scholarly journals The anaerobic digestion microbiome: a collection of 1600 metagenome-assembled genomes shows high species diversity related to methane production

2019 ◽  
Author(s):  
Stefano Campanaro ◽  
Laura Treu ◽  
Luis M Rodriguez-R ◽  
Adam Kovalovszki ◽  
Ryan M Ziels ◽  
...  
Keyword(s):  
Organic Matter ◽  
Anaerobic Digestion ◽  
Methane Production ◽  
Metabolic Reconstruction ◽  
Waste Biomass ◽  
Dynamic Composition ◽  
Extensive Evaluation ◽  
Wide Range ◽  
Biogas Reactors ◽  
High Flexibility

AbstractBackgroundMicroorganisms in biogas reactors are essential for degradation of organic matter and methane production through anaerobic digestion process. However, a comprehensive genome-centric comparison, including relevant metadata for each sample, is still needed to identify the globally distributed biogas community members and serve as a reliable repository.ResultsHere, 134 publicly available datasets derived from different biogas reactors were used to recover 1,635 metagenome-assembled genomes (MAGs) representing different bacterial and archaeal species. All genomes were estimated to be >50% complete and nearly half were ≥90% complete with ≤5% contamination. In most samples, specialized microbial communities were established, while only a few taxa were widespread among the different reactor systems. Metabolic reconstruction of the MAGs enabled the prediction of functional traits related to biomass degradation and methane production from waste biomass. An extensive evaluation of the replication index provided an estimation of the growth rate for microbes involved in different steps of the food chain. The recovery of many MAGs belonging to Candidate Phyla Radiation and other underexplored taxa suggests their specific involvement in the anaerobic degradation of organic matter.ConclusionsThe outcome of this study highlights a high flexibility of the biogas microbiome. The dynamic composition and adaptability to the environmental conditions, including temperatures and a wide range of substrates, were demonstrated. Our findings enhance the mechanistic understanding of anaerobic digestion microbiome and substantially extend the existing repository of genomes. The established database represents a relevant resource for future studies related to this engineered ecosystem.

scholarly journals New insights from the biogas microbiome by comprehensive genome-resolved metagenomics of nearly 1600 species originating from multiple anaerobic digesters

2019 ◽  
Author(s):  
Stefano Campanaro ◽  
Laura Treu ◽  
Luis M Rodriguez-Rojas ◽  
Adam Kovalovszki ◽  
Ryan M Ziels ◽  
...  
Keyword(s):  
Organic Matter ◽  
Methane Production ◽  
Metabolic Reconstruction ◽  
Waste Biomass ◽  
Anaerobic Digesters ◽  
Extensive Evaluation ◽  
Archaeal Species ◽  
Wide Range ◽  
Biogas Reactors ◽  
High Flexibility

Abstract Background Microorganisms in biogas reactors are essential for degradation of organic matter and methane production. However, a comprehensive genome-centric comparison, including relevant metadata for each sample, is still needed to identify the globally distributed biogas community members and serve as a reliable repository. Results Here, 134 publicly available metagenomes derived from different biogas reactors were used to recover 1,635 metagenome-assembled genomes (MAGs) representing different biogas bacterial and archaeal species. All genomes were estimated to be >50% complete and nearly half ≥90% complete with ≤5% contamination. In most samples, specialized microbial communities were established, while only a few taxa were widespread among the different reactor systems. Metabolic reconstruction of the MAGs enabled the prediction of functional traits related to biomass degradation and methane production from waste biomass. An extensive evaluation of the replication index provided an estimation of the growth rate for microbes involved in different steps of the food chain. The recovery of many MAGs belonging to Candidate Phyla Radiation and other underexplored taxa suggests their specific involvement in the anaerobic degradation of organic matter. Conclusions The outcome of this study highlights a high flexibility of the biogas microbiome, allowing it to modify its composition and to adapt to the environmental conditions, including temperatures and a wide range of substrates. Our findings enhance our mechanistic understanding of the AD microbiome and substantially extend the existing repository of genomes. The established database represents a relevant resource for future studies related to this engineered ecosystem. Keywords Anaerobic digestion, Metagenome-Assembled Genomes, Biogas, Microbial community structure, Functional reconstruction

scholarly journals New insights from the biogas microbiome by comprehensive genome-resolved metagenomics of nearly 1600 species originating from multiple anaerobic digesters

