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen, China
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6
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Wang L, Liu H. Microbial electrosynthesis of single cell protein and methane by coupling fast-growing Methanococcus maripaludis with microbial electrolysis cells. BIORESOURCE TECHNOLOGY 2024; 393:130025. [PMID: 37972904 DOI: 10.1016/j.biortech.2023.130025] [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: 10/21/2023] [Revised: 11/13/2023] [Accepted: 11/13/2023] [Indexed: 11/19/2023]
Abstract
Single cell protein (SCP) is a promising alternative protein source, as its production bypasses the disadvantages of animal protein production in industrial agriculture. Coupling a fast-growing hydrogen consuming organism with microbial electrolysis cells (MECs) could be a viable method for SCP production. In this study, a fast-growing and protein-rich methanogen, Methanococcus maripaludis was selected as the primary SCP source. The inoculation of M. maripaludis in MECs triggered cell synthesis with methane production. The doubling time measured was 11.2 h and the specific growth rate was 0.062 1/h. The highest SCP production rate was 13.7 mg/L/h. In the dried biomass, the weight of protein was over 60 %. Amino acid profiling of the harvested biomass demonstrated high abundance of essential amino acids. The electron flux analysis indicated that 31.3 % electrons in the electrochemical systems were directed into SCP synthesis. These results illustrated the potential for SCP production by coupling a fast-growing methanogen with MECs.
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Affiliation(s)
- Luguang Wang
- Department of Biological and Ecological Engineering, Oregon State University, Corvallis, OR 97331, United States; Department of Biological Engineering, Utah State University, Logan, UT 84322, United States
| | - Hong Liu
- Department of Biological and Ecological Engineering, Oregon State University, Corvallis, OR 97331, United States.
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7
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Baek G, Logan BE. A comprehensive analysis of key factors influencing methane production from CO 2 using microbial methanogenesis cells. WATER RESEARCH 2023; 245:120657. [PMID: 37778082 DOI: 10.1016/j.watres.2023.120657] [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: 05/02/2023] [Revised: 08/02/2023] [Accepted: 09/20/2023] [Indexed: 10/03/2023]
Abstract
With increasing attention on carbon capture and utilization (CCU) technologies for the conversion of CO2 into chemical products, microbial methanogenesis cells (MMCs) have been extensively studied over the past few decades for biomethane production. Using rapidly accumulating data for MMCs with varying configurations and operating conditions, a comprehensive analysis was conducted here to investigate the critical factors that influence methane production rates (MPR) in these systems. A comparison of MPR and set potentials or current densities showed weak linear relationships (R2 < 0.6, p < 0.05), indicating the significant contributions of other important factors impacting methane production. A non-quantitative analysis of these additional parameters indicated the potential importance of using metal catalysts for anode materials where oxygen evolution reaction occurs, while most previous MMC research focused more on cathode materials where the biocatalytic reaction occurs. The use of undefined mixed anaerobic cultures as inocula was found to be sufficient for producing high MPRs, as the electrochemical environment at the cathode provides a strong selective pressure to converge on desirable methanogenic cultures. Other operational parameters, such as catholyte pH control and CO2 supply methods, were also important factors impacting MPR in MMCs, indicating the cumulative impact of these various factors will require careful consideration in future research.
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Affiliation(s)
- Gahyun Baek
- Department of Integrative Biotechnology, Sungkyunkwan University, 2066 Seoburo, Jangan-gu, Suwon 16419, Republic of Korea.
| | - Bruce E Logan
- Department of Civil and Environmental Engineering, The Pennsylvania State University, 231Q Sackett Building, University Park, PA 16802, USA
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Abstract
Methanogenic archaea are the only organisms that produce CH4 as part of their energy-generating metabolism. They are ubiquitous in oxidant-depleted, anoxic environments such as aquatic sediments, anaerobic digesters, inundated agricultural fields, the rumen of cattle, and the hindgut of termites, where they catalyze the terminal reactions in the degradation of organic matter. Methanogenesis is the only metabolism that is restricted to members of the domain Archaea. Here, we discuss the importance of model organisms in the history of methanogen research, including their role in the discovery of the archaea and in the biochemical and genetic characterization of methanogenesis. We also discuss outstanding questions in the field and newly emerging model systems that will expand our understanding of this uniquely archaeal metabolism.
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Affiliation(s)
- Kyle C. Costa
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, Minnesota, USA
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Zhuravleva E, Kovalev A, Kovalev D, Kotova I, Shekhurdina S, Laikova A, Krasnovsky A, Pygamov T, Vivekanand V, Li L, He C, Litti Y. Does carbon cloth really improve thermophilic anaerobic digestion performance on a larger scale? focusing on statistical analysis and microbial community dynamics. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 341:118124. [PMID: 37172349 DOI: 10.1016/j.jenvman.2023.118124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 05/03/2023] [Accepted: 05/06/2023] [Indexed: 05/14/2023]
Abstract
Currently, the phenomenon of direct interspecies electron transfer (DIET) is of great interest in the technology of anaerobic digestion (AD) due to potential performance benefits. However, the conditions for the occurrence of DIET and its limits on improving AD under conditions close to real have not been studied enough. This research is concentrated on the effect of conductive carbon cloth (R3), in comparison with a dielectric fiberglass cloth (R2) and control (R1), on the AD performance in large (90 L) thermophilic reactors, fed with a mixture of simulated organic fraction of municipal solid waste and sewage sludge. While organic loading rate (OLR) was gradually increased from 2.4 to 8.66 kg VS/(m3 day), a statistically significant (p < 0.05) difference in biogas production was observed between R1 and both R2 and R3. However, at a maximum OLR of 12.12 kg VS/(m3 day) in R3, an increase in biogas production (p < 0.05) was observed both compared to R1 (by 8.97%) and R2 (by 4.24%). The content of volatile fatty acids in R3 as a whole was the lowest, especially at the maximum OLR. Biofilm on carbon cloth was rich in syntrophic microorganisms of the genera Tepidanaerobacter, as well as Defluviitoga, capable of DIET in mixed cultures with Methanothrix, which was the most abundant methanogen in biofilm. Suspended Bifidobacterium, Fervidobacterium and Anaerobaculum were negatively affected, while Defluviitoga, Methanothermobacter and Methanosarcina, on the contrary, were positively affected by the increase in OLR and showed, respectively, a negative and positive correlation (p < 0.05) with the main AD performance parameters.
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Affiliation(s)
- Elena Zhuravleva
- Federal Research Center "Fundamentals of Biotechnology" of the Russian Academy of Sciences; Moscow, Leninsky Prospekt, 33, 2, 119071, Russia; Department of Biology, Lomonosov Moscow State University; Moscow, Leninskie Gory, 1, 12, 119899, Russia.
| | - Andrey Kovalev
- Federal State Budgetary Scientific Institution "Federal Scientific Agroengineering Center VIM"; Moscow, 1st Institutskiy Proezd, 5, 109428, Russia.
| | - Dmitriy Kovalev
- Federal State Budgetary Scientific Institution "Federal Scientific Agroengineering Center VIM"; Moscow, 1st Institutskiy Proezd, 5, 109428, Russia.
| | - Irina Kotova
- Department of Biology, Lomonosov Moscow State University; Moscow, Leninskie Gory, 1, 12, 119899, Russia.
| | - Svetlana Shekhurdina
- Federal Research Center "Fundamentals of Biotechnology" of the Russian Academy of Sciences; Moscow, Leninsky Prospekt, 33, 2, 119071, Russia; Department of Biology, Lomonosov Moscow State University; Moscow, Leninskie Gory, 1, 12, 119899, Russia.
| | - Aleksandra Laikova
- Federal Research Center "Fundamentals of Biotechnology" of the Russian Academy of Sciences; Moscow, Leninsky Prospekt, 33, 2, 119071, Russia; Department of Biology, Lomonosov Moscow State University; Moscow, Leninskie Gory, 1, 12, 119899, Russia.
| | - Anatoly Krasnovsky
- National Research Tomsk State University, Tomsk, Lenin Ave., 36, 634050, Russia.
| | - Timur Pygamov
- Gubkin University, Moscow, Leninsky Prospekt, 65, 119991, Russia.
| | - Vivekanand Vivekanand
- Centre for Energy and Environment, Malaviya National Institute of Technology Jaipur, Jaipur, 302017, Rajasthan, India.
| | - Lianhua Li
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou, 510640, China.
| | - Chao He
- Key Laboratory of New Materials and Facilities for Rural Renewable Energy of China's Ministry of Agriculture and Rural Affairs, Henan Agricultural University, Zhengzhou, 450002, China.
| | - Yuriy Litti
- Federal Research Center "Fundamentals of Biotechnology" of the Russian Academy of Sciences; Moscow, Leninsky Prospekt, 33, 2, 119071, Russia.
