Potential of acetic acid to restore methane production in anaerobic reactors critically intoxicated by ammonia as evidenced by metabolic and microbial monitoring.
Lemaigre, Sébastien; Gerin, Patrick A; Adam, Gilleset al.
2023 • In Biotechnology for biofuels and bioproducts, 16 (1), p. 188
Anaerobic digestion; Free ammonia nitrogen intoxication; Microbial community monitoring; Process recovery; Restoration strategy; Ammonia-nitrogen; Anaerobic digestion process; CH 4; Free ammonia; Methanogenesis; Microbial communities; Restoration strategies; Biotechnology; Renewable Energy, Sustainability and the Environment; Applied Microbiology and Biotechnology; Energy (miscellaneous); Management, Monitoring, Policy and Law
Résumé :
[en] [en] BACKGROUND: Biogas and biomethane production from the on-farm anaerobic digestion (AD) of animal manure and agri-food wastes could play a key role in transforming Europe's energy system by mitigating its dependence on fossil fuels and tackling the climate crisis. Although ammonia is essential for microbial growth, it inhibits the AD process if present in high concentrations, especially under its free form, thus leading to economic losses. In this study, which includes both metabolic and microbial monitoring, we tested a strategy to restore substrate conversion to methane in AD reactors facing critical free ammonia intoxication.
RESULTS: The AD process of three mesophilic semi-continuous 100L reactors critically intoxicated by free ammonia (> 3.5 g_N L-1; inhibited hydrolysis and heterotrophic acetogenesis; interrupted methanogenesis) was restored by applying a strategy that included reducing pH using acetic acid, washing out total ammonia with water, re-inoculation with active microbial flora and progressively re-introducing sugar beet pulp as a feed substrate. After 5 weeks, two reactors restarted to hydrolyse the pulp and produced CH4 from the methylotrophic methanogenesis pathway. The acetoclastic pathway remained inhibited due to the transient dominance of a strictly methylotrophic methanogen (Candidatus Methanoplasma genus) to the detriment of Methanosarcina. Concomitantly, the third reactor, in which Methanosarcina remained dominant, produced CH4 from the acetoclastic pathway but faced hydrolysis inhibition. After 11 weeks, the hydrolysis, the acetoclastic pathway and possibly the hydrogenotrophic pathway were functional in all reactors. The methylotrophic pathway was no longer favoured. Although syntrophic propionate oxidation remained suboptimal, the final pulp to CH4 conversion ratio (0.41 ± 0.10 LN_CH4 g_VS-1) was analogous to the pulp biochemical methane potential (0.38 ± 0.03 LN_CH4 g_VS-1).
CONCLUSIONS: Despite an extreme free ammonia intoxication, the proposed process recovery strategy allowed CH4 production to be restored in three intoxicated reactors within 8 weeks, a period during which re-inoculation appeared to be crucial to sustain the process. Introducing acetic acid allowed substantial CH4 production during the recovery period. Furthermore, the initial pH reduction promoted ammonium capture in the slurry, which could allow the field application of the effluents produced by full-scale digesters recovering from ammonia intoxication.
Centre de recherche :
LIST - Luxembourg Institute of Science & Technology
Disciplines :
Biotechnologie
Auteur, co-auteur :
Lemaigre, Sébastien; Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Rue du Brill 41, L-4422, Belvaux, Luxembourg. sebastien.lemaigre@list.lu
Gerin, Patrick A; Earth and Life Institute, Bioengineering, Université Catholique de Louvain, Croix du Sud 2, Box L7.05.19, B-1348, Louvain-la-Neuve, Belgium
Adam, Gilles; Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Rue du Brill 41, L-4422, Belvaux, Luxembourg
Klimek, Dominika; Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Rue du Brill 41, L-4422, Belvaux, Luxembourg
Goux, Xavier; Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Rue du Brill 41, L-4422, Belvaux, Luxembourg
HEROLD, Malte ; University of Luxembourg ; Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Rue du Brill 41, L-4422, Belvaux, Luxembourg
Frkova, Zuzana; Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Rue du Brill 41, L-4422, Belvaux, Luxembourg
CALUSINSKA, Magdalena ; University of Luxembourg ; Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Rue du Brill 41, L-4422, Belvaux, Luxembourg
Potential of acetic acid to restore methane production in anaerobic reactors critically intoxicated by ammonia as evidenced by metabolic and microbial monitoring.
