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Undiandeye J, Gallegos D, Bonatelli ML, Kleinsteuber S, Bin-Hudari MS, Abdulkadir N, Stinner W, Sträuber H. Medium-chain carboxylates production from plant waste: kinetic study and effect of an enriched microbiome. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:79. [PMID: 38867271 PMCID: PMC11167882 DOI: 10.1186/s13068-024-02528-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 06/04/2024] [Indexed: 06/14/2024]
Abstract
BACKGROUND The need for addition of external electron donors such as ethanol or lactate impairs the economic viability of chain elongation (CE) processes for the production of medium-chain carboxylates (MCC). However, using feedstocks with inherent electron donors such as silages of waste biomass can improve the economics. Moreover, the use of an appropriate inoculum is critical to the overall efficiency of the CE process, as the production of a desired MCC can significantly be influenced by the presence or absence of specific microorganisms and their metabolic interactions. Beyond, it is necessary to generate data that can be used for reactor design, simulation and optimization of a given CE process. Such data can be obtained using appropriate mathematical models to predict the dynamics of the CE process. RESULTS In batch experiments using silages of sugar beet leaves, cassava leaves, and Elodea/wheat straw as substrates, caproate was the only MCC produced with maximum yields of 1.97, 3.48, and 0.88 g/kgVS, respectively. The MCC concentrations were accurately predicted with the modified Gompertz model. In a semi-continuous fermentation with ensiled sugar beet leaves as substrate and digestate from a biogas reactor as the sole inoculum, a prolonged lag phase of 7 days was observed for the production of MCC (C6-C8). The lag phase was significantly shortened by at least 4 days when an enriched inoculum was added to the system. With the enriched inoculum, an MCC yield of 93.67 g/kgVS and a productivity of 2.05 gMCC/L/d were achieved. Without the enriched inoculum, MCC yield and productivity were 43.30 g/kgVS and 0.95 gMCC/L/d, respectively. The higher MCC production was accompanied by higher relative abundances of Lachnospiraceae and Eubacteriaceae. CONCLUSIONS Ensiled waste biomass is a suitable substrate for MCC production using CE. For an enhanced production of MCC from ensiled sugar beet leaves, the use of an enriched inoculum is recommended for a fast process start and high production performance.
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Affiliation(s)
- Jerome Undiandeye
- Department of Biochemical Conversion, DBFZ Deutsches Biomasseforschungszentrum Gemeinnützige GmbH, 04347, Leipzig, Germany.
- Department of Chemical Engineering, University of Port Harcourt, PMB 5323, Port Harcourt, Nigeria.
| | - Daniela Gallegos
- Department of Biochemical Conversion, DBFZ Deutsches Biomasseforschungszentrum Gemeinnützige GmbH, 04347, Leipzig, Germany
| | - Maria L Bonatelli
- Department of Microbial Biotechnology, Helmholtz Centre for Environmental Research - UFZ, 04318, Leipzig, Germany
| | - Sabine Kleinsteuber
- Department of Microbial Biotechnology, Helmholtz Centre for Environmental Research - UFZ, 04318, Leipzig, Germany
| | - Mohammad Sufian Bin-Hudari
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, 04318, Leipzig, Germany
| | - Nafi'u Abdulkadir
- Research Unit for Comparative Microbiome Analysis, Helmholtz Munich, German Research Center for Environmental Health, 85764, Neuherberg, Germany
- Department of Microbiology, Sokoto State University, Sokoto, 852101, Nigeria
| | - Walter Stinner
- Department of Biochemical Conversion, DBFZ Deutsches Biomasseforschungszentrum Gemeinnützige GmbH, 04347, Leipzig, Germany
| | - Heike Sträuber
- Department of Microbial Biotechnology, Helmholtz Centre for Environmental Research - UFZ, 04318, Leipzig, Germany
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Liu Y, Chen L, Duan Y, Li R, Yang Z, Liu S, Li G. Recent progress and prospects for chain elongation of transforming biomass waste into medium-chain fatty acids. CHEMOSPHERE 2024; 355:141823. [PMID: 38552798 DOI: 10.1016/j.chemosphere.2024.141823] [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: 02/04/2024] [Revised: 03/18/2024] [Accepted: 03/26/2024] [Indexed: 04/06/2024]
Abstract
Chain elongation technology utilises microorganisms in anaerobic digestion to transform waste biomass into medium-chain fatty acids that have greater economic value. This innovative technology expands upon traditional anaerobic digestion methods, requiring abundant substrates that serve as electron donors and acceptors, and inoculating microorganisms with chain elongation functions. While this process may result in the production of by-products and elicit competitive responses, toxicity suppression of microorganisms by substrates and products remains a significant obstacle to the industrialisation of chain elongation technology. This study provides a comprehensive overview of existing research on widely employed electron donors and their synthetic reactions, competitive reactions, inoculum selection, toxicity inhibition of substrates and products, and increased chain elongation approaches. Additionally, it presents actionable recommendations for future research and development endeavours in this domain, intending to inspire and guide researchers in advancing the frontiers of chain elongation technology.
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Affiliation(s)
- Yuhao Liu
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450046, Henan Province, China.
| | - Long Chen
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450046, Henan Province, China
| | - Yacong Duan
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450046, Henan Province, China
| | - Ruihua Li
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450046, Henan Province, China
| | - Ziyan Yang
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450046, Henan Province, China
| | - Shuli Liu
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450046, Henan Province, China
| | - Guoting Li
- School of Environmental and Municipal Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450046, Henan Province, China
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Chen X, Hao K, Zhao L, Zong Y, Chen J. Carbon, nitrogen, and phosphorus metabolic relationships and reaction mechanisms in SBBR processes in the plateau habitat. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 195:1464. [PMID: 37955719 DOI: 10.1007/s10661-023-11961-9] [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: 11/26/2022] [Accepted: 10/05/2023] [Indexed: 11/14/2023]
Abstract
In this study, two laboratory-scale SBBR reactors were established in a plateau habitat. Using high flux sequencing, the SBBR process was compared by natural sediment and autotrophic sludge to characterize the functional modules and functional genes of carbon, nitrogen, and phosphorus metabolism under different working conditions and to analyze the reaction mechanism. The results showed that all the functional modules of carbon metabolism and nitrogen metabolism were found in the SBBR process, except for methane metabolism, which occurred at 25 °C in tank 2, the functional modules related to methane metabolism are enhanced at all working conditions. Except for methane metabolism, all functional genes in tank 2 are inhibited by different working conditions, whereas tank 1 shows a slight enhancement. The different working conditions in nitrogen metabolism demonstrate inhibition of functional modules and functional genes in both tanks. Oxidative phosphorylation was missing five functional modules, except for M00153, where only two genes, K00424 and K22501, are missing, all of the required genes are missing in the other four functional modules. Overall the different conditions demonstrated some inhibition in both reaction tanks of the SBBR process. It is preferable to use self-cultivated sludge for membrane acclimation when operating the SBBR process in a plateau habitat. The findings of this study can be used to further research microbial carbon, nitrogen, and phosphorus metabolism mechanisms in SBBR processes in plateau habitats.
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Affiliation(s)
- Xiangyu Chen
- College of Water Conservancy and Civil Engineering, Tibet Agriculture and Animal Husbandry University, Linzhi, 860000, People's Republic of China
| | - Kaiyue Hao
- Department of Municipal and Environmental Engineering, School of Water Resources and Hydroelectric Engineering, Xi'an University of Technology, Xi'an, 710048, People's Republic of China
| | - Lishuai Zhao
- College of Water Conservancy and Civil Engineering, Tibet Agriculture and Animal Husbandry University, Linzhi, 860000, People's Republic of China
| | - Yongchen Zong
- College of Water Conservancy and Civil Engineering, Tibet Agriculture and Animal Husbandry University, Linzhi, 860000, People's Republic of China.
| | - Jiaqing Chen
- College of Water Conservancy and Civil Engineering, Tibet Agriculture and Animal Husbandry University, Linzhi, 860000, People's Republic of China
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Pietruszka A, Maślanko M, Ciecholewska-Juśko D. Sanitization of Biomass in Agricultural Biogas Plants Depends on the Type of Substrates. Animals (Basel) 2023; 13:ani13050855. [PMID: 36899713 PMCID: PMC10000083 DOI: 10.3390/ani13050855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/20/2023] [Accepted: 02/24/2023] [Indexed: 03/02/2023] Open
Abstract
Large-scale pig farming is associated with the production of large amounts of animal excrement, which, after processing into the form of, e.g., slurry, are managed on agricultural land as natural fertilizers. The utilization of pig manure on agricultural land in an excessive and uncontrolled manner may pose a threat to zoonoses due to the significant amounts of potentially pathogenic microorganisms within its content. This study aims to determine the impact of the methane fermentation process carried out in two agricultural biogas plants on the efficiency of sanitization of pig slurry, input biomass, and digestate. The biogas plants differed in terms of the substrate used; one used pig slurry from a maternal (breeding) farm (BP-M), and the other utilized pig slurry from a fattening farm (BP-F). The physicochemical analyses showed that the slurry, input biomass, and digestate from the BP-F were characterized by a significantly higher contents of organic dry matter, ash, and ammonium nitrogen than the slurry, input biomass, and digestate from the BP-M. The parameters of the methane fermentation process, including temperature and pH, reached higher values in the BP-F compared to the BP-M. The microbiological analyses led to the conclusion that the efficiency of sanitization of input biomass, including pig slurry, was significantly higher in the BP-F compared to the BP-M. Due to the above findings, locating biogas plants near pig fattening farms should be recommended.
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Affiliation(s)
- Arkadiusz Pietruszka
- Department of Monogastric Animal Sciences, Faculty of Biotechnology and Animal Husbandry, West Pomeranian University of Technology in Szczecin, Klemensa Janickiego 29, 71-270 Szczecin, Poland
| | - Marta Maślanko
- Department of Microbiology and Biotechnology, Faculty of Biotechnology and Animal Husbandry, West Pomeranian University of Technology in Szczecin, Piastów 45, 70-311 Szczecin, Poland
| | - Daria Ciecholewska-Juśko
- Department of Microbiology and Biotechnology, Faculty of Biotechnology and Animal Husbandry, West Pomeranian University of Technology in Szczecin, Piastów 45, 70-311 Szczecin, Poland
- Correspondence:
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Gazzola G, Maria Braguglia C, Crognale S, Gallipoli A, Mininni G, Piemonte V, Rossetti S, Tonanzi B, Gianico A. Biorefining food waste through the anaerobic conversion of endogenous lactate into caproate: A fragile balance between microbial substrate utilization and product inhibition. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 150:328-338. [PMID: 35907330 DOI: 10.1016/j.wasman.2022.07.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 06/27/2022] [Accepted: 07/21/2022] [Indexed: 06/15/2023]
Abstract
New technologies development and renewable source exploitation are key tools to realize the European Green Deal and to boost the bio-based economy. In this context, fermentation of organic residues as food waste is an efficient method to obtain marketable products such as carboxylic acids widely applied in industrial production. Under favourable thermodynamic conditions, short chain fatty acids deriving from primary fermentation could be biologically converted into medium-chain fatty acids as caproate via chain elongation (CE) process, by using ethanol or lactate as electron donors. This study evaluates the effectivity of producing caproate from Food Waste extract rich in organics with in situ electron donor production. The test carried out at OLR 15 gCOD L-1d-1 showed high Volatile Fatty Acids (from acetic to caproic acid) yields (0.37 g g-1CODfed), with a maximum caproate concentration of 8 g L-1. The associated microbiome was composed by lactate-producing bacteria (Corynebacterium, Lactobacillus, and Olsenella) and by chain elongators (Clostridiaceae and Caproiciproducens). By stressing the system with OLR increase up to 20 gCOD L-1d-1, the CE process was inhibited by the high concentration of caproate (low occurrence of Clostridiaceae and Caproiciproducens). Nevertheless, after few days of stop-feeding regime imposed to the system, the microbiome restored its capability to proceed with lactate-based CE pathways. Different batch tests carried out with the inhibited biomass at increasing initial caproate concentration confirmed its impact on lactate utilization kinetics.