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10
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McCully AL, Loop Yao M, Brower KK, Fordyce PM, Spormann AM. Double emulsions as a high-throughput enrichment and isolation platform for slower-growing microbes. ISME COMMUNICATIONS 2023; 3:47. [PMID: 37160952 PMCID: PMC10169782 DOI: 10.1038/s43705-023-00241-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 03/27/2023] [Accepted: 04/12/2023] [Indexed: 05/11/2023]
Abstract
Our understanding of in situ microbial physiology is primarily based on physiological characterization of fast-growing and readily-isolatable microbes. Microbial enrichments to obtain novel isolates with slower growth rates or physiologies adapted to low nutrient environments are plagued by intrinsic biases for fastest-growing species when using standard laboratory isolation protocols. New cultivation tools to minimize these biases and enrich for less well-studied taxa are needed. In this study, we developed a high-throughput bacterial enrichment platform based on single cell encapsulation and growth within double emulsions (GrowMiDE). We showed that GrowMiDE can cultivate many different microorganisms and enrich for underrepresented taxa that are never observed in traditional batch enrichments. For example, preventing dominance of the enrichment by fast-growing microbes due to nutrient privatization within the double emulsion droplets allowed cultivation of slower-growing Negativicutes and Methanobacteria from stool samples in rich media enrichment cultures. In competition experiments between growth rate and growth yield specialist strains, GrowMiDE enrichments prevented competition for shared nutrient pools and enriched for slower-growing but more efficient strains. Finally, we demonstrated the compatibility of GrowMiDE with commercial fluorescence-activated cell sorting (FACS) to obtain isolates from GrowMiDE enrichments. Together, GrowMiDE + DE-FACS is a promising new high-throughput enrichment platform that can be easily applied to diverse microbial enrichments or screens.
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Affiliation(s)
- Alexandra L McCully
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, USA
| | - McKenna Loop Yao
- Department of Chemical Engineering, Stanford University, Stanford, CA, USA
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, USA
| | - Kara K Brower
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Polly M Fordyce
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Genetics, Stanford University, Stanford, CA, USA
- ChEM-H Institute, Stanford University, Stanford, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Alfred M Spormann
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, USA.
- Department of Chemical Engineering, Stanford University, Stanford, CA, USA.
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11
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Gupta D, Chen K, Elliott SJ, Nayak DD. MmcA is an electron conduit that facilitates both intracellular and extracellular electron transport in Methanosarcina acetivorans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.20.537704. [PMID: 37131651 PMCID: PMC10153276 DOI: 10.1101/2023.04.20.537704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Methanogens are a diverse group of Archaea that couple energy conservation to the production of methane gas. While most methanogens have no alternate mode of energy conservation, strains like Methanosarcina acetivorans are known to also conserve energy by dissimilatory metal reduction (DSMR) in the presence of soluble ferric iron or iron-containing minerals. The ecological ramifications of energy conservation decoupled from methane production in methanogens are substantial, yet the molecular details are poorly understood. In this work, we conducted in vitro and in vivo studies with a multiheme c-type cytochrome (MHC), called MmcA, to establish its role during methanogenesis and DSMR in M. acetivorans. MmcA purified from M. acetivorans can donate electrons to methanophenazine, a membrane-bound electron carrier, to facilitate methanogenesis. In addition, MmcA can also reduce Fe(III) and the humic acid analog anthraquinone-2,6-disulfonate (AQDS) during DSMR. Furthermore, mutants lacking mmcA have slower Fe(III) reduction rates. The redox reactivities of MmcA are consistent with the electrochemical data where MmcA displays reversible redox features ranging from -100 to -450 mV versus SHE. MmcA is prevalent in members of the Order Methanosarcinales but does not belong to a known family of MHCs linked to extracellular electron transfer, bioinformatically, and instead forms a distinct clade that is closely related to octaheme tetrathionate reductases. Taken together, this study shows that MmcA is widespread in methanogens with cytochromes where it acts as an electron conduit to support a variety of energy conservation strategies that extend beyond methanogenesis.
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Affiliation(s)
- Dinesh Gupta
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Keying Chen
- Department of Chemistry, Boston University, Boston, MA, USA
| | | | - Dipti D. Nayak
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
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12
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Al-Mamun A, Ahmed W, Jafary T, Nayak JK, Al-Nuaimi A, Sana A. Recent advances in microbial electrosynthesis system: Metabolic investigation and process optimization. Biochem Eng J 2023. [DOI: 10.1016/j.bej.2023.108928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
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13
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Metatranscriptomic insights into the microbial electrosynthesis of acetate by Fe 2+/Ni 2+ addition. World J Microbiol Biotechnol 2023; 39:109. [PMID: 36879133 DOI: 10.1007/s11274-023-03554-y] [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: 01/20/2023] [Accepted: 02/21/2023] [Indexed: 03/08/2023]
Abstract
As important components of enzymes and coenzymes involved in energy transfer and Wood-Ljungdahl (WL) pathways, Fe2+ and Ni2+ supplementation may promote the acetate synthesis through CO2 reduction by the microbial electrosynthesis (MES). However, the effect of Fe2+ and Ni2+ addition on acetate production in MES and corresponding microbial mechanisms have not been fully studied. Therefore, this study investigated the effect of Fe2+ and Ni2+ addition on acetate production in MES, and explored the underlying microbial mechanism from the metatranscriptomic perspective. Both Fe2+ and Ni2+ addition enhanced acetate production of the MES, which was 76.9% and 110.9% higher than that of control, respectively. Little effect on phylum level and small changes in genus-level microbial composition was caused by Fe2+ and Ni2+ addition. Gene expression of 'Energy metabolism', especially in 'Carbon fixation pathways in prokaryotes' was up-regulated by Fe2+ and Ni2+ addition. Hydrogenase was found as an important energy transfer mediator for CO2 reduction and acetate synthesis. Fe2+ addition and Ni2+ addition respectively enhanced the expression of methyl branch and carboxyl branch of the WL pathway, and thus promoted acetate production. The study provided a metatranscriptomic insight into the effect of Fe2+ and Ni2+ on acetate production by CO2 reduction in MES.
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14
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Recent Applications and Strategies to Enhance Performance of Electrochemical Reduction of CO2 Gas into Value-Added Chemicals Catalyzed by Whole-Cell Biocatalysts. Processes (Basel) 2023. [DOI: 10.3390/pr11030766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023] Open
Abstract
Carbon dioxide (CO2) is one of the major greenhouse gases that has been shown to cause global warming. Decreasing CO2 emissions plays an important role to minimize the impact of climate change. The utilization of CO2 gas as a cheap and sustainable source to produce higher value-added chemicals such as formic acid, methanol, methane, and acetic acid has been attracting much attention. The electrochemical reduction of CO2 catalyzed by whole-cell biocatalysts is a promising process for the production of value-added chemicals because it does not require costly enzyme purification steps and the supply of exogenous cofactors such as NADH. This study covered the recent applications of the diversity of microorganisms (pure cultures such as Shewanella oneidensis MR1, Sporomusa species, and Clostridium species and mixed cultures) as whole-cell biocatalysts to produce a wide range of value-added chemicals including methane, carboxylates (e.g., formate, acetate, butyrate, caproate), alcohols (e.g., ethanol, butanol), and bioplastics (e.g., Polyhydroxy butyrate). Remarkably, this study provided insights into the molecular levels of the proteins/enzymes (e.g., formate hydrogenases for CO2 reduction into formate and electron-transporting proteins such as c-type cytochromes) of microorganisms which are involved in the electrochemical reduction of CO2 into value-added chemicals for the suitable application of the microorganism in the chemical reduction of CO2 and enhancing the catalytic efficiency of the microorganisms toward the reaction. Moreover, this study provided some strategies to enhance the performance of the reduction of CO2 to produce value-added chemicals catalyzed by whole-cell biocatalysts.
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15
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Kambara H, Dinh HTT, Matsushita S, Aoi Y, Kindaichi T, Ozaki N, Ohashi A. New microbial electrosynthesis system for methane production from carbon dioxide coupled with oxidation of sulfide to sulfate. J Environ Sci (China) 2023; 125:786-797. [PMID: 36375960 DOI: 10.1016/j.jes.2022.02.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 02/16/2022] [Accepted: 02/18/2022] [Indexed: 06/16/2023]
Abstract
Microbial electrosynthesis system (MES) is a promising method that can use carbon dioxide, which is a greenhouse gas, to produce methane which acts as an energy source, without using organic substances. However, this bioelectrical reduction reaction can proceed at a certain high applied voltage when coupled with water oxidation in the anode coated with metallic catalyst. When coupled with the oxidation of HS- to SO42-, methane production is thermodynamically more feasible, thus implying its production at a considerably lower applied voltage. In this study, we demonstrated the possibility of electrotrophic methane production coupled with HS- oxidation in a cost-effective bioanode chamber in the MES without organic substrates at a low applied voltage of 0.2 V. In addition, microbial community analyses of biomass enriched in the bioanode and biocathode were used to reveal the most probable pathway for methane production from HS- oxidation. In the bioanode, electroautotrophic SO42- production accompanied with electron donation to the electrode is performed mainly by the following two steps: first, incomplete sulfide oxidation to sulfur cycle intermediates (SCI) is performed; then the produced SCI are disproportionated to HS- and SO42-. In the biocathode, methane is produced mainly via H2 and acetate by electron-accepting syntrophic bacteria, homoacetogens, and acetoclastic archaea. Here, a new eco-friendly MES with biological H2S removal is established.
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Affiliation(s)
- Hiromi Kambara
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527, Japan
| | - Ha T T Dinh
- Faculty of Environment, Ho Chi Minh City University of Natural Resources and Environment, 236 Le Van Sy, 1 Ward, Tan Binh District, Ho Chi Minh City, Vietnam
| | - Shuji Matsushita
- Agricultural Technology Research Center, Hiroshima Prefectural Technology Research Institute, 6869, Hara, Hachihonmatsu, Higashihiroshima, Hiroshima 739-0151, Japan
| | - Yoshiteru Aoi
- Program of Biotechnology, Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8530, Japan
| | - Tomonori Kindaichi
- Department of Civil and Environmental Engineering, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527, Japan
| | - Noriatsu Ozaki
- Department of Civil and Environmental Engineering, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527, Japan
| | - Akiyoshi Ohashi
- Department of Civil and Environmental Engineering, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527, Japan.