Influence of the reactor design on the dynamics of the microbial populations involved in the biomethanation process
Organisme subsidiant :
FNR - Fonds National de la Recherche
N° du Fonds :
CO11/SR/1280949
Subventionnement (détails) :
This work was supported by the Fonds National de la Recherche, Luxembourg (FNR CORE 2011 project GASPOP, CO11/SR/1280949: Influence of the Reactor Design and the Operational Parameters on the Dynamics of the Microbial Consortia Involved in the Biomethanation Process) and by LIST core funding.
Commentaire :
This research aims at optimizing the anaerobic digestion process, a nature-based process that convert all components of organic matter (lipids, proteins, carbohydrates), except lignin, into methane (energy vector) and eco-friendly fertilizers. Yet the process is biological in nature and complex, and is thus prone to deficiencies. The paper treats of one of the two most common process failures, alkalosis, and proposes a process recovery strategy suitable for on-farm application.
Bórawski P, Wyszomierski R, Bełdycka-Bórawska A, Mickiewicz B, Kalinowska B, Dunn JW, et al. Development of renewable energy sources in the European union in the context of sustainable development policy. Energies. 2022;15:1545. 10.3390/en15041545. DOI: 10.3390/en15041545
IPCC. Working Group III contribution to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. In: Core Writing Team, Jager-Waldau A, Sapkota T, editors. Climate Change 2022. Mitigation of Climate Change. Geneva, Switzerland: IPCC; 2022. p. 2913.
Xue S, Zhang S, Wang Y, Wang Y, Song J, Lyu X, et al. What can we learn from the experience of European countries in biomethane industry: taking China as an example? Renew Sustain Energy Rev. 2022;157: 112049. 10.1016/j.rser.2021.112049. DOI: 10.1016/j.rser.2021.112049
Pavičić J, Mavar KN, Brkić V, Simon K. Biogas and biomethane production and usage: technology development. Advant Chall Eur Energies. 2022;15:2940. 10.3390/en15082940. DOI: 10.3390/en15082940
Theuerl S, Herrmann C, Heiermann M, Grundmann P, Landwehr N, Kreidenweis U, et al. The future agricultural biogas plant in Germany: a vision. Energies. 2019;12:396. 10.3390/en12030396. DOI: 10.3390/en12030396
Ackrill R, Kay A. The growth of biofuels in the 21st century: policy drivers and market challenges. 1st ed. London, UK: Palgrave Macmillan; 2014. DOI: 10.1057/9781137307897
EC. Commission staff working document. State of play on the sustainability of solid and gaseous biomass used for electricity, heating and cooling in the EU. Brussels; 2014.
Lijó L, González-García S, Bacenetti J, Moreira MT. The environmental effect of substituting energy crops for food waste as feedstock for biogas production. Energy. 2017;137:1130–43. 10.1016/j.energy.2017.04.137. DOI: 10.1016/j.energy.2017.04.137
Yenigün O, Demirel B. Ammonia inhibition in anaerobic digestion: a review. Process Biochem. 2013;48:901–11. 10.1016/j.procbio.2013.04.012. DOI: 10.1016/j.procbio.2013.04.012
Bellucci M, Borruso L, Piergiacomo F, Brusetti L, Beneduce L. The effect of substituting energy crop with agricultural waste on the dynamics of bacterial communities in a two-stage anaerobic digester. Chemosphere. 2022;294: 133776. 10.1016/j.chemosphere.2022.133776. DOI: 10.1016/j.chemosphere.2022.133776
Jiang Y, McAdam E, Zhang Y, Heaven S, Banks C, Longhurst P. Ammonia inhibition and toxicity in anaerobic digestion: a critical review. J Water Process Eng. 2019;32: 100899. 10.1016/j.jwpe.2019.100899. DOI: 10.1016/j.jwpe.2019.100899