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Affiliation(s)
- Giulio Gazzola
- Water Research Institute, National Research Council of Italy, CNR-IRSA, Area della Ricerca RM1, Via Salaria km 29.300, 00015 Monterotondo, Roma, Italy
| | - Camilla Maria Braguglia
- Water Research Institute, National Research Council of Italy, CNR-IRSA, Area della Ricerca RM1, Via Salaria km 29.300, 00015 Monterotondo, Roma, Italy
| | - Simona Crognale
- Water Research Institute, National Research Council of Italy, CNR-IRSA, Area della Ricerca RM1, Via Salaria km 29.300, 00015 Monterotondo, Roma, Italy
| | - Agata Gallipoli
- Water Research Institute, National Research Council of Italy, CNR-IRSA, Area della Ricerca RM1, Via Salaria km 29.300, 00015 Monterotondo, Roma, Italy
| | - Giuseppe Mininni
- Water Research Institute, National Research Council of Italy, CNR-IRSA, Area della Ricerca RM1, Via Salaria km 29.300, 00015 Monterotondo, Roma, Italy
| | - Vincenzo Piemonte
- Faculty of Engineering, University Campus Bio-Medico, Via Alvaro del Portillo, 21, 00128 Roma, Italy
| | - Simona Rossetti
- Water Research Institute, National Research Council of Italy, CNR-IRSA, Area della Ricerca RM1, Via Salaria km 29.300, 00015 Monterotondo, Roma, Italy
| | - Barbara Tonanzi
- Water Research Institute, National Research Council of Italy, CNR-IRSA, Area della Ricerca RM1, Via Salaria km 29.300, 00015 Monterotondo, Roma, Italy
| | - Andrea Gianico
- Water Research Institute, National Research Council of Italy, CNR-IRSA, Area della Ricerca RM1, Via Salaria km 29.300, 00015 Monterotondo, Roma, Italy.
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Cao Q, Zhang W, Lian T, Wang S, Yin F, Zhou T, Zhang H, Zhu J, Dong H. Roles of micro-aeration on enhancing volatile fatty acids and lactic acid production from agricultural wastes. BIORESOURCE TECHNOLOGY 2022; 347:126656. [PMID: 34974096 DOI: 10.1016/j.biortech.2021.126656] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 12/26/2021] [Accepted: 12/27/2021] [Indexed: 06/14/2023]
Abstract
Micro-aeration was proven to be an environmentally friendly strategy for efficiently enhancing volatile fatty acids (VFAs) and lactic acid (LA) production. The roles of micro-aeration on mono-digestion of swine manure (SM) for VFAs production and co-digestion of SM with corn silage (CS) for LA production were investigated, respectively. In this study, micro-aeration increased the maximum VFAs concentration by 20.3% to 35.71 g COD/L, and shortened the time to reach the maximum from 18 days to 10 days. Micro-aeration limited the conversion of LA into VFAs, leading to LA accumulation effectively to be 26.08 g COD/L. Microbial community analysis suggested that Clostridium and Terrisporobacter were always the dominant bacteria with or without micro-aeration for VFAs production, but the relative abundance increased notably during the same period. However, Bifidobacterium, which could use the higher productivity metabolism pathway, i.e., Bifidum pathway to produce LA, increased from lower than 1% to 22.9% by micro-aeration.
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Affiliation(s)
- Qitao Cao
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Wanqin Zhang
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Tianjing Lian
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Shunli Wang
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Fubin Yin
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Tanlong Zhou
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Haiyan Zhang
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Jun Zhu
- Department of Biological and Agricultural Engineering, University of Arkansas, Fayetteville, AR 72701, USA
| | - Hongmin Dong
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China.
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Show BK, Banerjee S, Banerjee A, GhoshThakur R, Hazra AK, Mandal NC, Ross AB, Balachandran S, Chaudhury S. Insect gut bacteria: a promising tool for enhanced biogas production. REVIEWS IN ENVIRONMENTAL SCIENCE AND BIO/TECHNOLOGY 2022; 21:1-25. [DOI: 10.1007/s11157-021-09607-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 12/29/2021] [Indexed: 07/19/2023]
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Continuous hydrogen production and microbial community profile in the dark fermentation of tequila vinasse: Response to increasing loading rates and immobilization of biomass. Biochem Eng J 2021. [DOI: 10.1016/j.bej.2021.108049] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Microbial Ecological Mechanism for Long-Term Production of High Concentrations of n-Caproate via Lactate-Driven Chain Elongation. Appl Environ Microbiol 2021; 87:AEM.03075-20. [PMID: 33741616 DOI: 10.1128/aem.03075-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 03/10/2021] [Indexed: 12/11/2022] Open
Abstract
Lactate-driven chain elongation (LCE) has emerged as a new biotechnology to upgrade organic waste streams into a valuable biochemical and fuel precursor, medium-chain carboxylate, n-caproate. Considering that a low cost of downstream extraction is critical for biorefinery technology, a high concentration of n-caproate production is very important to improve the scale-up of the LCE process. We report here that in a nonsterile open environment, the n-caproate concentration was increased from the previous record of 25.7 g·liter-1 to a new high level of 33.7 g·liter-1 (76.8 g chemical oxygen demand [COD]·liter - 1), with the highest production rate being 11.5 g·liter-1·day-1 (26.2 g COD·liter - 1·day-1). In addition, the LCE process remained stable, with an average concentration of n-caproate production of 20.2 ± 5.62 g·liter-1 (46.1 ± 12.8 g COD·liter - 1) for 780 days. Dynamic changes in taxonomic composition integrated with metagenomic data reveal the microbial ecology for long-term production of high concentrations of n-caproate: (i) the core microbiome is related to efficient functional groups, such as Ruminococcaceae (with functional strain CPB6); (ii) the core bacteria can maintain stability for long-term operation; (iii) the microbial network has relatively low microbe-microbe interaction strength; and (iv) low relative abundance and variety of competitors. The network structure could be shaped by hydraulic retention time (HRT) over time, and long-term operation at an HRT of 8 days displayed higher efficacy.IMPORTANCE Our research revealed the microbial network of the LCE reactor microbiome for n-caproate production at high concentrations, which will provide a foundation for designing or engineering the LCE reactor microbiome to recover n-caproate from organic waste streams in the future. In addition, the hypothetical model of the reactor microbiome that we proposed may offer guidance for researchers to find the underlying microbial mechanism when they encounter low-efficiency n-caproate production from the LCE process. We anticipate that our research will rapidly advance LCE biotechnology with the goal of promoting the sustainable development of human society.
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Müller C, Knöller K, Lucas R, Kleinsteuber S, Trabitzsch R, Weiß H, Stollberg R, Richnow HH, Vogt C. Benzene degradation in contaminated aquifers: Enhancing natural attenuation by injecting nitrate. JOURNAL OF CONTAMINANT HYDROLOGY 2021; 238:103759. [PMID: 33461044 DOI: 10.1016/j.jconhyd.2020.103759] [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: 08/31/2020] [Revised: 12/11/2020] [Accepted: 12/21/2020] [Indexed: 06/12/2023]
Abstract
Natural attenuation processes depend on the availability of suitable electron acceptors. At the megasite Zeitz, concentrations of the main contaminant benzene were observed to increase constantly in the lower aquifer to levels of more than 2.5 mM. This was accompanied by decreasing concentrations of sulphate (SO42-), which has been previously shown to be the main electron acceptor for benzene oxidation at this site, resulting in an electron acceptor-limited, sulphidic benzene plume. Therefore, a field experiment was conducted to stimulate benzene biodegradation by injecting nitrate (NO3-) into the sulphidic benzene plume aiming (i) to recycle sulphate by nitrate-dependent sulphide oxidation, and (ii) to serve as direct electron acceptor for benzene oxidation. Within 60 days, 6.74 tons sodium nitrate (NaNO3) were injected into the lower aquifer, and the resulting biogeochemical effects within the benzene plume were monitored for more than one year by chemical and microbiological analyses of groundwater samples taken from various depths of ten monitoring wells located in three observation lines downstream of nitrate injection. Nitrate was microbiologically consumed, as shown by changes in δ15N-NO3- and δ18O-NO3- values, partial nitrite accumulation, and changing ratios of Na+/NO3-. Main electron donors for nitrate reduction were reduced sulphur compounds, verified by changing δ34S-SO42- and δ18O-SO42- values, partially increasing sulphate concentrations, and strongly increasing abundances of typical sulphur-oxidizing, nitrate-reducing bacterial taxa within the nitrate plume. The general absent hydrogen isotope fractionation of benzene, also in the sulphidic, nitrate-free part of the plume, indicates that benzene was not biodegraded by sulphate-reducing consortia. However, detected small carbon isotope fractionation of benzene points to in situ benzene biodegradation processes in the plume, probably supported by nitrate. In conclusion, nitrate injection resulted in changing redox conditions and recycling of sulphate in the sulphidic, sulphate-depleted benzene plume due to microbial oxidation of reduced sulphur species, leading to presumably favored conditions for in situ benzene biodegradation.
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Affiliation(s)
- Christin Müller
- Helmholtz-Centre for Environmental Research UFZ, Department Catchment Hydrology, Germany.
| | - Kay Knöller
- Helmholtz-Centre for Environmental Research UFZ, Department Catchment Hydrology, Germany
| | - Rico Lucas
- Helmholtz-Centre for Environmental Research UFZ, Department Environmental Microbiology, Germany
| | - Sabine Kleinsteuber
- Helmholtz-Centre for Environmental Research UFZ, Department Environmental Microbiology, Germany
| | - Ralf Trabitzsch
- Helmholtz-Centre for Environmental Research UFZ, Department Environmental Informatics, Germany
| | - Holger Weiß
- Helmholtz-Centre for Environmental Research UFZ, Department Environmental Informatics, Germany
| | - Reiner Stollberg
- Helmholtz-Centre for Environmental Research UFZ, Department Environmental Informatics, Germany
| | - Hans Hermann Richnow
- Helmholtz-Centre for Environmental Research UFZ, Department Isotope Biogeochemistry, Germany
| | - Carsten Vogt
- Helmholtz-Centre for Environmental Research UFZ, Department Isotope Biogeochemistry, Germany
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11
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Xu J, Guzman JJL, Angenent LT. Direct Medium-Chain Carboxylic Acid Oil Separation from a Bioreactor by an Electrodialysis/Phase Separation Cell. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:634-644. [PMID: 33347746 DOI: 10.1021/acs.est.0c04939] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Medium-chain carboxylic acids (MCCAs) are valuable platform chemicals and can be produced from waste biomass sources or syngas fermentation effluent through microbial chain elongation. We have previously demonstrated successful approaches to separate >90% purity oil with different MCCAs (MCCA oil) by integrating the anaerobic bioprocess with membrane-based liquid-liquid extraction (pertraction) and membrane electrolysis. However, two-compartment membrane electrolysis unit without pertraction was not able to separate MCCA oil. Therefore, we developed a five-compartment electrodialysis/phase separation cell (ED/PS). First, we tested an ED/PS cell in series with pertraction and achieved a maximum MCCA-oil flux of 1.7 × 103 g d-1 per projected area (m2) (19 mL oil d-1) and MCCA-oil transfer efficiency [100% × moles MCCA-oil moles electrons-1] of 74% at 15 A m-2. This extraction system at 15 A m-2 demonstrated a ∼10 times lower electric-power consumption (1.1 kWh kg-1 MCCA oil) than membrane electrolysis in series with pertraction (9.9 kWh kg-1 MCCA oil). Second, we evaluated our ED/PS as a stand-alone unit when integrated with the anaerobic bioprocess and demonstrated that we can selectively extract and separate MCCA oil directly from chain-elongating bioreactor broth with just an abiotic electrochemical cell. However, the electric-power consumption increased considerably due to the lower MCCA concentrations in the bioreactor broth compared to the pertraction broth.
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Affiliation(s)
- Jiajie Xu
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Juan J L Guzman
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Largus T Angenent
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, New York 14853, United States
- Environmental Biotechnology Group, Center for Applied Geosciences, University of Tübingen, 72076 Tübingen, Germany
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12
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Lv Z, Wang J, Chen Z, Chen X, Zhang L, Li C, Chen Z, Zhang J, Wu X, Jia H. Temperature regulations impose positive influence on the biomethane potential versus digesting modes treating agricultural residues. BIORESOURCE TECHNOLOGY 2020; 301:122747. [PMID: 31935643 DOI: 10.1016/j.biortech.2020.122747] [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: 11/12/2019] [Revised: 01/03/2020] [Accepted: 01/04/2020] [Indexed: 06/10/2023]
Abstract
Temperature regulations (mesophilic/thermophilic) and digesting modes (mono-/co-digestion) play key roles in the biomethane potential of anaerobic digestion, but limited research focus on the synergetic effects on microbial interconnections of the biomethane process. In this study, the pineapple and maize residues under different operations were monitored by batch biogas assays and 16S high-throughput sequencing to explore: 1) biomethane potential regarding different operations, 2) microbial communities in different treated reactors, and 3) significant factors determine microbial distribution. Results showed that the co-digestion had higher methanogenic abundance and biomethane production (~3300 mLn) versus mono-digestion under mesophilic condition. To the thermophilic condition, the co-digestion had less methanogenic abundance but more biomethane production (~5000 mLn). Statistical evidence uncovered that the Clostridiaceae and Thermoanaerobacteraceae dominated pathways linked closely with methanogenesis which may contribute the more biomethane production in the thermophilic condition. This study demonstrated the temperature regulations drove rare taxa as major contributors for biomethane production.
