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Effects of Alginate and Chitosan on Activated Carbon as Immobilisation Beads in Biohydrogen Production. Processes (Basel) 2020. [DOI: 10.3390/pr8101254] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In this study, the effects of alginate and chitosan as entrapped materials in the biofilm formation of microbial attachment on activated carbon was determined for biohydrogen production. Five different batch fermentations, consisting of mixed concentration alginate (Alg), were carried out in a bioreactor at temperature of 60 °C and pH 6.0, using granular activated carbon (GAC) as a primer for cell attachment and colonisation. It was found that the highest hydrogen production rate (HPR) of the GAC–Alg beads was 2.47 ± 0.47 mmol H2/l.h, and the H2 yield of 2.09 ± 0.22 mol H2/mol sugar was obtained at the ratio of 2 g/L of Alg concentration. Next, the effect of chitosan (C) as an external polymer layer of the GAC–Alg beads was investigated as an alternative approach to protecting the microbial population in the biofilm in a robust environment. The formation of GAC with Alg and chitosan (GAC–AlgC) beads gave the highest HPR of 0.93 ± 0.05 mmol H2/l.h, and H2 yield of 1.11 ± 0.35 mol H2/mol sugar was found at 2 g/L of C concentration. Hydrogen production using GAC-attached biofilm seems promising to achieve consistent HPRs at higher temperatures, using Alg as immobilised bead material, which has indicated a positive response in promoting the growth of hydrogen-producing bacteria and providing excellent conditions for microorganisms to grow and colonise high bacterial loads in a bioreactor.
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Jamali NS, Dzul Rashidi NF, Jahim JM, O-Thong S, Jehlee A, Engliman NS. Thermophilic biohydrogen production from palm oil mill effluent: Effect of immobilized cells on granular activated carbon in fluidized bed reactor. FOOD AND BIOPRODUCTS PROCESSING 2019. [DOI: 10.1016/j.fbp.2019.07.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Omar B, El-Gammal M, Abou-Shanab R, Fotidis IA, Angelidaki I, Zhang Y. Biogas upgrading and biochemical production from gas fermentation: Impact of microbial community and gas composition. BIORESOURCE TECHNOLOGY 2019; 286:121413. [PMID: 31078978 DOI: 10.1016/j.biortech.2019.121413] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 05/01/2019] [Accepted: 05/02/2019] [Indexed: 06/09/2023]
Abstract
The present study proposes a novel alternative method of the current biogas upgrading techniques by converting CO2 (in the biogas) into valuable chemicals (e.g., volatile fatty acids) using H2 as energy source and acetogenic mixed culture as biocatalyst. The influence of thermal treatment (90 °C) on the inhibition of the methanogenic archaea and enriching the acetogenic bacteria in different inocula (mesophilic and thermophilic) was initially tested. The most efficient inoculum that achieved the highest performance through the fermentation process was further used to define the optimum H2/CO2 gas ratio that secures maximum production yield of chemicals and maximum biogas upgrading efficiency. In addition, 16S rRNA analysis of the microbial community was conducted at the end of the experimental period to target functional microbes. The maximum biogas content (77% (v/v)) and acetate yield (72%) were achieved for 2H2:1CO2 ratio (v/v), with Moorella sp. 4 as the most dominant thermophilic acetogenic bacterium.
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Affiliation(s)
- Basma Omar
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet Bygning 115, DK-2800 Kgs. Lyngby, Denmark; Department of Environmental Sciences, Faculty of Science, Damietta University, 34517 Damietta, Egypt
| | - Maie El-Gammal
- Department of Environmental Sciences, Faculty of Science, Damietta University, 34517 Damietta, Egypt
| | - Reda Abou-Shanab
- Department of Environmental Biotechnology, City of Scientific Research and Technology Applications, Alexandria 21934, Egypt
| | - Ioannis A Fotidis
- 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
| | - Yifeng Zhang
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet Bygning 115, DK-2800 Kgs. Lyngby, Denmark.
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Penniston J, Gueguim Kana EB. Impact of medium pH regulation on biohydrogen production in dark fermentation process using suspended and immobilized microbial cells. BIOTECHNOL BIOTEC EQ 2017. [DOI: 10.1080/13102818.2017.1408430] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Affiliation(s)
- Joelle Penniston
- Discipline of Microbiology, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - Evariste Bosco Gueguim Kana
- Discipline of Microbiology, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
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Strang O, Ács N, Wirth R, Maróti G, Bagi Z, Rákhely G, Kovács KL. Bioaugmentation of the thermophilic anaerobic biodegradation of cellulose and corn stover. Anaerobe 2017; 46:104-113. [DOI: 10.1016/j.anaerobe.2017.05.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 05/16/2017] [Accepted: 05/24/2017] [Indexed: 12/26/2022]
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6
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Achmon Y, Fernández-Bayo JD, Hernandez K, McCurry DG, Harrold DR, Su J, Dahlquist-Willard RM, Stapleton JJ, VanderGheynst JS, Simmons CW. Weed seed inactivation in soil mesocosms via biosolarization with mature compost and tomato processing waste amendments. PEST MANAGEMENT SCIENCE 2017; 73:862-873. [PMID: 27391139 DOI: 10.1002/ps.4354] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 06/13/2016] [Accepted: 07/05/2016] [Indexed: 06/06/2023]
Abstract
BACKGROUND Biosolarization is a fumigation alternative that combines passive solar heating with amendment-driven soil microbial activity to temporarily create antagonistic soil conditions, such as elevated temperature and acidity, that can inactivate weed seeds and other pest propagules. The aim of this study was to use a mesocosm-based field trial to assess soil heating, pH, volatile fatty acid accumulation and weed seed inactivation during biosolarization. RESULTS Biosolarization for 8 days using 2% mature green waste compost and 2 or 5% tomato processing residues in the soil resulted in accumulation of volatile fatty acids in the soil, particularly acetic acid, and >95% inactivation of Brassica nigra and Solanum nigrum seeds. Inactivation kinetics data showed that near complete weed seed inactivation in soil was achieved within the first 5 days of biosolarization. This was significantly greater than the inactivation achieved in control soils that were solar heated without amendment or were amended but not solar heated. CONCLUSION The composition and concentration of organic matter amendments in soil significantly affected volatile fatty acid accumulation at various soil depths during biosolarization. Combining solar heating with organic matter amendment resulted in accelerated weed seed inactivation compared with either approach alone. © 2016 Society of Chemical Industry.
