scholarly journals Comparison of Bacterial And Archaeal Microbiome In Two Bioreactors Fed With Cattle Sewage And Corn Biomass

2021 ◽  
Author(s):  
Caterina Agrimonti ◽  
Giovanna Visoli ◽  
Graziano Ferrari ◽  
Anna Maria Sanangelantoni
Keyword(s):  
Volatile Fatty Acids ◽  
Intergenic Spacer ◽  
Archaeal Community ◽  
Operating Conditions ◽  
Pig Manure ◽  
Comparable Amount ◽  
Core Microbiome ◽  
Methanogenic Community ◽  
Molecular Approaches ◽  
Bacterial And Archaeal Communities

Abstract The bacterial and archaeal communities of two biogas producing plants (P1 and P2), associated with a 999 kW cogeneration unit, both located in North Italy, were analyzed at start up and fully operating phases, by means of various molecular approaches: i) Automated Ribosomal Intergenic Spacer Analysis; ii) cloning and sequencing of PCR amplicons of archaeal genes 16Srrna and mcrA; iii) 16S rDNA high throughput next generation sequencing. P1 and P2 use the same technology and both were fed with cattle manure and corn silage. During the study of P1 also the post digestor (fed with pig manure) was analyzed. The aim of this research was to characterize the bacterial and archaeal community in two very similar plants to profile the core microbiome. The results of this analysis highlighted that the two plants (producing comparable quantities of volatile fatty acids, biogas, and energy) differed in anerobic microbiota (Bacteria and Archaea). Notably the methanogenic community of P1 was dominated by the strict acetoclastic Methanosaeta (Methanothrix) (up to 23.05%) and the unculturable Candidatus Methanofastidiosum (up to 32.70%), while P2 was dominated by the acetoclastic, but more substrate-versatile, Methanosarcina archaeal genus (49.19%). The data demonstrated that the performances of plants with identical design, in similar operating conditions, yielding comparable amount of biogas (average of 8662 m3 /day and 7916 m3/day respectively for P1 and P2), VFA (1643 mg/L and 1634 mg/L) and energy recovery (23.90-24 MWh/d) depends on the stabilization of an effective and functionally optimized methanogenic community rather than on the species composition

Effect of hydraulic retention time on pretreatment of blended municipal sludge

2011 ◽  
Vol 64 (4) ◽  
pp. 967-973
Author(s):  
S. Koyunluoglu-Aynur ◽  
R. Riffat ◽  
S. Murthy
Keyword(s):  
Retention Time ◽  
Volatile Fatty Acids ◽  
Hydraulic Retention Time ◽  
Operating Conditions ◽  
Methane Yield ◽  
Municipal Sludge ◽  
Volatile Solids ◽  
Significant Difference ◽  
Autothermal Thermophilic Aerobic Digestion ◽  
Pretreatment Processes

The objective of the present work was to evaluate the effect of hydraulic retention time (HRT) on hydrolysis and acidogenesis for the pretreatment processes: acid phase digestion (APD) and autothermal thermophilic aerobic digestion (ATAD) using blended municipal sludge. The effect of the different pretreatment steps on mesophilic anaerobic digestion (MAD) was evaluated in terms of methane yield, keeping the operating conditions of the MAD the same for all systems. Best operating conditions for both APD and ATAD were observed for 2.5 d HRT with high total volatile fatty acids (tVFA), and the highest methane yield observed for MAD. No significant difference was observed between the two processes in terms of overall volatile solids (VS) reduction with same total HRT. The autothermal process produced heat of 14,300 J/g VS removed from hydrolytic and acetogenic reactions without compromising overall methane yields when the HRT was 2.5 d or lower and the total O2 used was 0.10 m3 O2/g VS added or lower. However, the process needs the input of oxygen and engineering analysis should balance these differences when considering the relative merits of the two pretreatment processes. This is the first study of its kind directly comparing these two viable pretreatment processes with the same sludge.