2020 ◽  
Author(s):  
Stefano Campanaro ◽  
Laura Treu ◽  
Luis M Rodriguez-Rojas ◽  
Adam Kovalovszki ◽  
Ryan M Ziels ◽  
...  
Keyword(s):  
Methane Production ◽  
Growth Dynamics ◽  
Metabolic Reconstruction ◽  
Waste Biomass ◽  
Anaerobic Digesters ◽  
Extensive Evaluation ◽  
Archaeal Species ◽  
Wide Range ◽  
Biogas Reactors ◽  
High Flexibility

Abstract BackgroundMicroorganisms in biogas reactors are essential for degradation of organic matter and methane production. However, a comprehensive genome-centric comparison, including relevant metadata for each sample, is still needed to identify the globally distributed biogas community members and serve as a reliable repository.ResultsHere, 134 publicly available metagenomes derived from different biogas reactors were used to recover 1,635 metagenome-assembled genomes (MAGs) representing different biogas bacterial and archaeal species. All genomes were estimated to be >50% complete and nearly half ≥90% complete with ≤5% contamination. In most samples, specialized microbial communities were established, while only a few taxa were widespread among the different reactor systems. Metabolic reconstruction of the MAGs enabled the prediction of functional traits related to biomass degradation and methane production from waste biomass. An extensive evaluation of the replication index provided an estimation of the growth dynamics for microbes involved in different steps of the food chain. ConclusionsThe outcome of this study highlights a high flexibility of the biogas microbiome, allowing it to modify its composition and to adapt to the environmental conditions, including temperatures and a wide range of substrates. Our findings enhance our mechanistic understanding of the AD microbiome and substantially extend the existing repository of genomes. The established database represents a relevant resource for future studies related to this engineered ecosystem.

scholarly journals Effects of sulfonamide antibiotics on digestion performance and microbial community during swine manure anaerobic digestion

2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Shaona Wang ◽  
Kang Du ◽  
Rongfang Yuan ◽  
Huilun Chen ◽  
Fei Wang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Anaerobic Digestion ◽  
Dissolved Organic Matter ◽  
Methane Production ◽  
Volatile Fatty Acids ◽  
High Throughput Sequencing ◽  
Batch Reactor ◽  
Inhibition Mechanism ◽  
Sulfonamide Antibiotics ◽  
High Concentration

The effects of four types of sulfonamide antibiotics (SAs), including sulfaquinoxaline, sulfamethoxazole, sulfamethoxydiazine and sulfathiazole, on the digestion performance during anaerobic digestion process were studied using a lab-scale anaerobic sequencing batch reactor, and the changes of the community structure in the presence of SAs were investigated with the help of high throughput sequencing. The results indicated that when SAs were added, the hydrolytic acidification process was inhibited, and the accumulation of volatile fatty acids (VFAs) was induced, resulting in the suppression of methane production. However, the inhibition mechanism of different SAs was quite different. The inhibitory effect of high concentration of SAs on the hydrolysis of solid particulate matter into dissolved organic matter followed the order of sulfaquinoxaline > sulfamethoxydiazine > sulfathiazole > sulfamethoxazole. SAs have obvious inhibitory effects on acidification and methanation of dissolved organic matter, especially sulfathiazole. The richness and the community composition of the microorganism including bacteria and archaea in the digestion system were affected by SAs. Under the effect of SAs, the relative abundance of many microorganisms is negatively correlated with methane production, among which Methanobrevibacter, a kind of Archaea, had the greatest influence on methane production.

