The comparison of the diversity of activated sludge plants

1998 ◽  
Vol 37 (4-5) ◽  
pp. 71-78 ◽  
Author(s):  
Thomas P. Curtis ◽  
Noel G. Craine
Keyword(s):  
Cluster Analysis ◽  
Activated Sludge ◽  
Treatment Process ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Optimal Sampling ◽  
Bacterial Populations ◽  
Large Numbers ◽  
Probable Presence ◽  
Gradient Gel Electrophoresis ◽  
Sampling Regime

The explicit engineering of bacterial populations requires that we know which organisms perform which tasks. The comparison of the bacterial diversity of activated sludge plants may give important information about the functions of different bacteria. This difficult task may be made easier by the use of technologies based on 16S rRNA based techniques. In this study we have used denaturing gradient gel electrophoresis (DGGE) to determine the optimal sampling regime for comparative studies and used cluster analysis to show how plants may be quantitatively compared. We sought evidence of spatial, diurnal and intrasample variation in a number of sites. No evidence for variation was found in the plants studied and we concluded that a single sample of an activated sludge plant was sufficient for a plant to plant comparison. The cluster analysis was able to distinguish between plants, though further work is required to find the most appropriate basis for such comparisons. We found organisms from raw sewage in the mixed liquor samples, these organisms may have no functional significance in the treatment process and thus complicate plant to plant comparisons as will the probable presence of heteroduplex rDNA products. Nevertheless we believe that these drawbacks do not outweigh the advantages of being able to take and compare relatively large numbers of samples.

Are some putative glycogen accumulating organisms (GAO) in anaerobic : aerobic activated sludge systems members of the α-Proteobacteria?

Microbiology ◽  
2004 ◽  
Vol 150 (7) ◽  
pp. 2267-2275 ◽  
Author(s):  
Michael Beer ◽  
Yun H. Kong ◽  
Robert J. Seviour
Keyword(s):  
Activated Sludge ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Bacterial Populations ◽  
Removal Capacity ◽  
Large Numbers ◽  
Gradient Gel Electrophoresis ◽  
Polyphosphate Accumulating Organisms

Activated sludge plants designed to remove phosphorus microbiologically often perform unreliably. One suggestion is that the polyphosphate-accumulating organisms (PAO) are out-competed for substrates by another group of bacteria, the glycogen-accumulating organisms (GAO) in the anaerobic zones of these processes. This study used fluorescence in situ hybridization (FISH) and denaturing gradient gel electrophoresis (DGGE) to analyse the communities from laboratory-scale anaerobic : aerobic sequencing batch reactors. Members of the genus Sphingomonas in the α-Proteobacteria were present in large numbers in communities with poor phosphorus removal capacity where the biomass had a high glycogen content. Their ability to store poly-β-hydroxyalkanoates anaerobically, but not aerobically, and not accumulate polyphosphate aerobically is consistent with these organisms behaving as GAO there. No evidence was found to support an important role for the γ-Proteobacteria as possible GAO in these communities, although these bacterial populations have been considered in other studies to act as possible competitors for the PAO.

scholarly journals Molecular methods for exploring the intestinal ecosystem

2002 ◽  
Vol 87 (S2) ◽  
pp. S199-S201 ◽  
Author(s):  
G. W. Tannock
Keyword(s):  
Intestinal Microflora ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Molecular Methods ◽  
Bacterial Populations ◽  
Disease States ◽  
Large Numbers ◽  
Gradient Gel Electrophoresis ◽  
Health And Disease ◽  
Polymerase Chain

Molecular methods have provided renewed impetus for the analysis of the composition of the intestinal microflora in health and disease. The polymerase chain reaction coupled with denaturing gradient gel electrophoresis provides a method whereby the bacterial communities in large numbers of samples can be compared efficiently and effectively. Altered bacterial populations associated with disease states can then be targeted for further investigation. In the long-term, an ‘abnormal microflora’ might be rectified by the use of probiotics or prebiotics.

