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Morais BP, Magalhães CP, Martins G, Pereira MA, Cavaleiro AJ. Effect of micro-aeration on syntrophic and methanogenic activity in anaerobic sludge. Appl Microbiol Biotechnol 2024; 108:192. [PMID: 38305902 PMCID: PMC10837232 DOI: 10.1007/s00253-023-12969-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 11/14/2023] [Accepted: 11/28/2023] [Indexed: 02/03/2024]
Abstract
Micro-aeration was shown to improve anaerobic digestion (AD) processes, although oxygen is known to inhibit obligate anaerobes, such as syntrophic communities of bacteria and methanogens. The effect of micro-aeration on the activity and microbial interaction in syntrophic communities, as well as on the potential establishment of synergetic relationships with facultative anaerobic bacteria (FAB) or aerobic bacteria (AB), was investigated. Anaerobic sludge was incubated with ethanol and increasing oxygen concentrations (0-5% in the headspace). Assays with acetate or H2/CO2 (direct substrates for methanogens) were also performed. When compared with the controls (0% O2), oxygen significantly decreased substrate consumption and initial methane production rate (MPR) from acetate or H2/CO2. At 0.5% O2, MPR from these substrates was inhibited 30-40%, and close to 100% at 5% O2. With ethanol, significant inhibition (>36%) was only observed for oxygen concentrations higher than 2.5%. Oxygen was consumed in the assays, pointing to the stimulation of AB/FAB by ethanol, which helped to protect the syntrophic consortia under micro-aerobic conditions. This highlights the importance of AB/FAB in maintaining functional and resilient syntrophic communities, which is relevant for real AD systems (in which vestigial O2 amounts are frequently present), as well as for AD systems using micro-aeration as a process strategy. KEY POINTS: •Micro-aeration impacts syntrophic communities of bacteria and methanogens. •Oxygen stimulates AB/FAB, maintaining functional and resilient consortia. •Micro-aeration studies are critical for systems using micro-aeration as a process strategy.
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Affiliation(s)
- Bruno P Morais
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
- LABBELS - Associate Laboratory, Braga/Guimarães, Portugal
- CICECO - Aveiro Institute of Materials, Universidade de Aveiro, Aveiro, Portugal
| | - Carla P Magalhães
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
- LABBELS - Associate Laboratory, Braga/Guimarães, Portugal
| | - Gilberto Martins
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
- LABBELS - Associate Laboratory, Braga/Guimarães, Portugal
| | - Maria Alcina Pereira
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
- LABBELS - Associate Laboratory, Braga/Guimarães, Portugal
| | - Ana J Cavaleiro
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal.
- LABBELS - Associate Laboratory, Braga/Guimarães, Portugal.
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Cavaleiro AJ, Alves JI, Salvador AF, Stams AJM, Pereira MA, Alves MM. Editorial: The microbiology of the biogas process. Front Microbiol 2023; 14:1235624. [PMID: 37408644 PMCID: PMC10319392 DOI: 10.3389/fmicb.2023.1235624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 06/12/2023] [Indexed: 07/07/2023] Open
Affiliation(s)
- Ana J. Cavaleiro
- CEB—Centre of Biological Engineering, University of Minho, Braga, Portugal
- LABBELS—Associate Laboratory, Braga, Portugal
| | - Joana I. Alves
- CEB—Centre of Biological Engineering, University of Minho, Braga, Portugal
- LABBELS—Associate Laboratory, Braga, Portugal
| | - Andreia F. Salvador
- CEB—Centre of Biological Engineering, University of Minho, Braga, Portugal
- LABBELS—Associate Laboratory, Braga, Portugal
| | - Alfons J. M. Stams
- CEB—Centre of Biological Engineering, University of Minho, Braga, Portugal
- LABBELS—Associate Laboratory, Braga, Portugal
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, Netherlands
| | - M. Alcina Pereira
- CEB—Centre of Biological Engineering, University of Minho, Braga, Portugal
- LABBELS—Associate Laboratory, Braga, Portugal
| | - M. Madalena Alves
- CEB—Centre of Biological Engineering, University of Minho, Braga, Portugal
- LABBELS—Associate Laboratory, Braga, Portugal
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Castro AR, Martins G, Salvador AF, Cavaleiro AJ. Iron Compounds in Anaerobic Degradation of Petroleum Hydrocarbons: A Review. Microorganisms 2022; 10:2142. [PMID: 36363734 PMCID: PMC9695802 DOI: 10.3390/microorganisms10112142] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 10/26/2022] [Accepted: 10/26/2022] [Indexed: 09/22/2023] Open
Abstract
Waste and wastewater containing hydrocarbons are produced worldwide by various oil-based industries, whose activities also contribute to the occurrence of oil spills throughout the globe, causing severe environmental contamination. Anaerobic microorganisms with the ability to biodegrade petroleum hydrocarbons are important in the treatment of contaminated matrices, both in situ in deep subsurfaces, or ex situ in bioreactors. In the latter, part of the energetic value of these compounds can be recovered in the form of biogas. Anaerobic degradation of petroleum hydrocarbons can be improved by various iron compounds, but different iron species exert distinct effects. For example, Fe(III) can be used as an electron acceptor in microbial hydrocarbon degradation, zero-valent iron can donate electrons for enhanced methanogenesis, and conductive iron oxides may facilitate electron transfers in methanogenic processes. Iron compounds can also act as hydrocarbon adsorbents, or be involved in secondary abiotic reactions, overall promoting hydrocarbon biodegradation. These multiple roles of iron are comprehensively reviewed in this paper and linked to key functional microorganisms involved in these processes, to the underlying mechanisms, and to the main influential factors. Recent research progress, future perspectives, and remaining challenges on the application of iron-assisted anaerobic hydrocarbon degradation are highlighted.