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Affiliation(s)
- Yigal Achmon
- Department of Food Science and Technology, University of California, Davis, CA, USA
- Department of Biological and Agricultural Engineering, University of California, Davis, CA, USA
| | - Jesús D Fernández-Bayo
- Department of Food Science and Technology, University of California, Davis, CA, USA
- Department of Biological and Agricultural Engineering, University of California, Davis, CA, USA
| | - Katie Hernandez
- University of California Cooperative Extension, Fresno County, Fresno, CA, USA
- School of Natural Sciences, Fresno Pacific University, Fresno, CA, USA
| | - Dlinka G McCurry
- University of California Cooperative Extension, Fresno County, Fresno, CA, USA
| | - Duff R Harrold
- Department of Biological and Agricultural Engineering, University of California, Davis, CA, USA
| | - Joey Su
- Department of Food Science and Technology, University of California, Davis, CA, USA
| | | | - James J Stapleton
- Statewide Integrated Pest Management Program, University of California, Kearney Agricultural Research and Extension Center, Parlier, CA, USA
| | - Jean S VanderGheynst
- Department of Biological and Agricultural Engineering, University of California, Davis, CA, USA
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Cabrol L, Marone A, Tapia-Venegas E, Steyer JP, Ruiz-Filippi G, Trably E. Microbial ecology of fermentative hydrogen producing bioprocesses: useful insights for driving the ecosystem function. FEMS Microbiol Rev 2017; 41:158-181. [DOI: 10.1093/femsre/fuw043] [Citation(s) in RCA: 154] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/05/2016] [Indexed: 11/13/2022] Open
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8
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Anand S, Kaur H, Mande SS. Comparative In silico Analysis of Butyrate Production Pathways in Gut Commensals and Pathogens. Front Microbiol 2016; 7:1945. [PMID: 27994578 PMCID: PMC5133246 DOI: 10.3389/fmicb.2016.01945] [Citation(s) in RCA: 133] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 11/18/2016] [Indexed: 12/22/2022] Open
Abstract
Biosynthesis of butyrate by commensal bacteria plays a crucial role in maintenance of human gut health while dysbiosis in gut microbiome has been linked to several enteric disorders. Contrastingly, butyrate shows cytotoxic effects in patients with oral diseases like periodontal infections and oral cancer. In addition to these host associations, few syntrophic bacteria couple butyrate degradation with sulfate reduction and methane production. Thus, it becomes imperative to understand the distribution of butyrate metabolism pathways and delineate differences in substrate utilization between pathogens and commensals. The bacteria utilize four pathways for butyrate production with different initial substrates (Pyruvate, 4-aminobutyrate, Glutarate and Lysine) which follow a polyphyletic distribution. A comprehensive mining of complete/draft bacterial genomes indicated conserved juxtaposed genomic arrangement in all these pathways. This gene context information was utilized for an accurate annotation of butyrate production pathways in bacterial genomes. Interestingly, our analysis showed that inspite of a beneficial impact of butyrate in gut, not only commensals, but a few gut pathogens also possess butyrogenic pathways. The results further illustrated that all the gut commensal bacteria (Faecalibacterium, Roseburia, Butyrivibrio, and commensal species of Clostridia etc) ferment pyruvate for butyrate production. On the contrary, the butyrogenic gut pathogen Fusobacterium utilizes different amino acid metabolism pathways like those for Glutamate (4-aminobutyrate and Glutarate) and Lysine for butyrogenesis which leads to a concomitant release of harmful by-products like ammonia in the process. The findings in this study indicate that commensals and pathogens in gut have divergently evolved to produce butyrate using distinct pathways. No such evolutionary selection was observed in oral pathogens (Porphyromonas and Filifactor) which showed presence of pyruvate as well as amino acid fermenting pathways which might be because the final product butyrate is itself known to be cytotoxic in oral diseases. This differential utilization of butyrogenic pathways in gut pathogens and commensals has an enormous ecological impact taking into consideration the immense influence of butyrate on different disorders in humans. The results of this study can potentially guide bioengineering experiments to design therapeutics/probiotics by manipulation of butyrate biosynthesis gene clusters in bacteria.
