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Kabaivanova L, Hubenov V, Dimitrova L, Simeonov I, Wang H, Petrova P. Archaeal and Bacterial Content in a Two-Stage Anaerobic System for Efficient Energy Production from Agricultural Wastes. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27051512. [PMID: 35268611 PMCID: PMC8911581 DOI: 10.3390/molecules27051512] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/17/2022] [Accepted: 02/21/2022] [Indexed: 12/22/2022]
Abstract
Anaerobic digestion (AD) is a microbially-driven process enabling energy production. Microorganisms are the core of anaerobic digesters and play an important role in the succession of hydrolysis, acidogenesis, acetogenesis, and methanogenesis processes. The diversity of participating microbial communities can provide new information on digester performance for biomass valorization and biofuel production. In this study anaerobic systems were used, operating under mesophilic conditions that realized biodegradation processes of waste wheat straw pretreated with NaOH-a renewable source for hydrogen and methane production. These processes could be managed and optimized for hydrogen and methane separately but combining them in a two-stage system can lead to higher yields and a positive energy balance. The aim of the study was to depict a process of biohydrogen production from lignocellulosic waste followed by a second one leading to the production of biomethane. Archaeal and bacterial consortia in a two-stage system operating with wheat straw were identified for the first time and the role of the most important representatives was elucidated. The mixed cultures were identified by the molecular-biological methods of metagenomics. The results showed that biohydrogen generation is most probably due to the presence of Proteiniphilum saccharofermentans, which was 28.2% to 45.4% of the microbial community in the first and the second bioreactor, respectively. Archaeal representatives belonging to Methanobacterium formicicum (0.71% of the community), Methanosarcina spelaei (0.03%), Methanothrix soehngenii (0.012%), and Methanobacterium beijingense (0.01%) were proven in the methane-generating reactor. The correlation between substrate degradation and biogas accumulation was calculated, together with the profile of fatty acids as intermediates produced during the processes. The hydrogen concentration in the biogas reached 14.43%, and the Methane concentration was 69%. Calculations of the energy yield during the two-stage process showed 1195.89 kWh·t-1 compared to a 361.62 kWh·t-1 cumulative yield of energy carrier for a one-stage process.
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Affiliation(s)
- Lyudmila Kabaivanova
- Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria; (V.H.); (L.D.); (I.S.)
- Correspondence: (L.K.); (P.P.); Tel.: +359-2-9793167/79 (L.K. & P.P.)
| | - Venelin Hubenov
- Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria; (V.H.); (L.D.); (I.S.)
| | - Lyudmila Dimitrova
- Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria; (V.H.); (L.D.); (I.S.)
| | - Ivan Simeonov
- Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria; (V.H.); (L.D.); (I.S.)
| | - Haoping Wang
- French-Chinese Laboratory LaFCAS, School of Automation, Nanjing University of Science and Technology, Nanjing 210094, China;
| | - Penka Petrova
- Institute of Microbiology, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria; (V.H.); (L.D.); (I.S.)
- Correspondence: (L.K.); (P.P.); Tel.: +359-2-9793167/79 (L.K. & P.P.)