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Affiliation(s)
- Ana R. Castro
- CEB—Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
- LABBELS—Associate Laboratory, 4704-553 Braga/Guimarães, Portugal
| | - Gilberto Martins
- CEB—Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
- LABBELS—Associate Laboratory, 4704-553 Braga/Guimarães, Portugal
| | - Andreia F. Salvador
- CEB—Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
- LABBELS—Associate Laboratory, 4704-553 Braga/Guimarães, Portugal
| | - Ana J. Cavaleiro
- CEB—Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
- LABBELS—Associate Laboratory, 4704-553 Braga/Guimarães, Portugal
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Holohan BC, Duarte MS, Szabo-Corbacho MA, Cavaleiro AJ, Salvador AF, Pereira MA, Ziels RM, Frijters CTMJ, Pacheco-Ruiz S, Carballa M, Sousa DZ, Stams AJM, O'Flaherty V, van Lier JB, Alves MM. Principles, Advances, and Perspectives of Anaerobic Digestion of Lipids. Environ Sci Technol 2022; 56:4749-4775. [PMID: 35357187 DOI: 10.1021/acs.est.1c08722] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Several problems associated with the presence of lipids in wastewater treatment plants are usually overcome by removing them ahead of the biological treatment. However, because of their high energy content, waste lipids are interesting yet challenging pollutants in anaerobic wastewater treatment and codigestion processes. The maximal amount of waste lipids that can be sustainably accommodated, and effectively converted to methane in anaerobic reactors, is limited by several problems including adsorption, sludge flotation, washout, and inhibition. These difficulties can be circumvented by appropriate feeding, mixing, and solids separation strategies, provided by suitable reactor technology and operation. In recent years, membrane bioreactors and flotation-based bioreactors have been developed to treat lipid-rich wastewater. In parallel, the increasing knowledge on the diversity of complex microbial communities in anaerobic sludge, and on interspecies microbial interactions, contributed to extend the knowledge and to understand more precisely the limits and constraints influencing the anaerobic biodegradation of lipids in anaerobic reactors. This critical review discusses the most important principles underpinning the degradation process and recent key discoveries and outlines the current knowledge coupling fundamental and applied aspects. A critical assessment of knowledge gaps in the field is also presented by integrating sectorial perspectives of academic researchers and of prominent developers of anaerobic technology.
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Affiliation(s)
- B Conall Holohan
- Microbial Ecology Laboratory, Microbiology, School of Natural Sciences and Ryan Institute, National University of Ireland, Galway H91 TK33, Ireland
- NVP Energy Ltd., IDA Technology and Business Park, Mervue, Galway H91 TK33, Ireland
| | - M Salomé Duarte
- CEB - Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
- LABBELS - Associate Laboratory, 4710-057 Braga, Guimarães, Portugal
| | - M Alejandra Szabo-Corbacho
- Department of Environmental Engineering and Water Technology, IHE Delft Institute for Water Education, Westvest 7, 2611 AX Delft, The Netherlands
| | - Ana J Cavaleiro
- CEB - Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
- LABBELS - Associate Laboratory, 4710-057 Braga, Guimarães, Portugal
| | - Andreia F Salvador
- CEB - Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
- LABBELS - Associate Laboratory, 4710-057 Braga, Guimarães, Portugal
| | - M Alcina Pereira
- CEB - Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
- LABBELS - Associate Laboratory, 4710-057 Braga, Guimarães, Portugal
| | - Ryan M Ziels
- Department of Civil Engineering, The University of British Columbia, 6250 Applied Science Lane, Vancouver, BC V6T 1Z 4, Canada
| | | | - Santiago Pacheco-Ruiz
- Biothane, Veolia Water Technologies, Tanthofdreef 21, 2623 EW Delft, The Netherlands
| | - Marta Carballa
- CRETUS, Department of Chemical Engineering, Universidad de Santiago de Compostela, 15705 Santiago de Compostela, Spain
| | - Diana Z Sousa
- Laboratory of Microbiology, Wageningen University and Research, 6708 WE, Wageningen, The Netherlands
| | - Alfons J M Stams
- Laboratory of Microbiology, Wageningen University and Research, 6708 WE, Wageningen, The Netherlands
| | - Vincent O'Flaherty
- Microbial Ecology Laboratory, Microbiology, School of Natural Sciences and Ryan Institute, National University of Ireland, Galway H91 TK33, Ireland
| | - Jules B van Lier
- Department of Environmental Engineering and Water Technology, IHE Delft Institute for Water Education, Westvest 7, 2611 AX Delft, The Netherlands
- Section Sanitary Engineering, CEG Faculty, Delft University of Technology, 2628 CN, Delft, The Netherlands
| | - M Madalena Alves
- CEB - Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
- LABBELS - Associate Laboratory, 4710-057 Braga, Guimarães, Portugal
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Martins VR, Freitas CJB, Castro AR, Silva RM, Gudiña EJ, Sequeira JC, Salvador AF, Pereira MA, Cavaleiro AJ. Corksorb Enhances Alkane Degradation by Hydrocarbonoclastic Bacteria. Front Microbiol 2021; 12:618270. [PMID: 34489874 PMCID: PMC8417381 DOI: 10.3389/fmicb.2021.618270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 07/26/2021] [Indexed: 11/13/2022] Open
Abstract
Biosorbent materials are effective in the removal of spilled oil from water, but their effect on hydrocarbonoclastic bacteria is not known. Here, we show that corksorb, a cork-based biosorbent, enhances growth and alkane degradation by Rhodococcus opacus B4 (Ro) and Alcanivorax borkumensis SK2 (Ab). Ro and Ab degraded 96 ± 1% and 72 ± 2%, respectively, of a mixture of n-alkanes (2 g L–1) in the presence of corksorb. These values represent an increase of 6 and 24%, respectively, relative to the assays without corksorb. The biosorbent also increased the growth of Ab by 51%. However, no significant changes were detected in the expression of genes involved in alkane uptake and degradation in the presence of corksorb relative to the control without the biosorbent. Nevertheless, transcriptomics analysis revealed an increased expression of rRNA and tRNA coding genes, which confirms the higher metabolic activity of Ab in the presence of corksorb. The effect of corksorb is not related to the release of soluble stimulating compounds, but rather to the presence of the biosorbent, which was shown to be essential. Indeed, scanning electron microscopy images and downregulation of pili formation coding genes, which are involved in cell mobility, suggest that cell attachment on corksorb is a determinant for the improved activity. Furthermore, the existence of native alkane-degrading bacteria in corksorb was revealed, which may assist in situ bioremediation. Hence, the use of corksorb in marine oil spills may induce a combined effect of sorption and stimulated biodegradation, with high potential for enhancing in situ bioremediation processes.