Wijesinghe DTN, Suter HC, Scales PJ, Chen D. Lignite addition during anaerobic digestion of ammonium rich swine manure enhances biogas production. J Environ Chem Eng. 2021;9: 104669. 10.1016/j.jece.2020.104669. DOI: 10.1016/j.jece.2020.104669
Yan M, Treu L, Zhu X, Tian H, Basile A, Fotidis IA, et al. Insights into ammonia adaptation and methanogenic precursor oxidation by genome-centric analysis. Environ Sci Technol. 2020;54:12568–82. 10.1021/acs.est.0c01945. DOI: 10.1021/acs.est.0c01945
Capson-Tojo G, Rouez M, Crest M, Trably E, Steyer JP, Bernet N, et al. Kinetic study of dry anaerobic co-digestion of food waste and cardboard for methane production. Waste Manag. 2017;69:470–9. 10.1016/j.wasman.2017.09.002. DOI: 10.1016/j.wasman.2017.09.002
Capson-Tojo G, Moscoviz R, Astals S, Robles A, Steyer JP. Unraveling the literature chaos around free ammonia inhibition in anaerobic digestion. Renew Sustain Energy Rev. 2020;117: 109487. 10.1016/j.rser.2019.109487. DOI: 10.1016/j.rser.2019.109487
Polag D, Heuwinkel H, Laukenmann S, Greule M, Keppler F. Evidence of anaerobic syntrophic acetate oxidation in biogas batch reactors by analysis of 13C carbon isotopes. Isotopes Environ Health Stud. 2013;49:365–77. 10.1080/10256016.2013.805758. DOI: 10.1080/10256016.2013.805758
Conrad R. Contribution of hydrogen to methane production and control of hydrogen concentrations in methanogenic soils and sediments. FEMS Microbiol Ecol. 2006;28:193–202. 10.1111/j.1574-6941.1999.tb00575.x. DOI: 10.1111/j.1574-6941.1999.tb00575.x
Ferry JG. Methanogenesis: ecology, physiology, biochemistry and genetics (Chapman & Hall Microbiology Series). 3rd ed. Berlin: SpringerScience + Business Media; 1993. DOI: 10.1007/978-1-4615-2391-8
Calli B, Mertoglu B, Inanc B, Yenigun O. Effects of high free ammonia concentrations on the performances of anaerobic bioreactors. Process Biochem. 2005;40:1285–92. 10.1016/j.procbio.2004.05.008. DOI: 10.1016/j.procbio.2004.05.008
Westerholm M, Levén L, Schnürer A. Bioaugmentation of syntrophic acetate-oxidizing culture in biogas reactors exposed to increasing levels of ammonia. Appl Environ Microbiol. 2012;78:7619–25. 10.1128/AEM.01637-12. DOI: 10.1128/AEM.01637-12
Koch M, Dolfing J, Wuhrmann K, Zehnder AJB. Pathways of propionate degradation by enriched methanogenic cultures. Appl Environ Microbiol. 1983;45:1411–4. 10.1128/aem.45.4.1411-1414.1983. DOI: 10.1128/aem.45.4.1411-1414.1983
Lemaigre S, Adam G, Goux X, Noo A, De Vos B, Gerin PA, et al. Transfer of a static PCA-MSPC model from a steady-state anaerobic reactor to an independent anaerobic reactor exposed to organic overload. Chemom Intell Lab Syst. 2016;159:20–30. 10.1016/j.chemolab.2016.09.010. DOI: 10.1016/j.chemolab.2016.09.010
Jo Y, Cayetano RDA, Kim G-B, Park J, Kim S-H. The effects of ammonia acclimation on biogas recovery and the microbial population in continuous anaerobic digestion of swine manure. Environ Res. 2022;212: 113483. 10.1016/j.envres.2022.113483. DOI: 10.1016/j.envres.2022.113483
Lemaigre S, Adam G, Gerin PA, Noo A, De Vos B, Klimek D, et al. Potential of multivariate statistical process monitoring based on the biogas composition to detect free ammonia intoxication in anaerobic reactors. Biochem Eng J. 2018;140:17–28. 10.1016/j.bej.2018.08.018. DOI: 10.1016/j.bej.2018.08.018
Khalil CA, Ghanimeh S, Medawar Y. Ammonia inhibition and recovery potential in anaerobic digesters: A review. In: Proceedings of the Air and Waste Management Association’s Annual Conference and Exhibition, AWMA. Pittsburgh, Pennsylvania; 2017. p. 275193.