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Affiliation(s)
- Zuopeng Lv
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life, Jiangsu Normal University, Xuzhou 221116, China
| | - Junyu Wang
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life, Jiangsu Normal University, Xuzhou 221116, China
| | - Zixuan Chen
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Xueru Chen
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Lina Zhang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Chunrui Li
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Zhongbing Chen
- Department of Applied Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 16500 Prague, Czech Republic
| | - Jianfeng Zhang
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xiayuan Wu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China.
| | - Honghua Jia
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China
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Liu B, Kleinsteuber S, Centler F, Harms H, Sträuber H. Competition Between Butyrate Fermenters and Chain-Elongating Bacteria Limits the Efficiency of Medium-Chain Carboxylate Production. Front Microbiol 2020; 11:336. [PMID: 32210937 PMCID: PMC7067704 DOI: 10.3389/fmicb.2020.00336] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 02/17/2020] [Indexed: 01/08/2023] Open
Abstract
Medium-chain carboxylates such as n-caproate and n-caprylate are valuable chemicals, which can be produced from renewable feedstock by anaerobic fermentation and lactate-based microbial chain elongation. Acidogenic microbiota involved in lactate-based chain elongation and their interplay with lactic acid bacteria have not been characterized in detail yet. Here, the metabolic and community dynamics were studied in a continuous bioreactor with xylan and lactate as sole carbon sources. Four succession stages were observed during 148 days of operation. After an adaptation period of 36 days, a relatively stable period of 28 days (stage I) was reached with n-butyrate, n-caproate and n-caprylate productivities of 7.2, 8.2 and 1.8 gCOD L-1 d-1, respectively. After a transition period, the process changed to another period (stage II), during which 46% more n-butyrate, 51% less n-caproate and 67% less n-caprylate were produced. Co-occurrence networks of species based on 16S rRNA amplicon sequences and correlations with process parameters were analyzed to infer ecological interactions and potential metabolic functions. Diverse functions including hydrolysis of xylan, primary fermentation of xylose to acids (e.g., to acetate by Syntrophococcus, to n-butyrate by Lachnospiraceae, and to lactate by Lactobacillus) and chain-elongation with lactate (by Ruminiclostridium 5 and Pseudoramibacter) were inferred from the metabolic network. In stage I, the sub-network characterized by strongest positive correlations was mainly related to the production of n-caproate and n-caprylate. Lactic acid bacteria of the genus Olsenella co-occurred with potentially chain-elongating bacteria of the genus Pseudoramibacter, and their abundance was positively correlated with n-caproate and n-caprylate concentrations. A new sub-network appeared in stage II, which was mainly related to n-butyrate production and revealed a network of different lactic acid bacteria (Bifidobacterium) and potential n-butyrate producers (Clostridium sensu stricto 12). The synergy effects between lactate-producing and lactate-consuming bacteria constitute a division of labor cooperation of mutual benefit. Besides cooperation, competition between different taxa determined the bacterial community assembly over the four succession stages in this resource-limited system. During long-term reactor operation under constant conditions, chain-elongating bacteria were outcompeted by butyrate-producing bacteria, leading to the increase of n-butyrate yield at the cost of medium-chain carboxylate yields in this closed model system.
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Affiliation(s)
| | | | | | | | - Heike Sträuber
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany
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Lv Z, Wu X, Zhou B, Wang Y, Sun Y, Wang Y, Chen Z, Zhang J. Effect of one step temperature increment from mesophilic to thermophilic anaerobic digestion on the linked pattern between bacterial and methanogenic communities. BIORESOURCE TECHNOLOGY 2019; 292:121968. [PMID: 31430671 DOI: 10.1016/j.biortech.2019.121968] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 08/05/2019] [Accepted: 08/06/2019] [Indexed: 05/28/2023]
Abstract
Process fluctuation caused by temperature modification of anaerobic digestion is routinely monitored via operational parameters, such as pH and gas production, but these parameters are lagging on microbial community performance. In this study, 13C isotope fractionation in CH4 and CO2 of biogas together with microbial community dynamics were applied to evaluate process stability in response to temperature increment. Results showed that the weakening correlated links between Firmicutes affiliated families and Methanomicrobiaceae were found regarding temperature increase. In contrast, Methanosarcinaceae and Methanobacteriaceae strengthened their links with multiple bacterial groups. This suggests that the 13C isotope fractionation in CH4 can predict the collapse of certain microbial interconnections and process instability, the new reinforced microbial links directly reflect the microbial community redundancy for maintaining function of syntrophic populations.
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Affiliation(s)
- Zuopeng Lv
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life, Jiangsu Normal University, Shanghai Road 101, 221116 Xuzhou, China.
| | - Xiayuan Wu
- Bioenergy Research Institute, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Bingqian Zhou
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life, Jiangsu Normal University, Shanghai Road 101, 221116 Xuzhou, China
| | - Yan Wang
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life, Jiangsu Normal University, Shanghai Road 101, 221116 Xuzhou, China
| | - Ying Sun
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life, Jiangsu Normal University, Shanghai Road 101, 221116 Xuzhou, China
| | - Yanfang Wang
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, School of Life, Jiangsu Normal University, Shanghai Road 101, 221116 Xuzhou, China
| | - Zhongbing Chen
- Department of Applied Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 16500 Prague, Czech Republic
| | - Jianfeng Zhang
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
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Syngas-aided anaerobic fermentation for medium-chain carboxylate and alcohol production: the case for microbial communities. Appl Microbiol Biotechnol 2019; 103:8689-8709. [PMID: 31612269 DOI: 10.1007/s00253-019-10086-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 08/06/2019] [Accepted: 08/07/2019] [Indexed: 01/01/2023]
Abstract
Syngas fermentation has been successfully implemented in commercial-scale plants and can enable the biochemical conversion of the driest fractions of biomass through synthesis gas (H2, CO2, and CO). The process relies on optimized acetogenic strains able to reach and maintain high productivity of ethanol and acetate. In parallel, microbial communities have shown to be the best choice for the production of valuable medium-chain carboxylates through anaerobic fermentation of biomass, demanding low technical complexity and being able to realize simultaneous hydrolysis of the substrate. Each of the two technologies benefits from different strong points and has different challenges to overcome. This review discusses the rationales for merging these two seemingly disparate technologies by analyzing previous studies and drawing opinions based on the lessons learned from such studies. For keeping the technical demands of the resulting process low, a case is built for using microbial communities instead of pure strains. For that to occur, a shift from conventional syngas-based to "syngas-aided" anaerobic fermentation is suggested. Strategies for tackling the intricacies of working simultaneously with communities and syngas, such as competing pathways, and thermodynamic aspects are discussed as well as the stoichiometry and economic feasibility of the concept. Overall, syngas-aided anaerobic fermentation seems to be a promising concept for the biorefinery of the future. However, the effects of process parameters on microbial interactions have to be understood in greater detail, in order to achieve and sustain feasible medium-chain carboxylate and alcohol productivity.
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16
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Keshri J, Chen Y, Pinto R, Kroupitski Y, Weinberg ZG, Sela Saldinger S. Bacterial Dynamics of Wheat Silage. Front Microbiol 2019; 10:1532. [PMID: 31354651 PMCID: PMC6632545 DOI: 10.3389/fmicb.2019.01532] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 06/19/2019] [Indexed: 11/13/2022] Open
Abstract
Knowledge regarding bacterial dynamics during crop ensiling is important for understanding of the fermentation process and may facilitate the production of nutritious and stable silage. The objective of this study was to analyze the bacterial dynamics associated with whole crop wheat silage with and without inoculants. Whole crop wheat was ensiled in laboratory silos, with and without Lactobacillus inoculants (L. plantarum, L. buchneri), for 3 months. Untreated and L. plantarum-treated silages were sampled at several times during ensiling, while L. buchneri-treated silage was sampled only at 3 months. Bacterial composition was studied using next generation sequencing approach. Dominant bacteria, before ensiling, were Pantoea (34.7%), Weissella (28.4%) and Pseudomonas (10.4%), Exiguobacterium (7.8%), and Paenibacillus (3.4%). Exogenous inoculants significantly affected bacterial composition and dynamics during ensiling. At 3 months of ensiling, Lactobacillus dominated the silage bacterial population and reached an abundance of 59.5, 92.5, and 98.2% in untreated, L. plantarum- and L. buchneri-treated silages, respectively. The bacterial diversity of the mature silage was lower in both treated silages compared to untreated silage. Functional profiling of the bacterial communities associated with the wheat ensiling demonstrated that the abundant pathways of membrane transporters, carbohydrate and amino acids metabolisms followed different pattern of relative abundance in untreated and L. plantarum-treated silages. Only three pathways, namely base-excision repair, pyruvate metabolism and transcription machinery, were significantly different between untreated and L. buchneri-treated silages upon maturation. Lactic acid content was higher in L. plantarum-treated silage compared to untreated and L. buchneri-treated silage. Still, the pH of both treated silages was lower in the two Lactobacillus-treated silages compared to untreated silage. Aerobic stability test demonstrated that L. plantarum-, but not L. buchneri-supplement, facilitated silage deterioration. The lower aerobic stability of the L. plantarum-treated silage may be attributed to lower content of acetic acid and other volatile fatty acids which inhibit aerobic yeasts and molds. Indeed, high yeast count was recorded, following exposure to air, only in L. plantarum-treated silage, supporting this notion. Analysis of bacterial community of crop silage can be used for optimization of the ensiling process and the selection of appropriate inoculants for improving aerobic stability.
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Affiliation(s)
- Jitendra Keshri
- Department of Food Science, Institute for Postharvest and Food Sciences, Agriculture Research Organization Volcani Center, Rishon LeZion, Israel
| | - Yaira Chen
- Department of Food Science, Institute for Postharvest and Food Sciences, Agriculture Research Organization Volcani Center, Rishon LeZion, Israel
| | - Riky Pinto
- Department of Food Science, Institute for Postharvest and Food Sciences, Agriculture Research Organization Volcani Center, Rishon LeZion, Israel
| | - Yulia Kroupitski
- Department of Food Science, Institute for Postharvest and Food Sciences, Agriculture Research Organization Volcani Center, Rishon LeZion, Israel
| | - Zwi G Weinberg
- Department of Food Science, Institute for Postharvest and Food Sciences, Agriculture Research Organization Volcani Center, Rishon LeZion, Israel
| | - Shlomo Sela Saldinger
- Department of Food Science, Institute for Postharvest and Food Sciences, Agriculture Research Organization Volcani Center, Rishon LeZion, Israel
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Rettenmaier R, Duerr C, Neuhaus K, Liebl W, Zverlov VV. Comparison of sampling techniques and different media for the enrichment and isolation of cellulolytic organisms from biogas fermenters. Syst Appl Microbiol 2019; 42:481-487. [DOI: 10.1016/j.syapm.2019.05.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 05/15/2019] [Accepted: 05/17/2019] [Indexed: 12/22/2022]
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18
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Liu Y, Tong T, Li B, Xie S. Dynamics of bacterial communities in a river water treatment wetland. ANN MICROBIOL 2019. [DOI: 10.1007/s13213-019-01454-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Lambrecht J, Cichocki N, Schattenberg F, Kleinsteuber S, Harms H, Müller S, Sträuber H. Key sub-community dynamics of medium-chain carboxylate production. Microb Cell Fact 2019; 18:92. [PMID: 31138218 PMCID: PMC6537167 DOI: 10.1186/s12934-019-1143-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 05/20/2019] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND The carboxylate platform is a promising technology for substituting petrochemicals in the provision of specific platform chemicals and liquid fuels. It includes the chain elongation process that exploits reverse β-oxidation to elongate short-chain fatty acids and forms the more valuable medium-chain variants. The pH value influences this process through multiple mechanisms and is central to effective product formation. Its influence on the microbiome dynamics was investigated during anaerobic fermentation of maize silage by combining flow cytometric short interval monitoring, cell sorting and 16S rRNA gene amplicon sequencing. RESULTS Caproate and caprylate titres of up to 6.12 g L-1 and 1.83 g L-1, respectively, were achieved in a continuous stirred-tank reactor operated for 241 days. Caproate production was optimal at pH 5.5 and connected to lactate-based chain elongation, while caprylate production was optimal at pH 6.25 and linked to ethanol utilisation. Flow cytometry recorded 31 sub-communities with cell abundances varying over 89 time points. It revealed a highly dynamic community, whereas the sequencing analysis displayed a mostly unchanged core community. Eight key sub-communities were linked to caproate or caprylate production (rS > | ± 0.7|). Amongst other insights, sorting and subsequently sequencing these sub-communities revealed the central role of Bifidobacterium and Olsenella, two genera of lactic acid bacteria that drove chain elongation by providing additional lactate, serving as electron donor. CONCLUSIONS High-titre medium-chain fatty acid production in a well-established reactor design is possible using complex substrate without the addition of external electron donors. This will greatly ease scaling and profitable implementation of the process. The pH value influenced the substrate utilisation and product spectrum by shaping the microbial community. Flow cytometric single cell analysis enabled fast, short interval analysis of this community and was coupled with 16S rRNA gene amplicon sequencing to reveal the major role of lactate-producing bacteria.
