scholarly journals Stability and Performance of Xanthobacter autotrophicus GJ10 during 1,2-Dichloroethane Biodegradation

2006 ◽  
Vol 72 (6) ◽  
pp. 4411-4418 ◽  
Author(s):  
Ines I. R. Baptista ◽  
Ludmila G. Peeva ◽  
Ning-Yi Zhou ◽  
David J. Leak ◽  
Athanasios Mantalaris ◽  
...  
Keyword(s):  
Microbial Community ◽  
Dominant Species ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Experimental Period ◽  
Synthetic Wastewater ◽  
Stable Complex ◽  
Stirred Tank Bioreactor ◽  
Xanthobacter Autotrophicus ◽  
Active Population ◽  
Gradient Gel Electrophoresis

ABSTRACT A nucleic acid-based approach was used to investigate the dynamics of a microbial community dominated by Xanthobacter autotrophicus GJ10 in the degradation of synthetic wastewater containing 1,2-dichloroethane (DCE). This study was performed over a 140-day period in a nonsterile continuous stirred-tank bioreactor (CSTB) subjected to different operational regimens: nutrient-limiting conditions, baseline operation, and the introduction of glucose as a cosubstrate. The microbial community was analyzed by a combination of fluorescence in situ hybridization (FISH) and denaturing gradient gel electrophoresis (DGGE). Under nutrient-limiting conditions, DCE degradation was restricted, but this did not affect the dominance of strain GJ10, determined by FISH to comprise 85% of the active population. During baseline operation, DCE degradation improved significantly to over 99.5% and then remained constant throughout the subsequent experimental period. DGGE profiles revealed a stable, complex community, while FISH indicated that strain GJ10 remained the dominant species. During the addition of glucose as a cosubstrate, DGGE profiles showed a proliferation of other species in the CSTB. The percentage of strain GJ10 dropped to 8% of the active population in just 5 days, although this did not affect the DCE biodegradation performance. The return to baseline conditions was accompanied by the reestablishment of strain GJ10 as the dominant species, suggesting that this system responds robustly to external perturbations, both at the functional biodegradation level and at the individual strain level.

Study of microbial community of brewery-treating granular sludge by denaturing gradient gel electrophoresis of 16S rRNA gene

2001 ◽  
Vol 43 (1) ◽  
pp. 77-82 ◽  
Author(s):  
O.-C. Chan ◽  
W.-T. Liu ◽  
H. H. Fang
Keyword(s):  
Microbial Community ◽  
16S Rrna ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Rrna Gene ◽  
Related Sequence ◽  
Gradient Gel Electrophoresis

The microbial community structure of granular sludge from an upflow anaerobic sludge blanket (UASB) reactor treating brewery effluent was studied by denaturing gradient gel electrophoresis (DGGE). Twelve major bands were observed in the DGGE fingerprint for the Bacteria domain and four bands for the Archaea domain. Of the bacterial bands observed, six were successfully purified and sequenced. Among them, three were related to the gram-positive low G+C group, one to the Delta subclass of the Proteobacteria, one to the Gamma subclass, and one to the Cytophaga group with no close related sequence. The 16S rRNA sequences of the four archaeal bands were closely associated with Methanosaeta concilii and Methanobacterium formicum.

Microbial Community Analysis of Underground Drinking Water Using Denaturing Gradient Gel Electrophoresis and Flow Cytometry Technologies

2014 ◽  
Vol 700 ◽  
pp. 519-524 ◽  
Author(s):  
Jie Liu ◽  
Yan Li Ding ◽  
Mark Bartlam ◽  
Ying Ying Wang
Keyword(s):  
Drinking Water ◽  
Microbial Community ◽  
Rural Areas ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Poyang Lake ◽  
Removal Rate ◽  
Underground Water ◽  
Water Sources ◽  
Gradient Gel Electrophoresis ◽  
Bacteria And Fungi