Chen Y, Cheng JJ, Creamer KS. Inhibition of anaerobic digestion process: a review. Bioresour Technol. 2008;99:4044–64. 10.1016/j.biortech.2007.01.057. DOI: 10.1016/j.biortech.2007.01.057
Nielsen HB, Angelidaki I. Strategies for optimizing recovery of the biogas process following ammonia inhibition. Bioresour Technol. 2008;99:7995–8001. 10.1016/J.BIORTECH.2008.03.049. DOI: 10.1016/J.BIORTECH.2008.03.049
Niu Q, Qiao W, Qiang H, Hojo T, Li Y-Y. Mesophilic methane fermentation of chicken manure at a wide range of ammonia concentration: stability, inhibition and recovery. Bioresour Technol. 2013;137:358–67. 10.1016/J.BIORTECH.2013.03.080. DOI: 10.1016/J.BIORTECH.2013.03.080
Rahman MS, Hoque MN, Puspo JA, Islam MR, Das N, Siddique MA, et al. Microbiome signature and diversity regulates the level of energy production under anaerobic condition. Sci Rep. 2021;11:19777. 10.1038/s41598-021-99104-3. DOI: 10.1038/s41598-021-99104-3
Goux X, Calusinska M, Lemaigre S, Marynowska M, Klocke M, Udelhoven T, et al. Microbial community dynamics in replicate anaerobic digesters exposed sequentially to increasing organic loading rate, acidosis, and process recovery. Biotechnol Biofuels. 2015;8:122. 10.1186/s13068-015-0309-9. DOI: 10.1186/s13068-015-0309-9
Fernandes TV, Keesman KJ, Zeeman G, van Lier JB. Effect of ammonia on the anaerobic hydrolysis of cellulose and tributyrin. Biomass Bioenerg. 2014;47:316–23. 10.1016/j.biombioe.2012.09.029. DOI: 10.1016/j.biombioe.2012.09.029
Li J, Rui J, Yao M, Zhang S, Yan X, Wang Y, et al. Substrate type and free ammonia determine bacterial community structure in full-scale mesophilic anaerobic digesters treating cattle or swine manure. Front Microbiol. 2015;6:1337. 10.3389/fmicb.2015.01337. DOI: 10.3389/fmicb.2015.01337
De Vrieze J, Hennebel T, Boon N, Verstraete W. Methanosarcina: the rediscovered methanogen for heavy duty biomethanation. Bioresour Technol. 2012;112:1–9. 10.1016/j.biortech.2012.02.079. DOI: 10.1016/j.biortech.2012.02.079
Lambie SC, Kelly WJ, Leahy SC, Li D, Reilly K, McAllister TA, et al. The complete genome sequence of the rumen methanogen Methanosarcina barkeri CM1. Stand Genomic Sci. 2015;10:1–8. 10.1186/s40793-015-0038-5. DOI: 10.1186/s40793-015-0038-5
Lü F, Hao L, Guan D, Qi Y, Shao L, He P. Synergetic stress of acids and ammonium on the shift in the methanogenic pathways during thermophilic anaerobic digestion of organics. Water Res. 2013;47:2297–306. 10.1016/j.watres.2013.01.049. DOI: 10.1016/j.watres.2013.01.049
Li L, Peng X, Wang X, Wu D. Anaerobic digestion of food waste: a review focusing on process stability. Biores Technol. 2018;248:20–8. 10.1016/j.biortech.2017.07.012. DOI: 10.1016/j.biortech.2017.07.012
Goux X, Calusinska M, Lemaigre S, Marynowska M, Klocke M, Udelhoven T, et al. Microbial community dynamics in replicate anaerobic digesters exposed sequentially to increasing organic loading rate, acidosis, and process recovery. Biotechnol Biofuels. 2015. 10.1186/S13068-015-0309-9. DOI: 10.1186/S13068-015-0309-9
Poirier S, Desmond-Le Quéméner E, Madigou C, Bouchez T, Chapleur O. Anaerobic digestion of biowaste under extreme ammonia concentration: identification of key microbial phylotypes. Bioresour Technol. 2016;207:92–101. 10.1016/j.biortech.2016.01.124. DOI: 10.1016/j.biortech.2016.01.124
