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Li Y, Yin DM, Du XJ, Li HX, Zhang XY, Mahboubi A. Genome-centric metagenomics and methanogenic pathway analysis for acclimated anaerobic digestion of chicken manure with high ammonia stressed under thermophilic condition. ENVIRONMENTAL RESEARCH 2024; 258:119453. [PMID: 38909951 DOI: 10.1016/j.envres.2024.119453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Revised: 05/30/2024] [Accepted: 06/18/2024] [Indexed: 06/25/2024]
Abstract
Thermophilic anaerobic digestion (AD) of animal manure offers various environmental benefits but the process requires a microbial community acclimatized to high ammonia. In current study, a lab-scale continuous stirred tank reactor (CSTR) fed with chicken manure was operated under thermophilic condition for 450 days in total. Results showed that the volumetric methane production decreased from 445 to 328 and sharply declined to 153 mL L-1·d-1 with feeding total solid (TS) step increased from 5% to 7.5% and 10%, respectively. While, after a long-term stop feeding for 80 days, highly disturbed reactor was able to recover methane generation to 739 mL L-1·d-1 at feeding TS of 10%. Isotope analysis indicted acetate converted to methane through the syntrophic acetate oxidation and hydrogenotrophic methanogenesis (SAO-HM) pathway increased from 33% to 63% as the concentration of ammonium increased from 2493 to 6258 mg L-1. Significant different in the genome expression of the SAO bacterial from 0.09% to 1.23%, combining with main hydrogenotrophic partners (Methanoculleus spp. and Methanothermobacter spp.) contented of 2.1% and 99.9% during inhibitory and recovery stages, respectively. The highly expressed KEGG pathway in level 3 (enzyme genes) for the Recovery sludge combining with the extraordinary high abundance of genera Halocella sp. suggested that Halocella sp. might be a highly efficient hydrolytic and acidogenic microorganism and enhance the process of SAO during carbon metabolic flow to methane. This report will be a basis for further study of AD studies on high nitrogen content of poultry manure.
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Affiliation(s)
- Yan Li
- School of Optoelectronic Engineering, Changzhou Institute of Technology, Changzhou, 213032, Jiangsu Province, China.
| | - Dong-Min Yin
- Institute of Urban and Rural Mining, Changzhou University, Changzhou, 213164, Jiangsu Province, China.
| | - Xiao-Jiao Du
- School of Optoelectronic Engineering, Changzhou Institute of Technology, Changzhou, 213032, Jiangsu Province, China.
| | - Hao-Xuan Li
- School of Optoelectronic Engineering, Changzhou Institute of Technology, Changzhou, 213032, Jiangsu Province, China.
| | - Xue-Ying Zhang
- School of Optoelectronic Engineering, Changzhou Institute of Technology, Changzhou, 213032, Jiangsu Province, China.
| | - Amir Mahboubi
- Swedish Centre for Resource Recovery, University of Borås, Borås, SE-50190, Sweden.
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Li C, Hao L, Lü F, Duan H, Zhang H, He P. Syntrophic Acetate-Oxidizing Microbial Consortia Enriched from Full-Scale Mesophilic Food Waste Anaerobic Digesters Showing High Biodiversity and Functional Redundancy. mSystems 2022; 7:e0033922. [PMID: 36073802 PMCID: PMC9600251 DOI: 10.1128/msystems.00339-22] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 08/15/2022] [Indexed: 12/24/2022] Open
Abstract
Syntrophic acetate oxidation (SAO) coupled with hydrogenotrophic methanogenesis (HM) plays a vital role in the anaerobic digestion of protein-rich feedstocks such as food wastes. However, current knowledge of the biodiversity and genetic potential of the involved microbial participants, especially syntrophic acetate-oxidizing bacteria (SAOB), is limited due to the low abundance of these microorganisms and challenges in their isolation. The intent of this study was to enrich and identify potential SAOB. Therefore, we conducted continuous acetate feeding under high ammonia concentrations using two separate inoculum consortia of microorganisms that originated from full-scale mesophilic food waste digesters, which lasted for more than 200 days. Using 16S rRNA gene amplicon and metagenomic analyses, we observed a convergence of the experimental microbial communities during the enrichment regarding taxonomic composition and metabolic functional composition. Stable carbon isotope analyses of biogas indicated that SAO-HM was the dominant methanogenic pathway during the enrichment process. The hydrogenotrophic methanogen Methanoculleus dominated the archaeal community. The enriched SAO community featured high biodiversity and metabolic functional redundancy. By analyzing the metagenome-assembled genomes, the known SAOB Syntrophaceticus schinkii and six uncultured populations were identified to have the genetic potential to perform SAO through the conventional reversed Wood-Ljungdahl pathway, while another six bacteria were found to encode the reversed Wood-Ljungdahl pathway combined with a glycine cleavage system as novel SAOB candidates. These results showed that the food waste anaerobic digesters harbor diverse SAOB and highlighted the importance of the glycine cleavage system for acetate oxidation. IMPORTANCE Syntrophic acetate oxidation to CO2 and H2, together with hydrogenotrophic methanogenesis, contributes to much of the carbon flux in the anaerobic digestion of organic wastes, especially at high ammonia concentrations. A deep understanding of the biodiversity, metabolic genetic potential, and ecology of the SAO community can help to improve biomethane production from wastes for clean energy production. Here, we enriched the SAO-HM functional guild obtained from full-scale food waste anaerobic digesters and recorded dynamic changes in community taxonomic composition and functional profiles. By reconstructing the metabolic pathways, diverse known and novel bacterial members were found to have SAO potential via the reversed Wood-Ljungdahl (WL) pathway alone, or via the reversed WL pathway with a glycine cleavage system (WLP-GCS), and those catalyzing WLP-GCS showed higher microbial abundance. This study revealed the biodiversity and metabolic functional redundancy of SAOB in full-scale anaerobic digester systems and provided inspiration for further genome-centric studies.