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16
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Luan L, Ji X, Guo B, Cai J, Dong W, Huang Y, Zhang S. Bioelectrocatalysis for CO 2 reduction: recent advances and challenges to develop a sustainable system for CO 2 utilization. Biotechnol Adv 2023; 63:108098. [PMID: 36649797 DOI: 10.1016/j.biotechadv.2023.108098] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 12/11/2022] [Accepted: 01/11/2023] [Indexed: 01/15/2023]
Abstract
Activation and turning CO2 into value added products is a promising orientation to address environmental issues caused by CO2 emission. Currently, electrocatalysis has a potent well-established role for CO2 reduction with fast electron transfer rate; but it is challenged by the poor selectivity and low faradic efficiency. On the other side, biocatalysis, including enzymes and microbes, has been also employed for CO2 conversion to target Cn products with remarkably high selectivity; however, low solubility of CO2 in the liquid reaction phase seriously affects the catalytic efficiency. Therefore, a new synergistic role in bioelectrocatalysis for CO2 reduction is emerging thanks to its outstanding selectivity, high faradic efficiency, and desirable valuable Cn products under mild condition that are surveyed in this review. Herein, we comprehensively discuss the results already obtained for the integration craft of enzymatic-electrocatalysis and microbial-electrocatalysis technologies. In addition, the intrinsic nature of the combination is highly dependent on the electron transfer. Thus, both direct electron transfer and mediated electron transfer routes are modeled and concluded. We also explore the biocompatibility and synergistic effects of electrode materials, which emerge in combination with tuned enzymes and microbes to improve catalytic performance. The system by integrating solar energy driven photo-electrochemical technics with bio-catalysis is further discussed. We finally highlight the significant findings and perspectives that have provided strong foundations for the remarkable development of green and sustainable bioelectrocatalysis for CO2 reduction, and that offer a blueprint for Cn valuable products originate from CO2 under efficient and mild conditions.
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Affiliation(s)
- Likun Luan
- Beijing Key Laboratory of Ionic Liquids Clean Process, CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing 101408, China
| | - Xiuling Ji
- Beijing Key Laboratory of Ionic Liquids Clean Process, CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Boxia Guo
- Beijing Key Laboratory of Ionic Liquids Clean Process, CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; Sino-Danish College, University of Chinese Academy of Sciences, Beijing 101408, China
| | - Jinde Cai
- Beijing Key Laboratory of Ionic Liquids Clean Process, CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Wanrong Dong
- Beijing Key Laboratory of Ionic Liquids Clean Process, CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Yuhong Huang
- Beijing Key Laboratory of Ionic Liquids Clean Process, CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
| | - Suojiang Zhang
- Beijing Key Laboratory of Ionic Liquids Clean Process, CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
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17
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Abuyen K, El-Naggar MY. Soluble Iron Enhances Extracellular Electron Uptake by Shewanella oneidensis MR-1. ChemElectroChem 2023; 10:e202200965. [PMID: 37649707 PMCID: PMC10465110 DOI: 10.1002/celc.202200965] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Indexed: 09/01/2023]
Abstract
Extracellular electron transfer (EET) is a process that microorganisms use to reduce or oxidize external insoluble electron acceptors or donors. Much of our mechanistic understanding of this process is derived from studies of transmembrane cytochrome complexes and extracellular redox shuttles that mediate outward EET to anodes and external electron acceptors. In contrast, there are knowledge gaps concerning the reverse process of inward EET from external electron donors to cells. Here, we describe a role for soluble iron (exogenous FeCl2) in enhancing EET from cathodes to the model EET bacterium Shewanella oneidensis MR-1, with fumarate serving as the intracellular electron acceptor. This iron concentration-dependent electron uptake was eradicated upon addition of an iron chelator and occurred only in the presence of fumarate reductase, confirming an electron pathway from cathodes to this periplasmic enzyme. Moreover, S. oneidensis mutants lacking specific outer membrane and periplasmic cytochromes exhibited significantly decreased current levels relative to wild-type. These results indicate that soluble iron can function as an electron carrier to the EET machinery of S. oneidensis.
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Affiliation(s)
- Karla Abuyen
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089
| | - Mohamed Y El-Naggar
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089
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18
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Li J, Akinyemi TS, Shao N, Chen C, Dong X, Liu Y, Whitman WB. Genetic and Metabolic Engineering of Methanococcus spp. CURRENT RESEARCH IN BIOTECHNOLOGY 2022. [DOI: 10.1016/j.crbiot.2022.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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19
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Wang B, Liu W, Liang B, Jiang J, Wang A. Microbial fingerprints of methanation in a hybrid electric-biological anaerobic digestion. WATER RESEARCH 2022; 226:119270. [PMID: 36323204 DOI: 10.1016/j.watres.2022.119270] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 08/26/2022] [Accepted: 10/16/2022] [Indexed: 06/16/2023]
Abstract
Biomethane as a sustainable, alternative, and carbon-neutral renewable energy source to fossil fuels is highly needed to alleviate the global energy crisis and climate change. The conventional anaerobic digestion (AD) process for biomethane production from waste(water) streams has been widely employed while struggling with a low production rate, low biogas qualities, and frequent instability. The electric-biologically hybrid microbial electrochemical anaerobic digestion system (MEC-AD) prospects more stable and robust biomethane generation, which facilitates complex organic substrates degradation and mediates functional microbial populations by giving a small input power (commonly voltages < 1.0 V), mainly enhancing the communication between electroactive microorganisms and (electro)methanogens. Despite numerous bioreactor tests and studies that have been conducted, based on the MEC-AD systems, the integrated microbial fingerprints, and cooperation, accelerating substrate degradation, and biomethane production, have not been fully summarized. Herein, we present a comprehensive review of this novel developing biotechnology, beginning with the principles of MEC-AD. First, we examine the fundamentals, configurations, classifications, and influential factors of the whole system's performances (reactor types, applied voltages, temperatures, conductive materials, etc.,). Second, extracellular electron transfer either between diverse microbes or between microbes and electrodes for enhanced biomethane production are analyzed. Third, we further conclude (electro)methanogenesis, and microbial interactions, and construct ecological networks of microbial consortia in MEC-AD. Finally, future development and perspectives on MEC-AD for biomethane production are proposed.
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Affiliation(s)
- Bo Wang
- State Key Lab of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, 518055 Shenzhen, China; Center for Electromicrobiology, Section for Microbiology, Department of Biology, Aarhus University, 8000 Aarhus C, Denmark; Department of Environmental and Resource Engineering, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Wenzong Liu
- State Key Lab of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, 518055 Shenzhen, China.
| | - Bin Liang
- State Key Lab of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, 518055 Shenzhen, China
| | - Jiandong Jiang
- Key Lab of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, China
| | - Aijie Wang
- State Key Lab of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, 518055 Shenzhen, China; CAS Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 100085 Beijing, China
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20
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Edel M, Philipp LA, Lapp J, Reiner J, Gescher J. Electron transfer of extremophiles in bioelectrochemical systems. Extremophiles 2022; 26:31. [PMID: 36222927 PMCID: PMC9556394 DOI: 10.1007/s00792-022-01279-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 10/02/2022] [Indexed: 11/30/2022]
Abstract
The interaction of bacteria and archaea with electrodes is a relatively new research field which spans from fundamental to applied research and influences interdisciplinary research in the fields of microbiology, biochemistry, biotechnology as well as process engineering. Although a substantial understanding of electron transfer processes between microbes and anodes and between microbes and cathodes has been achieved in mesophilic organisms, the mechanisms used by microbes under extremophilic conditions are still in the early stages of discovery. Here, we review our current knowledge on the biochemical solutions that evolved for the interaction of extremophilic organisms with electrodes. To this end, the available knowledge on pure cultures of extremophilic microorganisms has been compiled and the study has been extended with the help of bioinformatic analyses on the potential distribution of different electron transfer mechanisms in extremophilic microorganisms.
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Affiliation(s)
- Miriam Edel
- Institute of Technical Microbiology, Hamburg University of Technology, Hamburg, Germany
| | - Laura-Alina Philipp
- Institute of Technical Microbiology, Hamburg University of Technology, Hamburg, Germany
| | - Jonas Lapp
- Institute of Technical Microbiology, Hamburg University of Technology, Hamburg, Germany
| | - Johannes Reiner
- Karlsruhe Institute of Technology, Engler-Bunte-Institute, Karlsruhe, Germany
| | - Johannes Gescher
- Institute of Technical Microbiology, Hamburg University of Technology, Hamburg, Germany.
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21
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He K, Li W, Tang L, Li W, Lv S, Xing D. Suppressing Methane Production to Boost High-Purity Hydrogen Production in Microbial Electrolysis Cells. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:11931-11951. [PMID: 35969804 DOI: 10.1021/acs.est.2c02371] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Hydrogen gas (H2) is an attractive fuel carrier due to its high specific enthalpy; moreover, it is a clean source of energy because in the combustion reaction with oxygen (O2) it produces water as the only byproduct. The microbial electrolysis cell (MEC) is a promising technology for producing H2 from simple or complex organics present in wastewater and solid wastes. Methanogens and non-archaeal methane (CH4)-producing microorganisms (NAMPMs) often grow in the MECs and lead to rapid conversion of produced H2 to CH4. Moreover, non-archaeal methane production (NAMP) catalyzed by nitrogenase of photosynthetic bacteria was always overlooked. Thus, suppression of CH4 production is required to enhance H2 yield and production rate. This review comprehensively addresses the principles and current state-of-the-art technologies for suppressing methanogenesis and NAMP in MECs. Noteworthy, specific strategies aimed at the inhibition of methanogenic enzymes and nitrogenase could be a more direct approach than physical and chemical strategies for repressing the growth of methanogenic archaea. In-depth studies on the multiomics of CH4 metabolism can possibly provide insights into sustainable and efficient approaches for suppressing metabolic pathways of methanogenesis and NAMP. The main objective of this review is to highlight key concepts, directions, and challenges related to boosting H2 generation by suppressing CH4 production in MECs. Finally, perspectives are briefly outlined to guide and advance the future direction of MECs for production of high-purity H2 based on genetic and metabolic engineering and on the interspecific interactions.