Methanogenesis in sediments from deep lakes at different temperatures (2–70°C)

1997 ◽  
Vol 36 (6-7) ◽  
pp. 57-64 ◽  
Author(s):  
Alla N. Nozhevnikova ◽  
C. Holliger ◽  
A. Ammann ◽  
A. J. B. Zehnder
Keyword(s):  
Organic Matter ◽  
Microbial Communities ◽  
Methane Production ◽  
Low Temperatures ◽  
Main Question ◽  
Deep Lakes ◽  
Temperature Range ◽  
Wide Range ◽  
Thermophilic Conditions ◽  
Different Temperatures

Methanogenic degradation of organic matter occurs in a wide temperature range from psychrophilic to extreme thermophilic conditions. Mesophilic and thermophilic methanogenesis is relatively well investigated, but little is known about low temperature methanogenesis and psychrophilic methanogenic communities. The aim of the present work was to study methanogenesis in a wide range of temperatures with samples from sediments of deep lakes. These sediments may be considered deposits of different types of microorganisms, which are constantly exposed to low temperatures. The main question was how psychrophilic methanogenic microbial communities compare to mesophilic and thermophilic ones. Methanogenesis in a temperature range of 2–70°C was investigated using sediment samples from Baldegger lake (65 m) and Soppen lake (25 m), Switzerland. Methane production from organic matter of sediments occurred at all temperatures tested. An exponential dependence of methane production rate was found between 2 and 30°C. Methanogenesis occurred even at 70°C. At the same time stable methane production from organic matter of sediments was observed at temperatures below 10°C. Methanogenic microbial communities were enriched at different temperatures. The communities enriched at 4–8°C had the highest activity at low temperatures indicating that a specific psychrophilic community exists. Addition of substrates such as cellulose, volatile fatty acids (butyrate, propionate, acetate), methanol and H2/CO2 stimulated methane production at all temperatures. H2/CO2 as well as methanol were directly converted to methane under thermophilic conditions. At low temperatures these substrates were converted to methane by a two-step process. First acetate was formed, followed by methane production from acetate. When acetate concentrations were high, acetoclastic methanogenesis was inhibited at low temperatures. This reaction appears to be one of the “bottle neck” in psychrophilic methanogenesis.

Anaerobic Digestion of Solid Wastes Needs Research to Face an Increasing Industrial Success

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Pierre Buffiere ◽  
Liliana Delgadillo Mirquez ◽  
Jean Philippe Steyer ◽  
Nicolas Bernet ◽  
Jean Philippe Delgenes
Keyword(s):  
Organic Matter ◽  
Anaerobic Digestion ◽  
Methane Production ◽  
Biochemical Parameters ◽  
Energy Production ◽  
Solid Wastes ◽  
High Complexity ◽  
Intrinsic Kinetics ◽  
Anaerobic Biodegradability ◽  
Kinetics Of

Anaerobic digestion of solid wastes is an emerging solution for both waste management and energy production. The high complexity of the process is mostly attributed to the absence of descriptors for the design and the prediction of such a process. This paper presents an approach for the description of organic matter based on several biochemical parameters, established on 22 different organic wastes. The lignocellulosic content is the most important parameter for the prediction of anaerobic biodegradability and methane production; in addition, the knowledge of the carbohydrate, lipid and protein contents is also crucial and makes possible a prediction of the intrinsic kinetics of the reaction.

scholarly journals The synergy of combined free nitrous acid and Fenton technology in enhancing anaerobic digestion of real sewage waste activated sludge

2019 ◽  
Author(s):  
Razieh Karimi ◽  
Seyed Mostafa Hallaji
Keyword(s):  
Organic Matter ◽  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Methane Production ◽  
Nitrous Acid ◽  
Waste Activated Sludge ◽  
Free Nitrous Acid ◽  
Digestion Process ◽  
Treatment Technologies ◽  
Pre Treatment