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Szilágyi Á, Bodor A, Tolvai N, Kovács KL, Bodai L, Wirth R, Bagi Z, Szepesi Á, Markó V, Kakuk B, Bounedjoum N, Rákhely G. A comparative analysis of biogas production from tomato bio-waste in mesophilic batch and continuous anaerobic digestion systems. PLoS One 2021; 16:e0248654. [PMID: 33730081 PMCID: PMC7968646 DOI: 10.1371/journal.pone.0248654] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 03/02/2021] [Indexed: 12/22/2022] Open
Abstract
Annually, agricultural activity produces an enormous amount of plant biomass by-product. Many studies have reported the biomethane potential of agro-industrial wastes, but only a few studies have investigated applying the substrates in both batch and continuous mode. Tomato is one of the most popular vegetables globally; its processing releases a substantial amount of by-product, such as stems and leaves. This study examined the BMP of tomato plant (Solanum lycopersicum Mill. L. cv. Alfred) waste. A comparative test revealed that the BMPs of corn stover, tomato waste,and their combination were approximately the same, around 280 mL methane/g Volatile Solid. In contrast, the relative biogas production decreased in the presence of tomato waste in a continuous mesophilic anaerobic digestion system; the daily biogas productions were 860 ± 80, 290 ± 50, and 570 ± 70 mL biogas/gVolatile Solid/day in the case of corn stover, tomato waste, and their mixture, respectively. The methane content of biogas was around 46–48%. The fermentation parameters of the continuous AD experiments were optimal in all cases; thus, TW might have an inhibitory effect on the microbial community. Tomato plant materials contain e.g. flavonoids, glycoalkaloids (such as tomatine and tomatidine), etc. known as antimicrobial and antifungal agents. The negative effect of tomatine on the biogas yield was confirmed in batch fermentation experiments. Metagenomic analysis revealed that the tomato plant waste caused significant rearrangements in the microbial communities in the continuously operated reactors. The results demonstrated that tomato waste could be a good mono-substrate in batch fermentations or a co-substrate with corn stover in a proper ratio in continuous anaerobic fermentations for biogas production. These results also point to the importance of running long-term continuous fermentations to test the suitability of a novel biomass substrate for industrial biogas production.
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Affiliation(s)
- Árpád Szilágyi
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Attila Bodor
- Department of Biotechnology, University of Szeged, Szeged, Hungary
- Institute of Environmental Sciences, University of Szeged, Szeged, Hungary
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - Norbert Tolvai
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Kornél L. Kovács
- Department of Biotechnology, University of Szeged, Szeged, Hungary
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
- Department of Oral Biology and Experimental Dental Research, University of Szeged, Szeged, Hungary
| | - László Bodai
- Department of Biochemistry and Molecular Biology, University of Szeged, Szeged, Hungary
| | - Roland Wirth
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Zoltán Bagi
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Ágnes Szepesi
- Department of Plant Biology, University of Szeged, Szeged, Hungary
| | - Viktória Markó
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Balázs Kakuk
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Naila Bounedjoum
- Department of Biotechnology, University of Szeged, Szeged, Hungary
| | - Gábor Rákhely
- Department of Biotechnology, University of Szeged, Szeged, Hungary
- Institute of Environmental Sciences, University of Szeged, Szeged, Hungary
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary
- * E-mail:
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Rettenmaier R, Kowollik ML, Klingl A, Liebl W, Zverlov V. Ruminiclostridium herbifermentans sp. nov., a mesophilic and moderately thermophilic cellulolytic and xylanolytic bacterium isolated from a lab-scale biogas fermenter fed with maize silage. Int J Syst Evol Microbiol 2021; 71. [PMID: 33555241 DOI: 10.1099/ijsem.0.004692] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
An anaerobic bacterial strain, designated MA18T, was isolated from a laboratory-scale biogas fermenter fed with maize silage. Cells stained Gram-negative and performed Gram-negative in the KOH test. The peptidoglycan type was found to be A1y-meso-Dpm direct. The major cellular fatty acids were C14 : 0 iso, C15 : 0 iso, anteiso and iso DMA as well as a C16 unidentified fatty acid. Oxidase and catalase activities were absent. Cells were slightly curved rods, motile, formed spores and measured approximately 0.35 µm in diameter and 3.0-5.0 µm in length. When cultivated on GS2 agar with cellobiose, round, arched, shiny and slightly yellow-pigmented colonies were formed. The isolate was mesophilic to moderately thermophilic with a growth optimum between 40 and 48 °C. Furthermore, neutral pH values were preferred and up to 1.2 % (w/v) NaCl supplemented to the GS2 medium was tolerated. Producing mainly acetate and ethanol, MA18T fermented arabinose, cellobiose, crystalline and amorphous cellulose, ribose, and xylan. The genome of MA18T consists of 4 817 678 bp with a G+C content of 33.16 mol%. In the annotated protein sequences, cellulosomal components were detected. Phylogenetically, MA18T is most closely related to Ruminiclostridium sufflavum DSM 19573T (76.88 % average nucleotide identity of the whole genome sequence; 97.23 % 16S rRNA gene sequence similarity) and can be clustered into one clade with other species of the genus Ruminiclostridium, family Oscillospiraceae, class Clostridia. Based on morphological, physiological and genetic characteristics, this strain represents a novel species in the genus Ruminiclostridium. Therefore, the name Ruminiclostridium herbifermentans sp. nov. is proposed. The type strain is MA18T (=DSM 109966T=JCM 39124T).