Underground water is directly used as drinking water in most rural areas of developing countries due to limitations in infrastructure. As an important indicator of drinking water quality, however, microbial quality has been largely ignored for a long time. Microbial quality poses a great threat to the safety of underground drinking water, especially in rural areas. The current study compared microbial abundance and community structure of three different water sources, i.e. underground water, Poyang Lake and Hai River, combined with flow cytometry (FCM) and denaturing gradient gel electrophoresis (DGGE). FCM results showed that the bacterial concentration of underground water is the lowest (1.037×106cell/ml) of the three water sources, but still approximates that of the Poyang Lake. The removal rate of bacteria after filtration through a 0.45μm-pore-size filter is 98.16% in underground water. The removal rate for Poyang Lake and Hai River is much lower (i.e. 66.57% and 74.17% respectively). DGGE profiles demonstrated that the microbial community structure in underground water shares higher similarity to Poyang Lake (51.0% and 53.1% similarity for bacteria and fungi respectively) than Hai River. The microbial diversity index (i.e. Shannon-Weaver index) for bacteria and fungi are 2.906 and 2.847 respectively in underground water, which is lower than in Poyang Lake. The evenness (i.e. Simpson index) of groundwater was lowest among the three water sources tested. The results suggested that groundwater has a complex microbial community and hence it is critical to apply necessary hygienic barriers to remove microbes for the safety of underground drinking water.

Nutrients removal in hybrid fluidised bed bioreactors operated with aeration cycles

2007 ◽  
Vol 55 (8-9) ◽  
pp. 51-58 ◽  
Author(s):  
M.A. Martín Martín ◽  
L. López Enríquez ◽  
M. Fernández-Polanco ◽  
S. Villaverde ◽  
P.A. García-Encina
Keyword(s):  
Total Nitrogen ◽  
Industrial Wastewater ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Operating Conditions ◽  
Synthetic Wastewater ◽  
Fluidised Bed ◽  
Total N ◽  
Biological Communities ◽  
Gradient Gel Electrophoresis ◽  
Polymerase Chain

Two hybrid fluidised bed reactors filled with sepiolite and granular activated carbon (GAC) were operated with short cycled aeration for removing organic matter, total nitrogen and phosphorous, respectively. Both reactors were continuously operated with synthetic and/or industrial wastewater containing 350–500 mg COD/L, 110–130 mg NKT/L, 90–100 mg NH3-N/L and 12–15 mg P/L for 8 months. The reactor filled with sepiolite, treating only synthetic wastewater, removed COD, ammonia, total nitrogen and phosphorous up to 88, 91, 55 and 80% with a hydraulic retention time (HRT) of 10 h, respectively. These efficiencies correspond to removal rates of 0.95 kgCODm−3d−1 and 0.16 kg total N m−3d−1.The reactor filled with GAC was operated for 4 months with synthetic wastewater and 4 months with industrial wastewater, removing 98% of COD, 96% of ammonia, and 66% of total nitrogen, with an HRT of 13.6 h. No significant phosphorous removing activity was observed in this reactor. Microbial communities growing with both reactors were followed using polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) techniques. The microbial fingerprints, i.e. DGGE profiles, indicated that biological communities in both reactors were stable along the operational period even when the operating conditions were changed.

Characteristics of different fractions of microbial flocs and their role in membrane fouling

2011 ◽  
Vol 63 (2) ◽  
pp. 262-269 ◽  
Author(s):  
H. J. Lin ◽  
W. J. Gao ◽  
K. T. Leung ◽  
B. Q. Liao
Keyword(s):  
Microbial Community ◽  
Membrane Fouling ◽  
Extracellular Polymeric Substances ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Sludge Flocs ◽  
Microbial Flocs ◽  
Thermomechanical Pulping ◽  
Gradient Gel Electrophoresis ◽  
Sludge Cake ◽  
The Difference

Characteristics of different fractions (small flocs vs. large flocs) of sludge flocs from a submerged anaerobic membrane bioreactor treating thermomechanical pulping (TMP) whitewater were determined using various analytic techniques, including extraction and chemical analysis of extracellular polymeric substances (EPS), particle size analyzer, and polymer chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE). The results showed that the fraction of smaller flocs contained a higher level of bound EPS and had a higher fractal dimension as compared to the fraction of larger flocs. PCR-DGGE analysis indicated that there were significant differences in microbial community between the fraction of smaller flocs and large flocs. The microbial community of the smaller flocs was similar to that of the sludge cake layers, indicating the pioneering role of the microbial community in smaller flocs in membrane fouling. These findings provide a new insight in the difference of membrane fouling potential between smaller flocs and larger flocs fraction.