scholarly journals Diagnosis and Monitoring of Volatile Fatty Acids Production from Raw Cheese Whey by Multiscale Time-Series Analysis

2021 ◽  
Vol 11 (13) ◽  
pp. 5803
Author(s):  
Antonio Lara-Musule ◽  
Ervin Alvarez-Sanchez ◽  
Gloria Trejo-Aguilar ◽  
Laura Acosta-Dominguez ◽  
Hector Puebla ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Time Series ◽  
Time Series Analysis ◽  
Multiscale Analysis ◽  
Volatile Fatty Acids ◽  
Cheese Whey ◽  
Anaerobic Treatment ◽  
Operating Conditions ◽  
Series Analysis ◽  
Key Variables

Anaerobic treatment is a viable alternative for the treatment of agro-industrial waste. Anaerobic digestion reduces organic load and produces volatile fatty acids (VFA), which are precursors of value-added products such as methane-rich biogas, biohydrogen, and biopolymers. Nowadays, there are no low-cost diagnosis and monitoring systems that analyze the dynamic behavior of key variables in real time, representing a significant limitation for its practical implementation. In this work, the feasibility of using the multiscale analysis to diagnose and monitor the key variables in VFA production by anaerobic treatment of raw cheese whey is presented. First, experiments were carried out to evaluate the performance of the proposed methodology under different operating conditions. Then, experimental pH time series were analyzed using rescaled range (R/S) techniques. Time-series analysis shows that the anaerobic VFA production exhibits a multiscale behavior, identifying three characteristic regions (i.e., three values of Hurst exponent). In addition, the dynamic Hurst exponents show satisfactory correlations with the chemical oxygen demand (COD) consumption and VFA production. The multiscale analysis of pH time series is easy to implement and inexpensive. Hence, it could be used as a diagnosis and indirect monitoring system of key variables in the anaerobic treatment of raw cheese whey.

Composition of the archaeal community involved in methane production during the decomposition of Microcystis blooms in the laboratory

2012 ◽  
Vol 58 (10) ◽  
pp. 1153-1158 ◽  
Author(s):  
Peng Xing ◽  
Huabing Li ◽  
Qing Liu ◽  
Jiuwen Zheng
Keyword(s):  
Lake Taihu ◽  
Archaeal Community ◽  
Oxygen Depletion ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Polymorphism Analysis ◽  
Methanogenic Community ◽  
Controlled Systems ◽  
Microcystis Blooms ◽  
Different Temperatures

We investigated the microbial processes involved in methane (CH4) production from Microcystis bloom scums at different temperatures. A Microcystis slurry was collected from Lake Taihu and incubated in airtight bottles at 15, 25, and 35 °C. The production of CH4 was monitored, and the emission rate was calculated. The dynamics of the methanogenic community were analyzed by terminal restriction fragment length polymorphism analysis of archaeal 16S rRNA genes. Phylogenetic information for the methanogens was obtained by cloning and sequencing selected samples. Significant CH4 emission from the Microcystis scums was delayed by approximately 12 days by the natural oxygen depletion process, and CH4 production was enhanced at higher temperatures. Phylogenetic analysis indicated that the archaeal community was composed of Methanomicrobiales, Methanobacteriaceae, and a novel cluster of Archaea. An apparent succession of the methanogenic community was demonstrated, with a predominance of Methanobacteriaceae at higher temperatures. Higher temperatures enhanced the methanogenic transformation of the Microcystis biomass and the phylogenetic dominance of hydrogenotrophic methanogens, suggesting that H2 and CO2 might be the primary substrates for CH4 production during Microcystis decomposition without the participation of lake sediment. This work provides insight into the microbial components involved in Microcystis biomass fermentation in controlled systems.