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Affiliation(s)
- Swadha Anand
- Bio-Sciences R&D Division, TCS Research, Tata Consultancy Services Ltd. Pune, India
| | - Harrisham Kaur
- Bio-Sciences R&D Division, TCS Research, Tata Consultancy Services Ltd. Pune, India
| | - Sharmila S Mande
- Bio-Sciences R&D Division, TCS Research, Tata Consultancy Services Ltd. Pune, India
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9
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Sato Y, Hori T, Navarro RR, Habe H, Yanagishita H, Ogata A. Fine-scale monitoring of shifts in microbial community composition after high organic loading in a pilot-scale membrane bioreactor. J Biosci Bioeng 2016; 121:550-6. [DOI: 10.1016/j.jbiosc.2015.10.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 08/31/2015] [Accepted: 10/05/2015] [Indexed: 10/22/2022]
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10
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Sato Y, Hori T, Navarro RR, Habe H, Ogata A. Functional maintenance and structural flexibility of microbial communities perturbed by simulated intense rainfall in a pilot-scale membrane bioreactor. Appl Microbiol Biotechnol 2016; 100:6447-6456. [PMID: 27020291 DOI: 10.1007/s00253-016-7466-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 03/09/2016] [Accepted: 03/11/2016] [Indexed: 11/26/2022]
Abstract
Intense rainfall is one of the most serious and common natural events, causing the excessive inflow of rainwater into wastewater treatment plants. However, little is known about the impacts of rainwater dilution on the structure and function of the sludge microorganisms. Here, high-throughput sequencing of 16S ribosomal RNA (rRNA) genes was implemented to describe the microbial community dynamics during the simulated intense rainfall situation (event i) in which approximately 45 % of the sludge biomass was artificially overflowed by massive water supply in a pilot-scale membrane bioreactor. Thereafter, we investigated the functional and structural responses of the perturbed microbial communities to subsequent conditional changes, i.e., an increase in organic loading rate from 225 to 450 mg chemical oxygen demand (COD) l(-1) day(-1) (event ii) and an addition of a microbiota activator (event iii). Due to the event i, the COD removal declined to 78.2 %. This deterioration coincided with the decreased microbial diversity and the proliferation of the oligotrophic Aquabacterium sp. During the succeeding events ii and iii, the sludge biomass increased and the COD removal became higher (86.5-97.4 %). With the apparent recovery of the reactor performance, microbial communities became diversified and the compositions dynamically changed. Notably, various bacterial micropredators were highly enriched under the successive conditions, most likely being involved in the flexible reorganization of microbial communities. These results indicate that the activated sludge harbored functionally redundant microorganisms that were able to thrive and proliferate along with the conditional changes, thereby contributing to the functional maintenance of the membrane bioreactor.
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Affiliation(s)
- Yuya Sato
- Environmental Management Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki, 305-8569, Japan
| | - Tomoyuki Hori
- Environmental Management Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki, 305-8569, Japan
| | - Ronald R Navarro
- Environmental Management Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki, 305-8569, Japan
| | - Hiroshi Habe
- Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), AIST, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan.
| | - Atsushi Ogata
- Environmental Management Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki, 305-8569, Japan
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11
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Characterization of microbial compositions in a thermophilic chemostat of mixed culture fermentation. Appl Microbiol Biotechnol 2015; 100:1511-1521. [PMID: 26563549 DOI: 10.1007/s00253-015-7130-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 10/26/2015] [Accepted: 10/29/2015] [Indexed: 10/22/2022]
Abstract
The microbial community compositions of a chemostat enriched in a thermophilic (55 °C) mixed culture fermentation (MCF) for hydrogen production under different operational conditions were revealed in this work by integrating denaturing gradient gel electrophoresis (DGGE), Illumina Miseq high-throughput sequencing, and 16S rRNA clone library sequencing. The results showed that the community structure of the enriched cultures was relatively simple. Clones close to the genera of Thermoanaerobacter and/or Bacillus mainly dominated the bacteria. And homoacetogens and archaea were washed out and not detected even by Illumina Miseq high-throughput sequencing which supported the benefit for hydrogen production. On the other hand, the results revealed that the metabolic shift was clearly associated with the change of dominated bacterial groups. The effects of hydrogen partial pressure (PH2) and pH from 4.0 to 5.5 on the microbial compositions were not notable and Thermoanaerobacter was dominant, thus, the metabolites were also not changed. While Bacillus, Thermoanaerobacter and Propionispora hippei dominated the bacteria communities at neutral pH, or Bacillus and Thermoanaerobacter dominated at high influent glucose concentrations, consequently the main metabolites shifted to acetate, ethanol, propionate, or lactate. Thereby, the effect of microbial composition on the metabolite distribution and shift shall be considered when modeling thermophilic MCF in the future.