Christou ML, Vasileiadis S, Karpouzas DG, Angelidaki I, Kotsopoulos TA. Effects of organic loading rate and hydraulic retention time on bioaugmentation performance to tackle ammonia inhibition in anaerobic digestion. Bioresour Technol. 2021;334: 124323. 10.1016/j.biortech.2021.125246. DOI: 10.1016/j.biortech.2021.125246
Romsaiyud A, Songkasiri W, Nopharatana A, Chaiprasaert P. Combination effect of pH and acetate on enzymatic cellulose hydrolysis. J Environ Sci. 2009;21:965–70. 10.1016/S1001-0742(08)62369-4. DOI: 10.1016/S1001-0742(08)62369-4
Fu X, Liu Z, Zhu C, Mou H, Kong Q. Nondigestible carbohydrates, butyrate, and butyrate-producing bacteria. Crit Rev Food Sci Nutr. 2019;59:S130–52. 10.1080/10408398.2018.1542587. DOI: 10.1080/10408398.2018.1542587
Lang K, Schuldes J, Klingl A, Poehlein A, Daniel R, Brune A. New mode of energy metabolism in the seventh order of methanogens as revealed by comparative genome analysis of “Candidatus Methanoplasma termitum.” Appl Environ Microbiol. 2015;81:1338–52. 10.1128/AEM.03389-14. DOI: 10.1128/AEM.03389-14
Tian H, Treu L, Konstantopoulos K, Fotidis IA, Angelidaki I. 16s rRNA gene sequencing and radioisotopic analysis reveal the composition of ammonia acclimatized methanogenic consortia. Bioresour Technol. 2019;272:54–62. 10.1016/j.biortech.2018.09.128. DOI: 10.1016/j.biortech.2018.09.128
Lv Z, Leite AF, Harms H, Richnow HH, Liebetrau J, Nikolausz M. Influences of the substrate feeding regime on methanogenic activity in biogas reactors approached by molecular and stable isotope methods. Anaerobe. 2014;29:91–9. 10.1016/j.anaerobe.2013.11.005. DOI: 10.1016/j.anaerobe.2013.11.005
Zielińska M, Cydzik-Kwiatkowska A, Zieliński M, Dębowski M. Impact of temperature, microwave radiation and organic loading rate on methanogenic community and biogas production during fermentation of dairy wastewater. Bioresour Technol. 2013;129:308–14. 10.1016/j.biortech.2012.11.093. DOI: 10.1016/j.biortech.2012.11.093
Lebiocka M, Montusiewicz A, Cydzik-Kwiatkowska A. Effect of bioaugmentation on biogas yields and kinetics in anaerobic digestion of sewage sludge. Int J Environ Res Public Health. 2018. 10.3390/ijerph15081717. DOI: 10.3390/ijerph15081717
Nie E, He P, Zhang H, Hao L, Shao L, Lü F. How does temperature regulate anaerobic digestion? Renew Sustain Energy Rev. 2021;150: 111453. 10.1016/j.rser.2021.111453. DOI: 10.1016/j.rser.2021.111453
Calusinska M, Goux X, Fossépré M, Muller EEL, Wilmes P, Delfosse P. A year of monitoring 20 mesophilic full-scale bioreactors reveals the existence of stable but different core microbiomes in bio-waste and wastewater anaerobic digestion systems. Biotechnol Biofuels. 2018;11:196. 10.1186/s13068-018-1195-8. DOI: 10.1186/s13068-018-1195-8
Ma G, Chen Y, Ndegwa P. Association between methane yield and microbiota abundance in the anaerobic digestion process: a meta-regression. Renew Sustain Energy Rev. 2021;135: 110212. 10.1016/j.rser.2020.110212. DOI: 10.1016/j.rser.2020.110212
CHEMANALYST. Real-time price movement of 200+ chemical and petrochemical products for informed purchase decisions. Mark Overv. 2022;38.
