Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.3389/fmicb.2018.02921
Lizenz creative commons licence
Titel (primär) Ammonia inhibition of anaerobic volatile fatty acid degrading microbial communities
Autor Bonk, F.; Popp, D.; Weinrich, S.; Sträuber, H.; Kleinsteuber, S. ORCID logo ; Harms, H.; Centler, F.
Quelle Frontiers in Microbiology
Erscheinungsjahr 2018
Department UMB
Band/Volume 9
Seite von art. 2921
Sprache englisch
Keywords anaerobic digestion, biogas, methanogens, syntrophic propionate oxidation, 16S rRNA amplicon sequencing, T-RFLP, ADM1, chemostat
Abstract Ammonia inhibition is an important reason for reactor failures and economic losses in anaerobic digestion. Its impact on acetic acid degradation is well-studied, while its effect on propionic and butyric acid degradation has received little attention and is consequently not considered in the Anaerobic Digestion Model No. 1 (ADM1). To compare ammonia inhibition of the degradation of these three volatile fatty acids (VFAs), we fed a mixture of them as sole carbon source to three continuous stirred tank reactors (CSTRs) and increased ammonium bicarbonate concentrations in the influent from 52 to 277 mM. The use of this synthetic substrate allowed for the determination of degradation efficiencies for the individual acids. While butyric acid degradation was hardly affected by the increase of ammonia concentration, propionic acid degradation turned out to be even more inhibited than acetic acid degradation with degradation efficiencies dropping to 31 and 65% for propionic and acetic acid, respectively. The inhibited reactors acclimatized and approximated pre-disturbance degradation efficiencies toward the end of the experiment, which was accompanied by strong microbial community shifts, as observed by amplicon sequencing of 16S rRNA genes and terminal restriction fragment length polymorphism (T-RFLP) of mcrA genes. The acetoclastic methanogen Methanosaeta was completely replaced by Methanosarcina. The propionic acid degrading genus Syntrophobacter was replaced by yet unknown propionic acid degraders. The butyric acid degrading genus Syntrophomonas and hydrogenotrophic Methanomicrobiaceae were hardly affected. We hypothesized that the ammonia sensitivity of the initially dominating taxa Methanosaeta and Syntrophobacter led to a stronger inhibition of the acetic and propionic acid degradation compared to butyric acid degradation and hydrogenotrophic methanogenesis, which were facilitated by the ammonia tolerant taxa Syntrophomonas and Methanomicrobiaceae. We implemented this hypothesis into a multi-taxa extension of ADM1, which was able to simulate the dynamics of both microbial community composition and VFA concentration in the experiment. It is thus plausible that the effect of ammonia on VFA degradation strongly depends on the ammonia sensitivity of the dominating taxa, for syntrophic propionate degraders as much as for acetoclastic methanogens.
dauerhafte UFZ-Verlinkung
Bonk, F., Popp, D., Weinrich, S., Sträuber, H., Kleinsteuber, S., Harms, H., Centler, F. (2018):
Ammonia inhibition of anaerobic volatile fatty acid degrading microbial communities
Front. Microbiol. 9 , art. 2921 10.3389/fmicb.2018.02921