Austrian Science Fund project Phenylomicrobe
The role of anaerobic microorganisms during phenyl acid turnover in methanogenic systems
Start of the project
Andreas O. Wagner
The progressively improved exploitation of the chemically bound energy in substrates designated for anaerobic digestion (AD) increased both biogas yields and the risk of undesired by-product formation due to improved substrate disintegration. Phenyl acids (PAs) like phenylacetate,
-propionate and/or -butyrate exert a negative effect on AD processes; however, detailed information about the inhibitory effects of these aromatic compounds on methanogenic microbiomes is still missing.
The impact of PAs on methanogenic systems in general and on methanogenesis and acetogenesis in particular is not sufficiently studied. Strategies to manage PA accumulation are missing and knowledge on PA-utilizing pure or mixed cultures is still pending. These data are necessary to better understand the effects of PAs on the complex microbial interactions during AD.
In anaerobic digestion systems, the effect of PAs on microorganisms can partly be compensated due to functional redundancies within the microbiome. However, single and co-cultures, associated with acetogenesis and methanogenesis, are restricted to a small pool of biochemical reactions and are thus more likely affected by PAs. Parameters like temperature or pH can significantly impact these effects.
Alternative terminal electron acceptors (TEAs) – applied in an appropriate concentration – can reverse the accumulation of PAs in AD systems.
Cultures comprised of only few microorganisms are able to completely degrade PAs and thus generate methane and carbon dioxide out of these compounds.
Profound knowledge on the effects of PAs on different phases of anaerobic digestion in general as well as on methanogenic and acetogenic microorganisms in particular.
Evaluation of the effects of different alternative TEAs on PA accumulation / degradation dynamics thus on microorganisms engaged in the PA turn-over.
As we see a need for cultivation in general and for generation of pure cultures in particular, the project additionally aims at generating and investigating pure and/or co-cultures. These cultures – some were already generated in a previous project – will be used to elucidate i) which anaerobic organisms are involved in the mineralization of PAs, ii) which (syntrophic) interactions / dependencies are necessary to fully degrade PAs, and iii) which intermediates / end-products emerge and, thus, which degradation pathways are involved.
A mix of analytical, microbiological, and highly modern molecular techniques (for DNA and RNA) will be applied. This includes (but is not limited to) the use of GC, HPLC analyses, fluorescence-spectrophotometry, anaerobic cultivation procedures, 16S rRNA amplicon sequencing, shot-gun sequencing, metatranscriptomics, qPCR / dPCR, and bioinformatics data analyses.
Prem, E. M.; Duschl, S. F.; Wagner, A. O. (2023): Effects of increasing phenyl acid concentrations on the AD process of a multiple-biogas-reactor system. In: Biomass and Bioenergy 168C, 2023, 106686. DOI: 10.1016/j.biombioe.2022.106686
Prem, E.M.; Schwarzenberger, A.; Markt, R.; Wagner, A. O. (2023): Effects of phenyl acids on different degradation phases during thermophilic anaerobic digestion. In: Frontiers in Microbiology 14, Artikel 1087043. DOI: 10.3389/fmicb.2023.1087043.
Prem E.M.; Wagner A.O.: Microbial and phenyl acid dynamics during the start-up phase of anaerobic straw degradation in meso- and thermophilic batch reactors. International Conference on Biogas Microbiology, Braga, Portugal, May 2022.
Wunderer M.; Prem E.M.; Wagner, A.O.: The impact of phenyl acids on methanogenic pure cultures. International Conference on Biogas Microbiology, Braga, Portugal, May2022.
Prem E.M.; Wunderer M.; Markt R.; Wagner A.O.: Effects of phenyl acids on the active AD community at different pH conditions. Conference on Monitoring Process Control of Anaerobic Digestion Processes, Leipzig, Germany, March 2023.
Wunderer M.; Mullaymeri A.; Schmiedhofer A.; Prem E.M.; Wagner A.O.: Effects of phenyl acids on aceto- and methanogenesis. 12th International Symposium on Anaerobic Microbiology, Innsbruck, Austria, May 2023.
Prem E.M.; Schwarzenberger, A.; Markt, R.; Wagner, A.O.: Effects of phenyl acids on different degradation phases during thermophilic anaerobic digestion, 12th International Symposium on Anaerobic Microbiology, Innsbruck, Austria, May 2023
Andreas O. Wagner, Dep. of Microbiology, Univ. Innsbruck
Eva M. Prem, Dep. of Microbiology, Univ. Innsbruck
Mathias Wunderer, Dep. of Microbiology, Univ. Innsbruck
Katherina O. Fliegerova, Inst. of Animal Physiology, Academy of Science CZ
Blaz Strez, Dep. of Animal Science, Univ. of Ljubljana
Eva Maria Prem
Title: Effects of Inhibitory Substances on the Anaerobic Degradation of Organic Materials – Investigation of Impaired Methanogenic Fermentation System
2017 - 2022
Title: Role of Anaerobic Microorganisms During Degradation of Phenyl Acids in Methanogenic Systems
Simon Franz Duschl
Title: Establishment of an thermophilic, parallel, semi-continuous reactor system for analysing increasing phenyl acid concentrations during AD
Title: Effects of phenyl acids on the 4 degradation steps during mesophilic AD
Title: Establishment and start-up of an mesophilic biogas reactor system for testing the effects of increasing concentrations of phenyl acids during AD
Title: Degradation of phenyl acid in the presence of alternative electron acceptors
Title: Effects of phenyl acid pulses on anaerobic digestion and biogas production under thermophilic conditions
Title: Occurrence and performance of syntrophic acetate oxidizing bacteria (SAOBs) during anaerobic degradation of aromatic compounds in thermophilic systems
Title: Effects of phenyl acids on the acetoclastic methanogens Methanosarcina acetovorans and Methanosarcina thermophila
2022 - 2023
Title: Effects of phenyl acids on the acetoclastic methanogens Methanoculleus thermophilus and Methanocella arvoryzae
2022 - 2023
Title: Effects of phenyl acids on the hydrogenotrophic methanogen Methanothermobacter wolfeii and on the metylotrophic methanogen Methanomethylovorans thermophila