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Affiliation(s)
- Chao Li
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, People’s Republic of China
| | - Liping Hao
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, People’s Republic of China
| | - Fan Lü
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, People’s Republic of China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, People’s Republic of China
| | - Haowen Duan
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, People’s Republic of China
| | - Hua Zhang
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, People’s Republic of China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, People’s Republic of China
| | - Pinjing He
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai, People’s Republic of China
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Duan H, He P, Zhang H, Shao L, Lü F. Metabolic Regulation of Mesophilic Methanosarcina barkeri to Ammonium Inhibition. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:8897-8907. [PMID: 35588324 DOI: 10.1021/acs.est.2c01212] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Undesirable ammonium concentrations can lead to unstable anaerobic digestion processes, and Methanosarcina spp. are the representative methanogens under inhibition. However, no known work seems to exist for directly exploring the detailed metabolic regulation of pure cultured representative Methanosarcina spp. to ammonium inhibition. We used transcriptomics and proteomics to profile the metabolic regulation of Methanosarcina barkeri to 1, 4, and 7 g N/L of total ammoniacal nitrogen (TAN), where free ammonia concentrations were between 1.5 and 36.1 mg N/L. At the initial stages of ammonium inhibition, the genes participating in the acquisition and assimilation of reduced nitrogen sources showed significant upregulation where the minimal fold change of gene transcription was about 2. Apart from nitrogen metabolism, the transcription of some genes in methanogenesis also significantly increased at the initial stages. For example, the genes encoding alternative heterodisulfide reductase subunits (HdrAB), energy-converting hydrogenase subunit (EchC), and methanophenazine-dependent hydrogenase subunits (VhtAC) were significantly upregulated by at least 2.05 times. For the element translocation at the initial stages, the genes participating in the uptake of ferrous iron, potassium ion, and molybdate were significantly upregulated with a minimal fold change of 2.10. As the cultivation proceeded, the gene encoding the cell division protein subunit (FtsH) was significantly upregulated by 13.0 times at 7 g N/L of TAN; meanwhile, an increment in OD600 was observed at the terminal sampling point of 7 g N/L of TAN. The present study explored the metabolic regulation of M. barkeri in stress response, protein synthesis, signal transduction, nitrogen metabolism, methanogenesis, and element translocation. The results would contribute to the understanding of the metabolic effects of ammonium inhibition on methanogens and have significant practical implication in inhibited anaerobic digestion.
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Affiliation(s)
- Haowen Duan
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China
| | - Pinjing He
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai 200092, China
- Shanghai Multi-Source Solid Waste Collaborative Treatment and Energy Engineering Technology Research Center, Shanghai 200092, China
| | - Hua Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Liming Shao
- Institute of Waste Treatment and Reclamation, Tongji University, Shanghai 200092, China
| | - Fan Lü
- State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
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4
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Quispe-Cardenas E, Rogers S. Microbial adaptation and response to high ammonia concentrations and precipitates during anaerobic digestion under psychrophilic and mesophilic conditions. WATER RESEARCH 2021; 204:117596. [PMID: 34530226 DOI: 10.1016/j.watres.2021.117596] [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: 04/20/2021] [Revised: 07/19/2021] [Accepted: 08/22/2021] [Indexed: 06/13/2023]
Abstract
This study explored microbial adaptation to high ammonia concentrations (<1000 mg/L to 4000 mg/L) during anaerobic digestion (AD) under psychrophilic and mesophilic conditions, the latter of which yielded precipitates facilitating investigation of microbial response. The experimental setup was performed at bench-scale using microbial consortia from four different operating anaerobic digesters treating different organic wastes (WW-wastewater sludge, MN-manure, FW- food waste and CO-co-digestion (FW & MN)). Adaptation experiments were conducted with semi-continuous flow mode to resemble large-scale operation. Metagenome and 16S RNA analysis were performed for the first time in a psychrophilic reactor during an ammonia acclimation process. These analyses were also performed in mesophilic reactor exposed to precipitates and high ammonia levels. Diversity reduced when adaptation occurred successfully from 1.1 to 4 g/L of total ammonia nitrogen (TAN) under psychrophilic conditions, while the microbial community became more diverse under mesophilic conditions with ammonia inhibition. We report for the first time Methanocorposculum as a robust hydrogenotrophic methanogen at high ammoniacal concentrations under psychrophilic conditions. Additionally, Methanosarcina was present in low and high ammoniacal concentrations in mesophilic conditions, but there was a shift in species dominance. Methanosarcina barkeri stands out as a more resilient methanogen compared to Methanosarcina mazei, which initially dominated at <1.1 g/L TAN. We also explored the effects of sudden precipitates on methanogenic communities and methane production when they occurred under mesophilic conditions in two reactors. Methane production declined by more than 50% when precipitates occurred and was accompanied by pH reduction and VFA accumulation. Diversity data corroborated that methanogens were severely reduced. These two reactors were not able to recover with 50 days of added operation, demonstrating potential for long-term negative impacts of precipitate formation on AD performance stemming from negative impact to methanogenic communities.