Abstract Background Recently, free nitrous acid (FNA) pre-treatment of sewage waste activated sludge has been introduced as an economically attractive and environmentally friendly technique for enhancing methane production from the anaerobic digestion process. Fenton pre-treatment of sewage sludge, as an advanced oxidation process, has also been introduced as a powerful technique for methane improvement in a couple of studies. This study, for the first time, investigates the synergy of combined FNA and Fenton pre-treatment technologies in enhancing the methane production from the anaerobic digestion process and reducing waste sludge to be disposed of. Actual secondary waste activated sludge in laboratory-scale batch reactors was used to assess the synergistic effect of the pre-treatments. The mechanisms behind the methane enhancement were also put into perspective by measuring different microbial enzymes activity and solubilisation of organic matter. Result This study revealed that the combined pre-treatments release organic matter into the soluble phase significantly more than the bioreactors pre-treated with individual FNA and Fenton. For understanding the influence of pre-treatments on solubilisation of organic matter, soluble protein, soluble polysaccharide and soluble chemical oxygen demand (SCOD) were measured before and after the treatments and it was shown that they respectively increased by 973%, 33% and 353% after the treatments. Protease and cellulose activity, as the key constituents of the microbial community presenting in activated sludge, decreased considerably within the combined pre-treatments (42% and 32% respectively) and methane production enhanced by 43-69%. Furthermore, total solids and volatile solids destruction improved by 26% and 24% at the end of anaerobic digestion, which can reduce transport costs of sludge and improve the quality of sludge for application in farms and forests. Conclusions The results obtained from the experiments corroborate the synergic effect of the combined FNA and Fenton pre-treatment technologies in degrading the organic and microbial constituents in waste activated sludge, which improved methane production accordingly. This is of paramount importance because the total costs of wastewater treatment plants operation and greenhouse gas emission from sludge treatment and disposal processes would reduce considerably, which pave the way for the implementation of these technologies.

scholarly journals Organic Waste Conversion Via Continuous Anaerobic Co-Digestion of Oil Palm Empty Fruit Bunches and Cow Manure: Evaluation of Feeding Regime on Methane Production

2021 ◽  
Vol 24 (1) ◽  
pp. 8-13
Author(s):  
Darwin ◽  
Atmadian Pratama ◽  
Mardhotillah
Keyword(s):  
Organic Matter ◽  
Anaerobic Digestion ◽  
Oil Palm ◽  
Methane Production ◽  
Organic Waste ◽  
Cow Manure ◽  
Research Focus ◽  
Significant Drop ◽  
Empty Fruit Bunches ◽  
Waste Conversion

AbstractAnaerobic co-digestion of oil palm empty fruit bunches with cow manure was studied. The research focus was on the evaluation of feeding different solid concentrations of the substrate in the on-going process of anaerobic digestion. The solid concentrations ranged from 0.5 to 12% TS. Results of the study showed that the maximum methane production could be reached with the reactor digesting substrates with 4 to 8% TS, in which the methane produced was from 1300 to 1400 mL per day. A significant drop of pH from 7.02 to 5.97 occurred when the reactor was digesting substrates with 10 and 12% TS. Acidic condition caused by organic matter overloads lowered the efficiency of organic conversion represented in the low removal of COD, which was only 22.4%. This finding is highly significant for the waste management industries in terms of dealing with the digester upset due to the digestion of large amount of organic wastes.

scholarly journals Impact of Organic Loading Rate in Volatile Fatty Acids Production and Population Dynamics Using Microalgae Biomass as Substrate

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jose Antonio Magdalena ◽  
Silvia Greses ◽  
Cristina González-Fernández
Keyword(s):  
Fatty Acids ◽  
Population Dynamics ◽  
Organic Matter ◽  
Anaerobic Digestion ◽  
Volatile Fatty Acids ◽  
Building Blocks ◽  
Biofuel Production ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Wide Range

AbstractVolatile fatty acids (VFAs) are regarded as building blocks with a wide range of applications, including biofuel production. The traditional anaerobic digestion used for biogas production can be alternatively employed for VFAs production. The present study aimed at maximizing VFAs productions from Chlorella vulgaris through anaerobic digestion by assessing the effect of stepwise organic loading rates (OLR) increases (3, 6, 9, 12 and 15 g COD L−1 d−1). The biological system was proven to be robust as organic matter conversion efficiency into VFAs increased from 0.30 ± 0.02 COD-VFAs/CODin at 3 g COD L−1 d−1 to 0.37 ± 0.02 COD-VFAs/CODin at 12 g COD L−1d−1. Even though, the hydrolytic step was similar for all studied scenario sCOD/tCOD = 0.52–0.58), the highest OLR (15 g COD L−1 d−1) did not show any further increase in VFAs conversion (0.29 ± 0.01 COD-VFAs/CODin). This fact suggested acidogenesis inhibition at 15 g COD L−1d−1. Butyric (23–32%), acetic (19–26%) and propionic acids (11–17%) were the most abundant bioproducts. Population dynamics analysis revealed microbial specialization, with a high presence of Firmicutes followed by Bacteroidetes. In addition, this investigation showed the microbial adaptation of Euryarchaeota species at the highest OLR (15 g COD L−1d−1), evidencing one of the main challenges in VFAs production (out-competition of archaea community to avoid product consumption). Stepwise OLR increase can be regarded as a tool to promote VFAs productions. However, acidogenic inhibition was reported at the highest OLR instead of the traditional hydrolytic barriers. The operational conditions imposed together with the high VFAs and ammonium concentrations might have affected the system yields. The relative abundance of Firmicutes (74%) and Bacteroidetes (20%), as main phyla, together with the reduction of Euryarchaeota phylum (0.5%) were found the best combination to promote organic matter conversion into VFAs.