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12
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The biostimulation of anaerobic digestion with (semi)conductive ferric oxides: their potential for enhanced biomethanation. Appl Microbiol Biotechnol 2015; 99:10355-66. [DOI: 10.1007/s00253-015-6900-y] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 07/26/2015] [Accepted: 07/29/2015] [Indexed: 01/07/2023]
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13
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Kim J, Lee C. Response of a continuous biomethanation process to transient organic shock loads under controlled and uncontrolled pH conditions. WATER RESEARCH 2015; 73:68-77. [PMID: 25644629 DOI: 10.1016/j.watres.2015.01.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 01/06/2015] [Accepted: 01/08/2015] [Indexed: 06/04/2023]
Abstract
The organic loading rate (OLR) is a critical factor that controls the treatment efficiency and biogas production in anaerobic digestion (AD). Therefore, organic shock loads may cause significant process imbalances accompanied by a drop in pH and acid accumulation or even failure. This study investigated the response of a continuous mesophilic anaerobic bioreactor to a series of transient organic shock loads of the substrate whey permeate, a high-strength organic wastewater from cheese making. The reactor was subjected to organic shock loads of increasing magnitude (a one-day pulse of elevated feed organic concentration) under controlled (near 7) and uncontrolled pH conditions at a fixed HRT of 10 days. The reactor was resilient to up to a shock load of up to 8.0 g SCOD/L·d under controlled pH conditions but failed to recover from the serious imbalance caused by a 3.0-g SCOD/L·d shock load, thus indicating the critical effect of pH on system resilience. The acidified reactor was not restored by interrupted feeding under the acidic conditions that were formed (pH ≤ 4.5) but was successfully restored after pH adjustment to 7. The reactor subsequently reverted to continuous mode without pH control and showed a performance comparable to the stable performance at the design OLR of 1.0 g SCOD/L·d. The bacterial community structure shifted dynamically in association with disturbances in the reactor conditions, whereas the archaeal community structure remained simple and less variable during the shock loading experiments. The structural shifts of the bacterial community were well correlated with the process performance changes, and performance recovery was generally accompanied by recovery of the bacterial community structure. The overall results suggest that the reactor pH, rather than simply acting as an accumulation of organic acids, had a crucial effect on the resilience and robustness of the microbial community and thus on the reactor performance under organic shock loads.
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Affiliation(s)
- Jaai Kim
- School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan 689-798, Republic of Korea
| | - Changsoo Lee
- School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan 689-798, Republic of Korea.
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Ratti RP, Delforno TP, Okada DY, Varesche MBA. Bacterial communities in thermophilic H2-producing reactors investigated using 16S rRNA 454 pyrosequencing. Microbiol Res 2015; 173:10-7. [DOI: 10.1016/j.micres.2015.01.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 01/05/2015] [Accepted: 01/26/2015] [Indexed: 10/24/2022]
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15
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Hori T, Haruta S, Sasaki D, Hanajima D, Ueno Y, Ogata A, Ishii M, Igarashi Y. Reorganization of the bacterial and archaeal populations associated with organic loading conditions in a thermophilic anaerobic digester. J Biosci Bioeng 2015; 119:337-44. [DOI: 10.1016/j.jbiosc.2014.09.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Revised: 07/28/2014] [Accepted: 09/02/2014] [Indexed: 10/24/2022]
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16
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Xu S, Selvam A, Wong JWC. Optimization of micro-aeration intensity in acidogenic reactor of a two-phase anaerobic digester treating food waste. WASTE MANAGEMENT (NEW YORK, N.Y.) 2014; 34:363-9. [PMID: 24290969 DOI: 10.1016/j.wasman.2013.10.038] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 09/09/2013] [Accepted: 10/28/2013] [Indexed: 05/25/2023]
Abstract
Micro-aeration is known to promote the activities of hydrolytic exo-enzymes and used as a strategy to improve the hydrolysis of particulate substrate. The effect of different micro-aeration rates, 0, 129, 258, and 387 L-air/kg TS/d (denoted as LBR-AN, LBR-6h, LBR-3h and LBR-2h, respectively) on the solubilization of food waste was evaluated at 35°C in four leach bed reactors (LBR) coupled with methanogenic upflow anaerobic sludge blanket (UASB) reactor. Results indicate that the intensity of micro-aeration influenced the hydrolysis and methane yield. Adequate micro-aeration intensity in LBR-3h and LBR-2h significantly enhanced the carbohydrate and protein hydrolysis by 21-27% and 38-64% respectively. Due to the accelerated acidogenesis, more than 3-fold of acetic acid and butyric acid were produced in LBR-3h as compared to the anaerobic treatment LBR-AN resulting in the maximum methane yield of 0.27 L CH4/g VS(added) in the UASB. The performance of LBR-6h with inadequate aeration was similar to that of LBR-AN with a comparable hydrolysis degree. Nevertheless, higher aeration intensity in LBR-2h was also unfavorable for methane yield due to significant biomass generation and CO2 respiration of up to 18.5% and 32.8% of the total soluble hydrolysate, respectively. To conclude, appropriate micro-aeration rate can promote the hydrolysis of solid organic waste and methane yield without undesirable carbon loss and an aeration intensity of 258 L-air/kg TS/d is recommended for acidogenic LBR treating food waste.
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Affiliation(s)
- Suyun Xu
- Department of Environmental & Low-Carbon Science, School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, China; Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region
| | - Ammaiyappan Selvam
- Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region
| | - Jonathan W C Wong
- Sino-Forest Applied Research Centre for Pearl River Delta Environment, Department of Biology, Hong Kong Baptist University, Hong Kong Special Administrative Region.
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Zhang X, Qiu W, Chen H. Enhancing the hydrolysis and acidification of steam-exploded cornstalks by intermittent pH adjustment with an enriched microbial community. BIORESOURCE TECHNOLOGY 2012; 123:30-35. [PMID: 22929742 DOI: 10.1016/j.biortech.2012.07.054] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 07/13/2012] [Accepted: 07/16/2012] [Indexed: 06/01/2023]
Abstract
Intermittent pH adjustment was used to increase the degradation rate of steam-exploded cornstalks (SEC) and the production of organic acids by an enriched microbial community. The results showed that the degradation rate of SEC was as high as 75% and not affected by the intermittent pH adjustment within the range of 7.0-9.0. However, the total concentration of major water soluble metabolites (acetate and propionate) were increased with pH enhancement, showing the results of 1.86gL(-1) for pH 7.0, 2.04gL(-1) for pH 8.0 and 3.32gL(-1) for pH 9.0 after 84h of fermentation. Based on 16s rDNA analysis by denaturing gradient gel electrophoresis (DGGE), different strains were dominant due to pH shift by intermittent adjustment, which would consequently cause the change in fermentation pattern. Intermittent pH adjustment was considered to be a useful way to enhance bioconversion potentiality of lignocellulose.