Integration of nitrification and denitrification by combining anoxic and aerobic conditions in a membrane bioreactor

2010 ◽  
Vol 62 (11) ◽  
pp. 2590-2598 ◽  
Author(s):  
Jianfeng Li ◽  
Fenglin Yang ◽  
Dieudonné-Guy Ohandja ◽  
Fook-Sin Wong
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Membrane Bioreactor ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Biomass Concentration ◽  
Morphological Properties ◽  
Utilization Rate ◽  
Gradient Gel Electrophoresis ◽  
Microbial Characterization ◽  
Nitrification And Denitrification

A membrane bioreactor (MBR) was developed to achieve nitrogen removal by combining nitrification and denitrification conditions in one reactor. The activated sludge was alternated between aerobic and anoxic conditions using peristaltic pump. The biomass concentration and floc morphological properties were observed to be similar in anoxic and aerobic compartments. However, the homogeneous properties of the activated sludge did not lead to the failure of oxygen gradient formation in the reactor. Due to the position of the air diffuser, an anoxic compartment at the bottom and an aerobic compartment in the upper part of the reactor were formed after 40 days. The average total nitrogen (TN) removal efficiency was then observed to increase to 77%. The microbial characterization using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis, as well as the specific nitrogen utilization rate measurements, indicated that the nitrogen removal in the reactor occurred via nitrification and denitrification processes.

Enhancing nitrogen removal efficiency and reducing nitrate liquor recirculation ratio by improving simultaneous nitrification and denitrification in integrated fixed-film activated sludge (IFAS) process

2015 ◽  
Vol 73 (4) ◽  
pp. 827-834 ◽  
Author(s):  
Yang Bai ◽  
Yaobin Zhang ◽  
Xie Quan ◽  
Shuo Chen
Keyword(s):  
Activated Sludge ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Electricity Consumption ◽  
Simultaneous Nitrification And Denitrification ◽  
Recirculation Flow ◽  
Fixed Film ◽  
Gradient Gel Electrophoresis ◽  
Nitrification And Denitrification

An integrated fixed-film activated sludge (IFAS) process (G1) and an activated sludge anoxic–oxic process (G2) were operated at nitrate liquor recirculation ratio (R) of 100, 200 and 300% to investigate the feasibility of enhancing nitrogen removal efficiency (RTN) and reducing R by improving simultaneous nitrification and denitrification (SND) in the IFAS process. The results showed that the effluent NH4+-N and total nitrogen (TN) of G1 at R of 200% were less than 1.5 and 14.5 mg/L, satisfying the Chinese discharge standard (NH4+-N < 5 mg/L; TN < 15 mg/L). However, the effluent NH4+-N and TN of G2 at R of 300% were higher than 8.5 and 15.3 mg/L. It indicated that better RTN could be achieved at a lower R in the IFAS process. The polymerase chain reaction–denaturing gradient gel electrophoresis results implied that nitrifiers and denitrifiers co-existed in one microbial community, facilitating the occurrence of SND in the aerobic reactor of G1, and the contribution of SND to TN removal efficiency ranged 15–19%, which was the main reason that the RTN was improved in the IFAS process. Therefore, the IFAS process was an effective method for improving RTN and reducing R. In practical application, this advantage of the IFAS process can decrease the electricity consumption for nitrate liquor recirculation flow, thereby saving operational costs.