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Affiliation(s)
- Johannes Lambrecht
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318, Leipzig, Germany
| | - Nicolas Cichocki
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318, Leipzig, Germany
| | - Florian Schattenberg
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318, Leipzig, Germany
| | - Sabine Kleinsteuber
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318, Leipzig, Germany
| | - Hauke Harms
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318, Leipzig, Germany
| | - Susann Müller
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318, Leipzig, Germany.
| | - Heike Sträuber
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318, Leipzig, Germany
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20
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Lv Z, Liang J, Chen X, Chen Z, Jiang J, Loake GJ. Assessment of the start-up process of anaerobic digestion utilizing swine manure: 13C fractionation of biogas and microbial dynamics. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:13275-13285. [PMID: 30895553 DOI: 10.1007/s11356-019-04703-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Accepted: 02/25/2019] [Indexed: 06/09/2023]
Abstract
The aim of this study was to investigate how the microbial community structure adapts during the start-up phase and how the 13C fractionation of biogas reflects the microbial population dynamics in two parallel swine manure-fed anaerobic digesters. Two swine manure-fed reactors for the start-up of continuously stirred tank reactors at mesophilic condition were evaluated. Changes in community structure were monitored using 16S rRNA high-throughput sequencing to measure the abundance of fermenting bacteria and methanogens. Digesters with relatively stable Methanosarcinaceae started up successfully and contained high gas production and low levels of propionate. In contrast, the digester that experienced a difficult start-up period had reduced Methanosarcinaceae along with accumulated propionate and low gas production. Specific gas production, specific methane production, and 13C fractionation of biogas were influenced significantly by Methanosarcinaceae, Methanobacteriaceae, and Clostridiaceae, indicating that the 13C fractionation of biogas had significant potential to reflect microbial population changes and digester performance during the start-up period.
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Affiliation(s)
- Zuopeng Lv
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, Jiangsu Normal University, Road 101, Xuzhou, 221116, Shanghai, China.
- Jiangsu Normal University - Edinburgh University, Centre for Transformative Biotechnology of Medicinal and Food Plants, Jiangsu Normal University, 101 Shanghai Road, Xuzhou, People's Republic of China.
| | - Jiazhuo Liang
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, Jiangsu Normal University, Road 101, Xuzhou, 221116, Shanghai, China
- Jiangsu Normal University - Edinburgh University, Centre for Transformative Biotechnology of Medicinal and Food Plants, Jiangsu Normal University, 101 Shanghai Road, Xuzhou, People's Republic of China
| | - Xin Chen
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, Jiangsu Normal University, Road 101, Xuzhou, 221116, Shanghai, China
- Jiangsu Normal University - Edinburgh University, Centre for Transformative Biotechnology of Medicinal and Food Plants, Jiangsu Normal University, 101 Shanghai Road, Xuzhou, People's Republic of China
| | - Zhongbing Chen
- Department of Applied Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 16500, Prague, Czech Republic
| | - Jihong Jiang
- The Key Laboratory of Biotechnology for Medicinal Plants of Jiangsu Province, Jiangsu Normal University, Road 101, Xuzhou, 221116, Shanghai, China
- Jiangsu Normal University - Edinburgh University, Centre for Transformative Biotechnology of Medicinal and Food Plants, Jiangsu Normal University, 101 Shanghai Road, Xuzhou, People's Republic of China
| | - Gary J Loake
- Jiangsu Normal University - Edinburgh University, Centre for Transformative Biotechnology of Medicinal and Food Plants, Jiangsu Normal University, 101 Shanghai Road, Xuzhou, People's Republic of China.
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, King's Buildings, Edinburgh, EH9 3JH, UK.
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Wu Q, Bao X, Guo W, Wang B, Li Y, Luo H, Wang H, Ren N. Medium chain carboxylic acids production from waste biomass: Current advances and perspectives. Biotechnol Adv 2019; 37:599-615. [PMID: 30849433 DOI: 10.1016/j.biotechadv.2019.03.003] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 03/01/2019] [Accepted: 03/03/2019] [Indexed: 11/29/2022]
Abstract
Alternative chemicals to diverse fossil-fuel-based products is urgently needed to mitigate the adverse impacts of fossil fuel depletion on human development. To this end, researchers have focused on the production of biochemical from readily available and affordable waste biomass. This is consistent with current guidelines for sustainable development and provides great advantages related to economy and environment. The search for suitable biochemical products is in progress worldwide. Therefore, this review recommends a biochemical (i.e., medium chain carboxylic acids (MCCAs)) utilizing an emerging biotechnological production platform called the chain elongation (CE) process. This work covers comprehensive introduction of the CE mechanism, functional microbes, available feedstock types and corresponding utilization strategies, major methods to enhance the performance of MCCAs production, and the challenges that need to be addressed for practical application. This work is expected to provide a thorough understanding of the CE technology, to guide and inspire researchers to solve existing problems in depth, and motivate large-scale MCCAs production.
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Affiliation(s)
- Qinglian Wu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China
| | - Xian Bao
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China
| | - Wanqian Guo
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China.
| | - Bing Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China
| | - Yunxi Li
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China
| | - Haichao Luo
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China
| | - Huazhe Wang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China
| | - Nanqi Ren
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China
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22
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Bonk F, Popp D, Weinrich S, Sträuber H, Becker D, Kleinsteuber S, Harms H, Centler F. Determination of Microbial Maintenance in Acetogenesis and Methanogenesis by Experimental and Modeling Techniques. Front Microbiol 2019; 10:166. [PMID: 30800108 PMCID: PMC6375858 DOI: 10.3389/fmicb.2019.00166] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 01/22/2019] [Indexed: 11/21/2022] Open
Abstract
For biogas-producing continuous stirred tank reactors, an increase in dilution rate increases the methane production rate as long as substrate input can be converted fully. However, higher dilution rates necessitate higher specific microbial growth rates, which are assumed to have a strong impact on the apparent microbial biomass yield due to cellular maintenance. To test this, we operated two reactors at 37°C in parallel at dilution rates of 0.18 and 0.07 days-1 (hydraulic retention times of 5.5 and 14 days, doubling times of 3.9 and 9.9 days in steady state) with identical inoculum and a mixture of volatile fatty acids as sole carbon sources. We evaluated the performance of the Anaerobic Digestion Model No. 1 (ADM1), a thermodynamic black box approach (TBA), and dynamic flux balance analysis (dFBA), to describe the experimental observations. All models overestimated the impact of dilution rate on the apparent microbial biomass yield when using default parameter values. Based on our analysis, a maintenance coefficient value below 0.2 kJ per carbon mole of microbial biomass per hour should be used for the TBA, corresponding to 0.12 mmol ATP per gram dry weight per hour for dFBA, which strongly deviates from the value of 9.8 kJ Cmol h-1 that has been suggested to apply to all anaerobic microorganisms at 37°C. We hypothesized that a decrease in dilution rate might select taxa with minimized maintenance expenditure. However, no major differences in the dominating taxa between the reactors were observed based on amplicon sequencing of 16S rRNA genes and terminal restriction fragment length polymorphism analysis of mcrA genes. Surprisingly, Methanosaeta dominated over Methanosarcina even at a dilution rate of 0.18 days-1, which contradicts previous model expectations. Furthermore, only 23-49% of the bacterial reads could be assigned to known syntrophic fatty acid oxidizers, indicating that unknown members of this functional group remain to be discovered. In conclusion, microbial maintenance was found to be much lower for acetogenesis and methanogenesis than previously assumed, likely due to the exceptionally low growth rates in anaerobic digestion. This finding might also be relevant for other microbial systems operating at similarly low growth rates.
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Affiliation(s)
- Fabian Bonk
- Department of Environmental Microbiology, UFZ-Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Denny Popp
- Department of Environmental Microbiology, UFZ-Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Sören Weinrich
- Biochemical Conversion Department, DBFZ-Deutsches Biomasseforschungszentrum gGmbH, Leipzig, Germany
| | - Heike Sträuber
- Department of Environmental Microbiology, UFZ-Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Daniela Becker
- Department of Environmental Microbiology, UFZ-Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Sabine Kleinsteuber
- Department of Environmental Microbiology, UFZ-Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Hauke Harms
- Department of Environmental Microbiology, UFZ-Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Florian Centler
- Department of Environmental Microbiology, UFZ-Helmholtz Centre for Environmental Research, Leipzig, Germany
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23
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Influence of Temperature on Biogas Production Efficiency and Microbial Community in a Two-Phase Anaerobic Digestion System. WATER 2019. [DOI: 10.3390/w11010133] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In this study, the influence of temperature on biogas production efficiency and the microbial community structure was investigated in a two-phase anaerobic digestion reactor for co-digestion of cow manure and corn straw. The results illustrated that the contents of solluted chemical oxygen demand (SCOD) and volatile fatty acid (VFA) in the acidogenic phase and biogas production in the methanogenic phase maintained relatively higher levels at temperatures ranging from 35–25 °C. The methane content of biogas production could be maintained higher than 50% at temperatures above 25 °C. The microbial community structure analysis indicated that the dominant functional bacteria were Acinetobacter, Acetitomaculum, and Bacillus in the acidogenic phase and Cenarchaeum in the methanogenic phase at 35–25 °C. However, the performances of the acidogenic phase and the methanogenic phase could be significantly decreased at a lower temperature of 20 °C, and microbial activity was inhibited obviously. Accordingly, a low temperature was adverse for the performance of the acidogenic and methanogenic phases, while moderate temperatures above 25 °C were more conducive to high biogas production efficiency.