Influence of fine coal gasification slag on greenhouse gases emission and volatile fatty acids during pig manure composting

2020 ◽  
Vol 316 ◽  
pp. 123915
Author(s):  
Tao Liu ◽  
Mukesh Kumar Awasthi ◽  
Sanjeev Kumar Awasthi ◽  
Xiuna Ren ◽  
Xiangyu Liu ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Greenhouse Gases ◽  
Volatile Fatty Acids ◽  
Coal Gasification ◽  
Pig Manure ◽  
Fine Coal ◽  
Coal Gasification Slag

Regional variability in eukaryotic protist communities in the Amundsen Sea

2013 ◽  
Vol 25 (6) ◽  
pp. 741-751 ◽  
Author(s):  
Christian Wolf ◽  
Stephan Frickenhaus ◽  
Estelle S. Kilias ◽  
Ilka Peeken ◽  
Katja Metfies
Keyword(s):  
High Performance ◽  
Intergenic Spacer ◽  
Late Summer ◽  
Dominant Group ◽  
Regional Variability ◽  
Amundsen Sea ◽  
Entire Area ◽  
Molecular Approaches ◽  
Ribosomal Intergenic Spacer ◽  
Composition And Structure

AbstractWe determined the composition and structure of late summer eukaryotic protist assemblages along a west–east transect in the Amundsen Sea. We used state-of-the-art molecular approaches, such as automated ribosomal intergenic spacer analysis (ARISA) and 454-pyrosequencing, combined with pigment measurements via high performance liquid chromatography (HPLC) to study the protist assemblage. We found characteristic offshore and inshore communities. In general, total chlorophyll a and microeukaryotic contribution were higher in inshore samples. Diatoms were the dominant group across the entire area, of which Eucampia sp. and Pseudo-nitzschia sp. were dominant inshore and Chaetoceros sp. was dominant offshore. At the most eastern station, the assemblage was dominated by Phaeocystis sp. Under the ice, ciliates showed their highest and haptophytes their lowest abundance. This study delivers a taxon detailed overview of the eukaryotic protist composition in the Amundsen Sea during the summer 2010.

scholarly journals Pengaruh sumber karbon terhadap produksi bioplastik polihidroksialkanoat (PHA) dengan ralstonia eutropha

2018 ◽  
Vol 9 (1) ◽  
pp. 28
Author(s):  
Martha Aznury ◽  
Tjandra Setiadi ◽  
Adi Pancoro
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Carbon Source ◽  
Fermentation Process ◽  
Volatile Fatty Acids ◽  
Ralstonia Eutropha ◽  
Operating Conditions ◽  
Batch Bioreactor ◽  
Pha Production ◽  
Fructose Fermentation

Bioplastic Polyhidroxyalknoate (PHA) is a polyester type bioplastic with physicochemical properties resemble to those of polypropilen from petroleum. PHA production was investigated to determine the effect of carbon source on the fermentation process by Ralstonia eutropha. Specifically, Ralstonia eutropha was cultivated in a batch bioreactor to show the dynamics of P(3HB-co-3HV) copolymer production from glucose or fructose as C source. In adition, the effect of volatile fatty acids addition, as stimulator to the copolymer production, was also studied. The operating conditions in a 7 L bioreactor were at temperature 30 oC and pH 7.0. The concentration of carbon source glucose or fructose was 40 g/L, and after 20 hour fermentation, volatile fatty acids were added. With volatile fatty acids addition, the resulting fructose fermentation had PHA content of 32.78%, in which the HV percentage was 11.78%. Meanwhile, the fermentation of glucose, stimulated by volatile fatty acids, gave PHA as much as 20.19% with HV percentage of 8.71%. Therefore,, the Ralstonia eutropha fermentation of fructose as the carbon source gave a higher yield than glucose. Keywords: Volatil Fatty Acid, Fructose, Glucose, PHA, P(3HB-co-3HV), Ralstonia eutropha AbstrakBioplastik polihidroksialkanoat (PHA) adalah bioplastik dari kelompok poliester dengan sifat fisikokimia mirip dengan plastik polipropilen dari minyak bumi. Penelitian ini bertujuan untuk mempelajari pengaruh sumber karbon terhadap poduksi PHA yang dilakukan dengan proses fermentasi menggunakan Ralstonia eutropha. Ralstonia eutropha dikultivasi dalam bioreaktor batch untuk mempelajari dinamika produksi kopolimer P(3HB-co-3HV) dari sumber karbon glukosa atau fruktosa, serta mempelajari pengaruh sumber stimulator asam lemak volatil. Kondisi operasional fermentasi menggunakan bioreaktor 7 L adalah pada temperatur 30 oC dan pH 7. Konsentrasi sumber karbon glukosa atau fruktosa yang digunakan adalah 40 gr/L, dan setelah 20 jam fermentasi ditambahkan asam lemak volatil yang berfungsi sebagai stimulator dalam produksi P(3HB-co-3HV). Panen sel Ralstonia eutropha dilakukan setelah 60 jam. Hasil penelitian menunjukkan fermentasi Ralstonia eutropha dengan substrat fruktosa dan asam lemak volatil sebagai stimulator mempunyai kandungan PHA sebesar 32,78%, dengan kadar HV 11,78%. Pada pemberian substrat glukosa dan asam lemak volatil menunjukkan kandungan PHA sebesar 20,19%, dengan kadar HV 8.71%. Jadi fermentasi Ralstonia eutropha dengan menggunakan substrat fruktosa memberikan yield yang lebih tinggi dibandingkan menggunakan substrat glukosa.Kata Kunci: Asam lemak volatil, fruktosa, glukosa, PHA, P(3HB-co-3HV), Ralstonia eutropha