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Affiliation(s)
- Regina Rettenmaier
- Technical University of Munich, Chair of Microbiology, Emil-Ramann-Str. 4, 85354 Freising, Germany
| | - Marie-Louise Kowollik
- Technical University of Munich, Chair of Microbiology, Emil-Ramann-Str. 4, 85354 Freising, Germany
| | - Andreas Klingl
- LMU Munich, Plant Development & Electron Microscopy, Biocenter LMU Munich, Großhadernerstr. 2-4, 82152 Planegg-Martinsried, Germany
| | - Wolfgang Liebl
- Technical University of Munich, Chair of Microbiology, Emil-Ramann-Str. 4, 85354 Freising, Germany
| | - Vladimir Zverlov
- Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Kurchatov Sq. 2, 123182 Moscow, Russia.,Technical University of Munich, Chair of Microbiology, Emil-Ramann-Str. 4, 85354 Freising, Germany
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Rettenmaier R, Lo YK, Schmidt L, Munk B, Lagkouvardos I, Neuhaus K, Schwarz W, Liebl W, Zverlov V. A Novel Primer Mixture for GH48 Genes: Quantification and Identification of Truly Cellulolytic Bacteria in Biogas Fermenters. Microorganisms 2020; 8:E1297. [PMID: 32854333 PMCID: PMC7565076 DOI: 10.3390/microorganisms8091297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 08/21/2020] [Accepted: 08/23/2020] [Indexed: 12/22/2022] Open
Abstract
Genomic studies revealed the glycoside hydrolases of family 48 (GH48) as a powerful marker for the identification of truly cellulolytic bacteria. Here we report an improved method for detecting cellulolytic bacteria in lab-scale biogas fermenters by using GH48 genes as a molecular marker in DNA and RNA samples. We developed a mixture of primers for the specific amplification of a GH48 gene region in a broad range of bacteria. Additionally, we built a manually curated reference database containing GH48 gene sequences directly linked to the corresponding taxonomic information. Phylogenetic correlation analysis of GH48 to 16S rRNA gene sequences revealed that GH48 gene sequences with 94% identity belong with high confidence to the same genus. Applying this analysis, GH48 amplicon reads revealed that at mesophilic fermenter conditions, 50-99% of the OTUs appear to belong to novel taxa. In contrast, at thermophilic conditions, GH48 gene sequences from the genus Hungateiclostridium dominated with 60-91% relative abundance. The novel primer combinations enabled detection and relative quantification of a wide spectrum of GH48 genes in cellulolytic microbial communities. Deep phylogenetic correlation analysis and a simplified taxonomic identification with the novel database facilitate identification of cellulolytic organisms, including the detection of novel taxa in biogas fermenters.
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Affiliation(s)
- Regina Rettenmaier
- Chair of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, 85354 Freising, Germany; (R.R.); (Y.K.L.); (L.S.); (W.L.)
| | - Yat Kei Lo
- Chair of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, 85354 Freising, Germany; (R.R.); (Y.K.L.); (L.S.); (W.L.)
| | - Larissa Schmidt
- Chair of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, 85354 Freising, Germany; (R.R.); (Y.K.L.); (L.S.); (W.L.)
| | - Bernhard Munk
- Bavarian State Research Center for Agriculture, Central Department for Quality Assurance and Analytics, Lange Point 6, 85354 Freising, Germany;
| | - Ilias Lagkouvardos
- ZIEL—Core Facility Microbiome, Technical University of Munich, Weihenstephaner Berg 3, 85354 Freising, Germany; (I.L.); (K.N.)