Degradation of Nonylphenol Polyethoxylates and its Microflora Structure in an Anoxic-Oxic Activated Sludge Process

2012 ◽  
Vol 610-613 ◽  
pp. 331-336
Author(s):  
Yuan Hua Xie ◽  
Tong Zhu ◽  
Xiao Jiang Liu ◽  
Hui Liu ◽  
Jin Han
Keyword(s):  
In Situ Hybridization ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Gel Electrophoresis ◽  
Loading Rate ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Oxygen Demand ◽  
Activated Sludge Process ◽  
Gradient Gel Electrophoresis

An anoxic-oxic activated sludge process (AOASP) was carried out to degrade nonylphenol polyethoxylates (NPEOs). The carbon source in influent was replaced stepwise by a mixture of nonylphenol decaethoxylate (M-NP10EO). The 2nd-derivative UV-spectrometry was applied to determine the total amount of M-NP10EO in water samples. Chemical oxygen demand (COD) removal efficiency achieves about 85% under the highest M-NP10EO loading rate, and M-NP10EO removal efficiency is about 80%. Denaturing gradient gel electrophoresis (DGGE) results of activated sludges show that the microbe species decrease but gradually stabilize with the increase of M-NP10EO concentration in influent. Fluorescence in situ hybridization (FISH) results of activated sludges showe that the dominant microflora under the highest M-NP10EO loading rate is β-Proteobacteria (35%), followed by α-Proteobacteria (15%), γ-Proteobacteria (5%) and Actinobateria (4%).

Analysis of Bacterial Communities in A2O Membrane Bioreactor Treating Oily Wastewater

2013 ◽  
Vol 641-642 ◽  
pp. 87-91 ◽  
Author(s):  
Zheng Hua Duan ◽  
Liu Ming Pan ◽  
Hua Wang ◽  
Ning Tao Li
Keyword(s):  
Activated Sludge ◽  
Bacterial Communities ◽  
Membrane Bioreactor ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Membrane Separation ◽  
Diversity Index ◽  
Oily Wastewater ◽  
Wastewater Purification ◽  
Gradient Gel Electrophoresis ◽  
Dominant Bacteria

To improve the efficiency of oily wastewater purification, a laboratory-scale anaerobic/anoxic/aerobic (A2O) membrane bioreactor was designed to treat the oily wastewater based on the conventional A2O activated sludge process and membrane separation technology, and the variation of bacterial community structure in the activated sludge of key reactors were investigated by PCR-DGGE (denaturing gradient gel electrophoresis). The result of Shannon diversity index comparing indicated that MBR seemed to be more constant than the A/0 system. Four sensitive dominant bacteria were verified in the treatment of oily wastewater. They were Uncultured Comamonadaceae bacterium, Hydrogenophaga sp., uncultured beta proteobacterium, and uncultured Thiobacillus sp. It suggested that PCR-DGGE can be used as an effective supplementary method for verifying cultural dominant microorganisms in activated sludge of oily wastewater.

Decolorization and degradation of cationic red X-GRL by upflow blanket filter

2013 ◽  
Vol 67 (5) ◽  
pp. 976-982 ◽  
Author(s):  
Bin Qiu ◽  
Yan Dang ◽  
Xiang Cheng ◽  
Dezhi Sun
Keyword(s):  
Bacterial Community ◽  
Activated Sludge ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Stable State ◽  
Oxygen Demand ◽  
Dye Wastewater ◽  
Dominant Group ◽  
Chain Reaction ◽  
Gradient Gel Electrophoresis ◽  
Polymerase Chain

An anaerobic upflow blanket filter (UBF) was employed for the treatment of dye wastewater containing cationic red X-GRL (X-GRL) in this study. The bacterial community in the UBF at its stable state was investigated by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The results showed that all color and the majority of chemical oxygen demand (COD) (92–74%) can be removed as the dye load increased from 33 to 134 g/(m3 d). The removal of color and COD were mostly attributed to the anaerobic activated sludge in the reactor. According to the DGGE fingerprints, the bacterial community in the biofilm was more diverse than that in the activated sludge. The bacterial diversity of the activated sludge and the bioflim both decreased with the dye load increasing. The dominant group was found to be phyla proteobacteria including β-proteobacteria, γ-proteobacteria, δ-proteobacteria and ɛ-proteobacteria, suggesting that these microbes might play an important role in X-GRL decolorization and degradation.

