Project description:Industrial anaerobic digestion (AD) represents a relevant energy source beyond today’s fossil fuels, wherein organic matter is recycled to methane gas via an intricate and complex microbial food web. Despite its potential, anaerobic reactors often undergo process instability over time, mainly caused by substrate composition perturbations, making the system unreliable for stable energy production. To ensure the reliability of AD technologies, it is crucial to identify microbial- and system responses to better understand the effect of such perturbations and ultimately detect signatures indicative of process failure . Here, we investigate the effect of microalgal organic loading rate (OLR) on the fermentation products profile, microbiome dynamics, and disruption/recovery of major microbial metabolisms. Reactors subjected to low- and high-OLR disturbances were operated and monitored for fermentation products and biogas production over time, while microbial responses were investigated via 16S rRNA gene amplicon data, shotgun metagenomics and metagenome-centric metaproteomics.
Project description:Meta-proteomics analysis approach in the application of biogas production from anaerobic digestion has many advantages that has not been fully uncovered yet. This study aims to investigate biogas production from a stable 2-stage chicken manure fermentation system in chemical and biological perspective. The diversity and functional protein changes from the 1st stage to 2nd stage is a good indication to expose the differential metabolic processes in anaerobic digestion. The highlight of identified functional proteins explain the causation of accumulated ammonia and carbon sources for methane production. Due to the ammonia stress and nutrient limitation, the hydrogenotrophic methanogenic pathway is adopted as indicative of meta-proteomics data involving the key methanogenic substrates (formate and acetate). Unlike traditional meta-genomic analysis, this study could provide both species names of microorganism and enzymes to directly point the generation pathway of methane and carbon dioxide in investigating biogas production of chicken manure.
2021-02-08 | PXD022498 | Pride
Project description:Effects of reduced hydraulic retention time and self-induced mixing on two-stage anaerobic digestion utilizing acidogenic off-gas
Project description:Two-stage two-phase biogas reactor systems consisting each of one batch downflow hydrolysis reactor (HR, vol. 10 L), one process fluid storage tank (vol. 10 L), and one downstream upflow anaerobic filter reactor (AF, vol. 10 L), were operated at mesophilic (M, 37 °C) and thermophilic (T, 55 °C) temperatures and over a period of > 750 d (Figure 1, Additional file 1). For each reactor system and for each process temperature, two replicates were conducted in parallel, denominated further as biological replicates. Further process details were as previously published. Start-up of all fermenters were performed using liquid fermenter material from a biogas plant converting cattle manure in co-digestion with grass and maize silage and other biomass at varying concentrations and at mesophilic temperatures. Silage of perennial ryegrass (Lolium perenne L.) was digested as sole substrate in batches of varying amounts with retention times of 28 d (storage of bale silage at -20 °C, cutting length 3 cm, volatile substances (VS) 32 % of fresh mass (FM), total Kjeldahl nitrogen 7.6 g kgFM-1, NH4+-N 0.7 g kgFM-1, acetic acid 2.6 g kgFM-1, propionic acid < 0.04 g kgFM-1, lactic acid 2.6 g kgFM-1, ethanol 2.2 g kgFM-1, C/N ratio 19.3, chemical oxygen demand (COD) 357.7 g kgFM-1, analysis of chemical properties according to [6]. No spoilage was observed in the silage. Biogas yields were calculated as liters normalized to 0 °C and 1013 hPa (LN) per kilogram volatile substances (kgVS). For chemical analysis, samples were taken from the effluents of HR and AF. For sequencing of 16S rRNA gene amplicon libraries, microbial metagenomes, and microbial metatranscriptomes, samples were taken from the silage digestate in the HR digested for 2 d. At this time point, high AD rates were detected as indicated by the fast increase of volatile fatty acids (VFA), e.g., acetic acid. Sampling was performed at two different organic loading rates (OLR), i.e., batch-fermentation of 500 g (denominated as “low OLR”, samples MOLR500 and TOLR500) and 1,500 g silage (denominated as “increased OLR”, samples MOLR1500 and TOLR1500).
Project description:Dual utilization of aloe peel: Aloe peel-derived carbon quantum dots enhanced anaerobic co-digestion of aloe peel
| PRJNA890379 | ENA
Project description:Acidogenic gas utilization improves methane production in high-load digestion by alleviating fatty acid accumulation: effect of hydraulic retention time and insights into underlying mechanisms
Project description:Hong2004 - Genome-scale metabolic network of
Mannheimia succiniciproducens (iSH335)
This model is described in the article:
The genome sequence of the
capnophilic rumen bacterium Mannheimia succiniciproducens.
Hong SH, Kim JS, Lee SY, In YH, Choi
SS, Rih JK, Kim CH, Jeong H, Hur CG, Kim JJ.
Nat. Biotechnol. 2004 Oct; 22(10):
1275-1281
Abstract:
The rumen represents the first section of a ruminant
animal's stomach, where feed is collected and mixed with
microorganisms for initial digestion. The major gas produced in
the rumen is CO(2) (65.5 mol%), yet the metabolic
characteristics of capnophilic (CO(2)-loving) microorganisms
are not well understood. Here we report the 2,314,078 base pair
genome sequence of Mannheimia succiniciproducens MBEL55E, a
recently isolated capnophilic Gram-negative bacterium from
bovine rumen, and analyze its genome contents and metabolic
characteristics. The metabolism of M. succiniciproducens was
found to be well adapted to the oxygen-free rumen by using
fumarate as a major electron acceptor. Genome-scale metabolic
flux analysis indicated that CO(2) is important for the
carboxylation of phosphoenolpyruvate to oxaloacetate, which is
converted to succinic acid by the reductive tricarboxylic acid
cycle and menaquinone systems. This characteristic metabolism
allows highly efficient production of succinic acid, an
important four-carbon industrial chemical.
This model is hosted on
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and identified by:
MODEL1507180025.
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To the extent possible under law, all copyright and related or
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Project description:Inhibition of the anaerobic digestion process through accumulation of volatile fatty acids (VFA) is a recurring problem which is the result of unbalanced growth between acidogenic bacteria and methanogens. A speedy recovery is essential for an establishment of a feasible economical biogas productions. Yet, little is known regarding the organisms participating in the recovery. In this study the organisms involved in the recovery were studied using protein-stable isotope probing (Protein-SIP) and mapping this data onto a binned metagenome. Under acetate-accumulated simulating conditions a formation of 13C-labeled CO2 and CH4 was detected immediately after the addition of [U-13C]acetate, indicative of a high turnover rate of acetate. Several labeled peptides were detected in protein-SIP analysis. These 13C-labeled peptides were mapped onto a binned metagenome for improved taxanomical classification of the organisms involved. The results revealed that Methanosarcina and Methanoculleus were actively involved in acetate turnover, as were five subspecies of Clostridia and one Bacteroidetes. The organisms affiliating with Clostridia and Bacteroidetes all contained the FTFHS gene for formyltetrahydrofolate synthetase, a key enzyme for reductive acetogenesis; indicating that these organisms are possible syntrophic acetate-oxidizing bacteria (SAOB) that can facilitate acetate consumption via syntrophic acetate oxidation coupled with hydrogenotrophic methanogenesis (SAO-HM). This study represents the first study applying protein-SIP for analysis of complex biogas samples, a promising method for identifying key microorganisms involved in specific pathways.