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Wang G, Guo Y, Cai J, Wen H, Mao Z, Zhang H, Wang X, Ma L, Zhu M. Electricity production and the analysis of the anode microbial community in a constructed wetland-microbial fuel cell. RSC Adv 2019; 9:21460-21472. [PMID: 35521306 PMCID: PMC9066182 DOI: 10.1039/c8ra10130b] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 06/10/2019] [Indexed: 11/21/2022] Open
Abstract
The objective of this study is to assess bioelectricity generation, pollutant removal (COD, ammonium, nitrate) and the bacterial communities on anodes in constructed wetlands coupled with microbial fuel cells (CW-MFCs), through feeding the systems with three different types of synthetic wastewater (system 1: normal wastewater; system 2: ammonium-free wastewater; system 3: nitrate-free wastewater). Three CW-MFCs were operated with different wastewater concentrations and hydraulic retention times (HRTs) over a long time period (6 months). The results indicate that the maximum open circuit voltage (775.63 mV) and maximum power density (0.628 W m−3) were observed in system 3 (period 3), and that bioenergy production was inhibited in system 2, when feeding with ammonium-free wastewater continuously. COD removal rates in the three systems were similar during each period and ranged from 82.2 ± 6.8% to 98.3 ± 2.2%. Ammonium removal occurred at the air cathode of the CW-MFCs through nitrification, and a higher level of ammonium removal was found in system 1 (period 3) compared with the others. Meanwhile, denitrification occurred at the anaerobic anode of the CW-MFCs, and a large amount of nitrate was removed effectively. The highest nitrate removal rate was 98.8 ± 0.5% in system 2 (period 3). Additionally, four genera related to electricity generation were detected at the anode: Geothrix; Desulfovibrio; Desulfobulbus; and Geobacter. The relative abundances of Desulfovibrio, Desulfobulbus and Geothrix gradually increased during the three periods in system 3, which might be beneficial for bioelectricity generation. Further investigations are needed to optimize the CW-MFC performance and explain the mechanism behind the pollutant degradation and electron motion in the CW-MFCs. The objective of this study is to assess bioelectricity generation, pollutant removal and the bacterial communities on anodes in constructed wetlands coupled with microbial fuel cells, through feeding the systems with three different types of synthetic wastewater.![]()
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Affiliation(s)
- Guozhen Wang
- School of Life Science
- Jiangsu Normal University
- Xuzhou 221116
- China
| | - Yating Guo
- School of Life Science
- Jiangsu Normal University
- Xuzhou 221116
- China
| | - Jiaying Cai
- School of Life Science
- Jiangsu Normal University
- Xuzhou 221116
- China
| | - Hongyu Wen
- School of Life Science
- Jiangsu Normal University
- Xuzhou 221116
- China
| | - Zhen Mao
- School of Environment Science and Spatial Informatics
- China University of Mining and Technology
- Xuzhou 221116
- China
| | - Hao Zhang
- School of Life Science
- Jiangsu Normal University
- Xuzhou 221116
- China
| | - Xin Wang
- School of Life Science
- Jiangsu Normal University
- Xuzhou 221116
- China
| | - Lei Ma
- School of Life Science
- Jiangsu Normal University
- Xuzhou 221116
- China
| | - Mengqin Zhu
- School of Life Science
- Jiangsu Normal University
- Xuzhou 221116
- China
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Bonk F, Popp D, Weinrich S, Sträuber H, Kleinsteuber S, Harms H, Centler F. Ammonia Inhibition of Anaerobic Volatile Fatty Acid Degrading Microbial Communities. Front Microbiol 2018; 9:2921. [PMID: 30555446 PMCID: PMC6284035 DOI: 10.3389/fmicb.2018.02921] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 11/14/2018] [Indexed: 11/16/2022] Open
Abstract
Ammonia inhibition is an important reason for reactor failures and economic losses in anaerobic digestion. Its impact on acetic acid degradation is well-studied, while its effect on propionic and butyric acid degradation has received little attention and is consequently not considered in the Anaerobic Digestion Model No. 1 (ADM1). To compare ammonia inhibition of the degradation of these three volatile fatty acids (VFAs), we fed a mixture of them as sole carbon source to three continuous stirred tank reactors (CSTRs) and increased ammonium bicarbonate concentrations in the influent from 52 to 277 mM. The use of this synthetic substrate allowed for the determination of degradation efficiencies for the individual acids. While butyric acid degradation was hardly affected by the increase of ammonia concentration, propionic acid degradation turned out to be even more inhibited than acetic acid degradation with degradation efficiencies dropping to 31 and 65% for propionic and acetic acid, respectively. The inhibited reactors acclimatized and approximated pre-disturbance degradation efficiencies toward the end of the experiment, which was accompanied by strong microbial community shifts, as observed by amplicon sequencing of 16S rRNA genes and terminal restriction fragment length polymorphism (T-RFLP) of mcrA genes. The acetoclastic methanogen Methanosaeta was completely replaced by Methanosarcina. The propionic acid degrading genus Syntrophobacter was replaced by yet unknown propionic acid degraders. The butyric acid degrading genus Syntrophomonas and hydrogenotrophic Methanomicrobiaceae were hardly affected. We hypothesized that the ammonia sensitivity of the initially dominating taxa Methanosaeta and Syntrophobacter led to a stronger inhibition of the acetic and propionic acid degradation compared to butyric acid degradation and hydrogenotrophic methanogenesis, which were facilitated by the ammonia tolerant taxa Syntrophomonas and Methanomicrobiaceae. We implemented this hypothesis into a multi-taxa extension of ADM1, which was able to simulate the dynamics of both microbial community composition and VFA concentration in the experiment. It is thus plausible that the effect of ammonia on VFA degradation strongly depends on the ammonia sensitivity of the dominating taxa, for syntrophic propionate degraders as much as for acetoclastic methanogens.
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Affiliation(s)
- Fabian Bonk
- Department of Environmental Microbiology, UFZ–Helmholtz Center for Environmental Research, Leipzig, Germany
| | - Denny Popp
- Department of Environmental Microbiology, UFZ–Helmholtz Center for Environmental Research, Leipzig, Germany
| | - Sören Weinrich
- Biochemical Conversion Department, DBFZ-Deutsches Biomasseforschungszentrum gGmbH, Leipzig, Germany
| | - Heike Sträuber
- Department of Environmental Microbiology, UFZ–Helmholtz Center for Environmental Research, Leipzig, Germany
| | - Sabine Kleinsteuber
- Department of Environmental Microbiology, UFZ–Helmholtz Center for Environmental Research, Leipzig, Germany
| | - Hauke Harms
- Department of Environmental Microbiology, UFZ–Helmholtz Center for Environmental Research, Leipzig, Germany
| | - Florian Centler
- Department of Environmental Microbiology, UFZ–Helmholtz Center for Environmental Research, Leipzig, Germany
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26
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Bonk F, Popp D, Weinrich S, Sträuber H, Kleinsteuber S, Harms H, Centler F. Intermittent fasting for microbes: how discontinuous feeding increases functional stability in anaerobic digestion. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:274. [PMID: 30323859 PMCID: PMC6173896 DOI: 10.1186/s13068-018-1279-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 09/29/2018] [Indexed: 05/15/2023]
Abstract
BACKGROUND Demand-driven biogas production could play an important role for future sustainable energy supply. However, feeding a biogas reactor according to energy demand may lead to organic overloading and, thus, to process failures. To minimize this risk, digesters need to be actively steered towards containing more robust microbial communities. This study focuses on acetogenesis and methanogenesis as crucial process steps for avoiding acidification. We fed lab-scale anaerobic digesters with volatile fatty acids under various feeding regimes and disturbances. The resulting microbial communities were analyzed on DNA and RNA level by terminal restriction fragment length polymorphism of the mcrA gene, 16S rRNA gene amplicon sequencing, and a [2-13C]-acetate assay. A modified Anaerobic Digestion Model 1 (ADM1) that distinguishes between the acetoclastic methanogens Methanosaeta and Methanosarcina was developed and fitted using experimental abiotic and biotic process parameters. RESULTS Discontinuous feeding led to more functional resilience than continuous feeding, without loss in process efficiency. This was attributed to a different microbial community composition. Methanosaeta dominated the continuously fed reactors, while its competitor Methanosarcina was washed out. With discontinuous feeding, however, the fluctuating acetic acid concentrations provided niches to grow and co-exist for both organisms as shown by transcription analysis of the mcrA gene. Our model confirmed the higher functional resilience due to the higher abundance of Methanosarcina based on its higher substrate uptake rate and higher resistance to low pH values. Finally, we applied our model to maize silage as a more complex and practically relevant substrate and showed that our model is likely transferable to the complete AD process. CONCLUSIONS The composition of the microbial community determined the AD functional resilience against organic overloading in our experiments. In particular, communities with higher share of Methanosarcina showed higher process stability. The share of these microorganisms can be purposefully increased by discontinuous feeding. A model was developed that enables derivation of the necessary feeding regime for a more robust community with higher share of Methanosarcina.
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Affiliation(s)
- Fabian Bonk
- Department of Environmental Microbiology, UFZ–Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany
| | - Denny Popp
- Department of Environmental Microbiology, UFZ–Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany
| | - Sören Weinrich
- Biochemical Conversion Department, DBFZ Deutsches Biomasseforschungszentrum Gemeinnützige GmbH, Torgauer Str. 116, 04347 Leipzig, Germany
| | - Heike Sträuber
- Department of Environmental Microbiology, UFZ–Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany
| | - Sabine Kleinsteuber
- Department of Environmental Microbiology, UFZ–Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany
| | - Hauke Harms
- Department of Environmental Microbiology, UFZ–Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany
| | - Florian Centler
- Department of Environmental Microbiology, UFZ–Helmholtz Centre for Environmental Research, Permoserstr. 15, 04318 Leipzig, Germany
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Martins G, Salvador AF, Pereira L, Alves MM. Methane Production and Conductive Materials: A Critical Review. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:10241-10253. [PMID: 30118213 DOI: 10.1021/acs.est.8b01913] [Citation(s) in RCA: 163] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Conductive materials (CM) have been extensively reported to enhance methane production in anaerobic digestion processes. The occurrence of direct interspecies electron transfer (DIET) in microbial communities, as an alternative or complementary to indirect electron transfer (via hydrogen or formate), is the main explanation given to justify the improvement of methane production. Not disregarding that DIET can be promoted in the presence of certain CM, it surely does not explain all the reported observations. In fact, in methanogenic environments DIET was only unequivocally demonstrated in cocultures of Geobacter metallireducens with Methanosaeta harundinacea or Methanosarcina barkeri and frequently Geobacter sp. are not detected in improved methane production driven systems. Furthermore, conductive carbon nanotubes were shown to accelerate the activity of methanogens growing in pure cultures, where DIET is not expected to occur, and hydrogenotrophic activity is ubiquitous in full-scale anaerobic digesters treating for example brewery wastewaters, indicating that interspecies hydrogen transfer is an important electron transfer mechanism in those systems. This paper presents an overview of the effect of several iron-based and carbon-based CM in bioengineered systems, focusing on the improvement in methane production and in microbial communities' changes. Control assays, as fundamental elements to support major conclusions in reported experiments, are critically revised and discussed.
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Affiliation(s)
- Gilberto Martins
- Centre of Biological Engineering , University of Minho , Campus de Gualtar , 4710-057 Braga , Portugal
| | - Andreia F Salvador
- Centre of Biological Engineering , University of Minho , Campus de Gualtar , 4710-057 Braga , Portugal
| | - Luciana Pereira
- Centre of Biological Engineering , University of Minho , Campus de Gualtar , 4710-057 Braga , Portugal
| | - M Madalena Alves
- Centre of Biological Engineering , University of Minho , Campus de Gualtar , 4710-057 Braga , Portugal
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Scarborough MJ, Lynch G, Dickson M, McGee M, Donohue TJ, Noguera DR. Increasing the economic value of lignocellulosic stillage through medium-chain fatty acid production. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:200. [PMID: 30034526 PMCID: PMC6052542 DOI: 10.1186/s13068-018-1193-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 07/06/2018] [Indexed: 05/14/2023]
Abstract
BACKGROUND Lignocellulosic biomass is seen as an abundant renewable source of liquid fuels and chemicals that are currently derived from petroleum. When lignocellulosic biomass is used for ethanol production, the resulting liquid residue (stillage) contains large amounts of organic material that could be further transformed into recoverable bioproducts, thus enhancing the economics of the biorefinery. RESULTS Here we test the hypothesis that a bacterial community could transform the organics in stillage into valuable bioproducts. We demonstrate the ability of this microbiome to convert stillage organics into medium-chain fatty acids (MCFAs), identify the predominant community members, and perform a technoeconomic analysis of recovering MCFAs as co-products of ethanol production. Steady-state operation of a stillage-fed bioreactor showed that 18% of the organic matter in stillage was converted to MCFAs. Xylose and complex carbohydrates were the primary substrates transformed. During the MCFA production period, the five major genera represented more than 95% of the community, including Lactobacillus, Roseburia, Atopobium, Olsenella, and Pseudoramibacter. To assess the potential benefits of producing MCFAs from stillage, we modeled the economics of ethanol and MCFA co-production, at MCFA productivities observed during reactor operation. CONCLUSIONS The analysis predicts that production of MCFAs, ethanol, and electricity could reduce the minimum ethanol selling price from $2.15 to $1.76 gal-1 ($2.68 gal-1 gasoline equivalents) when compared to a lignocellulosic biorefinery that produces only ethanol and electricity.
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Affiliation(s)
- Matthew J. Scarborough
- The Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI USA
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI USA
| | - Griffin Lynch
- The Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI USA
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI USA
| | - Mitch Dickson
- The Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI USA
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI USA
| | - Mick McGee
- The Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI USA
| | - Timothy J. Donohue
- The Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI USA
| | - Daniel R. Noguera
- The Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI USA
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI USA
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Zamorano-López N, Moñino P, Borrás L, Aguado D, Barat R, Ferrer J, Seco A. Influence of food waste addition over microbial communities in an Anaerobic Membrane Bioreactor plant treating urban wastewater. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2018; 217:788-796. [PMID: 29660704 DOI: 10.1016/j.jenvman.2018.04.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 03/22/2018] [Accepted: 04/04/2018] [Indexed: 06/08/2023]
Abstract
Notorious changes in microbial communities were observed during and after the joint treatment of wastewater with Food Waste (FW) in an Anaerobic Membrane Bioreactor (AnMBR) plant. The microbial population was analysed by high-throughput sequencing of the 16S rRNA gene and dominance of Chloroflexi, Firmicutes, Synergistetes and Proteobacteria phyla was found. The relative abundance of these potential hydrolytic phyla increased as a higher fraction of FW was jointly treated. Moreover, whereas Specific Methanogenic Activity (SMA) rose from 10 to 51 mL CH4 g-1 VS, Methanosarcinales order increased from 34.0% over 80.0% of total Archaea, being Methanosaeta the dominant genus. The effect of FW over AnMBR biomass was observed during the whole experience, as methane production rose from 49.2 to 144.5 L CH4 · kg-1 influent COD. Furthermore, biomethanization potential was increased over 82% after the experience. AnMBR technology allows the established microbial community to remain in the bioreactor even after the addition of FW, improving the anaerobic digestion of urban wastewater.
