scholarly journals Transcriptomic and Physiological Insights into the Robustness of Long Filamentous Cells of Methanosaeta harundinacea, Prevalent in Upflow Anaerobic Sludge Blanket Granules

2014 ◽  
Vol 81 (3) ◽  
pp. 831-839 ◽  
Author(s):  
Liguang Zhou ◽  
Haiying Yu ◽  
Guomin Ai ◽  
Bo Zhang ◽  
Songnian Hu ◽  
...  

ABSTRACTMethanosaetaspp. are widely distributed in natural environments, and their filamentous cells contribute significantly to sludge granulation and the good performance of anaerobic reactors. A previous study indicated thatMethanosaeta harundinacea6Ac displays a quorum sensing-regulated morphological transition from short to long filaments, and more acetate is channeled into methane production in long filaments, whereas more is channeled into biomass synthesis in short filaments. Here, we performed transcriptomic and physiological analysis to gain insights into active methanogenesis in long filaments ofM. harundinacea6Ac. Both RNA sequencing (RNA-seq) and quantitative reverse transcription-PCR indicated that transcription of the genes involved in aceticlastic methanogenesis and energy metabolism was upregulated 1.2- to 10.3-fold in long filaments, while transcription of the genes for the methyl oxidative shunt was upregulated in short filaments. [2-13C]acetate trace experiments demonstrated that a relatively higher portion of the acetate methyl group was oxidized to CO2in short filaments than in long filaments. The long filaments exhibited higher catalase activity and oxygen tolerance than the short ones, which is consistent with increased transcription of the oxidant-scavenging genes. Moreover, transcription of genes for cell surface structures was upregulated in the long filaments, and transmission electron microscopy revealed a thicker cell envelope in the filaments. RNA-seq determined a >2-fold upregulation of a variety of antistress genes in short filaments, like those encoding chaperones and DNA repair systems, which implies that the short filaments can be stressed. This study reveals the genetic basis for the prevalence of the long filamentous morphology ofM. harundinaceacells in upflow anaerobic sludge blanket granules.

2019 ◽  
Vol 80 (3) ◽  
pp. 418-425 ◽  
Author(s):  
T. Bressani-Ribeiro ◽  
L. A. Chamhum-Silva ◽  
C. A. L. Chernicharo

Abstract There are hundreds of full-scale upflow anaerobic sludge blanket (UASB) reactors in operation in various parts of the tropical world, notably in India and Latin America, Brazil being the holder of the largest park of anaerobic reactors for sewage treatment in the world. Despite the recognized advantages of UASB reactors, there are problems that have prevented their maximum operational performance. Neglecting the existence and delaying the solution of these challenges can jeopardize the important advances made to date, impacting the future of anaerobic technology in Brazil and in other countries. This work aims to evaluate the operational performance of five full-scale UASB reactors in Brazil, taking into account a monitoring period ranging between two and six years. The main observed design, construction, and operational constraints are discussed. Some outlooks for important upcoming developments are also provided, considering that most of the observed drawbacks can be tackled without significant increases on reactor costs.


2014 ◽  
Vol 64 (Pt_5) ◽  
pp. 1770-1774 ◽  
Author(s):  
Masashi Hatamoto ◽  
Masami Kaneshige ◽  
Akinobu Nakamura ◽  
Takashi Yamaguchi

A mesophilic, anaerobic, cellulolytic and xylanolytic strain, UasXn-3T, was isolated from anaerobic granular sludge in a mesophilic upflow anaerobic sludge blanket reactor, which was used to treat municipal sewage. The cells were Gram-stain-negative, non-motile, and non-spore-forming rods. The optimal temperature for growth was 37–40 °C and the optimal pH for growth was pH 6.5–7.0. Strain UasXn-3T could grow on several polysaccharides and sugars, including cellulose, cellobiose, xylan, xylose, glucose, fructose, arabinose, mannose, raffinose, trehalose and starch. The DNA G+C content was 44.4 mol%. On the basis of comparative 16S rRNA gene sequence analysis, strain UasXn-3T was identified as a member of the genus Bacteroides and most closely related to Bacteroides oleiciplenus , B. intestinalis , B. cellulosilyticus and B. graminisolvens (sequence similarities of 91.3–91.6 %). Since the genetic and phenotypic properties suggest that strain UasXn-3T represents a novel species, we propose the name Bacteroides luti sp. nov. The type strain is UasXn-3T ( = JCM 19020T = DSM 26991T).


