Hydrophilicity/hydrophobicity of anaerobic granular sludge surface and their causes: An in situ research

2016 ◽  
Vol 220 ◽  
pp. 117-123 ◽  
Author(s):  
Yiyu Li ◽  
Ping Zheng ◽  
Meng Zhang ◽  
Zhuo Zeng ◽  
Zhiyao Wang ◽  
...  
Keyword(s):  
Granular Sludge ◽  
Anaerobic Granular Sludge

Microbial community evaluation of anaerobic granular sludge from a hybrid reactor treating pentachlorophenol by using fluorescence in situ hybridization

2003 ◽  
Vol 48 (6) ◽  
pp. 65-73 ◽  
Author(s):  
M.A.P. Montenegro ◽  
J.C. Araujo ◽  
R.F. Vazoller
Keyword(s):  
In Situ Hybridization ◽  
Microbial Community ◽  
Methanogenic Archaea ◽  
Granular Sludge ◽  
Hybrid Reactor ◽  
Anaerobic Granular Sludge ◽  
Bacterial Cells ◽  
Before And After ◽  
Community Evaluation

We used in situ hybridization with fluorescently labeled rRNA-targeted oligonucleotide probes concurrently with microscopic examinations and methane measurements to characterize the microbial community of an anaerobic hybrid reactor treating pentachlorophenol (PCP) with a mixture of fatty acids (propionic, butyric, acetic and lactic) and methanol. Archaeal cells detected with probe ARC915 prevailed in anaerobic granular sludge without and with the addition of PCP in a range of 2.0 to 21.0 mg/L to the reactor. This group accounted for 81 and 90% of the DAPI-stained cells before and after the addition of 21 mg/L of PCP, respectively. In these conditions, cells detected with the Methanosarcinales specific probe (MSMX860) were the only methanogenic Archaea found and accounted for 59 to 87.6% of the DAPI-stained cells. No cells were detected by the Methanomicrobiales (MG1200), Methanobacteriaceae (MB1174) and Methanococcaceae (MC1109) specific probes. Bacterial cells detected with probe EUB338 were found in very low numbers, which ranged from 5.7 to 1.0% of the DAPI-stained cells. This finding agrees with the scanning electron microscope examinations, in which cells morphologically resembling Methanosaeta and Methanosarcina were predominantly observed in the granular sludge. Results contributed to the investigation of the importance of the methanogens during PCP degradation.

Stimulation of methanol degradation in UASB reactors: In situ versus pre-loading cobalt on anaerobic granular sludge

2004 ◽  
Vol 87 (7) ◽  
pp. 897-904 ◽  
Author(s):  
Marcel H. Zandvoort ◽  
Jarno Gieteling ◽  
Gatze Lettinga ◽  
Piet N.L. Lens
Keyword(s):  
Granular Sludge ◽  
Anaerobic Granular Sludge ◽  
Uasb Reactors ◽  
Stimulation Of

Molecular ecology of anaerobic granular sludge grown at different conditions

2003 ◽  
Vol 48 (6) ◽  
pp. 57-64 ◽  
Author(s):  
E. Díaz ◽  
R. Amils ◽  
J.L. Sanz
Keyword(s):  
Inner Core ◽  
Molecular Ecology ◽  
Methanogenic Archaea ◽  
Granular Sludge ◽  
Anaerobic Granular Sludge ◽  
Bacterial Cells ◽  
High Concentration ◽  
Qualitative And Quantitative ◽  
Low Concentrations

Qualitative and quantitative diversity of microorganisms present in anaerobic granular sludges fed with different substrates, as well as the structure of these granules have been studied using fluorescent 16S rRNA-targeted in situ hybridization and electron microscopy. The granules showed a multi-layered structure, in which both densely packed and loose micro-colonies, channels and holes could be observed. Only bacteria were found in the outer shell of the granules, while both archaea and bacteria were detected in the inner core. Although high cell density was found in the granules (more than 1011 cells/gram, determined by DAPI-stain) only a low percentage of cells was able to hybridize with the rRNA-targeted probes. Significant quantitative and qualitative differences were observed in the composition of granules fed with different substrates (formate, acetate at high and low concentrations, propionate, sucrose, starch and peptone). Bacterial cells were mostly gram-positives. Active proteobacteria were scarce in the granules exposed to VFA. Syntrophobacteria became dominant in the propionate-grown biomass. Concerning methanogenic archaea, Methanosaeta was the predominant species using complex substrates or low acetate concentration fed granules, while Methanosarcina and members of Methanobacteriales were predominant in the granules grown at high concentration of acetate or formate, respectively. Other Methanomicrobiales and Methanococcales, have been detected in the anaerobic granular sludge in the conditions used in this work.