Ni K, Köster JR, Seidel A, Pacholski A. Field measurement of ammonia emissions after nitrogen fertilization-A comparison between micrometeorological and chamber methods. Eur J Agron. 2015;71:115–22. 10.1016/j.eja.2015.09.004. DOI: 10.1016/j.eja.2015.09.004
Rahman N, Forrestal PJ. Ammonium fertilizer reduces nitrous oxide emission compared to nitrate fertilizer while yielding equally in a temperate grassland. Agriculture. 2021;11:1141. 10.3390/agriculture11111141. DOI: 10.3390/agriculture11111141
Kim JM, To TK, Matsui A, Tanoi K, Kobayashi NI, Matsuda F, et al. Acetate-mediated novel survival strategy against drought in plants. Nat Plants. 2017;3:17097. 10.1038/nplants.2017.97. DOI: 10.1038/nplants.2017.97
Utsumi Y, Utsumi C, Tanaka M, Van HC, Takahashi S, Matsui A, et al. Acetic acid treatment enhances drought avoidance in cassava (Manihot esculenta crantz). Front Plant Sci. 2019;10:521. 10.3389/fpls.2019.00521. DOI: 10.3389/fpls.2019.00521
Rahman MM, Mostofa MG, Rahman MA, Islam MR, Keya SS, Das AK, et al. Acetic acid: a cost-effective agent for mitigation of seawater-induced salt toxicity in mung bean. Sci Rep. 2019;9:11. 10.1038/s41598-019-51178-w. DOI: 10.1038/s41598-019-51178-w
Goux X, Calusinska M, Fossépré M, Benizri E, Delfosse P. Start-up phase of an anaerobic full-scale farm reactor—appearance of mesophilic anaerobic conditions and establishment of the methanogenic microbial community. Bioresour Technol. 2016;212:217–26. 10.1016/j.biortech.2016.04.040. DOI: 10.1016/j.biortech.2016.04.040
Mayer F, Gerin PA, Noo A, Lemaigre S, Stilmant D, Schmit T, et al. Assessment of energy crops alternative to maize for biogas production in the Greater Region. Bioresour Technol. 2014;166:358–67. 10.1016/j.biortech.2014.05.054. DOI: 10.1016/j.biortech.2014.05.054
Van Kessel JS, Reeves JB. On-farm quick tests for estimating nitrogen in dairy manure. J Dairy Sci. 2000;83:1837–44. 10.3168/JDS.S0022-0302(00)75054-5. DOI: 10.3168/JDS.S0022-0302(00)75054-5
Hecht M, Clemens P, Wulf S. Entwicklung eines einfachen und für den Landwirt durchführbaren Verfahrens zur Überwachung der Prozessstabilität in landwirtschaftlichen Biogasanlagen. Schriftenr des Lehr- und Forschungsschwerpunktes USL. 2007;Nr. 151:51.
Adam G, Lemaigre S, Goux X, Delfosse P, Romain AC. Upscaling of an electronic nose for completely stirred tank reactor stability monitoring from pilot-scale to real-scale agricultural co-digestion biogas plant. Bioresour Technol. 2015;178:285–96. 10.1016/j.biortech.2014.09.106. DOI: 10.1016/j.biortech.2014.09.106
Edgar RC. Search and clustering orders of magnitude faster than BLAST. Bioinformatics. 2010;26:2460–1. 10.1093/bioinformatics/btq461. DOI: 10.1093/bioinformatics/btq461
Singh A, Schnürer A. AcetoBase Version 2: a database update and re-analysis of formyltetrahydrofolate synthetase amplicon sequencing data from anaerobic digesters. Database. 2022. 10.1093/database/baac041. DOI: 10.1093/database/baac041
Westerholm M, Calusinska M, Dolfing J. Syntrophic propionate-oxidizing bacteria in methanogenic systems. FEMS Microbiol Rev. 2022. 10.1093/femsre/fuab057. DOI: 10.1093/femsre/fuab057
Schloss PD, Westcott SL, Ryabin T, Justine RH, Hartmann M, Hollister EB, et al. Introducing mothur: open-source, platform-independent, community-supported software for describing and comparing microbial communities. Appl Environ Microbiol. 2009;75:7537–41. 10.1128/AEM.01541-09. DOI: 10.1128/AEM.01541-09
Dixon P. VEGAN, a package of R functions for community ecology. J Veg Sci. 2003;14:927–30. 10.1111/J.1654-1103.2003.TB02228.X. DOI: 10.1111/J.1654-1103.2003.TB02228.X