2019 ◽  
Vol 14 (2) ◽  
pp. 249-258
Author(s):  
S. R. Amaral ◽  
L. V. dos Santos ◽  
L. M. Lima ◽  
D. V. Vich ◽  
L. M. Queiroz

Abstract The aim of this paper was to evaluate the performance of two modified upflow anaerobic reactor (RAns) as a decentralized technology for the treatment of high-strength domestic wastewater. Two full-scale anaerobic reactors (Ran1 and Ran2) with the same configuration and total volume of 14.6 m³, total height of 2.57 m, and constructed from fibreglass reinforced plastics were operated with a 16-hour hydraulic retention time and submitted to a volumetric organic load less than 2.7 kg chemical oxygen demand (COD)·m−3·d−1. The RAns were monitored for 10 consecutive months and showed the capability to support the fluctuations of organic loading and volumetric rates. The compact anaerobic reactors proved to be effective in removing organic matter (biological oxygen demand removal efficiencies greater than 70% and the average soluble COD removal efficiencies greater than 57.4%). The solids profile in the reactor ranged from very dense particles with good settleability close to the bottom (sludge bed) to a more dispersed and light sludge close to the top of the reactor (sludge blanket), similar to conventional UASB reactors.


2012 ◽  
Vol 66 (12) ◽  
pp. 2562-2569 ◽  
Author(s):  
F. B. Queiroz ◽  
E. M. F. Brandt ◽  
S. F. Aquino ◽  
C. A. L. Chernicharo ◽  
R. J. C. F. Afonso

This work investigated the occurrence of pharmaceuticals and endocrine disrupting compounds (EDCs) in raw sewage (from Belo Horizonte city, Minas Gerais state, Brazil) and assessed their behavior in demo-scale upflow anaerobic sludge blanket reactors (UASB reactors) operated at different hydraulic retention times (HRT). The dissolved concentration of the studied micropollutants in the raw and treated sewage was obtained using solid phase extraction (SPE) followed by analysis in a liquid chromatography system coupled to a hybrid high resolution mass spectrometer consisting of an ion-trap and time of flight (LC-MS-IT-TOF). The natural (estradiol) and synthetic (ethinylestradiol) estrogens were hardly detected; when present, however, their concentrations were lower than the method quantification limits. The concentrations of bisphenol A and miconazole in raw sewage were similar to that reported in the literature (around 200 ng L−1 and hardly detected, respectively). The antibiotics sulfamethoxazole (median 13.0 ng L−1) and trimethoprim (median 61.5 ng L−1), and the other pharmaceutical compounds (diclofenac and bezafibrate, with median 99.9 and 94.4 ng L−1, respectively) were found in lower concentrations when compared with reports in the literature, which might indicate a lower consumption of such drugs in Brazil. The UASB reactors were inefficient in the removal of bisphenol A, and led to an increased concentration of nonylphenol in the effluent. The anaerobic reactors were also inefficient in the removal of diclofenac, and led to a partial removal of bezafibrate; whereas, for sulfamethoxazole there seemed to be a direct relationship between the HRT and removal efficiencies. For trimethoprim the sludge retention time (SRT) seemed to play an important role, although it was only partially removed in the UASB reactors.