scholarly journals Design and Evaluation of PCR Primers for Analysis of Bacterial Populations in Wine by Denaturing Gradient Gel Electrophoresis

2003 ◽  
Vol 69 (11) ◽  
pp. 6801-6807 ◽  
Author(s):  
Isabel Lopez ◽  
Fernanda Ruiz-Larrea ◽  
Luca Cocolin ◽  
Erica Orr ◽  
Trevor Phister ◽  
...  
Keyword(s):  
Lactic Acid ◽  
16S Rdna ◽  
Gel Electrophoresis ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Bacterial Species ◽  
Pcr Primers ◽  
Fungal Species ◽  
Bacterial Populations ◽  
Gradient Gel Electrophoresis ◽  
Primer Sets

ABSTRACT Denaturing gradient gel electrophoresis (DGGE) of PCR-amplified ribosomal DNA (rDNA) is routinely used to compare levels of diversity of microbial communities and to monitor population dynamics. While using PCR-DGGE to examine the bacteria in wine fermentations, we noted that several commonly used PCR primers for amplifying bacterial 16S rDNA also coamplified yeast, fungal, or plant DNA present in samples. Unfortunately, amplification of nonbacterial DNA can result in a masking of bacterial populations in DGGE profiles. To surmount this problem, we developed two new primer sets for specific amplification of bacterial 16S rDNA in wine fermentation samples without amplification of eukaryotic DNA. One primer set, termed WLAB1 and WLAB2, amplified lactic acid bacteria, while another, termed WBAC1 and WBAC2, amplified both lactic acid bacterial and acetic acid bacterial populations found in wine. Primer specificity and efficacy were examined with DNA isolated from numerous bacterial, yeast, and fungal species commonly found in wine and must samples. Importantly, both primer sets effectively distinguished bacterial species in wine containing mixtures of yeast and bacteria.

scholarly journals Molecular Detection, Isolation, and Physiological Characterization of Functionally Dominant Phenol-Degrading Bacteria in Activated Sludge

1998 ◽  
Vol 64 (11) ◽  
pp. 4396-4402 ◽  
Author(s):  
Kazuya Watanabe ◽  
Maki Teramoto ◽  
Hiroyuki Futamata ◽  
Shigeaki Harayama
Keyword(s):  
Activated Sludge ◽  
Chemostat Culture ◽  
Nucleotide Sequences ◽  
Pcr Analysis ◽  
Bacterial Populations ◽  
Direct Plating ◽  
Physiological Characterization ◽  
Degrading Bacteria ◽  
Culture Enrichment ◽  
Gradient Gel Electrophoresis

ABSTRACT DNA was isolated from phenol-digesting activated sludge, and partial fragments of the 16S ribosomal DNA (rDNA) and the gene encoding the largest subunit of multicomponent phenol hydroxylase (LmPH) were amplified by PCR. An analysis of the amplified fragments by temperature gradient gel electrophoresis (TGGE) demonstrated that two major 16S rDNA bands (bands R2 and R3) and two major LmPH gene bands (bands P2 and P3) appeared after the activated sludge became acclimated to phenol. The nucleotide sequences of these major bands were determined. In parallel, bacteria were isolated from the activated sludge by direct plating or by plating after enrichment either in batch cultures or in a chemostat culture. The bacteria isolated were classified into 27 distinct groups by a repetitive extragenic palindromic sequence PCR analysis. The partial nucleotide sequences of 16S rDNAs and LmPH genes of members of these 27 groups were then determined. A comparison of these nucleotide sequences with the sequences of the major TGGE bands indicated that the major bacterial populations, R2 and R3, possessed major LmPH genes P2 and P3, respectively. The dominant populations could be isolated either by direct plating or by chemostat culture enrichment but not by batch culture enrichment. One of the dominant strains (R3) which contained a novel type of LmPH (P3), was closely related toValivorax paradoxus, and the result of a kinetic analysis of its phenol-oxygenating activity suggested that this strain was the principal phenol digester in the activated sludge.

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