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Affiliation(s)
- Valdo R Martins
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - Carlos J B Freitas
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - A Rita Castro
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - Rita M Silva
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - Eduardo J Gudiña
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - João C Sequeira
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - Andreia F Salvador
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - M Alcina Pereira
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - Ana J Cavaleiro
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
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Duarte MS, Silva SA, Salvador AF, Cavaleiro AJ, Stams AJM, Alves MM, Pereira MA. Correction to Insight into the Role of Facultative Bacteria Stimulated by Microaeration in Continuous Bioreactors Converting LCFA to Methane. Environ Sci Technol 2021; 55:12130. [PMID: 34424681 DOI: 10.1021/acs.est.1c05021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
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7
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Silva AR, Cavaleiro AJ, Soares OSGP, Braga CS, Salvador AF, Pereira MFR, Alves MM, Pereira L. Detoxification of Ciprofloxacin in an Anaerobic Bioprocess Supplemented with Magnetic Carbon Nanotubes: Contribution of Adsorption and Biodegradation Mechanisms. Int J Mol Sci 2021; 22:ijms22062932. [PMID: 33805783 PMCID: PMC7999377 DOI: 10.3390/ijms22062932] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/01/2021] [Accepted: 03/10/2021] [Indexed: 12/26/2022] Open
Abstract
In anaerobic bioreactors, the electrons produced during the oxidation of organic matter can potentially be used for the biological reduction of pharmaceuticals in wastewaters. Common electron transfer limitations benefit from the acceleration of reactions through utilization of redox mediators (RM). This work explores the potential of carbon nanomaterials (CNM) as RM on the anaerobic removal of ciprofloxacin (CIP). Pristine and tailored carbon nanotubes (CNT) were first tested for chemical reduction of CIP, and pristine CNT was found as the best material, so it was further utilized in biological anaerobic assays with anaerobic granular sludge (GS). In addition, magnetic CNT were prepared and also tested in biological assays, as they are easier to be recovered and reused. In biological tests with CNM, approximately 99% CIP removal was achieved, and the reaction rates increased ≈1.5-fold relatively to the control without CNM. In these experiments, CIP adsorption onto GS and CNM was above 90%. Despite, after applying three successive cycles of CIP addition, the catalytic properties of magnetic CNT were maintained while adsorption decreased to 29 ± 3.2%, as the result of CNM overload by CIP. The results suggest the combined occurrence of different mechanisms for CIP removal: adsorption on GS and/or CNM, and biological reduction or oxidation, which can be accelerated by the presence of CNM. After biological treatment with CNM, toxicity towards Vibrio fischeri was evaluated, resulting in ≈ 46% detoxification of CIP solution, showing the advantages of combining biological treatment with CNM for CIP removal.
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Affiliation(s)
- Ana R. Silva
- CEB, Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal; (A.R.S.); (A.J.C.); (C.S.N.B.); (A.F.S.); (M.M.A.)
| | - Ana J. Cavaleiro
- CEB, Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal; (A.R.S.); (A.J.C.); (C.S.N.B.); (A.F.S.); (M.M.A.)
| | - O. Salomé G. P. Soares
- Laboratory of Separation and Reaction Engineering, Laboratory of Catalysis and Materials (LSRE-LCM), Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal; (O.S.G.P.S.); (M.F.R.P.)
| | - Cátia S.N. Braga
- CEB, Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal; (A.R.S.); (A.J.C.); (C.S.N.B.); (A.F.S.); (M.M.A.)
| | - Andreia F. Salvador
- CEB, Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal; (A.R.S.); (A.J.C.); (C.S.N.B.); (A.F.S.); (M.M.A.)
| | - M. Fernando R. Pereira
- Laboratory of Separation and Reaction Engineering, Laboratory of Catalysis and Materials (LSRE-LCM), Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal; (O.S.G.P.S.); (M.F.R.P.)
| | - M. Madalena Alves
- CEB, Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal; (A.R.S.); (A.J.C.); (C.S.N.B.); (A.F.S.); (M.M.A.)
| | - Luciana Pereira
- CEB, Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal; (A.R.S.); (A.J.C.); (C.S.N.B.); (A.F.S.); (M.M.A.)