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Affiliation(s)
| | - Shane Rogers
- Institute for a Sustainable Environment, Clarkson University, Potsdam 13699, NY, USA; Civil and Environmental Engineering, Clarkson University, Potsdam 13699, NY, USA.
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Yan M, Zhu X, Treu L, Ravenni G, Campanaro S, Goonesekera EM, Ferrigno R, Jacobsen CS, Zervas A, Angelidaki I, Fotidis IA. Comprehensive evaluation of different strategies to recover methanogenic performance in ammonia-stressed reactors. BIORESOURCE TECHNOLOGY 2021; 336:125329. [PMID: 34052546 DOI: 10.1016/j.biortech.2021.125329] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/20/2021] [Accepted: 05/21/2021] [Indexed: 06/12/2023]
Abstract
In this study, strategies for recovery of ammonia-stressed AD reactors were attempted, by addition of preserved bioaugmentation consortium in gel (BioG), fresh consortium in liquid medium (BioL), woodchip biochar (BW), and straw biochar (BS). In comparison to control group with ammonia, effective treatments, i.e., BioG, BioL, BW and BS raised the maximum methane production rate by 77%, 23%, 35%, and 24%, respectively. BW possibly acted as interspecies electrical conduits for Direct Electron Transfer based on conductivity and SEM analysis. BioG facilitated slow release of bioaugmentation inocula from gel into the AD system, which protected them from a direct environmental shock. According to microbial analysis, both BioG, BioL and BW resulted in increased relative abundance of Methanothermobacter thermautotrophicus; and BS induced selective raise of Methanosarcina thermophila. The increase of methanogens via these strategies led to the faster recovery of the AD process.
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Affiliation(s)
- Miao Yan
- Department of Environmental Engineering, Technical University of Denmark, Building 115, Kgs. Lyngby DK-2800, Denmark
| | - Xinyu Zhu
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, Building 227, Kgs. Lyngby DK-2800, Denmark
| | - Laura Treu
- Department of Biology, University of Padova, Via U. Bassi 58/b, Padova 35121, Italy
| | - Giulia Ravenni
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, Building 313, Roskilde 4000, Denmark
| | - Stefano Campanaro
- Department of Biology, University of Padova, Via U. Bassi 58/b, Padova 35121, Italy
| | - Estelle Maria Goonesekera
- Department of Environmental Engineering, Technical University of Denmark, Building 115, Kgs. Lyngby DK-2800, Denmark
| | - Rosa Ferrigno
- Department of Environmental Engineering, Technical University of Denmark, Building 115, Kgs. Lyngby DK-2800, Denmark
| | - Carsten S Jacobsen
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, Roskilde DK-4000, Denmark
| | - Athanasios Zervas
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, Roskilde DK-4000, Denmark
| | - Irini Angelidaki
- Department of Chemical and Biochemical Engineering, Technical University of Denmark, Building 227, Kgs. Lyngby DK-2800, Denmark
| | - Ioannis A Fotidis
- Department of Environmental Engineering, Technical University of Denmark, Building 115, Kgs. Lyngby DK-2800, Denmark; Faculty of Engineering and Natural Sciences, Tampere University, Tampere, Finland; School of Civil Engineering Southeast University Nanjing, 210096, China.
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6
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Ling Z, Thakur N, El-Dalatony MM, Salama ES, Li X. Protein biomethanation: insight into the microbial nexus. Trends Microbiol 2021; 30:69-78. [PMID: 34215486 DOI: 10.1016/j.tim.2021.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 06/08/2021] [Accepted: 06/08/2021] [Indexed: 01/01/2023]
Abstract
Biomethanation of carbohydrates (e.g., lignocellulosic biomass) and lipids (e.g., waste oils) has been well studied. However, investigations on the biomethanation of protein-rich biowastes (PRBs) and associated microbial communities have not been reported. This review summarizes the challenges in the metabolic process of anaerobic digestion of PRBs and the microbial instability associated with it. We discuss the diversity of bacterial and archaeal communities via metagenomics under PRB mono- and codigestion. A stable community structure with enhanced metabolic activity is a core factor in PRB biomethanation. The application of strategies such as codigestion of PRBs with carbon-rich biomass and microbial stimulation/augmentation would make PRB biomethanation more feasible.
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Affiliation(s)
- Zhenmin Ling
- MOE, Key Laboratory of Cell Activities and Stress Adaptations, Lanzhou University, Lanzhou 730000, Gansu Province, PR China
| | - Nandini Thakur
- MOE, Key Laboratory of Cell Activities and Stress Adaptations, Lanzhou University, Lanzhou 730000, Gansu Province, PR China; Department of Occupational and Environmental Health, School of Public Health, Lanzhou University, Lanzhou 730000, Gansu Province, PR China
| | - Marwa M El-Dalatony
- MOE, Key Laboratory of Cell Activities and Stress Adaptations, Lanzhou University, Lanzhou 730000, Gansu Province, PR China
| | - El-Sayed Salama
- Department of Occupational and Environmental Health, School of Public Health, Lanzhou University, Lanzhou 730000, Gansu Province, PR China.
| | - Xiangkai Li
- MOE, Key Laboratory of Cell Activities and Stress Adaptations, Lanzhou University, Lanzhou 730000, Gansu Province, PR China.