2005 ◽  
Vol 51 (12) ◽  
pp. 91-97 ◽  
Author(s):  
M. von Sperling ◽  
R.K.X. Bastos ◽  
M.T. Kato

Ponds following anaerobic reactors, such as Upflow Anaerobic Sludge Blanket (UASB) reactors, have been termed polishing ponds in the literature. The present paper analyses the removal of E. coli and helminth eggs in five UASB–polishing pond systems in Brazil. Since there were ponds in series, the total number of ponds was 10. The ponds had average retention times varying from 2 to 21 days, and depths ranging from 0.40 to 2.00 m. The shallow ponds in series, even with low retention times, were able to produce effluents complying with the coliform WHO guidelines for unrestricted irrigation (≤1000 MPN/100 ml). An equation for the coliform decay coefficient was proposed: Kb (dispersed flow)=0.710 H−0.955 (20 °C). The equation highlights the inverse relationship between the pond depth and the decay coefficient. All polishing pond systems were able to produce effluents with helminth eggs concentrations predominantly equal to zero, and satisfying the WHO guidelines for unrestricted and restricted irrigation (≤1 egg/L, arithmetic mean). The approximate range of helminth eggs removal efficiency was predicted satisfactorily.


2013 ◽  
Vol 63 (Pt_2) ◽  
pp. 533-539 ◽  
Author(s):  
Yan-Ling Qiu ◽  
Mizuho Muramatsu ◽  
Satoshi Hanada ◽  
Yoichi Kamagata ◽  
Rong-Bo Guo ◽  
...  

A mesophilic, obligately anaerobic, carbohydrate-fermenting bacterium, designated 8KG-4T, was isolated from an upflow anaerobic sludge blanket reactor treating high-strength organic wastewater from salted vegetable production processes. Cells of strain 8KG-4T were non-motile, spherical and 0.7–1.5 µm in diameter (mean, 1.0 µm). Spore formation was not observed under any culture conditions tested. The strain grew optimally at 37 °C (range for growth 25–40 °C) and pH 7.0 (range, pH 6.5–7.5), and could grow fermentatively on glucose, ribose, xylose, galactose and sucrose. The main end products of glucose fermentation were acetate, ethanol and hydrogen. Organic acids, alcohols and amino acids were not utilized for growth. Yeast extract was not required for growth. Nitrate, sulfate, thiosulfate, elemental sulfur, sulfite and Fe(III) nitrilotriacetate were not used as terminal electron acceptors. The G+C content of the genomic DNA was 61.1 mol%. 16S rRNA gene sequence analysis revealed that the isolate represented a previously uncultured lineage at the subphylum level within the phylum Lentisphaerae known as ‘WWE2 subgroup I’. The major cellular fatty acids were anteiso-C15 : 0, iso-C16 : 0, C16 : 0 and anteiso-C17 : 0. Respiratory quinones were not detected. The most abundant polar lipid of strain 8KG-4T was phosphatidylethanolamine. A novel genus and species, Oligosphaera ethanolica gen. nov., sp. nov., is proposed to accommodate strain 8KG-4T ( = JCM 17152T = DSM 24202T  = CGMCC 1.5160T). In addition, we formally propose Oligosphaeria classis nov. and the subordinate taxa Oligosphaerales order nov. and Oligosphaeraceae fam. nov.


2008 ◽  
Vol 57 (6) ◽  
pp. 863-868 ◽  
Author(s):  
D. Bhattacharyya ◽  
K. S. Singh

This research integrates two different concepts of anaerobic biotechnology- two-phase anaerobic treatment and anaerobic granular sludge bed technology, in treatment of colored wastewaters from textile industries. Four anaerobic reactors based on upflow anaerobic sludge blanket (UASB) technology were used as acid reactors and an expanded granular sludge bed (EGSB) reactor was used as a methane reactor. A conventional single-phase anaerobic reactor, working on EGSB technology was run in parallel to compare the performances of the two systems. Reactors were operated at different hydraulic retention times. The results from the study, which span over a period of 400 days, indicated that the two-phase system produces a higher quality of effluent in terms of color, COD and suspended solids than single-phase anaerobic treatment when operated under similar conditions. Alkalinity requirement of two-phase system was also observed to be lower than that of single-phase system which is important regarding design consideration.