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Affiliation(s)
- Xiang Zhang
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
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Sasaki K, Morita M, Sasaki D, Ohmura N, Igarashi Y. The membraneless bioelectrochemical reactor stimulates hydrogen fermentation by inhibiting methanogenic archaea. Appl Microbiol Biotechnol 2012; 97:7005-13. [DOI: 10.1007/s00253-012-4465-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Revised: 09/17/2012] [Accepted: 09/20/2012] [Indexed: 10/27/2022]
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19
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Sasaki K, Morita M, Sasaki D, Matsumoto N, Ohmura N, Igarashi Y. Single-chamber bioelectrochemical hydrogen fermentation from garbage slurry. Biochem Eng J 2012. [DOI: 10.1016/j.bej.2012.07.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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20
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Lü Y, Li N, Gong D, Wang X, Cui Z. The Effect of Temperature on the Structure and Function of a Cellulose-Degrading Microbial Community. Appl Biochem Biotechnol 2012; 168:219-33. [DOI: 10.1007/s12010-012-9731-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 05/08/2012] [Indexed: 11/30/2022]
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21
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Construction of hydrogen fermentation from garbage slurry using the membrane free bioelectrochemical system. J Biosci Bioeng 2012; 114:64-9. [DOI: 10.1016/j.jbiosc.2012.02.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Accepted: 02/28/2012] [Indexed: 11/17/2022]
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22
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Han W, Wang B, Zhou Y, Wang DX, Wang Y, Yue LR, Li YF, Ren NQ. Fermentative hydrogen production from molasses wastewater in a continuous mixed immobilized sludge reactor. BIORESOURCE TECHNOLOGY 2012; 110:219-223. [PMID: 22326329 DOI: 10.1016/j.biortech.2012.01.057] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 01/13/2012] [Accepted: 01/14/2012] [Indexed: 05/31/2023]
Abstract
A novel continuous mixed immobilized sludge reactor (CMISR) containing activated carbon as support carrier was used for fermentative hydrogen production from molasses wastewater. When the CMISR system operated at the conditions of influent COD of 2000-6000mg/L, hydraulic retention time (HRT) of 6h and temperature of 35°C, stable ethanol type fermentation was formed after 40days operation. The H(2) content in biogas and chemical oxygen demand (COD) removal were estimated to be 46.6% and 13%, respectively. The effects of organic loading rates (OLRs) on the CMISR hydrogen production system were also investigated. It was found that the maximum hydrogen production rate of 12.51mmol/hL was obtained at OLR of 32kg/m(3)d and the maximum hydrogen yield by substrate consumed of 130.57mmol/mol happened at OLR of 16kg/m(3)d. Therefore, the continuous mixed immobilized sludge reactor (CMISR) could be a promising immobilized system for fermentative hydrogen production.
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Affiliation(s)
- Wei Han
- School of Forestry, Northeast Forestry University, Harbin 150040, China
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Hung CH, Chang YT, Chang YJ. Roles of microorganisms other than Clostridium and Enterobacter in anaerobic fermentative biohydrogen production systems--a review. BIORESOURCE TECHNOLOGY 2011; 102:8437-8444. [PMID: 21429742 DOI: 10.1016/j.biortech.2011.02.084] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 02/18/2011] [Accepted: 02/20/2011] [Indexed: 05/30/2023]
Abstract
Anaerobic fermentative biohydrogen production, the conversion of organic substances especially from organic wastes to hydrogen gas, has become a viable and promising means of producing sustainable energy. Successful biological hydrogen production depends on the overall performance (results of interactions) of bacterial communities, i.e., mixed cultures in reactors. Mixed cultures might provide useful combinations of metabolic pathways for the processing of complex waste material ingredients, thereby supporting the more efficient decomposition and hydrogenation of biomass than pure bacteria species would. Therefore, understanding the relationships between variations in microbial composition and hydrogen production efficiency is the first step in constructing more efficient hydrogen-producing consortia, especially when complex and non-sterilized organic wastes are used as feeding substrates. In this review, we describe recent discoveries on bacterial community composition obtained from dark fermentation biohydrogen production systems, with emphasis on the possible roles of microorganisms that co-exist with common hydrogen producers.
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Affiliation(s)
- Chun-Hsiung Hung
- Department of Environmental Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 402, Taiwan.