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7
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Singh A, Müller B, Schnürer A. Profiling temporal dynamics of acetogenic communities in anaerobic digesters using next-generation sequencing and T-RFLP. Sci Rep 2021; 11:13298. [PMID: 34168213 PMCID: PMC8225771 DOI: 10.1038/s41598-021-92658-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 06/14/2021] [Indexed: 02/06/2023] Open
Abstract
Acetogens play a key role in anaerobic degradation of organic material and in maintaining biogas process efficiency. Profiling this community and its temporal changes can help evaluate process stability and function, especially under disturbance/stress conditions, and avoid complete process failure. The formyltetrahydrofolate synthetase (FTHFS) gene can be used as a marker for acetogenic community profiling in diverse environments. In this study, we developed a new high-throughput FTHFS gene sequencing method for acetogenic community profiling and compared it with conventional terminal restriction fragment length polymorphism of the FTHFS gene, 16S rRNA gene-based profiling of the whole bacterial community, and indirect analysis via 16S rRNA profiling of the FTHFS gene-harbouring community. Analyses and method comparisons were made using samples from two laboratory-scale biogas processes, one operated under stable control and one exposed to controlled overloading disturbance. Comparative analysis revealed satisfactory detection of the bacterial community and its changes for all methods, but with some differences in resolution and taxonomic identification. FTHFS gene sequencing was found to be the most suitable and reliable method to study acetogenic communities. These results pave the way for community profiling in various biogas processes and in other environments where the dynamics of acetogenic bacteria have not been well studied.
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Affiliation(s)
- Abhijeet Singh
- grid.6341.00000 0000 8578 2742Anaerobic Microbiology and Biotechnology Group, Department of Molecular Sciences, Swedish University of Agricultural Sciences, Almas Allé 5, Box 7025, 750 07 Uppsala, Sweden
| | - Bettina Müller
- grid.6341.00000 0000 8578 2742Anaerobic Microbiology and Biotechnology Group, Department of Molecular Sciences, Swedish University of Agricultural Sciences, Almas Allé 5, Box 7025, 750 07 Uppsala, Sweden
| | - Anna Schnürer
- grid.6341.00000 0000 8578 2742Anaerobic Microbiology and Biotechnology Group, Department of Molecular Sciences, Swedish University of Agricultural Sciences, Almas Allé 5, Box 7025, 750 07 Uppsala, Sweden
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8
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Awhangbo L, Bendoula R, Roger JM, Béline F. Detection of early imbalances in semi-continuous anaerobic co-digestion process based on instantaneous biogas production rate. WATER RESEARCH 2020; 171:115444. [PMID: 31918387 DOI: 10.1016/j.watres.2019.115444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 12/22/2019] [Accepted: 12/24/2019] [Indexed: 06/10/2023]
Abstract
The aim of this study was to investigate the use of biogas production rate kinetics for the monitoring of anaerobic co-digestion. Recent extensive studies of degradation pathways showed that acetoclastic methanogenesis is not always the main pathway. Hydrogenotrophic methanogenesis and syntrophic acetate oxidation can also dominate, mostly for operating conditions with high concentrations of ammonia or volatile fatty acids … These conditions are also known to cause instability in the digester's operation especially in co-digestion due to substrate variability. Therefore, co-digestion experiments were conducted with several co-substrates using a continuously stirred 35-L tank reactor. Degradation pathways and their potential shifts were identified by monitoring variations in biogas production rate kinetics using a principal component analysis model. The shifts in the degradation pathways were used to monitor the process. These shift points were found to provide early warnings of instabilities in the anaerobic co-digestion process.
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Affiliation(s)
- L Awhangbo
- Irstea, UR OPAALE, 17 av. de Cucillé, CS 64427, F-35044, Rennes, France; Univ. Bretagne Loire, France.
| | - R Bendoula
- Irstea, UMR ITAP, 361, rue J.F. Breton, BP 5095, F-34196, Montpellier, France.
| | - J M Roger
- Irstea, UMR ITAP, 361, rue J.F. Breton, BP 5095, F-34196, Montpellier, France.
| | - F Béline
- Irstea, UR OPAALE, 17 av. de Cucillé, CS 64427, F-35044, Rennes, France.
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Campanaro S, Treu L, Rodriguez-R LM, Kovalovszki A, Ziels RM, Maus I, Zhu X, Kougias PG, Basile A, Luo G, Schlüter A, Konstantinidis KT, Angelidaki I. New insights from the biogas microbiome by comprehensive genome-resolved metagenomics of nearly 1600 species originating from multiple anaerobic digesters. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:25. [PMID: 32123542 PMCID: PMC7038595 DOI: 10.1186/s13068-020-01679-y] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 02/08/2020] [Indexed: 05/20/2023]
Abstract
BACKGROUND Microorganisms in biogas reactors are essential for degradation of organic matter and methane production. However, a comprehensive genome-centric comparison, including relevant metadata for each sample, is still needed to identify the globally distributed biogas community members and serve as a reliable repository. RESULTS Here, 134 publicly available metagenomes derived from different biogas reactors were used to recover 1635 metagenome-assembled genomes (MAGs) representing different biogas bacterial and archaeal species. All genomes were estimated to be > 50% complete and nearly half ≥ 90% complete with ≤ 5% contamination. In most samples, specialized microbial communities were established, while only a few taxa were widespread among the different reactor systems. Metabolic reconstruction of the MAGs enabled the prediction of functional traits related to biomass degradation and methane production from waste biomass. An extensive evaluation of the replication index provided an estimation of the growth dynamics for microbes involved in different steps of the food chain. CONCLUSIONS The outcome of this study highlights a high flexibility of the biogas microbiome, allowing it to modify its composition and to adapt to the environmental conditions, including temperatures and a wide range of substrates. Our findings enhance our mechanistic understanding of the AD microbiome and substantially extend the existing repository of genomes. The established database represents a relevant resource for future studies related to this engineered ecosystem.
