scholarly journals Considering syntrophic acetate oxidation and ionic strength improves the performance of models for food waste anaerobic digestion

2021 ◽  
pp. 125802
Author(s):  
Gabriel Capson-Tojo ◽  
Sergi Astals ◽  
Ángel Robles
Keyword(s):  
Anaerobic Digestion ◽  
Ionic Strength ◽  
Food Waste ◽  
Acetate Oxidation ◽  
Syntrophic Acetate Oxidation

scholarly journals Methanosarcinaceae and Acetate-Oxidizing Pathways Dominate in High-Rate Thermophilic Anaerobic Digestion of Waste-Activated Sludge

2013 ◽  
Vol 79 (20) ◽  
pp. 6491-6500 ◽  
Author(s):  
Dang P. Ho ◽  
Paul D. Jensen ◽  
Damien J. Batstone
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Retention Time ◽  
Elevated Temperatures ◽  
Stable Carbon Isotope ◽  
High Rate ◽  
Continuous Reactor ◽  
Waste Activated Sludge ◽  
Acetate Oxidation ◽  
Syntrophic Acetate Oxidation

ABSTRACTThis study investigated the process of high-rate, high-temperature methanogenesis to enable very-high-volume loading during anaerobic digestion of waste-activated sludge. Reducing the hydraulic retention time (HRT) from 15 to 20 days in mesophilic digestion down to 3 days was achievable at a thermophilic temperature (55°C) with stable digester performance and methanogenic activity. A volatile solids (VS) destruction efficiency of 33 to 35% was achieved on waste-activated sludge, comparable to that obtained via mesophilic processes with low organic acid levels (<200 mg/liter chemical oxygen demand [COD]). Methane yield (VS basis) was 150 to 180 liters of CH4/kg of VSadded. According to 16S rRNA pyrotag sequencing and fluorescence in situ hybridization (FISH), the methanogenic community was dominated by members of theMethanosarcinaceae, which have a high level of metabolic capability, including acetoclastic and hydrogenotrophic methanogenesis. Loss of function at an HRT of 2 days was accompanied by a loss of the methanogens, according to pyrotag sequencing. The two acetate conversion pathways, namely, acetoclastic methanogenesis and syntrophic acetate oxidation, were quantified by stable carbon isotope ratio mass spectrometry. The results showed that the majority of methane was generated by nonacetoclastic pathways, both in the reactors and in off-line batch tests, confirming that syntrophic acetate oxidation is a key pathway at elevated temperatures. The proportion of methane due to acetate cleavage increased later in the batch, and it is likely that stable oxidation in the continuous reactor was maintained by application of the consistently low retention time.

scholarly journals Syntrophic acetate oxidation replaces acetoclastic methanogenesis during thermophilic digestion of biowaste

Microbiome ◽  
2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Stefan Dyksma ◽  
Lukas Jansen ◽  
Claudia Gallert
Keyword(s):  
Anaerobic Digestion ◽  
Amplicon Sequencing ◽  
Metabolic Reconstruction ◽  
Rrna Gene ◽  
Wastewater Management ◽  
Acetate Oxidation ◽  
Mineralization Of Organic Matter ◽  
Acetoclastic Methanogenesis ◽  
Syntrophic Acetate Oxidation ◽  
Production Knowledge

Abstract Background Anaerobic digestion (AD) is a globally important technology for effective waste and wastewater management. In AD, microorganisms interact in a complex food web for the production of biogas. Here, acetoclastic methanogens and syntrophic acetate-oxidizing bacteria (SAOB) compete for acetate, a major intermediate in the mineralization of organic matter. Although evidence is emerging that syntrophic acetate oxidation is an important pathway for methane production, knowledge about the SAOB is still very limited. Results A metabolic reconstruction of metagenome-assembled genomes (MAGs) from a thermophilic solid state biowaste digester covered the basic functions of the biogas microbial community. Firmicutes was the most abundant phylum in the metagenome (53%) harboring species that take place in various functions ranging from the hydrolysis of polymers to syntrophic acetate oxidation. The Wood-Ljungdahl pathway for syntrophic acetate oxidation and corresponding genes for energy conservation were identified in a Dethiobacteraceae MAG that is phylogenetically related to known SAOB. 16S rRNA gene amplicon sequencing and enrichment cultivation consistently identified the uncultured Dethiobacteraceae together with Syntrophaceticus, Tepidanaerobacter, and unclassified Clostridia as members of a potential acetate-oxidizing core community in nine full-scare digesters, whereas acetoclastic methanogens were barely detected. Conclusions Results presented here provide new insights into a remarkable anaerobic digestion ecosystem where acetate catabolism is mainly realized by Bacteria. Metagenomics and enrichment cultivation revealed a core community of diverse and novel uncultured acetate-oxidizing bacteria and point to a particular niche for them in dry fermentation of biowaste. Their genomic repertoire suggests metabolic plasticity besides the potential for syntrophic acetate oxidation.