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Lü Y, Wang X, Li N, Wang X, Ishii M, Igarashi Y, Cui Z. Characterization of the effective cellulose degrading strain CTL-6. J Environ Sci (China) 2011; 23:649-655. [PMID: 21793408 DOI: 10.1016/s1001-0742(10)60460-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
An efficient cellulose degrading bacteria exists in the thermophilic wheat straw-degrading community, WDC2. However, this strain cannot be isolated and cultured using conventional separation techniques under strict anaerobic conditions. We successfully isolated a strain of effective cellulose degrading bacteria CTL-6 using a wash, heat shock, and solid-liquid alternating process. Analysis of its properties revealed that, although the community containing the strain CTL-6 grew under aerobic conditions, the purified strain CTL-6 only grew under anaerobic culture conditions. The strain CTL-6 had a striking capability of degrading cellulose (80.9% weight loss after 9 days of culture). The highest efficiency value of the endocellulase (CMCase activity) was 0.404 micromol/(min mL), cellulose degradation efficiency by CTL-6 was remarkably high at 50-65 degrees C with the highest degradation efficiency observed at 60 degrees C. The 16S rRNA gene sequence analysis indicated that the closest relative to strain CTL-6 belonged to the genus Clostridium thermocellum. Strain CTL-6 was capable of utilizing cellulose, cellobiose, and glucose. Strain CTL-6 also grew with Sorbitol as the sole carbon source, whereas C. thermocellum is unable to do so.
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Affiliation(s)
- Yucai Lü
- Alan G. MacDiarmid Research Institute of Renewable Energy, China Three Gorges University, Yichang 443002, China.
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Sasaki D, Hori T, Haruta S, Ueno Y, Ishii M, Igarashi Y. Methanogenic pathway and community structure in a thermophilic anaerobic digestion process of organic solid waste. J Biosci Bioeng 2011; 111:41-6. [DOI: 10.1016/j.jbiosc.2010.08.011] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Revised: 08/05/2010] [Accepted: 08/20/2010] [Indexed: 10/19/2022]
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Mudhoo A, Forster-Carneiro T, Sánchez A. Biohydrogen production and bioprocess enhancement: A review. Crit Rev Biotechnol 2010; 31:250-63. [DOI: 10.3109/07388551.2010.525497] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Wongwilaiwalin S, Rattanachomsri U, Laothanachareon T, Eurwilaichitr L, Igarashi Y, Champreda V. Analysis of a thermophilic lignocellulose degrading microbial consortium and multi-species lignocellulolytic enzyme system. Enzyme Microb Technol 2010. [DOI: 10.1016/j.enzmictec.2010.07.013] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Luo G, Xie L, Zou Z, Wang W, Zhou Q. Evaluation of pretreatment methods on mixed inoculum for both batch and continuous thermophilic biohydrogen production from cassava stillage. BIORESOURCE TECHNOLOGY 2010; 101:959-964. [PMID: 19765981 DOI: 10.1016/j.biortech.2009.08.090] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Revised: 08/23/2009] [Accepted: 08/24/2009] [Indexed: 05/28/2023]
Abstract
Anaerobic sludges, pretreated by chloroform, base, acid, heat and loading-shock, as well as untreated sludge were evaluated for their thermophilic fermentative hydrogen-producing characters from cassava stillage in both batch and continuous experiments. Results showed that the highest hydrogen production was obtained by untreated sludge and there were significant differences (p<0.05) in hydrogen yields (varied from 32.9 to 65.3mlH(2)/gVS) among the tested pretreatment methods in batch experiments. However, the differences in hydrogen yields disappeared in continuous experiments, which indicated the pretreatment methods had only short-term effects on the hydrogen production. Further study showed that alkalinity was a crucial parameter influencing the fermentation process. When the influent was adjusted to pH 6 by NaHCO(3) instead of NaOH, the hydrogen yield increased from about 40 to 52mlH(2)/gVS in all the experiments. Therefore, pretreatment of anaerobic sludge is unnecessary for practical thermophilic fermentative hydrogen production from cassava stillage.
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Affiliation(s)
- Gang Luo
- State Key Laboratory of Pollution Control and Resources Reuse, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
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Blume F, Bergmann I, Nettmann E, Schelle H, Rehde G, Mundt K, Klocke M. Methanogenic population dynamics during semi‐continuous biogas fermentation and acidification by overloading. J Appl Microbiol 2010; 109:441-450. [DOI: 10.1111/j.1365-2672.2010.04682.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- F. Blume
- Technische Universität Berlin, Institut für Technischen Umweltschutz, Fachgebiet Umweltmikrobiologie, Franklinstrasse 29, Berlin, Germany
| | - I. Bergmann
- Technische Universität Berlin, Institut für Technischen Umweltschutz, Fachgebiet Umweltmikrobiologie, Franklinstrasse 29, Berlin, Germany
- Leibniz‐Institut für Agrartechnik Potsdam‐Bornim e.V. (ATB), Abteilung Bioverfahrenstechnik, Max‐Eyth‐Allee 100, Potsdam, Germany
| | - E. Nettmann
- Technische Universität Berlin, Institut für Technischen Umweltschutz, Fachgebiet Umweltmikrobiologie, Franklinstrasse 29, Berlin, Germany
- Leibniz‐Institut für Agrartechnik Potsdam‐Bornim e.V. (ATB), Abteilung Bioverfahrenstechnik, Max‐Eyth‐Allee 100, Potsdam, Germany
| | - H. Schelle
- Leibniz‐Institut für Agrartechnik Potsdam‐Bornim e.V. (ATB), Abteilung Bioverfahrenstechnik, Max‐Eyth‐Allee 100, Potsdam, Germany
| | - G. Rehde
- Leibniz‐Institut für Agrartechnik Potsdam‐Bornim e.V. (ATB), Abteilung Bioverfahrenstechnik, Max‐Eyth‐Allee 100, Potsdam, Germany
| | - K. Mundt
- Leibniz‐Institut für Agrartechnik Potsdam‐Bornim e.V. (ATB), Abteilung Bioverfahrenstechnik, Max‐Eyth‐Allee 100, Potsdam, Germany
| | - M. Klocke
- Leibniz‐Institut für Agrartechnik Potsdam‐Bornim e.V. (ATB), Abteilung Bioverfahrenstechnik, Max‐Eyth‐Allee 100, Potsdam, Germany