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Affiliation(s)
- Stefano Campanaro
- Department of Biology, University of Padova, Via U. Bassi 58/b, 35121 Padua, Italy
- CRIBI Biotechnology Center, University of Padova, 35131 Padua, Italy
| | - Laura Treu
- Department of Biology, University of Padova, Via U. Bassi 58/b, 35121 Padua, Italy
- Department of Environmental Engineering, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Luis M. Rodriguez-R
- School of Civil & Environmental Engineering and School of Biological Sciences (Adjunct), Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA 30332-0512 USA
| | - Adam Kovalovszki
- Department of Environmental Engineering, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Ryan M. Ziels
- Department of Civil Engineering, University of British Columbia, Vancouver, BC Canada
| | - Irena Maus
- Genome Research of Industrial Microorganisms, Center for Biotechnology (CeBiTec), Bielefeld University, Universitätsstr. 27, 33615 Bielefeld, Germany
| | - Xinyu Zhu
- Department of Environmental Engineering, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Panagiotis G. Kougias
- Hellenic Agricultural Organization DEMETER, Soil and Water Resources Institute, Thermi-Thessaloniki, Greece
| | - Arianna Basile
- Department of Biology, University of Padova, Via U. Bassi 58/b, 35121 Padua, Italy
| | - Gang Luo
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433 China
| | - Andreas Schlüter
- Hellenic Agricultural Organization DEMETER, Soil and Water Resources Institute, Thermi-Thessaloniki, Greece
| | - Konstantinos T. Konstantinidis
- School of Civil & Environmental Engineering and School of Biological Sciences (Adjunct), Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA 30332-0512 USA
| | - Irini Angelidaki
- Department of Environmental Engineering, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
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10
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Yan M, Fotidis IA, Tian H, Khoshnevisan B, Treu L, Tsapekos P, Angelidaki I. Acclimatization contributes to stable anaerobic digestion of organic fraction of municipal solid waste under extreme ammonia levels: Focusing on microbial community dynamics. BIORESOURCE TECHNOLOGY 2019; 286:121376. [PMID: 31030070 DOI: 10.1016/j.biortech.2019.121376] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 04/19/2019] [Accepted: 04/20/2019] [Indexed: 05/20/2023]
Abstract
The organic fraction of municipal solid waste (OFMSW) is an abundant and sustainable substrate for the anaerobic digestion (AD) process, yet ammonia released during OFMSW hydrolysis could result in suboptimal biogas production. Acclimatized ammonia tolerant microorganisms offer an efficient way to alleviate ammonia inhibition during AD. This study aimed to achieve an efficient AD of OFMSW under extreme ammonia levels and elucidate the dynamics of the acclimatized microbial community. Thus, two mesophilic continuous stirred tank reactors (CSTR), fed only with OFMSW, were successfully acclimatized up to 8.5 g NH4+-N/L, and their methane yields fluctuated <10%, compared to the methane yields without ammonia addition. Microbiological analyses showed that Methanosaeta concilii and Methanosarcina soligelidi were the dominant methanogens at low and high ammonia levels, respectively. Whilst, a unique metabolic pathway shift, from aceticlastic to hydrogenotrophic methanogenesis, of M. soligelidi was identified during the acclimatization process.
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Affiliation(s)
- Miao Yan
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet Bygning 115, DK-2800 Kgs. Lyngby, Denmark
| | - Ioannis A Fotidis
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet Bygning 115, DK-2800 Kgs. Lyngby, Denmark.
| | - Hailin Tian
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet Bygning 115, DK-2800 Kgs. Lyngby, Denmark
| | - Benyamin Khoshnevisan
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet Bygning 115, DK-2800 Kgs. Lyngby, Denmark
| | - Laura Treu
- Department of Biology, University of Padova, Via U. Bassi 58/b, 35121 Padova, Italy
| | - Panagiotis Tsapekos
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet Bygning 115, DK-2800 Kgs. Lyngby, Denmark
| | - Irini Angelidaki
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet Bygning 115, DK-2800 Kgs. Lyngby, Denmark
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11
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Kunath BJ, Minniti G, Skaugen M, Hagen LH, Vaaje-Kolstad G, Eijsink VGH, Pope PB, Arntzen MØ. Metaproteomics: Sample Preparation and Methodological Considerations. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1073:187-215. [DOI: 10.1007/978-3-030-12298-0_8] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Lv Z, Leite AF, Harms H, Glaser K, Liebetrau J, Kleinsteuber S, Nikolausz M. Microbial community shifts in biogas reactors upon complete or partial ammonia inhibition. Appl Microbiol Biotechnol 2018; 103:519-533. [DOI: 10.1007/s00253-018-9444-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 09/17/2018] [Accepted: 10/08/2018] [Indexed: 10/28/2022]
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Yin DM, Westerholm M, Qiao W, Bi SJ, Wandera SM, Fan R, Jiang MM, Dong RJ. An explanation of the methanogenic pathway for methane production in anaerobic digestion of nitrogen-rich materials under mesophilic and thermophilic conditions. BIORESOURCE TECHNOLOGY 2018; 264:42-50. [PMID: 29783130 DOI: 10.1016/j.biortech.2018.05.062] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 05/15/2018] [Accepted: 05/17/2018] [Indexed: 06/08/2023]
Abstract
The impact of temperature on the anaerobic digestion of chicken manure was investigated by studying the process performance and pathway for continuously-fed digesters under mesophilic and thermophilic conditions. The mesophilic digester obtained a 15% higher methane yield compared with the thermophilic digester. Mesophilic and thermophilic digester had free ammonia of 31 and 145 mg/L, respectively. The stable carbon isotope analysis indicated that 41% and 50% of acetate was converted to methane through the syntrophic acetate oxidation and hydrogenotrophic methanogenesis (SAO-HM) pathway under mesophilic and thermophilic conditions, respectively. The genus Pseudomonas represented 10% and 16% under mesophilic and thermophilic conditions, respectively. A high abundance of the methanogens genus Methanoculleus (94% of total methanogens) in mesophilic and the genus Methanothermobacter (96%) in thermophilic digesters indicated they were the main hydrogenotrophic partners in SAO. The present study therefore illustrated that methanogenic pathway shifting, induced by free ammonia, closely correlated to the process performance.