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Affiliation(s)
- N Zamorano-López
- CALAGUA - Unidad Mixta UV-UPV, Departament d'Enginyeria Química, Universitat de València, Avinguda de la Universitat s/n, Burjassot, Valencia, 46100, Spain.
| | - P Moñino
- CALAGUA - Unidad Mixta UV-UPV, Institut Universitari d'Investigació d'Enginyeria de l'Aigua i Medi Ambient - IIAMA, Universitat Politècnica de Valencia, Camí de Vera s/n, Valencia, 46022, Spain
| | - L Borrás
- CALAGUA - Unidad Mixta UV-UPV, Departament d'Enginyeria Química, Universitat de València, Avinguda de la Universitat s/n, Burjassot, Valencia, 46100, Spain
| | - D Aguado
- CALAGUA - Unidad Mixta UV-UPV, Institut Universitari d'Investigació d'Enginyeria de l'Aigua i Medi Ambient - IIAMA, Universitat Politècnica de Valencia, Camí de Vera s/n, Valencia, 46022, Spain
| | - R Barat
- CALAGUA - Unidad Mixta UV-UPV, Institut Universitari d'Investigació d'Enginyeria de l'Aigua i Medi Ambient - IIAMA, Universitat Politècnica de Valencia, Camí de Vera s/n, Valencia, 46022, Spain
| | - J Ferrer
- CALAGUA - Unidad Mixta UV-UPV, Institut Universitari d'Investigació d'Enginyeria de l'Aigua i Medi Ambient - IIAMA, Universitat Politècnica de Valencia, Camí de Vera s/n, Valencia, 46022, Spain
| | - A Seco
- CALAGUA - Unidad Mixta UV-UPV, Departament d'Enginyeria Química, Universitat de València, Avinguda de la Universitat s/n, Burjassot, Valencia, 46100, Spain
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Sträuber H, Bühligen F, Kleinsteuber S, Dittrich-Zechendorf M. Carboxylic acid production from ensiled crops in anaerobic solid-state fermentation - trace elements as pH controlling agents support microbial chain elongation with lactic acid. Eng Life Sci 2018; 18:447-458. [PMID: 32624926 DOI: 10.1002/elsc.201700186] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 03/23/2018] [Accepted: 04/10/2018] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND For the production of carboxylic acid platform chemicals like medium-chain fatty acids (MCFA) by anaerobic fermentation, pH control is required. However, adding buffer solutions is ineffective in leach-bed reactors. AIM In order to increase the MCFA production by maize silage fermentation and to engineer the process we investigated the effect of solid alkaline iron and manganese additives on the process performance and microbial community dynamics. RESULTS Without additives, the pH dropped to 3.9 and lactic acid bacteria were favored. Total product yields of 207 ± 5.4 g organic acids (C2-C6) and alcohols per kg volatile solids were reached. The addition of trace elements increased the pH value and the product spectrum and yields changed. With a commercial iron additive, the product yields were higher (293 ± 15.2 g/kgvolatile solids) and supposedly clostridia used lactic acid for microbial chain elongation of acetic acid producing n-butyric acid. With the addition of pure Fe(OH)3 or Mn(OH)2, the total product yields were lower than in the other reactors. However, increased production of MCFA and the occurrence of distinct bacterial taxa (Lachnospiraceae, Ruminococcaceae and Megasphaera) related to this metabolic function were observed. CONCLUSIONS The application of alkaline trace metal additives as pH stabilizing agents can mitigate spatial metabolic heterogeneities when trace metal deficient substrates like specific crops or residues thereof are applied.
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Affiliation(s)
- Heike Sträuber
- Department of Environmental Microbiology Helmholtz Centre for Environmental Research - UFZ Leipzig Germany
| | - Franziska Bühligen
- Department of Environmental Microbiology Helmholtz Centre for Environmental Research - UFZ Leipzig Germany
| | - Sabine Kleinsteuber
- Department of Environmental Microbiology Helmholtz Centre for Environmental Research - UFZ Leipzig Germany
| | - Michael Dittrich-Zechendorf
- Department Biochemical Conversion Deutsches Biomasseforschungszentrum gemeinnützige GmbH (DBFZ) Leipzig Germany
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31
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Tang Y, Li M, Xu D, Huang J, Sun J. Application potential of aerobic denitrifiers coupled with a biostimulant for nitrogen removal from urban river sediment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:5980-5993. [PMID: 29236243 DOI: 10.1007/s11356-017-0903-4] [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: 06/18/2017] [Accepted: 12/01/2017] [Indexed: 06/07/2023]
Abstract
Aerobic denitrifiers coupled with a denitrification agent were applied in the sediment of an urban river for the bioremediation of nitrogen pollution. The results revealed that 14.7% of the total nitrogen in the sediment was removed after 115 days of treatment and the nitrate nitrogen concentration removal rate was enhanced in the overlying water. Compared with the control, the total transferable nitrogen in the sediment increased from 0.097 to 0.166 mg/g, indicating that more nitrogen is likely to be involved in the biogeochemical cycling of nitrogen. Increased urease activity indicated the possible further potential of nitrogen biodegradation, while the decreased protease pointed to the low concentration of protein remaining in the sediment. Sequencing revealed that the bacterial community diversity in the sediment increased significantly after 43 days of treatment and that the effect persisted. Compared with other microcosms, the dominant phyla in the sediment after 43 days were Firmicutes, Elusimicrobia, Spirochaetae and Fibrobacteres; whereas, after 115 of treatment, the dominant bacteria were Nitrospirae, Deferribacteres and Chloroflexi. The dominant bacteria in the sediment are mainly associated with nitrogen cycling and thus contributed considerably to nitrogen removal in the sediment. Overall, the direction of species succession was similar to natural succession; namely, there were no undesirable ecological risks involved. This study highlights the possible benefits and feasibility of using bioaugmentation technology coupled with biostimulation to remediate nitrogen-polluted sediments.
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Affiliation(s)
- Yinqi Tang
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, People's Republic of China
- State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin, 300350, People's Republic of China
| | - Meng Li
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, People's Republic of China
- State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin, 300350, People's Republic of China
| | - Danning Xu
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, People's Republic of China
- State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin, 300350, People's Republic of China
| | - Jianjun Huang
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, People's Republic of China
| | - Jingmei Sun
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, People's Republic of China.
- State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin, 300350, People's Republic of China.
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Xin X, He J, Li L, Qiu W. Enzymes catalyzing pre-hydrolysis facilitated the anaerobic fermentation of waste activated sludge with acidogenic and microbiological perspectives. BIORESOURCE TECHNOLOGY 2018; 250:69-78. [PMID: 29153652 DOI: 10.1016/j.biortech.2017.09.211] [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: 08/22/2017] [Revised: 09/28/2017] [Accepted: 09/30/2017] [Indexed: 06/07/2023]
Abstract
This study investigated acidogenic and microbiological perspectives in the anaerobic fermentation (AF) of waste activated sludge (WAS) pre-hydrolyzed by enzymes catalysis. The enzymes catalysis boosted WAS biodegradability dramatically with nearly 8500 mg/L soluble chemical oxygen demand (SCOD) increase just within 4 h. The volatile fatty acids (VFAs) in the acidogenesis were accumulated effectively with over 3200 mg COD/L in 12 d, which reached 0.687 kWh/kg VSS electricity conversion efficiency (2.5 times higher than the control test). The fermentation process favored the compression of fermentative sludge with the distribution spread index (DSI) rising. The core populations of bacteria and archaea shifting enlarged the dissimilarity of communities at different fermentation stages. Increase of community diversity contributed to VFAs accumulation stability. Moreover, the intermediate bacterial community evenness favored VFAs accumulation potentially. The enzymes catalysis might be a promising solution for strengthening VFAs accumulation in the WAS fermentation with boosting the electricity conversion potential.
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Affiliation(s)
- Xiaodong Xin
- School of Municipal and Environmental Engineering, Harbin Institute of Technology (HIT), Harbin 150090, China
| | - Junguo He
- School of Municipal and Environmental Engineering, Harbin Institute of Technology (HIT), Harbin 150090, China
| | - Lin Li
- School of Municipal and Environmental Engineering, Harbin Institute of Technology (HIT), Harbin 150090, China
| | - Wei Qiu
- School of Municipal and Environmental Engineering, Harbin Institute of Technology (HIT), Harbin 150090, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology (SKLUWRE, HIT), Harbin 150090, China.
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Detman A, Mielecki D, Pleśniak Ł, Bucha M, Janiga M, Matyasik I, Chojnacka A, Jędrysek MO, Błaszczyk MK, Sikora A. Methane-yielding microbial communities processing lactate-rich substrates: a piece of the anaerobic digestion puzzle. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:116. [PMID: 29721040 PMCID: PMC5910564 DOI: 10.1186/s13068-018-1106-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 04/04/2018] [Indexed: 05/02/2023]
Abstract
BACKGROUND Anaerobic digestion, whose final products are methane and carbon dioxide, ensures energy flow and circulation of matter in ecosystems. This naturally occurring process is used for the production of renewable energy from biomass. Lactate, a common product of acidic fermentation, is a key intermediate in anaerobic digestion of biomass in the environment and biogas plants. Effective utilization of lactate has been observed in many experimental approaches used to study anaerobic digestion. Interestingly, anaerobic lactate oxidation and lactate oxidizers as a physiological group in methane-yielding microbial communities have not received enough attention in the context of the acetogenic step of anaerobic digestion. This study focuses on metabolic transformation of lactate during the acetogenic and methanogenic steps of anaerobic digestion in methane-yielding bioreactors. RESULTS Methane-yielding microbial communities instead of pure cultures of acetate producers were used to process artificial lactate-rich media to methane and carbon dioxide in up-flow anaerobic sludge blanket reactors. The media imitated the mixture of acidic products found in anaerobic environments/digesters where lactate fermentation dominates in acidogenesis. Effective utilization of lactate and biogas production was observed. 16S rRNA profiling was used to examine the selected methane-yielding communities. Among Archaea present in the bioreactors, the order Methanosarcinales predominated. The acetoclastic pathway of methane formation was further confirmed by analysis of the stable carbon isotope composition of methane and carbon dioxide. The domain Bacteria was represented by Bacteroidetes, Firmicutes, Proteobacteria, Synergistetes, Actinobacteria, Spirochaetes, Tenericutes, Caldithrix, Verrucomicrobia, Thermotogae, Chloroflexi, Nitrospirae, and Cyanobacteria. Available genome sequences of species and/or genera identified in the microbial communities were searched for genes encoding the lactate-oxidizing metabolic machinery homologous to those of Acetobacterium woodii and Desulfovibrio vulgaris. Furthermore, genes for enzymes of the reductive acetyl-CoA pathway were present in the microbial communities. CONCLUSIONS The results indicate that lactate is oxidized mainly to acetate during the acetogenic step of AD and this comprises the acetotrophic pathway of methanogenesis. The genes for lactate utilization under anaerobic conditions are widespread in the domain Bacteria. Lactate oxidation to the substrates for methanogens is the most energetically attractive process in comparison to butyrate, propionate, or ethanol oxidation.
