Metabolic and microbial community dynamics during the anaerobic digestion of maize silage in a two-phase process
- 832 Downloads
Two-phasic anaerobic digestion processes (hydrolysis/acidogenesis separated from acetogenesis/methanogenesis) can be used for biogas production on demand or a combined chemicals/bioenergy production. For an effective process control, detailed knowledge about the microbial catalysts and their correlation to process conditions is crucial. In this study, maize silage was digested in a two-phase process and interrelationships between process parameters and microbial communities were revealed. In the first-phase reactor, alternating metabolic periods were observed which emerged independently from the feeding frequency. During the L-period, up to 11.8 g L-1 lactic acid was produced which significantly correlated to lactic acid bacteria of the genus Lactobacillus as the most abundant community members. During the alternating G-period, the production of volatile fatty acids (up to 5.3, 4.0 and 3.1 g L−1 for propionic, n-butyric and n-caproic acid, respectively) dominated accompanied by a high gas production containing up to 28 % hydrogen. The relative abundance of various Clostridiales increased during this metabolic period. In the second-phase reactor, the metabolic fluctuations of the first phase were smoothed out resulting in a stable biogas production as well as stable bacterial and methanogenic communities. However, the biogas composition followed the metabolic dynamics of the first phase: the hydrogen content increased during the L-period whereas highest CH4/CO2 ratios (up to 2.8) were reached during the G-period. Aceticlastic Methanosaeta as well as hydrogenotrophic Methanoculleus and Methanobacteriaceae were identified as dominant methanogens. Consequently, a directed control of the first-phase stabilizing desired metabolic states can lead to an enhanced productivity regarding chemicals and bioenergy.
KeywordsAcidogenesis 454 Pyrosequencing T-RFLP Anaerobic fermentation Lactic acid Volatile fatty acids
This work was supported by the Initiative and Networking Fund of the Helmholtz Association. We would like to thank Ronny Kirbach and Peter Keil for operating the two-phase reactor system and analysis of process parameters. We thank our collaboration partners from the Department Biochemical Conversion of the Deutsches Biomasseforschungszentrum (DBFZ) for contributing to the analytical measurements. Furthermore, we thank Dorota Rzechonek and Anne Kuchenbuch for T-RFLP analyses of bacterial communities, Franziska Bühligen for T-RFLP analyses of the methanogenic community and Ute Lohse for technical assistance with 454 pyrosequencing.
Compliance with ethical standards
The authors declare that they have no conflict of interest. This article does not contain any studies with human participants or animals performed by any of the authors.
- Chojnacka A, Blaszczyk MK, Szczesny P, Nowak K, Suminska M, Tomczyk-Zak K, Zielenkiewicz U, Sikora A (2011) Comparative analysis of hydrogen-producing bacterial biofilms and granular sludge formed in continuous cultures of fermentative bacteria. Bioresour Technol 102(21):10057–10064. doi: 10.1016/j.biortech.2011.08.063 PubMedCrossRefGoogle Scholar
- Dodsworth JA, Blainey PC, Murugapiran SK, Swingley WD, Ross CA, Tringe SG, Chain PS, Scholz MB, Lo C-C, Raymond J (2013) Single-cell and metagenomic analyses indicate a fermentative and saccharolytic lifestyle for members of the OP9 lineage. Nat Commun 4:1854. doi: 10.1038/ncomms2884 PubMedCrossRefGoogle Scholar
- Heckel M (2007) Einfluß von Siliermitteln auf Siliererfolg und Biogasproduktion verschiedener Energiepflanzen. University of Potsdam, Diploma thesisGoogle Scholar
- Lucas R, Kuchenbuch A, Fetzer I, Harms H, Kleinsteuber S (2015) Long-term monitoring reveals stable and remarkably similar microbial communities in parallel full-scale biogas reactors digesting energy crops. FEMS Microbiol Ecol 91(3). doi:10.1093/femsec/fiv004Google Scholar
- Lykidis A, Chen CL, Tringe SG, McHardy AC, Copeland A, Kyrpides NC, Hugenholtz P, Macarie H, Olmos A, Monroy O, Liu WT (2011) Multiple syntrophic interactions in a terephthalate-degrading methanogenic consortium. ISME J 5(1):122–130. doi: 10.1038/ismej.2010.125 PubMedPubMedCentralCrossRefGoogle Scholar
- Mähnert P (2007) Kinetik der Biogasproduktion aus nachwachsenden Rohstoffen und Gülle. Humboldt University Berlin, DissertationGoogle Scholar
- McDonald D, Price MN, Goodrich J, Nawrocki EP, DeSantis TZ, Probst A, Andersen GL, Knight R, Hugenholtz P (2012) An improved Greengenes taxonomy with explicit ranks for ecological and evolutionary analyses of bacteria and archaea. ISME J 6(3):610–618. doi: 10.1038/ismej.2011.139 PubMedPubMedCentralCrossRefGoogle Scholar
- Naumann C, Bassler R (2006) Handbuch der landwirtschaftlichen Versuchs- und Untersuchungsmethodik (VDLUFA-Methodenbuch), vol Bd. III Die chemische Untersuchung von Futtermitteln, VDLUFA-Verlag, Darmstadt, GermanyGoogle Scholar
- Oksanen J (2011) Multivariate analysis of ecological communities in R: vegan tutorial. 2.0-6 ednGoogle Scholar
- Pelletier E, Kreimeyer A, Bocs S, Rouy Z, Gyapay G, Chouari R, Riviere D, Ganesan A, Daegelen P, Sghir A, Cohen GN, Medigue C, Weissenbach J, Le Paslier D (2008) “Candidatus Cloacamonas acidaminovorans”: genome sequence reconstruction provides a first glimpse of a new bacterial division. J Bacteriol 190(7):2572–2579. doi: 10.1128/JB.01248-07 PubMedPubMedCentralCrossRefGoogle Scholar
- Popp D, Schrader S, Kleinsteuber S, Harms H, Sträuber H (2015) Biogas production from coumarin-rich plants—impact of coumarin on process parameters and microbial community. FEMS Microbiol Ecol 91(9). doi: 10.1093/femsec/fiv103
- R Development Core Team (2011) R: a language and environment for statistical computing. 0.97.551 edn. R Foundation for Statistical Computing, Vienna, AustriaGoogle Scholar
- Seedorf H, Fricke WF, Veith B, Brüggemann H, Liesegang H, Strittmatter A, Miethke M, Buckel W, Hinderberger J, Li F, Hagemeier C, Thauer RK, Gottschalk G (2008) The genome of Clostridium kluyveri, a strict anaerobe with unique metabolic features. Proc Natl Acad Sci U S A 105(6):2128–2133. doi: 10.1073/pnas.0711093105 PubMedPubMedCentralCrossRefGoogle Scholar
- Sikora A, Zielenkiewicz U, Błaszczyk M, Jurkowski M (2013) Lactic acid bacteria in hydrogen-producing consortia: on purpose or by coincidence? In: Kongo JM (ed) Lactic acid bacteria—R & D for food, health and livestock purposes. InTech. doi:10.5772/50364Google Scholar
- Wei T (2011) corrplot: visualization of a correlation matrix. http://CRAN.R-project.org/package=corrplot.
- Weißbach F, Strubelt C (2008) Die Korrektur des Trockensubstanzgehaltes von Maissilagen als Substrat für Biogasanlagen. Landtechnik 63(2):2–4Google Scholar