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Nettmann E, Bergmann I, Mundt K, Linke B, Klocke M. Archaea diversity within a commercial biogas plant utilizing herbal biomass determined by 16S rDNA and mcrA analysis. J Appl Microbiol 2009; 105:1835-50. [PMID: 19120632 DOI: 10.1111/j.1365-2672.2008.03949.x] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS The Archaea diversity was evaluated in an agricultural biogas plant supplied with cattle liquid manure and maize silage under mesophilic conditions. METHODS AND RESULTS Two different genes (16S rRNA; methyl-coenzyme-M-reductase, MCR) targeted by three different PCR primer sets were selected and used for the construction of three clone libraries comprising between 104 and 118 clones. The clone libraries were analysed by restriction fragment polymorphism (RFLP). Between 11 and 31 operational taxonomic units (OTUs) were detected and assigned to orders Methanomicrobiales, Methanosarcinales and Methanobacteriales. Over 70% of all Archaea OTUs belong to the order Methanomicrobiales which mostly include hydrogenotrophic methanogens. Acetotrophic methanogens were detected in minor rates. Similar relative values were obtained by a quantitative real-time PCR analysis. CONCLUSIONS The results implied that in this biogas plant the most of the methane formation resulted from the conversion of H(2) and CO(2). SIGNIFICANCE AND IMPACT OF THE STUDY This study reports, for the first time, a molecular analysis of the archaeal community in this type of agricultural biogas plants. Therein the hydrogenotrophic methanogenesis seems to be the major pathway of methane formation. These results are in contrast with the common thesis that in biogas fermentations the primary substrate for methanogenesis is acetate.
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Affiliation(s)
- E Nettmann
- Leibniz-Institut für Agrartechnik Potsdam-Bornim eV, Abteilung Bioverfahrenstechnik, Potsdam-Bornim, Germany
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Zhu M, Lü F, Hao LP, He PJ, Shao LM. Regulating the hydrolysis of organic wastes by micro-aeration and effluent recirculation. WASTE MANAGEMENT (NEW YORK, N.Y.) 2009; 29:2042-2050. [PMID: 19157839 DOI: 10.1016/j.wasman.2008.12.023] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2008] [Revised: 12/12/2008] [Accepted: 12/15/2008] [Indexed: 05/27/2023]
Abstract
In this study, the effects of micro-aeration and liquid recirculation on the hydrolysis of vegetable and flower wastes during two-phase solid-liquid anaerobic digestion were assessed. To accomplish this, we evaluated the hydrolysis of five batches of waste that were treated under the following conditions: anaerobic, insufficient micro-aeration (aeration for 5 min every 24 h), and sufficient micro-aeration (aeration for 5 min every 12, 4 and 1h). Hydrolysis was found to depend on the level of micro-aeration. Specifically, insufficient micro-aeration led to unstable and decreased performance. Conversely, sufficient micro-aeration promoted the hydrolysis of easily biodegradable carbohydrates and proteins, but the microbial activity was later impaired by liquid recirculation using methanogenic effluent. The hydrolysis efficiency under anaerobic conditions was comparable to the efficiency observed under sufficient micro-aeration, while the cumulative TOC of the anaerobic batch was 1.4-2.4 times higher than that of the micro-aerated batches. In addition, liquid recirculation did not have a negative effect on the development of microbial activity under anaerobic conditions, which resulted in the lignocelluloses having a higher hydrolysis efficiency.
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Affiliation(s)
- Min Zhu
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China
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Lü F, Shao LM, Bru V, Godon JJ, He PJ. Synergetic effect of pH and biochemical components on bacterial diversity during mesophilic anaerobic fermentation of biomass-origin waste. J Appl Microbiol 2009; 106:580-91. [DOI: 10.1111/j.1365-2672.2008.04029.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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O-Thong S, Prasertsan P, Birkeland NK. Evaluation of methods for preparing hydrogen-producing seed inocula under thermophilic condition by process performance and microbial community analysis. BIORESOURCE TECHNOLOGY 2009; 100:909-18. [PMID: 18768309 DOI: 10.1016/j.biortech.2008.07.036] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2008] [Revised: 07/17/2008] [Accepted: 07/19/2008] [Indexed: 05/08/2023]
Abstract
Five methods for preparation of hydrogen-producing seeds (base, acid, 2-bromoethanesulfonic acid (BESA), load-shock and heat shock treatments) as well as an untreated anaerobic digested sludge were compared for their hydrogen production performance and responsible microbial community structures under thermophilic condition (60 degrees C). The results showed that the load-shock treatment method was the best for enriching thermophilic hydrogen-producing seeds from mixed anaerobic cultures as it completely repressed methanogenic activity and gave the a maximum hydrogen production yield of 1.96 mol H(2) mol(-1) hexose with an hydrogen production rate of 11.2 mmol H(2) l(-1)h(-1). Load-shock and heat-shock treatments resulted in a dominance of Thermoanaerobacterium thermosaccharolyticum with acetic acid and butyric acid type of fermentation while base- and acid-treated seeds were dominated by Clostridium sp. and BESA-treated seeds were dominated by Bacillus sp. The comparative experimental results from hydrogen production performance and microbial community analysis showed that the load-shock treatment method was better than the other four methods for enriching thermophilic hydrogen-producing seeds from anaerobic digested sludge. Load-shock treated sludge was implemented in palm oil mill effluent (POME) fermentation and was found to give maximum hydrogen production rates of 13.34 mmol H(2) l(-1)h(-1) and resulted in a dominance of Thermoanaerobacterium spp. Load-shock treatment is an easy and practical method for enriching thermophilic hydrogen-producing bacteria from anaerobic digested sludge.