- Correspondence:
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Alves JI, Salvador AF, Castro AR, Zheng Y, Nijsse B, Atashgahi S, Sousa DZ, Stams AJM, Alves MM, Cavaleiro AJ. Long-Chain Fatty Acids Degradation by Desulfomonile Species and Proposal of " Candidatus Desulfomonile Palmitatoxidans". Front Microbiol 2021; 11:539604. [PMID: 33391191 PMCID: PMC7773648 DOI: 10.3389/fmicb.2020.539604] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 11/24/2020] [Indexed: 11/13/2022] Open
Abstract
Microbial communities with the ability to convert long-chain fatty acids (LCFA) coupled to sulfate reduction can be important in the removal of these compounds from wastewater. In this work, an enrichment culture, able to oxidize the long-chain fatty acid palmitate (C16 : 0) coupled to sulfate reduction, was obtained from anaerobic granular sludge. Microscopic analysis of this culture, designated HP culture, revealed that it was mainly composed of one morphotype with a typical collar-like cell wall invagination, a distinct morphological feature of the Desulfomonile genus. 16S rRNA gene amplicon and metagenome-assembled genome (MAG) indeed confirmed that the abundant phylotype in HP culture belong to Desulfomonile genus [ca. 92% 16S rRNA gene sequences closely related to Desulfomonile spp.; and ca. 82% whole genome shotgun (WGS)]. Based on similar cell morphology and average nucleotide identity (ANI) (77%) between the Desulfomonile sp. in HP culture and the type strain Desulfomonile tiedjei strain DCB-1T, we propose a novel species designated as "Candidatus Desulfomonile palmitatoxidans." This bacterium shares 94.3 and 93.6% 16S rRNA gene identity with Desulfomonile limimaris strain DCB-MT and D. tiedjei strain DCB-1T, respectively. Based on sequence abundance of Desulfomonile-morphotype in HP culture, its predominance in the microscopic observations, and presence of several genes coding for enzymes involved in LCFA degradation, the proposed species "Ca. Desulfomonile palmitatoxidans" most probably plays an important role in palmitate degradation in HP culture. Analysis of the growth of HP culture and D. tiedjei strain DCB-1T with short- (butyrate), medium- (caprylate) and long-chain fatty acids (palmitate, stearate, and oleate) showed that both cultures degraded all fatty acids coupled to sulfate reduction, except oleate that was only utilized by HP culture. In the absence of sulfate, neither HP culture, nor D. tiedjei strain DCB-1T degraded palmitate when incubated with Methanobacterium formicicum as a possible methanogenic syntrophic partner. Unlike D. tiedjei strain DCB-1T, "Ca. Desulfomonile palmitatoxidans" lacks reductive dehalogenase genes in its genome, and HP culture was not able to grow by organohalide respiration. An emended description of the genus Desulfomonile is proposed. Our study reveals an unrecognized LCFA degradation feature of the Desulfomonile genus.
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Affiliation(s)
- Joana I Alves
- Centre of Biological Engineering, University of Minho, Braga, Portugal
| | | | - A Rita Castro
- Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - Ying Zheng
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, Netherlands
| | - Bart Nijsse
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, Netherlands.,Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Wageningen, Netherlands
| | - Siavash Atashgahi
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, Netherlands
| | - Diana Z Sousa
- Centre of Biological Engineering, University of Minho, Braga, Portugal.,Laboratory of Microbiology, Wageningen University & Research, Wageningen, Netherlands
| | - Alfons J M Stams
- Centre of Biological Engineering, University of Minho, Braga, Portugal.,Laboratory of Microbiology, Wageningen University & Research, Wageningen, Netherlands
| | - M Madalena Alves
- Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - Ana J Cavaleiro
- Centre of Biological Engineering, University of Minho, Braga, Portugal
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9
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Cavaleiro AJ, Guedes AP, Silva SA, Arantes AL, Sequeira JC, Salvador AF, Sousa DZ, Stams AJM, Alves MM. Effect of Sub-Stoichiometric Fe(III) Amounts on LCFA Degradation by Methanogenic Communities. Microorganisms 2020; 8:microorganisms8091375. [PMID: 32906848 PMCID: PMC7564256 DOI: 10.3390/microorganisms8091375] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/01/2020] [Accepted: 09/04/2020] [Indexed: 02/06/2023] Open
Abstract
Long-chain fatty acids (LCFA) are common contaminants in municipal and industrial wastewater that can be converted anaerobically to methane. A low hydrogen partial pressure is required for LCFA degradation by anaerobic bacteria, requiring the establishment of syntrophic relationships with hydrogenotrophic methanogens. However, high LCFA loads can inhibit methanogens, hindering biodegradation. Because it has been suggested that anaerobic degradation of these compounds may be enhanced by the presence of alternative electron acceptors, such as iron, we investigated the effect of sub-stoichiometric amounts of Fe(III) on oleate (C18:1 LCFA) degradation by suspended and granular methanogenic sludge. Fe(III) accelerated oleate biodegradation and hydrogenotrophic methanogenesis in the assays with suspended sludge, with H2-consuming methanogens coexisting with iron-reducing bacteria. On the other hand, acetoclastic methanogenesis was delayed by Fe(III). These effects were less evident with granular sludge, possibly due to its higher initial methanogenic activity relative to suspended sludge. Enrichments with close-to-stoichiometric amounts of Fe(III) resulted in a microbial community mainly composed of Geobacter, Syntrophomonas, and Methanobacterium genera, with relative abundances of 83-89%, 3-6%, and 0.2-10%, respectively. In these enrichments, oleate was biodegraded to acetate and coupled to iron-reduction and methane production, revealing novel microbial interactions between syntrophic LCFA-degrading bacteria, iron-reducing bacteria, and methanogens.
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Affiliation(s)
- Ana J. Cavaleiro
- Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; (A.P.G.); (S.A.S.); (A.L.A.); (J.C.S.); (A.F.S.); (D.Z.S.); (A.J.M.S.); (M.M.A.)