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Affiliation(s)
- Kuanchang He
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan 523808, China
| | - Wei Li
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan 523808, China
| | - Longxiang Tang
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan 523808, China
| | - Wei Li
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan 523808, China
| | - Sihao Lv
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan 523808, China
| | - Defeng Xing
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
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22
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Bao J, de Dios Mateos E, Scheller S. Efficient CRISPR/Cas12a-Based Genome-Editing Toolbox for Metabolic Engineering in Methanococcus maripaludis. ACS Synth Biol 2022; 11:2496-2503. [PMID: 35730587 PMCID: PMC9295151 DOI: 10.1021/acssynbio.2c00137] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
![]()
The rapid-growing
and genetically tractable methanogen Methanococcus
maripaludis is a promising host organism
for the biotechnological conversion of carbon dioxide and renewable
hydrogen to fuels and value-added products. Expansion of its product
scope through metabolic engineering necessitates reliable and efficient
genetic tools, particularly for genome edits that affect the primary
metabolism and cell growth. Here, we have designed a genome-editing
toolbox by utilizing Cas12a from Lachnospiraceae bacterium ND2006 (LbCas12a) in combination with the homology-directed repair
machinery endogenously present in M. maripaludis. This toolbox can delete target genes with a success rate of up
to 95%, despite the hyperpolyploidy of M. maripaludis. For the purpose of demonstrating a large deletion, the M. maripaludis flagellum operon (∼8.9 kbp)
was replaced by the Escherichia coli β-glucuronidase gene. To facilitate metabolic engineering
and flux balancing in M. maripaludis, the relative strength of 15 different promoters was quantified
in the presence of two common growth substrates, either formate or
carbon dioxide and hydrogen. This CRISPR/LbCas12a toolbox can be regarded
as a reliable and quick method for genome editing in a methanogen.
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Affiliation(s)
- Jichen Bao
- Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, FI-02150 Espoo, Finland
| | - Enrique de Dios Mateos
- Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, FI-02150 Espoo, Finland
| | - Silvan Scheller
- Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, FI-02150 Espoo, Finland
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23
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Dinh HTT, Kambara H, Matsushita S, Aoi Y, Kindaichi T, Ozaki N, Ohashi A. Biological methane production coupled with sulfur oxidation in a microbial electrosynthesis system without organic substrates. J Environ Sci (China) 2022; 116:68-78. [PMID: 35219426 DOI: 10.1016/j.jes.2021.07.027] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 07/12/2021] [Accepted: 07/27/2021] [Indexed: 06/14/2023]
Abstract
Methane is produced in a microbial electrosynthesis system (MES) without organic substrates. However, a relatively high applied voltage is required for the bioelectrical reactions. In this study, we demonstrated that electrotrophic methane production at the biocathode was achieved even at a very low voltage of 0.1 V in an MES, in which abiotic HS- oxidized to SO42- at the anodic carbon-cloth surface coated with platinum powder. In addition, microbial community analysis revealed the most probable pathway for methane production from electrons. First, electrotrophic H2 was produced by syntrophic bacteria, such as Syntrophorhabdus, Syntrophobacter, Syntrophus, Leptolinea, and Aminicenantales, with the direct acceptance of electrons at the biocathode. Subsequently, most of the produced H2 was converted to acetate by homoacetogens, such as Clostridium and Spirochaeta 2. In conclusion, the majority of the methane was indirectly produced by a large population of acetoclastic methanogens, namely Methanosaeta, via acetate. Further, hydrogenotrophic methanogens, including Methanobacterium and Methanolinea, produced methane via H2.
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Affiliation(s)
- Ha T T Dinh
- Department of Civil and Environmental Engineering, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashihiroshima, Hiroshima 739-8527, Japan; Faculty of Environment, Ho Chi Minh City University of Natural Resources and Environment, 236 Le Van Sy, 1 Ward, Tan Binh District, Ho Chi Minh City, Viet Nam
| | - Hiromi Kambara
- Department of Civil and Environmental Engineering, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashihiroshima, Hiroshima 739-8527, Japan
| | - Shuji Matsushita
- Department of Civil and Environmental Engineering, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashihiroshima, Hiroshima 739-8527, Japan; Agricultural Technology Research Center, Hiroshima Prefectural Technology Research Institute, 6869, Hara, Hachihonmatsu, Higashihiroshima, Hiroshima 739-0151, Japan
| | - Yoshiteru Aoi
- Program of Biotechnology, Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1, Kagamiyama, Higashihiroshima, Hiroshima 739-8530, Japan
| | - Tomonori Kindaichi
- Department of Civil and Environmental Engineering, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashihiroshima, Hiroshima 739-8527, Japan
| | - Noriatsu Ozaki
- Department of Civil and Environmental Engineering, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashihiroshima, Hiroshima 739-8527, Japan
| | - Akiyoshi Ohashi
- Department of Civil and Environmental Engineering, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1, Kagamiyama, Higashihiroshima, Hiroshima 739-8527, Japan.
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24
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Li Y, Ma Y, Zhan J, Zhang Y, Zhao Z, Zhao Z. Combining metal-microbe and microbe-microbe dual direct electron transfer on Fe(0)-cathode of bio-electrochemical system to enhance anaerobic digestion of cellulose wastewater. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2021.09.097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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25
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Gharbi R, Gomez Vidales A, Omanovic S, Tartakovsky B. Mathematical model of a microbial electrosynthesis cell for the conversion of carbon dioxide into methane and acetate. J CO2 UTIL 2022. [DOI: 10.1016/j.jcou.2022.101956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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26
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Jiang Z, Yu Q, Sun C, Wang Z, Jin Z, Zhu Y, Zhao Z, Zhang Y. Additional electric field alleviates acidity suppression in anaerobic digestion of kitchen wastes via enriching electro-active methanogens in cathodic biofilms. WATER RESEARCH 2022; 212:118118. [PMID: 35091224 DOI: 10.1016/j.watres.2022.118118] [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: 11/11/2021] [Revised: 01/15/2022] [Accepted: 01/21/2022] [Indexed: 06/14/2023]
Abstract
The aim of this study was to investigate the feasibility that the suppression of acidity in anaerobic digestion of kitchen wastes could be alleviated with additional electric field. The results showed that, the accumulation of acidity seriously suppressed methanogenesis, and no methane was detected in the electrode-supplemented digester without applied voltage. In contrast, with applied voltages of 0.6-1.2 V, the suppression of acidity was alleviated, and methane production rates reached 558-669 L/kg-volatile suspended solid that were higher than that previously reported with carbon-based conductive materials, such as granular active carbon and biochar. Although the reduced peak with a potential ranging from -0.3 V to -0.2 V close to the reduced potential of CO2/CH4 detected via cyclic voltammetry, the maximum methane yield derived from cathodic reduction of CO2 only accounted for 0.13-0.33% of total methane yield with applied voltages. Microbial community analysis showed that, Methanosarcina species were specially enriched with applied voltages, accounting for ca. 40-70% of the communities. Together with the increase in the relative abundance of Syntrophomonas species, Methanosarcina species directly accepting electrons from Syntrophomonas species via DIET might be the primary reason for alleviating the suppression of acidity. Further investigations via three-dimensional excitation emission matrix and in-situ electrochemical Fourier transform infrared spectroscopy found that additional electric field stimulated the secretion of EPS primarily comprised of protein-like substance, which might mediate the EET between Syntrophomonas and Methanosarcina species.
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Affiliation(s)
- Zhihao Jiang
- Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Qilin Yu
- Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Cheng Sun
- Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Zhenxin Wang
- Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Zhen Jin
- Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Yahui Zhu
- Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Zhiqiang Zhao
- Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Yaobin Zhang
- Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
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Logroño W, Nikolausz M, Harms H, Kleinsteuber S. Physiological Effects of 2-Bromoethanesulfonate on Hydrogenotrophic Pure and Mixed Cultures. Microorganisms 2022; 10:microorganisms10020355. [PMID: 35208809 PMCID: PMC8877471 DOI: 10.3390/microorganisms10020355] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/28/2022] [Accepted: 02/01/2022] [Indexed: 01/27/2023] Open
Abstract
Mixed or pure cultures can be used for biomethanation of hydrogen. Sodium 2-bromoethanesulfonate (BES) is an inhibitor of methanogenesis used to investigate competing reactions like homoacetogenesis in mixed cultures. To understand the effect of BES on the hydrogenotrophic metabolism in a biomethanation process, anaerobic granules from a wastewater treatment plant, a hydrogenotrophic enrichment culture, and pure cultures of Methanococcus maripaludis and Methanobacterium formicicum were incubated under H2/CO2 headspace in the presence or absence of BES, and the turnover of H2, CO2, CH4, formate and acetate was analyzed. Anaerobic granules produced the highest amount of formate after 24 h of incubation in the presence of BES. Treating the enrichment culture with BES led to the accumulation of formate. M. maripaludis produced more formate than M. formicicum when treated with BES. The non-inhibited methanogenic communities produced small amounts of formate whereas the pure cultures did not. The highest amount of acetate was produced by the anaerobic granules concomitantly with formate consumption. These results indicate that formate is an important intermediate of hydrogenotrophic metabolism accumulating upon methanogenesis inhibition.