Process optimization and effect of thermal, alkaline, H2O2 Oxidation and combination pre-treatment of sewage sludge on solubilisation and anaerobic digestion

2020 ◽  
Author(s):  
Salar Siami ◽  
Behnoush Aminzadeh ◽  
Razieh Karimi ◽  
Seyed Mostafa Hallaji
Keyword(s):  
Hydrogen Peroxide ◽  
Response Surface Methodology ◽  
Organic Matter ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Thermal Energy ◽  
Methane Production ◽  
Quadratic Model ◽  
Waste Activated Sludge ◽  
Pre Treatment

Abstract Background This study investigated the feasibility of enhancing anaerobic digestion of sewage sludge with triple, dual, and individual pre-treatment of waste activated sludge with heat, alkalinity, and hydrogen peroxide. These pre-treatments disrupt sludge flocs, organisms’ cell walls, extracellular polymeric substance, and intracellular organic matter, which increase biodegradability and hydrolysis rate of organic matter. In addition, the influence of various variables on methane production was analyzed using the response surface methodology with the quadratic model. Eventually, an optimized temperature and chemical concentration for the highest methane production and lowest chemical usage is suggested.Results The highest amount of methane production was obtained from the sludge pretreated with triple pretreatment (heat (90°C), alkalinity (pH=12), and hydrogen peroxide (30 mg H2O2 /g TS)), which had better performance with 96% higher than that of the control sample with Temperature of 25°C approximately and alkalinity of pH=8. Response surface methodology with the quadratic model was also used for analyzing the influence of temperature, pH, and hydrogen peroxide concentration on anaerobic digestion efficiency. It was revealed that the optimized temperature, pH, and hydrogen peroxide concentration for maximizing methane production and solubilisation of organic matter and minimizing thermal energy and chemical additives of the pre-treatments are 83.2°C, pH=10.6 and 34.8 mg H2O2 /g TS, respectively, has the desirability of 0.67.Conclusion This study reveals that triple pre-treatment of waste activated sludge performs better than dual and individual pre-treatment, Respectively. The enhanced methane production can be used as an important renewable energy resource in wastewater treatment plants for producing electrical and thermal energy. Furthermore, exploiting a higher amount of methane in the anaerobic digestion stage decreases methane emission to the atmosphere in dewatering and landfilling stages and enhances the quality of digested sludge, bringing about environmentally friendly and economically attractive sewage sludge treatment process.

scholarly journals Microwave and its combined processes: an effective way for enhancing anaerobic digestion and dewaterability of sewage sludge?

2015 ◽  
Vol 5 (3) ◽  
pp. 264-270 ◽  
Author(s):  
Jibao Liu ◽  
Juan Tong ◽  
Yuansong Wei ◽  
Yawei Wang
Keyword(s):  
Organic Matter ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Methane Production ◽  
Combined Processes ◽  
Soluble Organic Matter ◽  
Capillary Suction ◽  
Sludge Dewaterability

The enhancement for sludge anaerobic digestion and dewaterability were investigated in sludge pretreated by microwave (MW) and its combined processes. The results showed that microwave and its combined processes can efficiently release soluble organic matter and thus enhance anaerobic digestion of sludge. The cumulative methane production in the test of the MW-H2O2-OH (0.2) process was increased by 13.34% compared with that of the control. The MW-H process was effective in improving sludge dewaterability, e.g., the capillary suction time (CST) at only 9.85S.

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