| | - Klaus Neuhaus
- ZIEL—Core Facility Microbiome, Technical University of Munich, Weihenstephaner Berg 3, 85354 Freising, Germany; (I.L.); (K.N.)
| | - Wolfgang Schwarz
- Aspratis GmbH. Munich, Germany, Hübnerstr. 11, 80637 Munich, Germany;
| | - Wolfgang Liebl
- Chair of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, 85354 Freising, Germany; (R.R.); (Y.K.L.); (L.S.); (W.L.)
| | - Vladimir Zverlov
- Chair of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, 85354 Freising, Germany; (R.R.); (Y.K.L.); (L.S.); (W.L.)
- Institute of Molecular Genetics of National Research Centre (Kurchatov Institute), Kurchatov Sq. 2, 123182 Moscow, Russia
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Rettenmaier R, Schneider M, Munk B, Lebuhn M, Jünemann S, Sczyrba A, Maus I, Zverlov V, Liebl W. Importance of Defluviitalea raffinosedens for Hydrolytic Biomass Degradation in Co-Culture with Hungateiclostridium thermocellum. Microorganisms 2020; 8:E915. [PMID: 32560349 PMCID: PMC7355431 DOI: 10.3390/microorganisms8060915] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/06/2020] [Accepted: 06/11/2020] [Indexed: 01/02/2023] Open
Abstract
Bacterial hydrolysis of polysaccharides is an important step for the production of sustainable energy, for example during the conversion of plant biomass to methane-rich biogas. Previously, Hungateiclostridium thermocellum was identified as cellulolytic key player in thermophilic biogas microbiomes with a great frequency as an accompanying organism. The aim of this study was to physiologically characterize a recently isolated co-culture of H. thermocellum and the saccharolytic bacterium Defluviitalea raffinosedens from a laboratory-scale biogas fermenter. The characterization focused on cellulose breakdown by applying the measurement of cellulose hydrolysis, production of metabolites, and the activity of secreted enzymes. Substrate degradation and the production of volatile metabolites was considerably enhanced when both organisms acted synergistically. The metabolic properties of H. thermocellum have been studied well in the past. To predict the role of D. raffinosedens in this bacterial duet, the genome of D. raffinosedens was sequenced for the first time. Concomitantly, to deduce the prevalence of D. raffinosedens in anaerobic digestion, taxonomic composition and transcriptional activity of different biogas microbiomes were analyzed in detail. Defluviitalea was abundant and metabolically active in reactor operating at highly efficient process conditions, supporting the importance of this organism for the hydrolysis of the raw substrate.
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Affiliation(s)
- Regina Rettenmaier
- Chair of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, 85354 Freising, Germany; (R.R.); (M.S.); (W.L.)
| | - Martina Schneider
- Chair of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, 85354 Freising, Germany; (R.R.); (M.S.); (W.L.)
| | - Bernhard Munk
- Department for Quality Assurance and Analytics, Bavarian State Research Center for Agriculture, Lange Point 6, 85354 Freising, Germany; (B.M.); (M.L.)
| | - Michael Lebuhn
- Department for Quality Assurance and Analytics, Bavarian State Research Center for Agriculture, Lange Point 6, 85354 Freising, Germany; (B.M.); (M.L.)
| | - Sebastian Jünemann
- Center for Biotechnology (CeBiTec), Universitätsstr. 27, 33615 Bielefeld, Germany;
- Faculty of Technology, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany;
| | - Alexander Sczyrba
- Faculty of Technology, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany;
| | - Irena Maus
- Center for Biotechnology (CeBiTec), Universitätsstr. 27, 33615 Bielefeld, Germany;
| | - Vladimir Zverlov
- Chair of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, 85354 Freising, Germany; (R.R.); (M.S.); (W.L.)
- Institute of Molecular Genetics, RAS, Kurchatov Sq. 2, 123182 Moscow, Russia
| | - Wolfgang Liebl
- Chair of Microbiology, Technical University of Munich, Emil-Ramann-Str. 4, 85354 Freising, Germany; (R.R.); (M.S.); (W.L.)
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