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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: 26] [Impact Index Per Article: 13.0] [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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Wang XT, Zhang YF, Wang B, Wang S, Xing X, Xu XJ, Liu WZ, Ren NQ, Lee DJ, Chen C. Enhancement of methane production from waste activated sludge using hybrid microbial electrolysis cells-anaerobic digestion (MEC-AD) process - A review. BIORESOURCE TECHNOLOGY 2022; 346:126641. [PMID: 34973405 DOI: 10.1016/j.biortech.2021.126641] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 12/22/2021] [Accepted: 12/24/2021] [Indexed: 06/14/2023]
Abstract
Hybrid microbial electrolysis cells-anaerobic digestion (MEC-AD) was proved to increase methane productivity and methane yield of waste activated sludge (WAS) by establishing direct interspecies electron transfer method and enriching functional microorganisms. This review first summarized the pretreatment methods of WAS for MEC-AD and then reviewed the reactor configurations, operation parameters, and the economic benefit of MEC-AD. Furthermore, the enhancement mechanisms of MEC-AD were reviewed based on the analysis of thermodynamics and microbial community. It was found that the decrease of hydrogen partial pressure due to the hydrogenotrophic methanogens enriched in cathodic biofilm and direct interspecies electron transfer between exoelectrogens and anode were the core mechanisms for improving acidogenesis, acetogenesis, and methanogenesis. Finally, the potentially technological issues that need to be addressed to increase energy efficiency in large-scale MEC-AD processes were discussed.
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Affiliation(s)
- Xue-Ting Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China; Department of Environmental Engineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Yi-Feng Zhang
- Department of Environmental Engineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Bo Wang
- Department of Environmental Engineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Song Wang
- Department of Environmental Engineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Xue Xing
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China
| | - Xi-Jun Xu
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China
| | - Wen-Zong Liu
- School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China
| | - Nan-Qi Ren
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China
| | - Duu-Jong Lee
- Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan
| | - Chuan Chen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, Heilongjiang Province 150090, China.
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Novel Methanobacterium Strain Induces Severe Corrosion by Retrieving Electrons from Fe0 under a Freshwater Environment. Microorganisms 2022; 10:microorganisms10020270. [PMID: 35208725 PMCID: PMC8880523 DOI: 10.3390/microorganisms10020270] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 01/17/2022] [Accepted: 01/20/2022] [Indexed: 02/06/2023] Open
Abstract
Methanogens capable of accepting electrons from Fe0 cause severe corrosion in anoxic conditions. In previous studies, all iron-corrosive methanogenic isolates were obtained from marine environments. However, the presence of methanogens with corrosion ability using Fe0 as an electron donor and their contribution to corrosion in freshwater systems is unknown. Therefore, to understand the role of methanogens in corrosion under anoxic conditions in a freshwater environment, we investigated the corrosion activities of methanogens in samples collected from groundwater and rivers. We enriched microorganisms that can grow with CO2/NaHCO3 and Fe0 as the sole carbon source and electron donor, respectively, in ground freshwater. Methanobacterium sp. TO1, which induces iron corrosion, was isolated from freshwater. Electrochemical analysis revealed that strain TO1 can uptake electrons from the cathode at lower than −0.61 V vs SHE and has a redox-active component with electrochemical potential different from those of other previously reported methanogens with extracellular electron transfer ability. This study indicated the corrosion risk by methanogens capable of taking up electrons from Fe0 in anoxic freshwater environments and the necessity of understanding the corrosion mechanism to contribute to risk diagnosis.
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Deconstructing Methanosarcina acetivorans into an acetogenic archaeon. Proc Natl Acad Sci U S A 2022; 119:2113853119. [PMID: 34992140 PMCID: PMC8764690 DOI: 10.1073/pnas.2113853119] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/16/2021] [Indexed: 12/02/2022] Open
Abstract
The reductive acetyl-coenzyme A (acetyl-CoA) pathway is the only carbon fixation pathway that can also be used for energy conservation like it is known for acetogenic bacteria. In methanogenic archaea, this pathway is extended with one route toward acetyl-CoA formation for anabolism and another route toward methane formation for catabolism. Which of these traits is ancestral in evolution has not been resolved. By diverging virtually all substrate carbon from methanogenesis to flow through acetyl-CoA, Methanosarcina acetivorans can be converted to an acetogenic organism. Being able to deconstruct methanogenic into the seemingly simpler acetogenic energy metabolism provides compelling evidence that methanogens are not nearly as metabolically limited as previously thought and suggests that methanogenesis might have evolved from the acetyl-CoA pathway. The reductive acetyl-coenzyme A (acetyl-CoA) pathway, whereby carbon dioxide is sequentially reduced to acetyl-CoA via coenzyme-bound C1 intermediates, is the only autotrophic pathway that can at the same time be the means for energy conservation. A conceptually similar metabolism and a key process in the global carbon cycle is methanogenesis, the biogenic formation of methane. All known methanogenic archaea depend on methanogenesis to sustain growth and use the reductive acetyl-CoA pathway for autotrophic carbon fixation. Here, we converted a methanogen into an acetogen and show that Methanosarcina acetivorans can dispense with methanogenesis for energy conservation completely. By targeted disruption of the methanogenic pathway, followed by adaptive evolution, a strain was created that sustained growth via carbon monoxide–dependent acetogenesis. A minute flux (less than 0.2% of the carbon monoxide consumed) through the methane-liberating reaction remained essential, indicating that currently living methanogens utilize metabolites of this reaction also for anabolic purposes. These results suggest that the metabolic flexibility of methanogenic archaea might be much greater than currently known. Also, our ability to deconstruct a methanogen into an acetogen by merely removing cellular functions provides experimental support for the notion that methanogenesis could have evolved from the reductive acetyl-coenzyme A pathway.
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Contreras G, Thomsen J, Pfitzer M, Hafenbradl D, Kostner D, Holtmann D, Schmitz R, Rother M, Molitor B. New perspectives for biotechnological applications of methanogens. CURRENT RESEARCH IN BIOTECHNOLOGY 2022. [DOI: 10.1016/j.crbiot.2022.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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Fang Z, Zhou J, Zhou X, Koffas MAG. Abiotic-biotic hybrid for CO 2 biomethanation: From electrochemical to photochemical process. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 791:148288. [PMID: 34118677 DOI: 10.1016/j.scitotenv.2021.148288] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/01/2021] [Accepted: 06/01/2021] [Indexed: 06/12/2023]
Abstract
Converting CO2 into sustainable fuels (e.g., CH4) has great significance to solve carbon emission and energy crisis. Generally, CO2 methanation needs abundant of energy input to overcome the eight-electron-transfer barrier. Abiotic-biotic hybrid system represents one of the cutting-edge technologies that use renewable electric/solar energy to realize eight-electron-transfer CO2 biomethanation. However, the incompatible abiotic-biotic hybrid can result in low efficiency of electron transfer and CO2 biomethanation. Herein, we present the comprehensive review to highlight how to design abiotic-biotic hybrid for electric/solar-driven CO2 biomethanation. We primarily introduce the CO2 biomethanation mechanism, and further summarize state-of-the-art electrochemical and photochemical CO2 biomethanation in hybrid systems. We also propose excellent synthetic biology strategies, which are useful to design tunable methanogenic microorganisms or enzymes when cooperating with electrode/semiconductor in hybrid systems. This review provides theoretical guidance of abiotic-biotic hybrid and also shows the bright future of sustainable fuel production in the form of CO2 biomethanation.
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Affiliation(s)
- Zhen Fang
- Biofuels Institute, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China.
| | - Jun Zhou
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Xiangtong Zhou
- Institute of Environmental Health and Ecological Safety, Jiangsu University, Zhenjiang 212013, China
| | - Mattheos A G Koffas
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
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Response of Methanogen Communities to the Elevation of Cathode Potentials in Bioelectrochemical Reactors Amended with Magnetite. Appl Environ Microbiol 2021; 87:e0148821. [PMID: 34432490 DOI: 10.1128/aem.01488-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Electromethanogenesis refers to the process whereby methanogens utilize current for the reduction of CO2 to CH4. Setting low cathode potentials is essential for this process. In this study, we tested if magnetite, an iron oxide mineral widespread in the environment, can facilitate the adaptation of methanogen communities to the elevation of cathode potentials in electrochemical reactors. Two-chamber electrochemical reactors were constructed with inoculants obtained from paddy field soil. We elevated cathode potentials stepwise from the initial -0.6 V versus the standard hydrogen electrode (SHE) to -0.5 V and then to -0.4 V over the 130 days of acclimation. Only weak current consumption and CH4 production were observed in the bioreactors without magnetite. However, significant current consumption and CH4 production were recorded in the magnetite bioreactors. The robustness of electroactivity of the magnetite bioreactors was not affected by the elevation of cathode potentials from -0.6 V to -0.4 V. However, the current consumption and CH4 production were halted in the bioreactors without magnetite when the cathode potentials were elevated to -0.4 V. Methanogens related to Methanospirillum were enriched on the cathode surfaces of magnetite bioreactors at -0.4 V, while Methanosarcina relatively dominated in the bioreactors without magnetite. Methanobacterium also increased in the magnetite bioreactors but stayed off electrodes at -0.4 V. Apparently, the magnetite greatly facilitates the development of biocathodes, and it appears that with the aid of magnetite, Methanospirillum spp. can adapt to the high cathode potentials, performing efficient electromethanogenesis. IMPORTANCE Converting CO2 to CH4 through bioelectrochemistry is a promising approach to the development of green energy biotechnology. This process, however, requires low cathode potentials, which entails a cost. In this study, we tested if magnetite, a conductive iron mineral, can facilitate the adaptation of methanogens to the elevation of cathode potentials. In two-chamber reactors constructed by using inoculants obtained from paddy field soil, biocathodes developed robustly in the presence of magnetite, whereas only weak activities in CH4 production and current consumption were observed in the bioreactors without magnetite. The elevation of cathode potentials did not affect the robustness of electroactivity of the magnetite bioreactors over the 130 days of acclimation. Methanospirillum strains were identified as the key methanogens associated with the cathode surfaces during the operation at high potentials. The findings reported in this study shed new light on the adaptation of methanogen communities to the elevated cathode potentials in the presence of magnetite.