2020 ◽  
Author(s):  
Gede H Cahyana

Telah dikembangkan reaktor anaerob kecepatan tinggi (high rate) yang merupakan modifikasi reaktor konvensional. Di antaranya berupa (bio)reaktor pertumbuhan tersuspensi (contoh: UASB, Upflow Anaerobic Sludge Blanket) dan reaktor pertumbuhan lekat (Fixed Bed atau Biofilter, Fluidized Bed, Expanded Bed, Rotating Biodisc dan Baffled Reactor). Kedua tipe reaktor di atas memiliki sejumlah kelebihan dan kekurangan. Untuk mengoptimalkan nilai positifnya (terutama untuk keperluan desain) maka reaktor tersebut, pada penelitian ini, disusun menjadi satu urutan yang disebut Reaktor Hibrid Anaerob (Rehan) yakni UASB di bawah dan AF di atasnya. Lebih lanjut, penelitian ini diharapkan dapat memberikan informasi tentang kinerja Rehan dalam mengolah air limbah (substrat) yang konsentrasi zat organiknya (COD) sangat tinggi dan suatu model matematika yang dapat mewakili reaktor tersebut.


1999 ◽  
Vol 40 (11-12) ◽  
pp. 67-75 ◽  
Author(s):  
Sigrun J. Jahren ◽  
Jukka A. Rintala ◽  
Hallvard Ødegaard

Thermomechanical pulping (TMP) whitewater was treated in thermophilic (55°C) anaerobic laboratory-scale reactors using three different reactor configurations. In all reactors up to 70% COD removals were achieved. The anaerobic hybrid reactor, composed of an upflow anaerobic sludge blanket (UASB) and a filter, gave degradation rates up to 10 kg COD/m3d at loading rates of 15 kg COD/m3d and hydraulic retention time (HRT) of 3.1 hours. The anaerobic multi-stage reactor, consisting of three compartments, each packed with granular sludge and carrier elements, gave degradation rates up to 9 kg COD/m3d at loading rates of 15-16 kg COD/m3d, and HRT down to 2.6 hours. Clogging and short circuiting eventually became a problem in the multi-stage reactor, probably caused by too high packing of the carriers. The anaerobic moving bed biofilm reactor performed similar to the other reactors at loading rates below 1.4 kg COD/m3d, which was the highest loading rate applied. The use of carriers in the anaerobic reactors allowed short HRT with good treatment efficiencies for TMP whitewater.


1997 ◽  
Vol 36 (6-7) ◽  
pp. 383-390 ◽  
Author(s):  
J. E. Teer ◽  
D. J. Leak ◽  
A. W. L. Dudeney ◽  
A. Narayanan ◽  
D. C. Stuckey

The presence of small amounts of iron (>0.013% Fe) in sand creates problems in the manufacture of high quality glass. Removal by hot sulphuric acid is possible, but creates environmental problems, and is costly. Hence organic acids such as oxalic have been investigated since they are effective in removing iron, and can be degraded anaerobically. The aim of this work was to identify key intermediates in the anaerobic degradation of oxalate in an upflow anaerobic sludge blanket reactor (UASB) which was removing iron from solution in the sulphide form, and to determine the bacterial species involved. 2-bromoethanesulfonic acid (BES) and molybdenum were selected as suitable inhibitors for methanogenic and sulphate reducing bacteria (SRB) respectively. 40mM molybdenum was used to inhibit the SRB in a reactor with a 12hr HRT. Total SRB inhibition took place in 20 hrs, with a complete breakthrough of influent sulphate. The lack of an immediate oxalate breakthrough confirmed Desulfovibrio vulgaris subspecies oxamicus was not the predominant oxalate utilising species. Nevertheless, high concentrations of molybdenum were found to inhibit oxalate utilising bacteria in granular reactors but not in suspended population reactors; this observation was puzzling, and at present cannot be explained. Based on the intermediates identified, it was postulated that oxalate was degraded to formate by an oxalate utilising bacteria such as Oxalobacter formigenes, and the formate used by the SRBs to reduce sulphate. Acetate, as a minor intermediate, existed primarily as a source of cell carbon for oxalate utilising bacteria. Methanogenic inhibition identified that 62% of the CH4 in the reactor operated at 37°C originated from hydrogenotrophic methanogenesis, whilst this figure was 80% at 20°C. Possible irreversible effects were recorded with hydrogenotrophic methanogens.


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