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Affiliation(s)
- Dong-Min Yin
- College of Engineering, China Agricultural University, Beijing 100083, China; R&D Center for Efficient Production and Comprehensive Utilization of Biobased Gaseous Fuels, Energy Authority, National Development and Reform Committee (BGFeuls), Beijing 100083, China
| | - Maria Westerholm
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, Uppsala BioCenter, Box 7025, SE-750 07 Uppsala, Sweden
| | - Wei Qiao
- College of Engineering, China Agricultural University, Beijing 100083, China; R&D Center for Efficient Production and Comprehensive Utilization of Biobased Gaseous Fuels, Energy Authority, National Development and Reform Committee (BGFeuls), Beijing 100083, China.
| | - Shao-Jie Bi
- College of Engineering, China Agricultural University, Beijing 100083, China; R&D Center for Efficient Production and Comprehensive Utilization of Biobased Gaseous Fuels, Energy Authority, National Development and Reform Committee (BGFeuls), Beijing 100083, China
| | - Simon M Wandera
- College of Engineering, China Agricultural University, Beijing 100083, China; R&D Center for Efficient Production and Comprehensive Utilization of Biobased Gaseous Fuels, Energy Authority, National Development and Reform Committee (BGFeuls), Beijing 100083, China
| | - Run Fan
- College of Engineering, China Agricultural University, Beijing 100083, China; R&D Center for Efficient Production and Comprehensive Utilization of Biobased Gaseous Fuels, Energy Authority, National Development and Reform Committee (BGFeuls), Beijing 100083, China
| | - Meng-Meng Jiang
- College of Engineering, China Agricultural University, Beijing 100083, China; R&D Center for Efficient Production and Comprehensive Utilization of Biobased Gaseous Fuels, Energy Authority, National Development and Reform Committee (BGFeuls), Beijing 100083, China
| | - Ren-Jie Dong
- College of Engineering, China Agricultural University, Beijing 100083, China; R&D Center for Efficient Production and Comprehensive Utilization of Biobased Gaseous Fuels, Energy Authority, National Development and Reform Committee (BGFeuls), Beijing 100083, China
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Ruiz-Sánchez J, Campanaro S, Guivernau M, Fernández B, Prenafeta-Boldú FX. Effect of ammonia on the active microbiome and metagenome from stable full-scale digesters. BIORESOURCE TECHNOLOGY 2018; 250:513-522. [PMID: 29197774 DOI: 10.1016/j.biortech.2017.11.068] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 11/17/2017] [Accepted: 11/22/2017] [Indexed: 05/20/2023]
Abstract
Four full-scale anaerobic digesters with a long history of stable operation were characterized in terms of active microbiome and metagenome. Isotopic fractionation of biogas demonstrated that acetotrophy was rather prevalent in reactors operated at <3 gTAN L-1 while hydrogenotrophy was predominant at >6 gTAN L-1, suggesting that syntrophic acetate oxidizing bacteria (SAOB) played a significant role in the latter. These results were generally coherent with the observed active bacterial and archaeal communities but no known SAOB were observed. Metagenome descriptions yielded 73 assembled population genomes, of which only 7 could be assigned at the species level. Gene annotation and association to relevant metabolic pathways indicated that the phyla Chloroflexi and Bacteroidales might encompass new, currently undescribed, SAOB/formate producing species that would metabolize acetate via the glycine cleavage system. The predominant hydrogenotrophic counterpart at a high ammonia content belonged to the genus Methanoculleus, which could also grow on acetate to a certain extent.