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Empower C1: Combination of Electrochemistry and Biology to Convert C1 Compounds. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2021; 180:213-241. [PMID: 34518909 DOI: 10.1007/10_2021_171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The idea to somehow combine electrical current and biological systems is not new. It was subject of research as well as of science fiction literature for decades. Nowadays, in times of limited resources and the need to capture greenhouse gases like CO2, this combination gains increasing interest, since it might allow to use C1 compounds and highly oxidized compounds as substrate for microbial production by "activating" them with additional electrons. In this chapter, different possibilities to combine electrochemistry and biology to convert C1 compounds into useful products will be discussed. The chapter first shows electrochemical conversion of C1 compounds, allowing the use of the product as substrate for a subsequent biosynthesis in uncoupled systems, further leads to coupled systems of biology and electrochemical conversion, and finally reaches the discipline of bioelectrosynthesis, where electrical current and C1 compounds are directly converted by microorganisms or enzymes. This overview will give an idea about the potentials and challenges of combining electrochemistry and biology to convert C1 molecules.
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Wang H, Liu Y, Du H, Zhu J, Peng L, Yang C, Luo F. Exploring the effect of voltage on biogas production performance and the methanogenic pathway of microbial electrosynthesis. Biochem Eng J 2021. [DOI: 10.1016/j.bej.2021.108028] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Liu C, Xiao J, Li H, Chen Q, Sun D, Cheng X, Li P, Dang Y, Smith JA, Holmes DE. High efficiency in-situ biogas upgrading in a bioelectrochemical system with low energy input. WATER RESEARCH 2021; 197:117055. [PMID: 33789202 DOI: 10.1016/j.watres.2021.117055] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/23/2021] [Accepted: 03/14/2021] [Indexed: 06/12/2023]
Abstract
Biogas produced from anaerobic digestion usually contains 30%-50% CO2, much of which must be removed, before utilization. Bioelectrochemical biogas upgrading approaches show promise, however, they have not yet been optimized for practical applications. In this study, a bioelectrochemical system with low energy input (applied cathode potential of -0.5 V vs. standard hydrogen electrode, SHE) was used for in-situ biogas upgrading. High efficiency CO2 conversion (318.5 mol/d/m2) was achieved when the system was operated with an organic load of 1.7 kgCOD/(m3 d). Methane content in the upgraded biogas was 97.0% and CO2 concentrations stayed below 3%, which is comparable to biogas upgraded with more expensive and less sustainable physiochemical approaches. The high efficiency of this approach could likely be attributed to a significant enrichment of Methanothrix (92.7%) species on the cathode surface that were expressing genes involved in both acetogenic methanogenesis and direct electron transfer (DET). Electromethanogenesis by these organisms also increased proton consumption and created a higher pH that increased the solubility of CO2 in the bioreactor. In addition, CO2 removal from the biogas was likely further enhanced by an enrichment of Actinobacillus species known to be capable of CO2 fixation. Artificial neural network (ANN) models were also used to estimate CH4 production under different loading conditions. The ANN architecture with 10 neurons at hidden layers fit best with a mean square error of 6.06 × 10-3 and R2 of 0.99.
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Affiliation(s)
- Chuanqi Liu
- Beijing Key Laboratory for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control and Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, 35 Tsinghua East Road, Beijing, 100083, China
| | - Jiewen Xiao
- Beijing Key Laboratory for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control and Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, 35 Tsinghua East Road, Beijing, 100083, China
| | - Haoyong Li
- Beijing Key Laboratory for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control and Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, 35 Tsinghua East Road, Beijing, 100083, China
| | - Qian Chen
- Beijing Key Laboratory for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control and Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, 35 Tsinghua East Road, Beijing, 100083, China
| | - Dezhi Sun
- Beijing Key Laboratory for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control and Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, 35 Tsinghua East Road, Beijing, 100083, China
| | - Xiang Cheng
- Beijing Key Laboratory for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control and Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, 35 Tsinghua East Road, Beijing, 100083, China
| | - Pengsong Li
- Beijing Key Laboratory for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control and Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, 35 Tsinghua East Road, Beijing, 100083, China
| | - Yan Dang
- Beijing Key Laboratory for Source Control Technology of Water Pollution, Engineering Research Center for Water Pollution Source Control and Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, 35 Tsinghua East Road, Beijing, 100083, China.
| | - Jessica A Smith
- Department of Biomolecular Sciences, Central Connecticut State University, 1615 Stanley Street, New Britain, CR 06050, USA
| | - Dawn E Holmes
- Department of Physical and Biological Sciences, Western New England University, 1215 Wilbraham Rd, Springfield, MA 01119, USA
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Alqahtani MF, Bajracharya S, Katuri KP, Ali M, Xu J, Alarawi MS, Saikaly PE. Enrichment of salt-tolerant CO 2-fixing communities in microbial electrosynthesis systems using porous ceramic hollow tube wrapped with carbon cloth as cathode and for CO 2 supply. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 766:142668. [PMID: 33077225 DOI: 10.1016/j.scitotenv.2020.142668] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 09/20/2020] [Accepted: 09/20/2020] [Indexed: 06/11/2023]
Abstract
Microbial inocula from marine origins are less explored for CO2 reduction in microbial electrosynthesis (MES) system, although effective CO2-fixing communities in marine environments are well-documented. We explored natural saline habitats, mainly salt marsh (SM) and mangrove (M) sediments, as potential inoculum sources for enriching salt-tolerant CO2 reducing community using two enrichment strategies: H2:CO2 (80:20) enrichment in serum vials and enrichment in cathode chamber of MES reactors operated at -1.0 V vs. Ag/AgCl. Porous ceramic hollow tube wrapped with carbon cloth was used as cathode and for direct CO2 delivery to CO2 reducing communities growing on the cathode surface. Methanogenesis was dominant in both the M- and SM-seeded MES and the methanogenic Archaea Methanococcus was the most dominant genus. Methane production was slightly higher in the SM-seeded MES (4.9 ± 1.7 mmol) compared to the M-seeded MES (3.8 ± 1.1 mmol). In contrast, acetate production was almost two times higher in the M-seeded MES (3.1 ± 0.9 mmol) than SM-seeded MES (1.5 ± 1.3 mmol). The high relative abundance of the genus Acetobacterium in the M-seeded serum vials correlates with the high acetate production obtained. The different enrichment strategies affected the community composition, though the communities in MES reactors and serum vials were performing similar functions (methanogenesis and acetogenesis). Despite similar operating conditions, the microbial community composition of M-seeded serum vials and MES reactors differed from the SM-seeded serum vials and MES reactors, supporting the importance of inoculum source in the evolution of CO2-reducing microbial communities.
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Affiliation(s)
- Manal F Alqahtani
- Biological and Environmental Science and Engineering (BESE) Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Suman Bajracharya
- Biological and Environmental Science and Engineering (BESE) Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Krishna P Katuri
- Biological and Environmental Science and Engineering (BESE) Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Muhammad Ali
- Biological and Environmental Science and Engineering (BESE) Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Jiajie Xu
- Biological and Environmental Science and Engineering (BESE) Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Mohammed S Alarawi
- Computational Biosciences Research Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Pascal E Saikaly
- Biological and Environmental Science and Engineering (BESE) Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
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An alternative resource allocation strategy in the chemolithoautotrophic archaeon Methanococcus maripaludis. Proc Natl Acad Sci U S A 2021; 118:2025854118. [PMID: 33879571 DOI: 10.1073/pnas.2025854118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Most microorganisms in nature spend the majority of time in a state of slow or zero growth and slow metabolism under limited energy or nutrient flux rather than growing at maximum rates. Yet, most of our knowledge has been derived from studies on fast-growing bacteria. Here, we systematically characterized the physiology of the methanogenic archaeon Methanococcus maripaludis during slow growth. M. maripaludis was grown in continuous culture under energy (formate)-limiting conditions at different dilution rates ranging from 0.09 to 0.002 h-1, the latter corresponding to 1% of its maximum growth rate under laboratory conditions (0.23 h-1). While the specific rate of methanogenesis correlated with growth rate as expected, the fraction of cellular energy used for maintenance increased and the maintenance energy per biomass decreased at slower growth. Notably, proteome allocation between catabolic and anabolic pathways was invariant with growth rate. Unexpectedly, cells maintained their maximum methanogenesis capacity over a wide range of growth rates, except for the lowest rates tested. Cell size, cellular DNA, RNA, and protein content as well as ribosome numbers also were largely invariant with growth rate. A reduced protein synthesis rate during slow growth was achieved by a reduction in ribosome activity rather than via the number of cellular ribosomes. Our data revealed a resource allocation strategy of a methanogenic archaeon during energy limitation that is fundamentally different from commonly studied versatile chemoheterotrophic bacteria such as E. coli.