- Correspondence: ; Tel.: +35-1253604423
| | - Ana P. Guedes
- Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; (A.P.G.); (S.A.S.); (A.L.A.); (J.C.S.); (A.F.S.); (D.Z.S.); (A.J.M.S.); (M.M.A.)
| | - Sérgio A. Silva
- Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; (A.P.G.); (S.A.S.); (A.L.A.); (J.C.S.); (A.F.S.); (D.Z.S.); (A.J.M.S.); (M.M.A.)
| | - Ana L. Arantes
- Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; (A.P.G.); (S.A.S.); (A.L.A.); (J.C.S.); (A.F.S.); (D.Z.S.); (A.J.M.S.); (M.M.A.)
| | - João C. Sequeira
- Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; (A.P.G.); (S.A.S.); (A.L.A.); (J.C.S.); (A.F.S.); (D.Z.S.); (A.J.M.S.); (M.M.A.)
| | - Andreia F. Salvador
- Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; (A.P.G.); (S.A.S.); (A.L.A.); (J.C.S.); (A.F.S.); (D.Z.S.); (A.J.M.S.); (M.M.A.)
| | - Diana Z. Sousa
- Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; (A.P.G.); (S.A.S.); (A.L.A.); (J.C.S.); (A.F.S.); (D.Z.S.); (A.J.M.S.); (M.M.A.)
- Laboratory of Microbiology, Wageningen University & Research, 6708 WE Wageningen, The Netherlands
| | - Alfons J. M. Stams
- Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; (A.P.G.); (S.A.S.); (A.L.A.); (J.C.S.); (A.F.S.); (D.Z.S.); (A.J.M.S.); (M.M.A.)
- Laboratory of Microbiology, Wageningen University & Research, 6708 WE Wageningen, The Netherlands
| | - M. Madalena Alves
- Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal; (A.P.G.); (S.A.S.); (A.L.A.); (J.C.S.); (A.F.S.); (D.Z.S.); (A.J.M.S.); (M.M.A.)
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Duarte MS, Salvador AF, Cavaleiro AJ, Stams AJM, Pereira MA, Alves MM. Multiple and flexible roles of facultative anaerobic bacteria in microaerophilic oleate degradation. Environ Microbiol 2020; 22:3650-3659. [DOI: 10.1111/1462-2920.15124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 06/07/2020] [Indexed: 11/28/2022]
Affiliation(s)
- M. Salomé Duarte
- 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
| | - Ana J. Cavaleiro
- Centre of Biological Engineering University of Minho Campus de Gualtar, 4710‐057 Braga Portugal
| | - Alfons J. M. Stams
- Centre of Biological Engineering University of Minho Campus de Gualtar, 4710‐057 Braga Portugal
- Laboratory of Microbiology Wageningen University & Research Stippeneng 4, 6708 WE, Wageningen The Netherlands
| | - M. Alcina 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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11
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Abreu AA, Tavares F, Alves MM, Cavaleiro AJ, Pereira MA. Garden and food waste co-fermentation for biohydrogen and biomethane production in a two-step hyperthermophilic-mesophilic process. Bioresour Technol 2019; 278:180-186. [PMID: 30703635 DOI: 10.1016/j.biortech.2019.01.085] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 01/15/2019] [Accepted: 01/19/2019] [Indexed: 06/09/2023]
Abstract
Co-fermentation of garden waste (GW) and food waste (FW) was assessed in a two-stage process coupling hyperthermophilic dark-fermentation and mesophilic anaerobic digestion (AD). In the first stage, biohydrogen production from individual substrates was tested at different volatile solids (VS) concentrations, using a pure culture of Caldicellulosiruptor saccharolyticus as inoculum. FW concentrations (in VS) above 2.9 g L-1 caused a lag phase of 5 days on biohydrogen production. No lag phase was observed for GW concentrations up to 25.6 g L-1. In the co-fermentation experiments, the highest hydrogen yield (46 ± 1 L kg-1) was achieved for GW:FW 90:10% (w/w). In the second stage, a biomethane yield of 682 ± 14 L kg-1 was obtained using the end-products of GW:FW 90:10% co-fermentation. The energy generation predictable from co-fermentation and AD of GW:FW 90:10% is 0.5 MJ kg-1 and 24.4 MJ kg-1, respectively, which represents an interesting alternative for valorisation of wastes produced locally in communities.
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Affiliation(s)
- A A Abreu
- Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
| | - F Tavares
- Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
| | - M M Alves
- Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal.
| | - A J Cavaleiro
- Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal.
| | - M A Pereira
- Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal.
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12
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Duarte MS, Silva SA, Salvador AF, Cavaleiro AJ, Stams AJM, Alves MM, Pereira MA. Insight into the Role of Facultative Bacteria Stimulated by Microaeration in Continuous Bioreactors Converting LCFA to Methane. Environ Sci Technol 2018; 52:6497-6507. [PMID: 29763542 DOI: 10.1021/acs.est.8b00894] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Conversion of unsaturated long chain fatty acids (LCFA) to methane in continuous bioreactors is not fully understood. Palmitate (C16:0) often accumulates during oleate (C18:1) biodegradation in methanogenic bioreactors, and the reason why this happens and which microorganisms catalyze this reaction remains unknown. Facultative anaerobic bacteria are frequently found in continuous reactors operated at high LCFA loads, but their function is unclear. To get more insight on the role of these bacteria, LCFA conversion was studied under microaerophilic conditions. For that, we compared bioreactors treating oleate-based wastewater (organic loading rates of 1 and 3 kg COD m-3 d-1), operated under different redox conditions (strictly anaerobic-AnR, -350 mV; microaerophilic-MaR, -250 mV). At the higher load, palmitate accumulated 7 times more in the MaR, where facultative anaerobes were more abundant, and only the biomass from this reactor could recover the methanogenic activity after a transient inhibition. In a second experiment, the abundance of facultative anaerobic bacteria, particularly Pseudomonas spp. (from which two strains were isolated), was strongly correlated ( p < 0.05) with palmitate-to-total LCFA percentage in the biofilm formed in a continuous plug flow reactor fed with very high loads of oleate. This work strongly suggests that microaeration stimulates the development of facultative bacteria that are critical for achieving LCFA conversion to methane in continuous bioreactors. Microbial networks and interactions of facultative and strict anaerobes in microbial communities should be considered in future studies.