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Affiliation(s)
- J Ruiz-Sánchez
- GIRO Joint Research Unit IRTA-UPC, IRTA Torre Marimon, 08140 Caldes de Montbui (Barcelona), Catalonia, Spain.
| | - S Campanaro
- Department of Biology, University of Padua, Via U.Bassi 58/b 35121, Padua, Italy
| | - M Guivernau
- GIRO Joint Research Unit IRTA-UPC, IRTA Torre Marimon, 08140 Caldes de Montbui (Barcelona), Catalonia, Spain
| | - B Fernández
- GIRO Joint Research Unit IRTA-UPC, IRTA Torre Marimon, 08140 Caldes de Montbui (Barcelona), Catalonia, Spain
| | - F X Prenafeta-Boldú
- GIRO Joint Research Unit IRTA-UPC, IRTA Torre Marimon, 08140 Caldes de Montbui (Barcelona), Catalonia, Spain
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Westerholm M, Müller B, Singh A, Karlsson Lindsjö O, Schnürer A. Detection of novel syntrophic acetate-oxidizing bacteria from biogas processes by continuous acetate enrichment approaches. Microb Biotechnol 2017; 11:680-693. [PMID: 29239113 PMCID: PMC6011928 DOI: 10.1111/1751-7915.13035] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 11/11/2017] [Accepted: 11/12/2017] [Indexed: 11/27/2022] Open
Abstract
To enrich syntrophic acetate‐oxidizing bacteria (SAOB), duplicate chemostats were inoculated with sludge from syntrophic acetate oxidation (SAO)‐dominated systems and continuously supplied with acetate (0.4 or 7.5 g l−1) at high‐ammonia levels. The chemostats were operated under mesophilic (37°C) or thermophilic (52°C) temperature for about six hydraulic retention times (HRT 28 days) and were sampled over time. Irrespective of temperature, a methane content of 64–69% and effluent acetate level of 0.4–1.0 g l−1 were recorded in chemostats fed high acetate. Low methane production in the low‐acetate chemostats indicated that the substrate supply was below the threshold for methanization of acetate via SAO. Novel representatives within the family Clostridiales and genus Syntrophaceticus (class Clostridia) were identified to represent putative SAOB candidates in mesophilic and thermophilic conditions respectively. Known SAOB persisted at low relative abundance in all chemostats. The hydrogenotrophic methanogens Methanoculleus bourgensis (mesophilic) and Methanothermobacter thermautotrophicus (thermophilic) dominated archaeal communities in the high‐acetate chemostats. In line with the restricted methane production in the low‐acetate chemostats, methanogens persisted at considerably lower abundance in these chemostats. These findings strongly indicate involvement in SAO and tolerance to high ammonia levels of the species identified here, and have implications for understanding community function in stressed anaerobic processes.
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Affiliation(s)
- Maria Westerholm
- Uppsala BioCenter, Department of Molecular Sciences, Swedish University of Agricultural Sciences, Box 7025, SE-750 07, Uppsala, Sweden
| | - Bettina Müller
- Uppsala BioCenter, Department of Molecular Sciences, Swedish University of Agricultural Sciences, Box 7025, SE-750 07, Uppsala, Sweden
| | - Abhijeet Singh
- Uppsala BioCenter, Department of Molecular Sciences, Swedish University of Agricultural Sciences, Box 7025, SE-750 07, Uppsala, Sweden
| | - Oskar Karlsson Lindsjö
- Uppsala BioCenter, Department of Molecular Sciences, Swedish University of Agricultural Sciences, Box 7025, SE-750 07, Uppsala, Sweden
| | - Anna Schnürer
- Uppsala BioCenter, Department of Molecular Sciences, Swedish University of Agricultural Sciences, Box 7025, SE-750 07, Uppsala, Sweden
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Anaerobic digestion of pig manure supernatant at high ammonia concentrations characterized by high abundances of Methanosaeta and non-euryarchaeotal archaea. Sci Rep 2017; 7:15077. [PMID: 29118356 PMCID: PMC5678120 DOI: 10.1038/s41598-017-14527-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 10/06/2017] [Indexed: 11/22/2022] Open
Abstract
We examined the effect of ammonium and temperature on methane production in high rate upflow anaerobic sludge bed reactors treating pig manure supernatant. We operated four reactors at two ammonium concentrations (‘low’ at 1.9, ‘high’ at 3.7 g L−1, termed LA and HA reactors, respectively) and at variable temperatures over 358 days. Archaeal and bacterial communities were characterized by Illumina sequencing of 16S rRNA amplicons. Ammonium was a major selective factor for bacterial and archaeal community structure. After ~200 days of adaptation to high ammonium levels, acetate and propionate removal and methane production improved substantially in HA reactors. Aceticlastic Methanosaeta was abundant and positively correlated to methane yield in the HA reactors, whereas Methanosarcina was more abundant in LA reactors. Furthermore, a group of monophyletic OTUs that was related to Thaumarchaeota in phylogenetic analysis was highly abundant in the archaeal communities, particularly in the HA reactors. The most abundant bacterial OTU in LA reactors, representing Syntrophomonadaceae, was also positively correlated to methane yield in the HA reactors, indicating its importance in methane production under ammonia stress. In conclusion, efficient methane production, involving aceticlastic methanogenesis by Methanosaeta took place in the reactors at free ammonia concentrations as high as 1 g L−1.