Spatial variation in microbial community structure, richness, and diversity in an alluvial aquifer

2012 ◽  
Vol 58 (9) ◽  
pp. 1135-1151 ◽  
Author(s):  
P.G. Medihala ◽  
J.R. Lawrence ◽  
G.D.W. Swerhone ◽  
D.R. Korber
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Spatial Variability ◽  
Microbial Communities ◽  
Microbial Community Structure ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Microbial Community Composition ◽  
Alluvial Aquifer ◽  
Gradient Gel Electrophoresis

Relatively little is known regarding the spatial variability of microbial communities in aquifers where well fouling is an issue. In this study 2 water wells were installed in an alluvial aquifer located adjacent to the North Saskatchewan River and an associated piezometer network developed to facilitate the study of microbial community structure, richness, and diversity. Carbon utilization data analysis revealed reduced microbial activity in waters collected close to the wells. Functional PCR and quantitative PCR analysis indicated spatial variability in the potential for iron-, sulphate-, and nitrate-reducing activity at all locations in the aquifer. Denaturing gradient gel electrophoresis analysis of aquifer water samples using principal components analyses indicated that the microbial community composition was spatially variable, and denaturing gradient gel electrophoresis sequence analysis revealed that bacteria belonging to the genera Acidovorax , Rhodobacter , and Sulfuricurvum were common throughout the aquifer. Shannon’s richness (H′) and Pielou’s evenness (J′) indices revealed a varied microbial diversity (H′ = 1.488–2.274) and an even distribution of microbial communities within the aquifer (J′ = 0.811–0.917). Overall, these analyses revealed that the aquifer’s microbial community varied spatially in terms of composition, richness, and metabolic activity. Such information may facilitate the diagnosis, prevention, and management of fouling.

Microbial community analysis in the autotrophic denitrification process using spent sulfidic caustic by denaturing gradient gel electrophoresis of PCR-amplified genes

2011 ◽  
Vol 63 (3) ◽  
pp. 475-483 ◽  
Author(s):  
J. -H. Lee ◽  
S. -M. Lee ◽  
G. -C. Choi ◽  
H. -S. Park ◽  
D. -H. Kang ◽  
...  
Keyword(s):  
Microbial Community ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Carbon Sources ◽  
Community Analysis ◽  
Microbial Community Analysis ◽  
Autotrophic Denitrification ◽  
High Concentration ◽  
Spent Sulfidic Caustic ◽  
Gradient Gel Electrophoresis ◽  
Sulfidic Caustic

Spent sulfidic caustic (SSC) produced from petrochemical plants contains a high concentration of hydrogen sulfide and alkalinity, and some almost non-biodegradable organic compounds such as benzene, toluene, ethylbenzene and xylenes (BTEX). SSC is mainly incinerated with auxiliary fuel, leading to secondary pollution problems. The reuse of this waste is becoming increasingly important from economic and environmental viewpoints. To denitrify wastewater with low COD/N ratio, additional carbon sources are required. Thus, autotrophic denitrification has attracted increasing attention. In this study, SSC was injected as an electron donor for sulfur-based autotrophic denitrification in the modified Ludzack-Ettinger (MLE) process. The efficiencies of nitrification, COD, and total nitrogen (TN) removal were evaluated with varying SSC dosage. Adequate SSC injection exhibited stable autotrophic denitrification. No BTEX were detected in the monitored BTEX concentrations of the effluent. To analyse the microbial community of the MLE process, PCR-DGGE based on 16 S rDNA with EUB primers, TD primers and nirK gene with nirK primers was performed in order to elucidate the application of the MLE process to SSC.

Start-up of bio-hydrogen production reactor seeded with sewage sludge and its microbial community analysis

2005 ◽  
Vol 52 (1-2) ◽  
pp. 115-121 ◽  
Author(s):  
M.L. Gong ◽  
N.Q. Ren ◽  
D.F. Xing
Keyword(s):  
Microbial Community ◽  
Sewage Sludge ◽  
Hydrogen Production ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Community Analysis ◽  
Microbial Community Analysis ◽  
Organic Loading Rate ◽  
Start Up ◽  
Gradient Gel Electrophoresis ◽  
Continuously Stirred Tank Reactor

Start-up of a continuously stirred tank reactor for bio-hydrogen production under different initial organic loading rate (OLR) of 3, 7 and 10 kgCOD/m3 d, respectively, was carried out with sewage sludge as inoculum. Molasses wastewater was used as substrate and hydraulic retention time was kept at 6 h. This study aimed to assess OLR on the formation of fermentation types and the structure of microbial communities during the start-up period. It was found that at an initial OLR of 7 kgCOD/m3 d and an initial biomass of 6.24 gVSS/L, an equilibrial microbial community of ethanol-type fermentation could be established within 30 days. The observed average specific hydrogen production rate was 276 mLH2/gVSS d, which was 40% higher than that of the one acclimated with 3 kgCOD/m3 d. Based on denaturing gradient gel electrophoresis profiles, significant microbial population shifts took place at the first 15 days, but a longer period up to 30 days was required to establish a microbial community with stable metabolic activity.

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