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Zheng T, Xu B, Ji Y, Zhang W, Xin F, Dong W, Wei P, Ma J, Jiang M. A staged representation electrochemical stimulated strategy to regulate intracellular reducing power for improving succinate production by Escherichia coli AFP111. Biotechnol J 2021; 16:e2000415. [PMID: 33580738 DOI: 10.1002/biot.202000415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 01/06/2021] [Accepted: 01/12/2021] [Indexed: 01/02/2023]
Abstract
BACKGROUND Escherichia coli AFP111 was previously engineered for succinate production by eliminating byproducts of synthesis pathways. Still, the succinate yield is limited due to the insufficient NADH supplement, when fed with glucose. Microbial electrolysis cell (MEC) allows microorganisms to perform unbalanced fermentation by establishing polarized cathode interaction. METHODS AND RESULTS In this study, a cathode electrode was used as an additional electron donor to improve succinate synthesis by E. coli AFP111. In MEC with -0.65 V (vs. Ag/AgCl) poised on cathode electrode, 95.72% electrons were transferred into cells via neutral red (NR), and the ratio of NADH/NAD+ increased by 2.5-fold. Meanwhile, compared with the control experiment, the value of oxidation-reduction potential (ORP) changed from -240 to -265 mV in MEC, which was beneficial for NADH generation. During two-stage fermentation (no potential growth stage followed by electric stimulation) in MEC, succinate yield was increased by 29.09% (the final yield was 0.71 g g-1 ), and glucose consumption rate was enhanced by 36.22%. In addition, the carbon flux was pumped to succinate and pyruvate metabolism was enhanced. CONCLUSION AND IMPLICATIONS Staged representation of electrochemical stimulated strategy is effective for succinate producing in engineered E. coli by regulating intracellular reducing power, which provides a new concept for producing reduced metabolite in unbalanced fermentation.
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Affiliation(s)
- Tianwen Zheng
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, P. R. China
| | - Bin Xu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, P. R. China
| | - Yaliang Ji
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, P. R. China
| | - Wenming Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, P. R. China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, P. R. China
| | - Fengxue Xin
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, P. R. China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, P. R. China
| | - Weiliang Dong
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, P. R. China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, P. R. China
| | - Ping Wei
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, P. R. China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, P. R. China
| | - Jiangfeng Ma
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, P. R. China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, P. R. China
| | - Min Jiang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, P. R. China.,Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, P. R. China
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Analysis of a Methanogen and an Actinobacterium Dominating the Thermophilic Microbial Community of an Electromethanogenic Biocathode. ACTA ACUST UNITED AC 2021; 2021:8865133. [PMID: 33746613 PMCID: PMC7943316 DOI: 10.1155/2021/8865133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 02/09/2021] [Accepted: 02/15/2021] [Indexed: 12/13/2022]
Abstract
Electromethanogenesis refers to the bioelectrochemical synthesis of methane from CO2 by biocathodes. In an electromethanogenic system using thermophilic microorganisms, metagenomic analysis along with quantitative real-time polymerase chain reaction and fluorescence in situ hybridization revealed that the biocathode microbiota was dominated by the methanogen Methanothermobacter sp. strain EMTCatA1 and the actinobacterium Coriobacteriaceae sp. strain EMTCatB1. RNA sequencing was used to compare the transcriptome profiles of each strain at the methane-producing biocathodes with those in an open circuit and with the methanogenesis inhibitor 2-bromoethanesulfonate (BrES). For the methanogen, genes related to hydrogenotrophic methanogenesis were highly expressed in a manner similar to those observed under H2-limited conditions. For the actinobacterium, the expression profiles of genes encoding multiheme c-type cytochromes and membrane-bound oxidoreductases suggested that the actinobacterium directly takes up electrons from the electrode. In both strains, various stress-related genes were commonly induced in the open-circuit biocathodes and biocathodes with BrES. This study provides a molecular inventory of the dominant species of an electromethanogenic biocathode with functional insights and therefore represents the first multiomics characterization of an electromethanogenic biocathode.
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Gao K, Lu Y. Putative Extracellular Electron Transfer in Methanogenic Archaea. Front Microbiol 2021; 12:611739. [PMID: 33828536 PMCID: PMC8019784 DOI: 10.3389/fmicb.2021.611739] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 03/03/2021] [Indexed: 11/14/2022] Open
Abstract
It has been suggested that a few methanogens are capable of extracellular electron transfers. For instance, Methanosarcina barkeri can directly capture electrons from the coexisting microbial cells of other species. Methanothrix harundinacea and Methanosarcina horonobensis retrieve electrons from Geobacter metallireducens via direct interspecies electron transfer (DIET). Recently, Methanobacterium, designated strain YSL, has been found to grow via DIET in the co-culture with Geobacter metallireducens. Methanosarcina acetivorans can perform anaerobic methane oxidation and respiratory growth relying on Fe(III) reduction through the extracellular electron transfer. Methanosarcina mazei is capable of electromethanogenesis under the conditions where electron-transfer mediators like H2 or formate are limited. The membrane-bound multiheme c-type cytochromes (MHC) and electrically-conductive cellular appendages have been assumed to mediate the extracellular electron transfer in bacteria like Geobacter and Shewanella species. These molecules or structures are rare but have been recently identified in a few methanogens. Here, we review the current state of knowledge for the putative extracellular electron transfers in methanogens and highlight the opportunities and challenges for future research.
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Affiliation(s)
- Kailin Gao
- College of Urban and Environmental Sciences, Peking University, Beijing, China
| | - Yahai Lu
- College of Urban and Environmental Sciences, Peking University, Beijing, China
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Dinh HTT, Kambara H, Harada Y, Matsushita S, Aoi Y, Kindaichi T, Ozaki N, Ohashi A. Bioelectrical Methane Production with an Ammonium Oxidative Reaction under the No Organic Substance Condition. Microbes Environ 2021; 36. [PMID: 34135211 PMCID: PMC8209456 DOI: 10.1264/jsme2.me21007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The present study investigated bioelectrical methane production from CO2 without organic substances. Even though microbial methane production has been reported at relatively high electric voltages, the amount of voltage required and the organisms contributing to the process currently remain unknown. Methane production using a biocathode was investigated in a microbial electrolysis cell coupled with an NH4+ oxidative reaction at an anode coated with platinum powder under a wide range of applied voltages and anaerobic conditions. A microbial community analysis revealed that methane production simultaneously occurred with biological denitrification at the biocathode. During denitrification, NO3– was produced by chemical NH4+ oxidation at the anode and was provided to the biocathode chamber. H2 was produced at the biocathode by the hydrogen-producing bacteria Petrimonas through the acceptance of electrons and protons. The H2 produced was biologically consumed by hydrogenotrophic methanogens of Methanobacterium and Methanobrevibacter with CO2 uptake and by hydrogenotrophic denitrifiers of Azonexus. This microbial community suggests that methane is indirectly produced without the use of electrons by methanogens. Furthermore, bioelectrical methane production occurred under experimental conditions even at a very low voltage of 0.05 V coupled with NH4+ oxidation, which was thermodynamically feasible.
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Affiliation(s)
- Ha T T Dinh
- Department of Civil and Environmental Engineering, Graduate School of Advanced Science and Engineering, Hiroshima University.,Faculty of Environment, Ho Chi Minh City University of Natural Resources and Environment
| | - Hiromi Kambara
- Department of Civil and Environmental Engineering, Graduate School of Advanced Science and Engineering, Hiroshima University
| | - Yoshiki Harada
- Department of Civil and Environmental Engineering, Graduate School of Advanced Science and Engineering, Hiroshima University
| | - Shuji Matsushita
- Department of Civil and Environmental Engineering, Graduate School of Advanced Science and Engineering, Hiroshima University.,Agricultural Technology Research Center, Hiroshima Prefectural Technology Research Institute
| | - Yoshiteru Aoi
- Program of Biotechnology, Graduate School of Integrated Sciences for Life, Hiroshima University
| | - Tomonori Kindaichi
- Department of Civil and Environmental Engineering, Graduate School of Advanced Science and Engineering, Hiroshima University
| | - Noriatsu Ozaki
- Department of Civil and Environmental Engineering, Graduate School of Advanced Science and Engineering, Hiroshima University
| | - Akiyoshi Ohashi
- Department of Civil and Environmental Engineering, Graduate School of Advanced Science and Engineering, Hiroshima University
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Pfeifer K, Ergal İ, Koller M, Basen M, Schuster B, Rittmann SKMR. Archaea Biotechnology. Biotechnol Adv 2020; 47:107668. [PMID: 33271237 DOI: 10.1016/j.biotechadv.2020.107668] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 11/19/2020] [Accepted: 11/20/2020] [Indexed: 12/13/2022]
Abstract
Archaea are a domain of prokaryotic organisms with intriguing physiological characteristics and ecological importance. In Microbial Biotechnology, archaea are historically overshadowed by bacteria and eukaryotes in terms of public awareness, industrial application, and scientific studies, although their biochemical and physiological properties show a vast potential for a wide range of biotechnological applications. Today, the majority of microbial cell factories utilized for the production of value-added and high value compounds on an industrial scale are bacterial, fungal or algae based. Nevertheless, archaea are becoming ever more relevant for biotechnology as their cultivation and genetic systems improve. Some of the main advantages of archaeal cell factories are the ability to cultivate many of these often extremophilic organisms under non-sterile conditions, and to utilize inexpensive feedstocks often toxic to other microorganisms, thus drastically reducing cultivation costs. Currently, the only commercially available products of archaeal cell factories are bacterioruberin, squalene, bacteriorhodopsin and diether-/tetraether-lipids, all of which are produced utilizing halophiles. Other archaeal products, such as carotenoids and biohydrogen, as well as polyhydroxyalkanoates and methane are in early to advanced development stages, respectively. The aim of this review is to provide an overview of the current state of Archaea Biotechnology by describing the actual state of research and development as well as the industrial utilization of archaeal cell factories, their role and their potential in the future of sustainable bioprocessing, and to illustrate their physiological and biotechnological potential.