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Affiliation(s)
- M Salomé Duarte
- Centre of Biological Engineering , University of Minho , Campus de Gualtar , 4710-057 Braga , Portugal
| | - Sérgio A Silva
- 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
| | - Ana J Cavaleiro
- Centre of Biological Engineering , University of Minho , Campus de Gualtar , 4710-057 Braga , Portugal
| | - Alfons J M Stams
- Centre of Biological Engineering , University of Minho , Campus de Gualtar , 4710-057 Braga , Portugal
- Laboratory of Microbiology , Wageningen University , Stippeneng 4 , 6708 WE Wageningen , The Netherlands
| | - M Madalena Alves
- Centre of Biological Engineering , University of Minho , Campus de Gualtar , 4710-057 Braga , Portugal
| | - M Alcina Pereira
- Centre of Biological Engineering , University of Minho , Campus de Gualtar , 4710-057 Braga , Portugal
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13
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Salvador AF, Martins G, Melle-Franco M, Serpa R, Stams AJM, Cavaleiro AJ, Pereira MA, Alves MM. Carbon nanotubes accelerate methane production in pure cultures of methanogens and in a syntrophic coculture. Environ Microbiol 2017; 19:2727-2739. [PMID: 28447396 DOI: 10.1111/1462-2920.13774] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 04/12/2017] [Accepted: 04/19/2017] [Indexed: 11/30/2022]
Abstract
Carbon materials have been reported to facilitate direct interspecies electron transfer (DIET) between bacteria and methanogens improving methane production in anaerobic processes. In this work, the effect of increasing concentrations of carbon nanotubes (CNT) on the activity of pure cultures of methanogens and on typical fatty acid-degrading syntrophic methanogenic coculture was evaluated. CNT affected methane production by methanogenic cultures, although acceleration was higher for hydrogenotrophic methanogens than for acetoclastic methanogens or syntrophic coculture. Interestingly, the initial methane production rate (IMPR) by Methanobacterium formicicum cultures increased 17 times with 5 g·L-1 CNT. Butyrate conversion to methane by Syntrophomonas wolfei and Methanospirillum hungatei was enhanced (∼1.5 times) in the presence of CNT (5 g·L-1 ), but indications of DIET were not obtained. Increasing CNT concentrations resulted in more negative redox potentials in the anaerobic microcosms. Remarkably, without a reducing agent but in the presence of CNT, the IMPR was higher than in incubations with reducing agent. No growth was observed without reducing agent and without CNT. This finding is important to re-frame discussions and re-interpret data on the role of conductive materials as mediators of DIET in anaerobic communities. It also opens new challenges to improve methane production in engineered methanogenic processes.
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Affiliation(s)
- Andreia F Salvador
- Centre of Biological Engineering, University of Minho, Campus de Gualtar, Braga, 4710-057, Portugal
| | - Gilberto Martins
- Centre of Biological Engineering, University of Minho, Campus de Gualtar, Braga, 4710-057, Portugal
| | - Manuel Melle-Franco
- Ciceco - Aveiro Institute of Materials, University of Aveiro, Campus Universitário de Santiago, Aveiro, 3810-193, Portugal
| | - Ricardo Serpa
- Centre of Biological Engineering, University of Minho, Campus de Gualtar, Braga, 4710-057, Portugal
| | - Alfons J M Stams
- Centre of Biological Engineering, University of Minho, Campus de Gualtar, Braga, 4710-057, Portugal.,Laboratory of Microbiology, Wageningen University, Stippeneng 4, Wageningen, 6708 WE The Netherlands
| | - Ana J Cavaleiro
- Centre of Biological Engineering, University of Minho, Campus de Gualtar, Braga, 4710-057, Portugal
| | - M Alcina Pereira
- Centre of Biological Engineering, University of Minho, Campus de Gualtar, Braga, 4710-057, Portugal
| | - M Madalena Alves
- Centre of Biological Engineering, University of Minho, Campus de Gualtar, Braga, 4710-057, Portugal
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14
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Silva SA, Salvador AF, Cavaleiro AJ, Pereira MA, Stams AJM, Alves MM, Sousa DZ. Toxicity of long chain fatty acids towards acetate conversion by Methanosaeta concilii and Methanosarcina mazei. Microb Biotechnol 2016; 9:514-8. [PMID: 27273786 PMCID: PMC4919993 DOI: 10.1111/1751-7915.12365] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 03/30/2016] [Accepted: 04/08/2016] [Indexed: 01/26/2023] Open
Abstract
Long‐chain fatty acids (LCFA) can inhibit methane production by methanogenic archaea. The effect of oleate and palmitate on pure cultures of Methanosaeta concilii and Methanosarcina mazei was assessed by comparing methane production rates from acetate before and after LCFA addition. For both methanogens, a sharp decrease in methane production (> 50%) was observed at 0.5 mmol L−1 oleate, and no methane was formed at concentrations higher than 2 mmol L−1 oleate. Palmitate was less inhibitory than oleate, and M. concilii was more tolerant to palmitate than M. mazei, with 2 mmol L−1 palmitate causing 11% and 64% methanogenic inhibition respectively. This study indicates that M. concilii and M. mazei tolerate LCFA concentrations similar to those previously described for hydrogenotrophic methanogens. In particular, the robustness of M. concilii might contribute to the observed prevalence of Methanosaeta species in anaerobic bioreactors used to treat LCFA‐rich wastewater.