scholarly journals Estimation of microbial metabolism and co-occurrence patterns in fracture groundwaters of deep crystalline bedrock at Olkiluoto, Finland

2015 ◽  
Vol 12 (16) ◽  
pp. 13819-13857 ◽  
Author(s):  
M. Bomberg ◽  
T. Lamminmäki ◽  
M. Itävaara
Keyword(s):  
Microbial Communities ◽  
Physicochemical Parameters ◽  
Calvin Cycle ◽  
Acid Oxidation ◽  
Core Microbiome ◽  
Rare Taxa ◽  
The Core ◽  
Crystalline Bedrock ◽  
Bacterial And Archaeal Communities ◽  
Archaeal Communities

Abstract. The microbial diversity in oligotrophic isolated crystalline Fennoscandian Shield bedrock fracture groundwaters is great but the core community has not been identified. Here we characterized the bacterial and archaeal communities in 12 water conductive fractures situated at depths between 296 and 798 m by high throughput amplicon sequencing using the Illumina HiSeq platform. The great sequencing depth revealed that up to 95 and 99 % of the bacterial and archaeal communities, respectively, were composed of only a few common species, i.e. the core microbiome. However, the remaining rare microbiome contained over 3 and 6 fold more bacterial and archaeal taxa. Several clusters of co-occurring rare taxa were identified, which correlated significantly with physicochemical parameters, such as salinity, concentration of inorganic or organic carbon, sulphur, pH and depth. The metabolic properties of the microbial communities were predicted using PICRUSt. The rough prediction showed that the metabolic pathways included commonly fermentation, fatty acid oxidation, glycolysis/gluconeogenesis, oxidative phosphorylation and methanogenesis/anaerobic methane oxidation, but carbon fixation through the Calvin cycle, reductive TCA cycle and the Wood-Ljungdahl pathway was also predicted. The rare microbiome is an unlimited source of genomic functionality in all ecosystems. It may consist of remnants of microbial communities prevailing in earlier conditions on Earth, but could also be induced again if changes in their living conditions occur. In this study only the rare taxa correlated with any physicochemical parameters. Thus these microorganisms can respond to environmental change caused by physical or biological factors that may lead to alterations in the diversity and function of the microbial communities in crystalline bedrock environments.

scholarly journals Enhancement of Methane Production in Thermophilic Anaerobic Co-Digestion of Exhausted Sugar Beet Pulp and Pig Manure