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Affiliation(s)
- Anna Detman
- Department of Molecular Biology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Damian Mielecki
- Department of Molecular Biology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Łukasz Pleśniak
- Department of Molecular Biology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Michał Bucha
- Faculty of Earth Sciences, University of Silesia in Katowice, Sosnowiec, Poland
| | - Marek Janiga
- Oil and Gas Institute, National Research Institute, Cracow, Poland
| | - Irena Matyasik
- Oil and Gas Institute, National Research Institute, Cracow, Poland
| | - Aleksandra Chojnacka
- Department of Molecular Biology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | | | | | - Anna Sikora
- Department of Molecular Biology, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
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Koch C, Korth B, Harnisch F. Microbial ecology-based engineering of Microbial Electrochemical Technologies. Microb Biotechnol 2018; 11:22-38. [PMID: 28805354 PMCID: PMC5743830 DOI: 10.1111/1751-7915.12802] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 07/11/2017] [Accepted: 07/12/2017] [Indexed: 11/27/2022] Open
Abstract
Microbial ecology is devoted to the understanding of dynamics, activity and interaction of microorganisms in natural and technical ecosystems. Bioelectrochemical systems represent important technical ecosystems, where microbial ecology is of highest importance for their function. However, whereas aspects of, for example, materials and reactor engineering are commonly perceived as highly relevant, the study and engineering of microbial ecology are significantly underrepresented in bioelectrochemical systems. This shortfall may be assigned to a deficit on knowledge and power of these methods as well as the prerequisites for their thorough application. This article discusses not only the importance of microbial ecology for microbial electrochemical technologies but also shows which information can be derived for a knowledge-driven engineering. Instead of providing a comprehensive list of techniques from which it is hard to judge the applicability and value of information for a respective one, this review illustrates the suitability of selected techniques on a case study. Thereby, best practice for different research questions is provided and a set of key questions for experimental design, data acquisition and analysis is suggested.
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Affiliation(s)
- Christin Koch
- Department of Environmental MicrobiologyHelmholtz Centre for Environmental Research GmbH ‐ UFZPermoserstraße 1504318LeipzigGermany
| | - Benjamin Korth
- Department of Environmental MicrobiologyHelmholtz Centre for Environmental Research GmbH ‐ UFZPermoserstraße 1504318LeipzigGermany
| | - Falk Harnisch
- Department of Environmental MicrobiologyHelmholtz Centre for Environmental Research GmbH ‐ UFZPermoserstraße 1504318LeipzigGermany
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Wang J, Song X, Wang Y, Bai J, Li M, Dong G, Lin F, Lv Y, Yan D. Bioenergy generation and rhizodegradation as affected by microbial community distribution in a coupled constructed wetland-microbial fuel cell system associated with three macrophytes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 607-608:53-62. [PMID: 28686895 DOI: 10.1016/j.scitotenv.2017.06.243] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 06/26/2017] [Accepted: 06/27/2017] [Indexed: 06/07/2023]
Abstract
Rhizodeposits excreted by various macrophytes might lead to the potential discrepancy of microbial community distribution in constructed wetland coupled with microbial fuel cell (CW-MFC), which has been considered as main factors for the variations of bioelectricity generation during wastewater treatment. In this study, CW-MFC has been associated with three macrophytes (J. effuses, T. orientalis and S. validus) for domestic sewage treatment, also unplanted CW-MFC was performed as a control system. Macrophyte T. orientalis and S. validus can significantly strengthen the bioenergy output in CW-MFC. Highest current (94.27mAm-2) and power densities (21.53mWm-2) were obtained in CW-MFC planted with T. orientalis. Removal efficiencies of COD, NO3-N and NH3-N in CW-MFC planted with S. validus was respectively 5.8%, 7.2%, and 23.9% higher than that of unplanted system. Notably, the oxygen depletion in S. validus CW-MFC reactor during the dark cycle was higher that of other reactors. Results of high-throughput sequencing analysis showed that higher biodiversity was observed in rhizosphere than that of anode material, and the relative abundance of Desulfobulbus sp. and Geobacter sp. has been apparently promoted in the samples of rhizosphere. However, a higher relative abundance of electrochemically active bacteria (Proteobacteria) was observed on the surface of anode electrode material. In addition, microbes (Cytophagales, Clostridium sp., and Dechloromonas sp., and so forth) found in rhizosphere show a capability to decompose refractory contaminants. These contaminants and death roots in the upper part of wetland could be oxidized to fat acids, which may be used as the electrons acceptors for promoting the bioelectricity generation during wastewater treatment.
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Affiliation(s)
- Junfeng Wang
- College of Environmental Science and Engineering, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Donghua University, Shanghai 201620, China
| | - Xinshan Song
- College of Environmental Science and Engineering, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Donghua University, Shanghai 201620, China.
| | - Yuhui Wang
- College of Environmental Science and Engineering, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Donghua University, Shanghai 201620, China.
| | - Junhong Bai
- School of Environment, Beijing Normal University, Beijing 100038, China
| | - Manjie Li
- State Key Laboratory Hydroscience and Engineering, Tsinghua University, Beijing 100084, China
| | - Guoqiang Dong
- College of Environmental Science and Engineering, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Donghua University, Shanghai 201620, China
| | - Fanda Lin
- College of Environmental Science and Engineering, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Donghua University, Shanghai 201620, China
| | - Yanfeng Lv
- College of Environmental Science and Engineering, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Donghua University, Shanghai 201620, China
| | - Denghua Yan
- China Institute of Water Resource and Hydropower Research, Beijing 100038, China
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Bozan M, Akyol Ç, Ince O, Aydin S, Ince B. Application of next-generation sequencing methods for microbial monitoring of anaerobic digestion of lignocellulosic biomass. Appl Microbiol Biotechnol 2017; 101:6849-6864. [PMID: 28779289 DOI: 10.1007/s00253-017-8438-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 07/14/2017] [Accepted: 07/17/2017] [Indexed: 10/19/2022]
Abstract
The anaerobic digestion of lignocellulosic wastes is considered an efficient method for managing the world's energy shortages and resolving contemporary environmental problems. However, the recalcitrance of lignocellulosic biomass represents a barrier to maximizing biogas production. The purpose of this review is to examine the extent to which sequencing methods can be employed to monitor such biofuel conversion processes. From a microbial perspective, we present a detailed insight into anaerobic digesters that utilize lignocellulosic biomass and discuss some benefits and disadvantages associated with the microbial sequencing techniques that are typically applied. We further evaluate the extent to which a hybrid approach incorporating a variation of existing methods can be utilized to develop a more in-depth understanding of microbial communities. It is hoped that this deeper knowledge will enhance the reliability and extent of research findings with the end objective of improving the stability of anaerobic digesters that manage lignocellulosic biomass.
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Affiliation(s)
- Mahir Bozan
- Institute of Environmental Sciences, Boğaziçi University, Bebek, 34342, Istanbul, Turkey
| | - Çağrı Akyol
- Institute of Environmental Sciences, Boğaziçi University, Bebek, 34342, Istanbul, Turkey
| | - Orhan Ince
- Department of Environmental Engineering, Istanbul Technical University, Maslak, 34469, Istanbul, Turkey
| | - Sevcan Aydin
- Department of Genetics and Bioengineering, Nişantaşı University, Maslak, 34469, Istanbul, Turkey.
| | - Bahar Ince
- Institute of Environmental Sciences, Boğaziçi University, Bebek, 34342, Istanbul, Turkey
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Poszytek K, Pyzik A, Sobczak A, Lipinski L, Sklodowska A, Drewniak L. The effect of the source of microorganisms on adaptation of hydrolytic consortia dedicated to anaerobic digestion of maize silage. Anaerobe 2017; 46:46-55. [DOI: 10.1016/j.anaerobe.2017.02.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 01/28/2017] [Accepted: 02/14/2017] [Indexed: 12/26/2022]
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Tao Y, Zhu X, Wang H, Wang Y, Li X, Jin H, Rui J. Complete genome sequence of Ruminococcaceae bacterium CPB6: A newly isolated culture for efficient n-caproic acid production from lactate. J Biotechnol 2017; 259:91-94. [PMID: 28774671 DOI: 10.1016/j.jbiotec.2017.07.036] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 07/27/2017] [Accepted: 07/30/2017] [Indexed: 11/29/2022]
Abstract
n-caproic acid (CA) is a valuable chemical feedstock for various industrial applications. Biological production of CA from renewable carbon sources has attracted a lot of attentions recently. We lately reported the new culture Ruminococcaceae bacterium CPB6, which was isolated from a microbiome for efficient CA production from lactate. To further elucidate its metabolism, we sequenced the whole genome of the strain. The size of the complete genome is 2,069,994bp with 50.58% GC content; no plasmid was identified. Sets of genes involved in the fatty acid biosynthesis via acyl carrier protein (ACP) and coenzyme A (CoA) as well as lactate oxidation/reduction pathways were identified in the genome. These genes were inferred to be correlated with the CA production. The complete genome sequence provides essential information for the elucidation of the metabolism for CA production from lactate, and further improvement of the strain through genetic engineering for enhanced CA production and other biotechnological purposes.
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Affiliation(s)
- Yong Tao
- Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, & Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
| | - Xiaoyu Zhu
- Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, & Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
| | - Han Wang
- Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, & Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
| | - Yi Wang
- Department of Biosystems Engineering, Auburn University, Auburn, AL 36849, USA.
| | - Xiangzhen Li
- Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, & Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
| | - Hong Jin
- Chengdu Medical College, Chengdu 610083, China
| | - Junpeng Rui
- Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, & Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China.
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Khor WC, Andersen S, Vervaeren H, Rabaey K. Electricity-assisted production of caproic acid from grass. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:180. [PMID: 28702085 PMCID: PMC5504738 DOI: 10.1186/s13068-017-0863-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 06/28/2017] [Indexed: 05/25/2023]
Abstract
BACKGROUND Medium chain carboxylic acids, such as caproic acid, are conventionally produced from food materials. Caproic acid can be produced through fermentation by the reverse β-oxidation of lactic acid, generated from low value lignocellulosic biomass. In situ extraction of caproic acid can be achieved by membrane electrolysis coupled to the fermentation process, allowing recovery by phase separation. RESULTS Grass was fermented to lactic acid in a leach-bed-type reactor, which was then further converted to caproic acid in a secondary fermenter. The lactic acid concentration was 9.36 ± 0.95 g L-1 over a 33-day semi-continuous operation, and converted to caproic acid at pH 5.5-6.2, with a concentration of 4.09 ± 0.54 g L-1 during stable production. The caproic acid product stream was extracted in its anionic form, concentrated and converted to caproic acid by membrane electrolysis, resulting in a >70 wt% purity solution. In a parallel test exploring the upper limits of production rate through cell retention, we achieved the highest reported caproic acid production rate to date from a lignocellulosic biomass (grass, via a coupled process), at 0.99 ± 0.02 g L-1 h-1. The fermenting microbiome (mainly consisting of Clostridium IV and Lactobacillus) was capable of producing a maximum caproic acid concentration of 10.92 ± 0.62 g L-1 at pH 5.5, at the border of maximum solubility of protonated caproic acid. CONCLUSIONS Grass can be utilized as a substrate to produce caproic acid. The biological intermediary steps were enhanced by separating the steps to focus on the lactic acid intermediary. Notably, the pipeline was almost completely powered through electrical inputs, and thus could potentially be driven from sustainable energy without need for chemical input.Graphical abstractMicrobial and electrochemical production of lactic acid, caproic acid and decane from grass.
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Affiliation(s)
- Way Cern Khor
- Department of Biochemical and Microbial Technology, Centre for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Stephen Andersen
- Department of Biochemical and Microbial Technology, Centre for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Han Vervaeren
- Department of Biochemical and Microbial Technology, Centre for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium
| | - Korneel Rabaey
- Department of Biochemical and Microbial Technology, Centre for Microbial Ecology and Technology (CMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium
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Zhu X, Zhou Y, Wang Y, Wu T, Li X, Li D, Tao Y. Production of high-concentration n-caproic acid from lactate through fermentation using a newly isolated Ruminococcaceae bacterium CPB6. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:102. [PMID: 28439295 PMCID: PMC5399333 DOI: 10.1186/s13068-017-0788-y] [Citation(s) in RCA: 128] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 04/12/2017] [Indexed: 05/06/2023]
Abstract
BACKGROUND n-Caproic acid (CA), as a medium-chain carboxylic acid, is a valuable chemical feedstock for various industrial applications. The fermentative production of CA from renewable carbon sources has attracted a lot of attentions. Lactate is a significant intermediate waste in the anaerobic breakdown of carbohydrates that comprise 18-70% of the chemical oxygen demand (COD) in municipal and some industrial wastewaters. Recently, researchers (including our own group) reported the CA production using lactate as electron donor with newly identified microbiome systems. However, within such processes, it was hard to determine whether the CA production was completed by a single strain or by the co-metabolism of different microorganisms. RESULTS Here, we report the CA production using lactate as electron donor using the strain CPB6, which we isolated from a microbiome for CA production as described previously. Strain CPB6 is affiliated with Clostridium cluster IV of the family of Ruminococcaceae based on 16S rRNA gene sequence analysis. The strain prefers acidic initial pH condition (pH 5.0-6.5), and the temperature ranging from 30 to 40 °C for CA production. In a fed-batch fermentation with non-sterilized lactate-containing organic wastewater as feedstock, strain CPB6 produced 16.6 g/L CA (from 45.1 g/L lactate) with a maximum productivity of 5.29 g/L/day. Enzyme assays with crude cell extract showed that CPB6 can metabolize acetate and butyryl-CoA to produce n-butyric acid, and acetate/n-butyrate and caproyl-CoA to produce CA, respectively. CONCLUSION This study demonstrated that high concentration of CA production can be obtained by a newly isolated pure culture CPB6. This strain can be employed as a powerful workhorse for high-efficient CA recovery from lactate-containing waste streams. Our preliminary investigation suggested that the CA production from lactate in strain CPB6 might be via the chain elongation pathway of the reverse β-oxidation; the detailed mechanism, however, warrants further investigation using various molecular microbiology techniques.