Quantification of methanogen cell density in anaerobic granular sludge consortia by fluorescence in-situ hybridization

2000 ◽  
Vol 42 (3-4) ◽  
pp. 77-82 ◽  
Author(s):  
T. Tagawa ◽  
K. Syutsubo ◽  
Y. Sekiguchil ◽  
A. Ohashi ◽  
H. Harada
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Cell Density ◽  
Methane Production ◽  
Granular Sludge ◽  
Fish Analysis ◽  
Anaerobic Granular Sludge ◽  
Strongly Correlated ◽  
Production Activity

Whole cell fluorescence in-situ hybridization (FISH) with 16S rRNA targeted oligonucleotides was applied to reveal the microbial ecological structure of UASB-grown granular sludge. The FISH analysis indicated that the members of the domain Archaea accounted for 28 to 53% of the total cells in various granular sludge sources, while Methanosaeta and Methanobacteriaceae cells accounted for 13 to 38%, and 4 to 27%, respectively. Methanosaeta cell density and Methanobacteriaceae cell density were strongly correlated, respectively, with acetate-utilizing methane production activity and with hydrogen-utilizing methane production activity.

scholarly journals Distribution, Localization, and Phylogeny of Abundant Populations of Crenarchaeota in Anaerobic Granular Sludge

2005 ◽  
Vol 71 (11) ◽  
pp. 7523-7527 ◽  
Author(s):  
Gavin Collins ◽  
Leanne O'Connor ◽  
Thérèse Mahony ◽  
Armin Gieseke ◽  
Dirk de Beer ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Gene Cloning ◽  
Fluorescent In Situ Hybridization ◽  
Close Association ◽  
Granular Sludge ◽  
Rrna Gene ◽  
Anaerobic Granular Sludge ◽  
Substrate Uptake

ABSTRACT Eight anaerobic granular sludges were surveyed for Crenarchaeota using rRNA gene cloning. Microbial arrangement and substrate uptake patterns were elucidated by fluorescent in situ hybridization and beta imaging. Group 1.3 Crenarchaeota represented up to 50% of Archaea and 25% of the total microbiota in five sludges. Crenarchaeota were localized in close association with methanogenic Archaea.

Toxicity of Sulfite and Cadmium to Anaerobic Granular Sludge

1994 ◽  
Vol 29 (4) ◽  
pp. 581-598
Author(s):  
C.F. Shew ◽  
N. Kosaric
Keyword(s):  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Shock Load ◽  
Anaerobic Sludge ◽  
Anaerobic Granular Sludge ◽  
Scanning Electron Micrographs ◽  
Bacterial Growth Rate ◽  
Digestion Rate ◽  
Sulfate Reducing ◽  
Load Conditions

Abstract Toxicity of sulfite (Na2SO3) and cadmium (CdCl2) ions to anaerobic granular sludge was investigated in 1.2 litre bench-scale upflow anaerobic sludge blanket (UASB) reactors during process acclimation and shock load conditions. Minimal sulfite toxicity was observed under gradual and shock load conditions at sulfite concentrations of up to 1000 mg S/L if proper acclimation was allowed to occur. No long-term toxic effects were observed although the COD digestion rate was temporarily inhibited by shock load of sulfite. Scanning electron micrographs indicated that more sulfate-reducing bacteria were present in the granules developed in the reactors with sulfite supplement although rod-shaped Methanosaeta-like bacteria were still dominant. High bacterial growth rate was observed in the reactors which were supplied with the feed containing sulfite. The COD digestion rate was inhibited at a cadmium loading rate of 2.4 g Cd per day under both acclimation and shock load conditions. Acclimation did not seem to improve the bacteria to tolerate the toxicity of cadmium. The concentration of free cadmium was very low in the reactors under normal conditions, but increased rapidly when the COD digestion in the reactors ceased. The bacteria could not be reactivated after inhibited by cadmium. When reactors were operated at low specific COD loading rates, more inorganic precipitates were formed inside the granules which consequently settled faster.

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