Deep insights into the network of acetate metabolism in anaerobic digestion: focusing on syntrophic acetate oxidation and homoacetogenesis

2021 ◽  
Vol 190 ◽  
pp. 116774
Author(s):  
Xiaofang Pan ◽  
Lixin Zhao ◽  
Chunxing Li ◽  
Irini Angelidaki ◽  
Nan Lv ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Acetate Metabolism ◽  
Acetate Oxidation ◽  
Syntrophic Acetate Oxidation

Application of Anaerobic Digestion Model No. 1 to describe the syntrophic acetate oxidation of poultry litter in thermophilic anaerobic digestion

2014 ◽  
Vol 167 ◽  
pp. 495-502 ◽  
Author(s):  
Víctor Rivera-Salvador ◽  
Irineo L. López-Cruz ◽  
Teodoro Espinosa-Solares ◽  
Juan S. Aranda-Barradas ◽  
David H. Huber ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Poultry Litter ◽  
Acetate Oxidation ◽  
Thermophilic Anaerobic Digestion ◽  
Syntrophic Acetate Oxidation

Syntrophic acetate oxidation in two-phase (acid–methane) anaerobic digesters

2011 ◽  
Vol 64 (9) ◽  
pp. 1812-1820 ◽  
Author(s):  
T. Shimada ◽  
E. Morgenroth ◽  
M. Tandukar ◽  
S. G. Pavlostathis ◽  
A. Smith ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Anaerobic Digestion ◽  
Full Scale ◽  
Laboratory Scale ◽  
Gene Clone ◽  
Rrna Gene ◽  
Acetate Oxidation ◽  
Two Phase ◽  
Anaerobic Digesters ◽  
Syntrophic Acetate Oxidation

The microbial processes involved in two-phase anaerobic digestion were investigated by operating a laboratory-scale acid-phase (AP) reactor and analyzing two full-scale, two-phase anaerobic digesters operated under mesophilic (35 °C) conditions. The digesters received a blend of primary sludge and waste activated sludge (WAS). Methane levels of 20% in the laboratory-scale reactor indicated the presence of methanogenic activity in the AP. A phylogenetic analysis of an archaeal 16S rRNA gene clone library of one of the full-scale AP digesters showed that 82% and 5% of the clones were affiliated with the orders Methanobacteriales and Methanosarcinales, respectively. These results indicate that substantial levels of aceticlastic methanogens (order Methanosarcinales) were not maintained at the low solids retention times and acidic conditions (pH 5.2–5.5) of the AP, and that methanogenesis was carried out by hydrogen-utilizing methanogens of the order Methanobacteriales. Approximately 43, 31, and 9% of the archaeal clones from the methanogenic phase (MP) digester were affiliated with the orders Methanosarcinales, Methanomicrobiales, and Methanobacteriales, respectively. A phylogenetic analysis of a bacterial 16S rRNA gene clone library suggested the presence of acetate-oxidizing bacteria (close relatives of Thermacetogenium phaeum, ‘Syntrophaceticus schinkii,’ and Clostridium ultunense). The high abundance of hydrogen consuming methanogens and the presence of known acetate-oxidizing bacteria suggest that acetate utilization by acetate oxidizing bacteria in syntrophic interaction with hydrogen-utilizing methanogens was an important pathway in the second-stage of the two-phase digestion, which was operated at high ammonium-N concentrations (1.0 and 1.4 g/L). A modified version of the IWA Anaerobic Digestion Model No. 1 (ADM1) with extensions for syntrophic acetate oxidation and weak-acid inhibition adequately described the dynamic profiles of volatile acid production/degradation and methane generation observed in the laboratory-scale AP reactor. The model was validated with historical data from the full-scale digesters.

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