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Hagen LH, Frank JA, Zamanzadeh M, Eijsink VGH, Pope PB, Horn SJ, Arntzen MØ. Quantitative Metaproteomics Highlight the Metabolic Contributions of Uncultured Phylotypes in a Thermophilic Anaerobic Digester. Appl Environ Microbiol 2017; 83:e01955-16. [PMID: 27815274 PMCID: PMC5203625 DOI: 10.1128/aem.01955-16] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 10/31/2016] [Indexed: 01/23/2023] Open
Abstract
In this study, we used multiple meta-omic approaches to characterize the microbial community and the active metabolic pathways of a stable industrial biogas reactor with food waste as the dominant feedstock, operating at thermophilic temperatures (60°C) and elevated levels of free ammonia (367 mg/liter NH3-N). The microbial community was strongly dominated (76% of all 16S rRNA amplicon sequences) by populations closely related to the proteolytic bacterium Coprothermobacter proteolyticus. Multiple Coprothermobacter-affiliated strains were detected, introducing an additional level of complexity seldom explored in biogas studies. Genome reconstructions provided metabolic insight into the microbes that performed biomass deconstruction and fermentation, including the deeply branching phyla Dictyoglomi and Planctomycetes and the candidate phylum "Atribacteria" These biomass degraders were complemented by a synergistic network of microorganisms that convert key fermentation intermediates (fatty acids) via syntrophic interactions with hydrogenotrophic methanogens to ultimately produce methane. Interpretation of the proteomics data also suggested activity of a Methanosaeta phylotype acclimatized to high ammonia levels. In particular, we report multiple novel phylotypes proposed as syntrophic acetate oxidizers, which also exert expression of enzymes needed for both the Wood-Ljungdahl pathway and β-oxidation of fatty acids to acetyl coenzyme A. Such an arrangement differs from known syntrophic oxidizing bacteria and presents an interesting hypothesis for future studies. Collectively, these findings provide increased insight into active metabolic roles of uncultured phylotypes and presents new synergistic relationships, both of which may contribute to the stability of the biogas reactor. IMPORTANCE Biogas production through anaerobic digestion of organic waste provides an attractive source of renewable energy and a sustainable waste management strategy. A comprehensive understanding of the microbial community that drives anaerobic digesters is essential to ensure stable and efficient energy production. Here, we characterize the intricate microbial networks and metabolic pathways in a thermophilic biogas reactor. We discuss the impact of frequently encountered microbial populations as well as the metabolism of newly discovered novel phylotypes that seem to play distinct roles within key microbial stages of anaerobic digestion in this stable high-temperature system. In particular, we draft a metabolic scenario whereby multiple uncultured syntrophic acetate-oxidizing bacteria are capable of syntrophically oxidizing acetate as well as longer-chain fatty acids (via the β-oxidation and Wood-Ljundahl pathways) to hydrogen and carbon dioxide, which methanogens subsequently convert to methane.
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Affiliation(s)
- Live H Hagen
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Jeremy A Frank
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Mirzaman Zamanzadeh
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Vincent G H Eijsink
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Phillip B Pope
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Svein J Horn
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Magnus Ø Arntzen
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
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From Genomes to Phenotypes: Traitar, the Microbial Trait Analyzer. mSystems 2016; 1:mSystems00101-16. [PMID: 28066816 PMCID: PMC5192078 DOI: 10.1128/msystems.00101-16] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 11/12/2016] [Indexed: 01/17/2023] Open
Abstract
Bacteria are ubiquitous in our ecosystem and have a major impact on human health, e.g., by supporting digestion in the human gut. Bacterial communities can also aid in biotechnological processes such as wastewater treatment or decontamination of polluted soils. Diverse bacteria contribute with their unique capabilities to the functioning of such ecosystems, but lab experiments to investigate those capabilities are labor-intensive. Major advances in sequencing techniques open up the opportunity to study bacteria by their genome sequences. For this purpose, we have developed Traitar, software that predicts traits of bacteria on the basis of their genomes. It is applicable to studies with tens or hundreds of bacterial genomes. Traitar may help researchers in microbiology to pinpoint the traits of interest, reducing the amount of wet lab work required. The number of sequenced genomes is growing exponentially, profoundly shifting the bottleneck from data generation to genome interpretation. Traits are often used to characterize and distinguish bacteria and are likely a driving factor in microbial community composition, yet little is known about the traits of most microbes. We describe Traitar, the microbial trait analyzer, which is a fully automated software package for deriving phenotypes from a genome sequence. Traitar provides phenotype classifiers to predict 67 traits related to the use of various substrates as carbon and energy sources, oxygen requirement, morphology, antibiotic susceptibility, proteolysis, and enzymatic activities. Furthermore, it suggests protein families associated with the presence of particular phenotypes. Our method uses L1-regularized L2-loss support vector machines for phenotype assignments based on phyletic patterns of protein families and their evolutionary histories across a diverse set of microbial species. We demonstrate reliable phenotype assignment for Traitar to bacterial genomes from 572 species of eight phyla, also based on incomplete single-cell genomes and simulated draft genomes. We also showcase its application in metagenomics by verifying and complementing a manual metabolic reconstruction of two novel Clostridiales species based on draft genomes recovered from commercial biogas reactors. Traitar is available at https://github.com/hzi-bifo/traitar. IMPORTANCE Bacteria are ubiquitous in our ecosystem and have a major impact on human health, e.g., by supporting digestion in the human gut. Bacterial communities can also aid in biotechnological processes such as wastewater treatment or decontamination of polluted soils. Diverse bacteria contribute with their unique capabilities to the functioning of such ecosystems, but lab experiments to investigate those capabilities are labor-intensive. Major advances in sequencing techniques open up the opportunity to study bacteria by their genome sequences. For this purpose, we have developed Traitar, software that predicts traits of bacteria on the basis of their genomes. It is applicable to studies with tens or hundreds of bacterial genomes. Traitar may help researchers in microbiology to pinpoint the traits of interest, reducing the amount of wet lab work required.
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