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Affiliation(s)
- Sérgio A Silva
- Centre of Biological Engineering, University of Minho, Braga, Portugal
| | | | - Ana J Cavaleiro
- Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - M Alcina Pereira
- Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - Alfons J M Stams
- Centre of Biological Engineering, University of Minho, Braga, Portugal.,Laboratory of Microbiology, Wageningen University, Wageningen, The Netherlands
| | - M Madalena Alves
- Centre of Biological Engineering, University of Minho, Braga, Portugal
| | - Diana Z Sousa
- Centre of Biological Engineering, University of Minho, Braga, Portugal.,Laboratory of Microbiology, Wageningen University, Wageningen, The Netherlands
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Cavaleiro AJ, Pereira MA, Guedes AP, Stams AJM, Alves MM, Sousa DZ. Conversion of Cn-Unsaturated into Cn-2-Saturated LCFA Can Occur Uncoupled from Methanogenesis in Anaerobic Bioreactors. Environ Sci Technol 2016; 50:3082-3090. [PMID: 26810160 DOI: 10.1021/acs.est.5b03204] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Fat, oils, and grease present in complex wastewater can be readily converted to methane, but the energy potential of these compounds is not always recyclable, due to incomplete degradation of long chain fatty acids (LCFA) released during lipids hydrolysis. Oleate (C18:1) is generally the dominant LCFA in lipid-containing wastewater, and its conversion in anaerobic bioreactors results in palmitate (C16:0) accumulation. The reason why oleate is continuously converted to palmitate without further degradation via β-oxidation is still unknown. In this work, the influence of methanogenic activity in the initial conversion steps of unsaturated LCFA was studied in 10 bioreactors continuously operated with saturated or unsaturated C16- and C18-LCFA, in the presence or absence of the methanogenic inhibitor bromoethanesulfonate (BrES). Saturated Cn-2-LCFA accumulated both in the presence and absence of BrES during the degradation of unsaturated Cn-LCFA, and represented more than 50% of total LCFA. In the presence of BrES further conversion of saturated intermediates did not proceed, not even when prolonged batch incubation was applied. As the initial steps of unsaturated LCFA degradation proceed uncoupled from methanogenesis, accumulation of saturated LCFA can be expected. Analysis of the active microbial communities suggests a role for facultative anaerobic bacteria in the initial steps of unsaturated LCFA biodegradation. Understanding this role is now imperative to optimize methane production from LCFA.
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Affiliation(s)
- Ana J Cavaleiro
- Centre of Biological Engineering, University of Minho , Campus de Gualtar, 4710-057 Braga, Portugal
| | - Maria Alcina Pereira
- Centre of Biological Engineering, University of Minho , Campus de Gualtar, 4710-057 Braga, Portugal
| | - Ana P Guedes
- Centre of Biological Engineering, University of Minho , Campus de Gualtar, 4710-057 Braga, Portugal
| | - Alfons J M Stams
- Centre of Biological Engineering, University of Minho , Campus de Gualtar, 4710-057 Braga, Portugal
- Laboratory of Microbiology, Wageningen University , Dreijenplein 10, 6703 HB Wageningen, The Netherlands
| | - M Madalena Alves
- Centre of Biological Engineering, University of Minho , Campus de Gualtar, 4710-057 Braga, Portugal
| | - Diana Z Sousa
- Centre of Biological Engineering, University of Minho , Campus de Gualtar, 4710-057 Braga, Portugal
- Laboratory of Microbiology, Wageningen University , Dreijenplein 10, 6703 HB Wageningen, The Netherlands
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16
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Cavaleiro AJ, Ferreira T, Pereira F, Tommaso G, Alves MM. Biochemical methane potential of raw and pre-treated meat-processing wastes. Bioresour Technol 2013; 129:519-525. [PMID: 23266854 DOI: 10.1016/j.biortech.2012.11.083] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 11/17/2012] [Accepted: 11/19/2012] [Indexed: 06/01/2023]
Abstract
Raw and pre-treated greaves and rinds, two meat-processing wastes, were assessed for biochemical methane potential (BMP). Combinations of temperature (25, 55, 70 and 120 °C), NaOH (0.3 g g(-1) waste volatile solids) and lipase from Candida rugosa (10 U g(-1) fat) were applied to promote wastes hydrolysis, and the effect on BMP was evaluated. COD solubilisation was higher (66% for greaves; 55% for rinds) when greaves were pre-treated with NaOH at 55 °C and lipase was added to rinds after autoclaving. Maximum fat hydrolysis (52-54%) resulted from NaOH addition, at 55 °C for greaves and 25 °C for rinds. BMP of raw greaves and rinds was 707±46 and 756±56 L CH4 (at standard temperature and pressure) kg(-1)VS, respectively. BMP of rinds improved 25% by exposure to 70 °C; all other strategies tested had no positive effect on BMP of both wastes, and anaerobic biodegradability was even reduced by the combined action of base and temperature.
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Affiliation(s)
- A J Cavaleiro
- Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
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17
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Cavaleiro AJ, Sousa DZ, Alves MM. Methane production from oleate: assessing the bioaugmentation potential of Syntrophomonas zehnderi. Water Res 2010; 44:4940-4947. [PMID: 20696454 DOI: 10.1016/j.watres.2010.07.039] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Revised: 07/02/2010] [Accepted: 07/13/2010] [Indexed: 05/29/2023]
Abstract
The potential for improving long-chain fatty acids (LCFA) conversion to methane was evaluated by bioaugmenting a non-acclimated anaerobic granular sludge with Syntrophomonas zehnderi. Batch bioaugmentation assays were performed with and without the solid microcarrier sepiolite, using 1 mM oleate as sole carbon and energy source. When S. zehnderi was added to the anaerobic sludge methane production from oleate was faster. High methane yields, i.e. 89 ± 5% and 72 ± 1%, were observed in bioaugmented assays in the absence and presence of sepiolite, respectively. Sepiolite stimulated a faster methane production from oleate and prevented the accumulation of acetate. Acetoclastic activity was affected by oleate in the absence of sepiolite, where methane production rate was 26% lower than in assays with microcarrier.