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Affiliation(s)
- Sompong O-Thong
- Department of Biology, Faculty of Science, Thaksin University, Patthalung 93110, Thailand
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Calli B, Chung LC, Arslan D, Vanbroekhoven K. H2 production potential in thermophilic mixed fermentation. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2009; 44:78-86. [PMID: 19085598 DOI: 10.1080/10934520802515418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The effect of pH on dark fermentative H(2) production at 55 degrees C was studied using three different inocula namely windrow yard waste compost (G), anaerobic organic waste compost (H) and activated sludge (A) and 2 g/L glucose as substrate. The sequential batch experiments were performed by controlling the pH at 5, 5.5 and 6. The highest molar H(2) yields were found to be 1.7 at pH 5 for G and H and 1.6 at pH 5.5 for A, while severe drops in the subsequent runs were associated with lactate fermentation. At pH 5.5 in G, despite the butyrate formation ceased, lower but more stable H(2) yields of about 1.1 were obtained through acetate-ethanol fermentation. Besides, the clostridial thermopiles prevalent at pH 5 were substituted by Thermoanaerobacterium-related species at pH 5.5 and 6. The findings suggested that for a stable H(2) yield through acetate-butyrate fermentation at 55 degrees C with compost inoculum G or H, the pH has to be controlled between pH 5 and 5.5. This is one of the few papers discussing the effects of pH on H(2) production through thermophilic mixed fermentation of glucose by using three different natural mixed culture inocula.
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Affiliation(s)
- Baris Calli
- Environmental Engineering Department, Faculty of Engineering, Marmara University, Goztepe, Istanbul, Turkey.
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Stress of pH and acetate on product formation of fermenting polysaccharide-rich organic waste. Biochem Eng J 2008. [DOI: 10.1016/j.bej.2007.08.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Yokoyama H, Waki M, Ogino A, Ohmori H, Tanaka Y. Hydrogen fermentation properties of undiluted cow dung. J Biosci Bioeng 2007; 104:82-5. [PMID: 17697988 DOI: 10.1263/jbb.104.82] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2007] [Accepted: 04/07/2007] [Indexed: 11/17/2022]
Abstract
Anaerobic treatment of undiluted cow dung (15% total solids), so-called dry fermentation, produced hydrogen (743 ml-H(2)/kg-cow dung) at an optimum temperature of 60 degrees C, with butyrate and acetate formation. The hydrogen production was inhibited by the addition of NH(4)(+) in a dose-dependent manner. A bacterium with similarity to Clostridium cellulosi was detected in the fermented dung by a 16S rDNA analysis.
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Affiliation(s)
- Hiroshi Yokoyama
- Waste Recycling Research Team, National Institute of Livestock and Grassland Science (NILGS), 2 Ikenodai, Tsukuba, Ibaraki, Japan.
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Cirne DG, Lehtomäki A, Björnsson L, Blackall LL. Hydrolysis and microbial community analyses in two-stage anaerobic digestion of energy crops. J Appl Microbiol 2007; 103:516-27. [PMID: 17714384 DOI: 10.1111/j.1365-2672.2006.03270.x] [Citation(s) in RCA: 158] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS The roles of the diverse populations of micro-organisms responsible for biodegradation of organic matter to form methane and carbon dioxide are rudimentarily understood. To expand the knowledge on links between microbial communities and the rate limiting, hydrolytic stage of two-stage biogas production from energy crops, this study was performed. METHODS AND RESULTS The process performance and microbial communities (as determined by fluorescence in situ hybridization) in two separate two-stage batch digestions of sugar beets and grass/clover were studied. The microbial populations developed in the hydrolytic stage of anaerobic digestion of beets and grass/clover showed very few similarities, despite that the hydrolysis dynamics were similar. In both substrates, the solubilization of organic material was rapid for the first 10 days and accompanied by a build-up of volatile fatty acids (VFAs) and lactate. Between days 10 and 15, VFA and lactate concentrations decreased, as did the solubilization rates. For both substrates, Archaea started to appear in the hydrolytic stage between days 10 and 15, and the fraction of Bacteria decreased. The major bacterial group detected in the leachate fraction for beets was Alphaproteobacteria, whereas for grass/clover it was Firmicutes. The number of cells that bound to probes specifically targeting bacteria with cellulolytic activity was higher in the digestion of grass than in the digestion of beet. CONCLUSIONS This study allowed the identification of the general bacterial groups involved, and the identification of a clear shift in the microbial population when hydrolysis rate became limiting for each of the substrates investigated. SIGNIFICANCE AND IMPACT OF THE STUDY The findings from this study could be considered as a first step towards the development of strategies to stimulate hydrolysis further and ultimately increasing the methane production rates and yields from reactor-based digestion of these substrates.
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Affiliation(s)
- D G Cirne
- Department of Biotechnology, Lund University, Lund, Sweden.
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