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Affiliation(s)
- Xiaoyu Zhu
- Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041 People’s Republic of China
| | - Yan Zhou
- Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041 People’s Republic of China
- College of Life Science, Sichuan University, Chengdu, 610041 People’s Republic of China
| | - Yi Wang
- Department of Biosystems Engineering, Auburn University, Auburn, AL 36849 USA
| | - Tingting Wu
- Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041 People’s Republic of China
| | - Xiangzhen Li
- Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041 People’s Republic of China
| | - Daping Li
- Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041 People’s Republic of China
| | - Yong Tao
- Key Laboratory of Environmental and Applied Microbiology, Chinese Academy of Sciences, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041 People’s Republic of China
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Hegner R, Koch C, Riechert V, Harnisch F. Microbiome-based carboxylic acids production: from serum bottles to bioreactors. RSC Adv 2017. [DOI: 10.1039/c6ra28259h] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We propose a cheap, time and resource efficient screening and upscaling strategy for microbiome-based production of bio-based fuels and chemicals.
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Affiliation(s)
- Richard Hegner
- Helmholtz Center for Environmental Research – UFZ
- Department of Environmental Microbiology
- 04318 Leipzig
- Germany
| | - Christin Koch
- Helmholtz Center for Environmental Research – UFZ
- Department of Environmental Microbiology
- 04318 Leipzig
- Germany
| | - Vanessa Riechert
- Helmholtz Center for Environmental Research – UFZ
- Department of Environmental Microbiology
- 04318 Leipzig
- Germany
| | - Falk Harnisch
- Helmholtz Center for Environmental Research – UFZ
- Department of Environmental Microbiology
- 04318 Leipzig
- Germany
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42
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Wang J, Song X, Wang Y, Abayneh B, Ding Y, Yan D, Bai J. Microbial community structure of different electrode materials in constructed wetland incorporating microbial fuel cell. BIORESOURCE TECHNOLOGY 2016; 221:697-702. [PMID: 27717561 DOI: 10.1016/j.biortech.2016.09.116] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 09/26/2016] [Accepted: 09/28/2016] [Indexed: 06/06/2023]
Abstract
The microbial fuel cell coupled with constructed wetland (CW-MFC) microcosms were operated under fed-batch mode for evaluating the effect of electrode materials on bioelectricity generation and microbial community composition. Experimental results indicated that the bioenergy output in CW-MFC increased with the substrate concentration; maximum average voltage (177mV) was observed in CW-MFC with carbon fiber felt (CFF). In addition, the four different materials resulted in the formation of significantly different microbial community distribution around the anode electrode. The relative abundance of Proteobacteria in CFF and foamed nickel (FN) was significantly higher than that in stainless steel mesh (SSM) and graphite rod (GR) samples. Notably, the findings indicate that CW-MFC utilizing FN anode electrode could apparently improve relative abundance of Dechloromonas, which has been regarded as a denitrifying and phosphate accumulating microorganism.
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Affiliation(s)
- Junfeng Wang
- College of Environmental Science and Engineering, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Donghua University, Shanghai 201620, China
| | - Xinshan Song
- College of Environmental Science and Engineering, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Donghua University, Shanghai 201620, China.
| | - Yuhui Wang
- College of Environmental Science and Engineering, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Donghua University, Shanghai 201620, China
| | - Befkadu Abayneh
- College of Environmental Science and Engineering, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Donghua University, Shanghai 201620, China
| | - Yi Ding
- College of Environmental Science and Engineering, State Environmental Protection Engineering Center for Pollution Treatment and Control in Textile Industry, Donghua University, Shanghai 201620, China
| | - Denghua Yan
- Department of Water Resources, China Institute of Water Resource and Hydropower Research, Beijing 100038, China
| | - Junhong Bai
- School of Environment, Beijing Normal University, Beijing 100038, China
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Leite AF, Janke L, Harms H, Richnow HH, Nikolausz M. Lessons learned from the microbial ecology resulting from different inoculation strategies for biogas production from waste products of the bioethanol/sugar industry. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:144. [PMID: 27429647 PMCID: PMC4947286 DOI: 10.1186/s13068-016-0548-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 06/08/2016] [Indexed: 06/06/2023]
Abstract
BACKGROUND During strategic planning of a biogas plant, the local availability of resources for start-up and operation should be taken into consideration for a cost-efficient process. Because most bioethanol/sugar industries in Brazil are located in remote areas, the use of fresh cattle manure from local farms could be a solution for the inoculation of the biogas process. This study investigated the diversity and dynamics of bacterial and archaeal communities and the performance of biogas reactors inoculated with manure and a mixed inoculum from different biogas reactors as for a controlled start-up until steady state. RESULTS Laboratory-scale biogas reactors were fed semi-continuously with sugarcane filter cake alone (mono-digestion) or together with bagasse (co-digestion). At the initial start-up, the reactors inoculated with the mixed inoculum displayed a less diverse taxonomic composition, but with higher presence of significant abundances compared to reactors inoculated with manure. However, in the final steady state, the communities of the differently inoculated reactors were very similarly characterized by predominance of the methanogenic genera Methanosarcina and Methanobacterium, the bacterial families Bacteroidaceae, Prevotellaceae and Porphyromonadaceae (phylum Bacteroidetes) and Synergistaceae (phylum Synergistetes). In the mono-digestion reactors, the methanogenic communities varied greater than in the co-digestion reactors independently of the inoculation strategy. CONCLUSION The microbial communities involved in the biogas production from waste products of the Brazilian bioethanol/sugar industry were relatively similar and stable at the reactor's steady phase independently of the inoculum source (manure or mixed inoculum). Therefore, the locally available manure can be used as inoculum for start-up of the biogas process, since it also contains the microbial resources needed. The strong fluctuation of methanogenic communities in mono-digestion reactors indicates higher risk of process instability than in co-digestion reactors.
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Affiliation(s)
- Athaydes Francisco Leite
- />Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Leandro Janke
- />Department of Biochemical Conversion, Deutsches Biomasseforschungszentrum gemeinnützige GmbH, Torgauerstrasse 116, 04347 Leipzig, Germany
| | - Hauke Harms
- />Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Hans-Hermann Richnow
- />Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Marcell Nikolausz
- />Department of Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
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Kucek LA, Nguyen M, Angenent LT. Conversion of L-lactate into n-caproate by a continuously fed reactor microbiome. WATER RESEARCH 2016; 93:163-171. [PMID: 26905795 DOI: 10.1016/j.watres.2016.02.018] [Citation(s) in RCA: 118] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Revised: 02/08/2016] [Accepted: 02/09/2016] [Indexed: 05/06/2023]
Abstract
Conversion of lactate to n-caproate had been described for the type strain Megasphaera elsdenii in batch systems. Recently, investigators have also described production of n-caproate from endogenous or exogenous lactate with batch-fed reactor microbiome systems. However, no reports exist of lactate to n-caproate conversion within a continuously fed bioreactor. Since continuously fed systems are advantageous for biotechnology production platforms, our objective was to develop such a system. Here, we demonstrated continuous lactate to n-caproate conversion for more than 165 days. The volumetric n-caproate production rate (productivity) was improved when we decreased the operating pH from 5.5 to 5.0, and was again improved when we utilized in-line product recovery via pertraction (membrane-based liquid-liquid extraction). We observed a maximum n-caproate productivity of 6.9 g COD/L-d for a period of 17 days at an L-lactate loading rate of 9.1 g COD/L-d, representing the highest sustained lactate to n-caproate conversion rate ever reported. We had to manage two competing lactate conversion pathways: 1) the reverse β-oxidation pathway to n-caproate; and 2) the acrylate pathway to propionate. We found that maintaining a low residual lactate concentration in the bioreactor broth was necessary to direct lactate conversion towards n-caproate instead of propionate. These findings provide a foundation for the development of new resource recovery processes to produce higher-value liquid products (e.g., n-caproate) from carbon-rich wastewaters containing lactate or lactate precursors (e.g., carbohydrates).
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Affiliation(s)
- Leo A Kucek
- Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA.
| | - Mytien Nguyen
- Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA.
| | - Largus T Angenent
- Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA.
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45
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Assessment of hydrogen metabolism in commercial anaerobic digesters. Appl Microbiol Biotechnol 2016; 100:4699-710. [DOI: 10.1007/s00253-016-7436-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 02/29/2016] [Accepted: 03/03/2016] [Indexed: 01/13/2023]
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46
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Angenent LT, Richter H, Buckel W, Spirito CM, Steinbusch KJJ, Plugge CM, Strik DPBTB, Grootscholten TIM, Buisman CJN, Hamelers HVM. Chain Elongation with Reactor Microbiomes: Open-Culture Biotechnology To Produce Biochemicals. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:2796-810. [PMID: 26854969 DOI: 10.1021/acs.est.5b04847] [Citation(s) in RCA: 274] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Chain elongation into medium-chain carboxylates, such as n-caproate and n-caprylate, with ethanol as an electron donor and with open cultures of microbial consortia (i.e., reactor microbiomes) under anaerobic conditions is being developed as a biotechnological production platform. The goal is to use the high thermodynamic efficiency of anaerobic fermentation to convert organic biomass or organic wastes into valuable biochemicals that can be extracted. Several liter-scale studies have been completed and a first pilot-plant study is underway. However, the underlying microbial pathways are not always well understood. In addition, an interdisciplinary approach with knowledge from fields ranging from microbiology and chemical separations to biochemistry and environmental engineering is required. To bring together research from different fields, we reviewed the literature starting with the microbiology and ending with the bioprocess engineering studies that already have been performed. Because understanding the microbial pathways is so important to predict and steer performance, we delved into a stoichiometric and thermodynamic model that sheds light on the effect of substrate ratios and environmental conditions on product formation. Finally, we ended with an outlook.
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Affiliation(s)
- Largus T Angenent
- Department of Biological and Environmental Engineering, Cornell University , 226 Riley-Robb Hall, Ithaca, New York 14853, United States
| | - Hanno Richter
- Department of Biological and Environmental Engineering, Cornell University , 226 Riley-Robb Hall, Ithaca, New York 14853, United States
| | - Wolfgang Buckel
- Laboratorium für Mikrobiologie, Fachbereich Biologie and SYNMIKRO, Philipps-Universität , 35032 Marburg, Germany
- Max-Planck-Institut für terrestrische Mikrobiologie, Karl-von-Frisch-Str. 10, 35043 Marburg, Germany
| | - Catherine M Spirito
- Department of Biological and Environmental Engineering, Cornell University , 226 Riley-Robb Hall, Ithaca, New York 14853, United States
| | - Kirsten J J Steinbusch
- Sub-Department of Environmental Technology, Wageningen University , P.O. Box 17, 6700 AA Wageningen, The Netherlands
- Delft Advanced Biorenewables (DAB), Julianalaan 67, 2628 BC Delft, The Netherlands
| | - Caroline M Plugge
- Laboratory of Microbiology, Wageningen University , Dreijenplein 10, 6703 HB Wageningen, The Netherlands
- Wetsus - European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, The Netherlands
| | - David P B T B Strik
- Sub-Department of Environmental Technology, Wageningen University , P.O. Box 17, 6700 AA Wageningen, The Netherlands
| | - Tim I M Grootscholten
- Sub-Department of Environmental Technology, Wageningen University , P.O. Box 17, 6700 AA Wageningen, The Netherlands
- Royal Cosun, P.O. Box 3411, 4800 MG Breda, The Netherlands
| | - Cees J N Buisman
- Sub-Department of Environmental Technology, Wageningen University , P.O. Box 17, 6700 AA Wageningen, The Netherlands
- Wetsus - European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, The Netherlands
| | - Hubertus V M Hamelers
- Wetsus - European Centre of Excellence for Sustainable Water Technology, Oostergoweg 9, 8911 MA Leeuwarden, The Netherlands
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