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Affiliation(s)
- Kevin Pfeifer
- Archaea Physiology & Biotechnology Group, Department of Functional and Evolutionary Ecology, Universität Wien, Wien, Austria; Institute of Synthetic Bioarchitectures, Department of Nanobiotechnology, University of Natural Resources and Life Sciences, Wien, Austria
| | - İpek Ergal
- Archaea Physiology & Biotechnology Group, Department of Functional and Evolutionary Ecology, Universität Wien, Wien, Austria
| | - Martin Koller
- Office of Research Management and Service, c/o Institute of Chemistry, University of Graz, Austria
| | - Mirko Basen
- Microbial Physiology Group, Division of Microbiology, Institute of Biological Sciences, University of Rostock, Rostock, Germany
| | - Bernhard Schuster
- Institute of Synthetic Bioarchitectures, Department of Nanobiotechnology, University of Natural Resources and Life Sciences, Wien, Austria
| | - Simon K-M R Rittmann
- Archaea Physiology & Biotechnology Group, Department of Functional and Evolutionary Ecology, Universität Wien, Wien, Austria.
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45
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Ragab A, Shaw DR, Katuri KP, Saikaly PE. Effects of set cathode potentials on microbial electrosynthesis system performance and biocathode methanogen function at a metatranscriptional level. Sci Rep 2020; 10:19824. [PMID: 33188217 PMCID: PMC7666199 DOI: 10.1038/s41598-020-76229-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 10/12/2020] [Indexed: 11/09/2022] Open
Abstract
Microbial electrosynthesis exploits the catalytic activity of microorganisms to utilize a cathode as an electron donor for reducing waste CO2 to valuable fuels and chemicals. Electromethanogenesis is the process of CO2 reduction to CH4 catalyzed by methanogens using the cathode directly as a source of electrons or indirectly via H2. Understanding the effects of different set cathode potentials on the functional dynamics of electromethanogenic communities is crucial for the rational design of cathode materials. Replicate enriched electromethanogenic communities were subjected to different potentials (- 1.0 V and - 0.7 V vs. Ag/AgCl) and the potential-induced changes were analyzed using a metagenomic and metatranscriptomic approach. The most abundant and transcriptionally active organism on the biocathodes was a novel species of Methanobacterium sp. strain 34x. The cathode potential-induced changes limited electron donor availability and negatively affected the overall performance of the reactors in terms of CH4 production. Although high expression of key genes within the methane and carbon metabolism pathways was evident, there was no significant difference in transcriptional response to the different set potentials. The acetyl-CoA decarbonylase/synthase (ACDS) complex were the most highly expressed genes, highlighting the significance of carbon assimilation under limited electron donor conditions and its link to the methanogenesis pathway.
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Affiliation(s)
- Ala'a Ragab
- Biological and Environmental Science and Engineering Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Dario Rangel Shaw
- Biological and Environmental Science and Engineering Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Krishna P Katuri
- Biological and Environmental Science and Engineering Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Pascal E Saikaly
- Biological and Environmental Science and Engineering Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.
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Bio-Electrochemical Enhancement of Hydrogen and Methane Production in a Combined Anaerobic Digester (AD) and Microbial Electrolysis Cell (MEC) from Dairy Manure. SUSTAINABILITY 2020. [DOI: 10.3390/su12208491] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Anaerobic digestion (AD) is a biological-based technology that generates methane-enriched biogas. A microbial electrolysis cell (MEC) uses electricity to initiate bacterial oxidization of organic matter to produce hydrogen. This study determined the effect of energy production and waste treatment when using dairy manure in a combined AD and MEC (AD-MEC) system compared to AD without MEC (AD-only). In the AD-MEC system, a single chamber MEC (150 mL) was placed inside a 10 L digester on day 20 of the digestion process and run for 272 h (11 days) to determine residual treatment and energy capacity with an MEC included. Cumulative H2 and CH4 production in the AD-MEC (2.43 L H2 and 23.6 L CH4) was higher than AD-only (0.00 L H2 and 10.9 L CH4). Hydrogen concentration during the first 24 h of MEC introduction constituted 20% of the produced biogas, after which time the H2 decreased as the CH4 concentration increased from 50% to 63%. The efficiency of electrical energy recovery (ηE) in the MEC was 73% (ηE min.) to 324% (ηE max.), with an average increase of 170% in total energy compared to AD-only. Chemical oxygen demand (COD) removal was higher in the AD-MEC (7.09 kJ/g COD removed) system compared to AD-only (6.19 kJ/g COD removed). This study showed that adding an MEC during the digestion process could increase overall energy production and organic removal from dairy manure.
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Chen H, Simoska O, Lim K, Grattieri M, Yuan M, Dong F, Lee YS, Beaver K, Weliwatte S, Gaffney EM, Minteer SD. Fundamentals, Applications, and Future Directions of Bioelectrocatalysis. Chem Rev 2020; 120:12903-12993. [DOI: 10.1021/acs.chemrev.0c00472] [Citation(s) in RCA: 118] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Hui Chen
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Olja Simoska
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Koun Lim
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Matteo Grattieri
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Mengwei Yuan
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Fangyuan Dong
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Yoo Seok Lee
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Kevin Beaver
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Samali Weliwatte
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Erin M. Gaffney
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
| | - Shelley D. Minteer
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, United States
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McCully AL, Spormann AM. Direct cathodic electron uptake coupled to sulfate reduction by Desulfovibrio ferrophilus IS5 biofilms. Environ Microbiol 2020; 22:4794-4807. [PMID: 32939950 DOI: 10.1111/1462-2920.15235] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 09/11/2020] [Accepted: 09/13/2020] [Indexed: 11/28/2022]
Abstract
Direct electron uptake is emerging as a key process for electron transfer in anaerobic microbial communities, both between species and from extracellular sources, such as zero-valent iron (Fe0 ) or cathodic surfaces. In this study, we investigated cathodic electron uptake by Fe0 -corroding Desulfovibrio ferrophilus IS5 and showed that electron uptake is dependent on direct cell contact via a biofilm on the cathode surface rather than through secreted intermediates. Induction of cathodic electron uptake by lactate-starved D. ferrophilus IS5 cells resulted in the expression of all components necessary for electron uptake; however, protein synthesis was required for full biofilm formation. Notably, proteinase K treatment uncoupled electron uptake from biofilm formation, likely through proteolytic degradation of proteinaceous components of the electron uptake machinery. We also showed that cathodic electron uptake is dependent on SO4 2- reduction. The insensitivity of Fe0 corrosion to proteinase K treatment suggests that electron uptake from a cathode might involve different mechanism(s) than those involved in Fe0 corrosion.
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Affiliation(s)
- Alexandra L McCully
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, USA
| | - Alfred M Spormann
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, USA.,Department of Chemical Engineering, Stanford University, Stanford, CA, USA
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Neethu B, Bhowmick G, Fathima A, Ghangrekar M. Anodic inoculum pre-treatment by extracts of Azadirachta indica leaves and Allium sativum peels for improved bioelectricity recovery from microbial fuel cell. INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 2020. [DOI: 10.1016/j.ijhydene.2020.06.086] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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50
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Semiquantitative Detection of Hydrogen-Associated or Hydrogen-Free Electron Transfer within Methanogenic Biofilm of Microbial Electrosynthesis. Appl Environ Microbiol 2020; 86:AEM.01056-20. [PMID: 32561585 DOI: 10.1128/aem.01056-20] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 06/13/2020] [Indexed: 12/19/2022] Open
Abstract
Hydrogen-entangled electron transfer has been verified as an important extracellular pathway of sharing reducing equivalents to regulate biofilm activities within a diversely anaerobic environment, especially in microbial electrosynthesis systems. However, with a lack of useful methods for in situ hydrogen detection in cathodic biofilms, the role of hydrogen involvement in electron transfer is still debatable. Here, a cathodic biofilm was constructed in CH4-produced microbial electrosynthesis reactors, in which the hydrogen evolution dynamic was analyzed to confirm the presence of hydrogen-associated electron transfer near the cathode within a micrometer scale. Fluorescent in situ hybridization images indicated that a colocalized community of archaea and bacteria developed within a 58.10-μm-thick biofilm at the cathode, suggesting that the hydrogen gradient detected by the microsensor was consumed by the collaboration of bacteria and archaea. Coupling of a microsensor and cyclic voltammetry test further provided semiquantitative results of the hydrogen-associated contribution to methane generation (around 21.20% ± 1.57% at a potential of -0.5 V to -0.69 V). This finding provides deep insight into the mechanism of electron transfer in biofilm on conductive materials.IMPORTANCE Electron transfer from an electrode to biofilm is of great interest to the fields of microbial electrochemical technology, bioremediation, and methanogenesis. It has a promising potential application to boost more value-added products or pollutant degradation. Importantly, the ability of microbes to obtain electrons from electrodes and utilize them brings new insight into direct interspecies electron transfer during methanogenesis. Previous studies verified the direct pathway of electron transfer from the electrode to a pure-culture bacterium, but it was rarely reported how the methanogenic biofilm of mixed cultures shares electrons by a hydrogen-associated or hydrogen-free pathway. In the current study, a combination method of microsensor and cyclic voltammetry successfully semiquantified the role of hydrogen in electron transfer from an electrode to methanogenic biofilm.
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