2019 ◽  
Vol 9 (9) ◽  
pp. 1791 ◽  
Author(s):  
Xiomara Gómez-Quiroga ◽  
Kaoutar Aboudi ◽  
Carlos José Álvarez-Gallego ◽  
Luis Isidoro Romero-García
Keyword(s):  
Sugar Beet ◽  
Methane Production ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Methanogenic Archaea ◽  
Sugar Beet Pulp ◽  
Pig Manure ◽  
Thermophilic Conditions ◽  
Beet Pulp ◽  
The Individual

In this paper, the viability of thermophilic anaerobic co-digestion of exhausted sugar beet pulp (ESBP) and pig manure (PM) was evaluated. The effect of the proportion of ESBP on biogas production was investigated by using a series of lab-scale batch assays, in duplicates. The following five ESBP:PM mixture ratios were studied: 0:100, 10:90, 25:75, 50:50, and 100:0. The highest cumulative methane production (212.4 mL CH4/g VSadded) was reached for the mixture 25:75. The experimental results showed that the increase in the proportion of ESBP in the mixture led to the distortion of the process, due to acidification by the volatile fatty acids generated. Acetic acid was the predominant acid in all the cases, representing more than 78% of the total acidity. Moreover, the results obtained by operating at thermophilic temperatures have been compared with those obtained in a previous study conducted at mesophilic temperatures. The results have shown that in the individual digestion of ESBP, the activity of acetoclastic methanogens was affected in both temperatures, but especially in thermophilic conditions. Thus, the methane produced in the individual thermophilic digestion of ESBP came almost entirely from the activity of hydrogen-utilizing methanogenic archaea.

scholarly journals Effect of Temperature on Anaerobic Ethanol Oxidation and Methanogenesis in Acidic Peat from a Northern Wetland

2005 ◽  
Vol 71 (12) ◽  
pp. 8191-8200 ◽  
Author(s):  
Martina Metje ◽  
Peter Frenzel
Keyword(s):  
Volatile Fatty Acids ◽  
Archaeal Community ◽  
Dry Weight ◽  
Effect Of Temperature ◽  
Rrna Gene ◽  
Polymorphism Analysis ◽  
Optimum Temperature ◽  
Hydrogenotrophic Methanogenesis ◽  
Acetoclastic Methanogenesis ◽  
Fe Reduction

ABSTRACT The effects of temperature on rates and pathways of CH4 production and on the abundance and structure of the archaeal community were investigated in acidic peat from a mire in northern Scandinavia (68°N). We monitored the production of CH4 and CO2 over time and measured the turnover of Fe(II), ethanol, and organic acids. All experiments were performed with and without specific inhibitors (2-bromoethanesulfonate [BES] for methanogenesis and CH3F for acetoclastic methanogenesis). The optimum temperature for methanogenesis was 25°C (2.3 μmol CH4 · g [dry weight]−1 · day−1), but the activity was relatively high even at 4°C (0.25 μmol CH4 · g [dry weight]−1 · day−1). The theoretical lower limit for methanogenesis was calculated to be at −5°C. The optimum temperature for growth as revealed by real-time PCR was 25°C for both archaea and bacteria. The population structure of archaea was studied by terminal restriction fragment length polymorphism analysis and remained constant over a wide temperature range. Hydrogenotrophic methanogenesis accounted for about 80% of the total methanogenesis. Most 16S rRNA gene sequences that were affiliated with methanogens and all McrA sequences clustered with the exclusively hydrogenotrophic order Methanobacteriales, correlating with the prevalence of hydrogenotrophic methanogenesis. Fe reduction occurred parallel to methanogenesis and was inhibited by BES, suggesting that methanogens were involved in Fe reduction. Based upon the observed balance of substrates and thermodynamic calculations, we concluded that the ethanol pool was oxidized to acetate by the following two processes: syntrophic oxidation with methanogenesis (i) as an H2 sink and (ii) as a reductant for Fe(III). Acetate accumulated, but a considerable fraction was converted to butyrate, making volatile fatty acids important end products of anaerobic metabolism.

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