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Affiliation(s)
- A J Cavaleiro
- Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
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18
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Alves MM, Pereira MA, Sousa DZ, Cavaleiro AJ, Picavet M, Smidt H, Stams AJM. Waste lipids to energy: how to optimize methane production from long-chain fatty acids (LCFA). Microb Biotechnol 2009; 2:538-50. [PMID: 21255287 PMCID: PMC3815362 DOI: 10.1111/j.1751-7915.2009.00100.x] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2008] [Accepted: 02/13/2009] [Indexed: 11/28/2022] Open
Abstract
The position of high-rate anaerobic technology (HR-AnWT) in the wastewater treatment and bioenergy market can be enhanced if the range of suitable substrates is expanded. Analyzing existing technologies, applications and problems, it is clear that, until now, wastewaters with high lipids content are not effectively treated by HR-AnWT. Nevertheless, waste lipids are ideal potential substrates for biogas production, since theoretically more methane can be produced, when compared with proteins or carbohydrates. In this minireview, the classical problems of lipids methanization in anaerobic processes are discussed and new concepts to enhance lipids degradation are presented. Reactors operation, feeding strategies and prospects of technological developments for wastewater treatment are discussed. Long-chain fatty acids (LCFA) degradation is accomplished by syntrophic communities of anaerobic bacteria and methanogenic archaea. For optimal performance these syntrophic communities need to be clustered in compact aggregates, which is often difficult to achieve with wastewaters that contain fats and lipids. Driving the methane production from lipids/LCFA at industrial scale without risk of overloading and inhibition is still a challenge that has the potential for filling a gap in the existing processes and technologies for biological methane production associated to waste and wastewater treatment.
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Affiliation(s)
- M Madalena Alves
- IBB - Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Braga, Portugal.
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Cavaleiro AJ, Salvador AF, Alves JI, Alves M. Continuous high rate anaerobic treatment of oleic acid based wastewater is possible after a step feeding start-up. Environ Sci Technol 2009; 43:2931-2936. [PMID: 19475973 DOI: 10.1021/es8031264] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Mineralization of a synthetic effluent containing 50% COD as oleic acid was achieved in a continuous anaerobic reactor at organic loading rates up to 21 kg COD m(-3) day(-1), HRT of 9 h, attaining 99% of COD removal efficiency and a methane yield higher than 70%. A maximum specific methane production rate of 1170 +/- 170 mg COD-CH4 g VS(-1) day(-1) was measured during the reactor's operation. A start-up strategy combining feeding phases and batch degradation phases was applied to promote the development of an anaerobic community efficient for long chain fatty acids (LCFA) mineralization. Through the start-up period, the methane yield increased gradually from 67% to 91%, and LCFA accumulated onto the sludge only during the first 60 days of operation. For the first time, it is demonstrated that a step feeding start-up is required to produce a specialized and efficient anaerobic community for continuous high rate anaerobic treatment of LCFA-rich wastewater.
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Affiliation(s)
- Ana J Cavaleiro
- Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University ofMinho, Campus de Gualtar, 4710-057 Braga, Portugal
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20
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Cavaleiro AJ, Pereira MA, Alves M. Enhancement of methane production from long chain fatty acid based effluents. Bioresour Technol 2008; 99:4086-4095. [PMID: 18006304 DOI: 10.1016/j.biortech.2007.09.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2007] [Revised: 09/02/2007] [Accepted: 09/04/2007] [Indexed: 05/25/2023]
Abstract
Two anaerobic sludges previously loaded with oleate and palmitate accumulated 4570+/-257 and 5200+/-9 mgCOD-LCFAgVSS(-1), respectively. These sludges were incubated in batch assays and methane production was recorded after addition of 100-900 mg L(-1) of oleate and palmitate, respectively. The batch assays were conducted before and after allowing the depletion of the biomass-associated LCFA. The presence of biomass-associated LCFA decreased the capacity of both sludges to convert the added LCFA to methane. After the degradation of biomass-associated LCFA, the lag phases observed before the onset of methane production were significantly reduced, evidencing an increase in the tolerance of the acetotrophic methanogens to the presence of LCFA. In another experiment, three recurrent pulses were performed with a real dairy wastewater containing 3.6 gCOD L(-1), from which 53% was fat. Methane yields of 0.45+/-0.01, 0.88+/-0.02 and 1.29+/-0.08 gCOD-CH(4) gCOD(fed)(-1) were achieved in the first, second and third pulses, respectively, evidencing an increasing capacity of the sludge to convert substrate accumulated in previous additions.
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Affiliation(s)
- A J Cavaleiro
- IBB - Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
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21
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Pereira MA, Cavaleiro AJ, Mota M, Alves MM. Accumulation of long chain fatty acids onto anaerobic sludge under steady state and shock loading conditions: effect on acetogenic and methanogenic activity. Water Sci Technol 2003; 48:33-40. [PMID: 14640197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Accumulation of substrate onto the biomass was quantified under steady-state and shock conditions in a fixed bed reactor fed with an oleic acid-based synthetic effluent. The accumulation of substrate onto the sludge was more dependent on oleic acid concentration than on oleic acid loading rate and decreased the acetogenic, acetoclastic and hydrogenophilic activity. However, even when the methanogenic activity measurements indicate a severe inhibition, the anaerobic sludge was able to methanise efficiently the accumulated substrate that was mainly adsorbed LCFA. Methanogenic activity measurements for a sludge loaded with 2,861 mg COD/gVSS as LCFA, revealed that only hydrogenophilic activity was detected, whereas the methanogenic activities with acetate, propionate and butyrate as substrates were null. However the methanogenic activity of the same sludge after allowing the depletion of the adsorbed LCFA were significantly enhanced in the presence of all substrates, except in propionate. A discussion about the relative importance of metabolic inhibition and transport limitations for the anaerobic degradation of LCFA is launched.
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Affiliation(s)
- M A Pereira
- Centro de Engenharia Biológica, Universidade do Minho, 4710-057 Braga Portugal
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