Microbial community of biological phosphorus removal process fed with municipal wastewater under different electron acceptor conditions

2006 ◽  
Vol 54 (1) ◽  
pp. 81-89 ◽  
Author(s):  
T. Shoji ◽  
T. Nittami ◽  
M. Onuki ◽  
H. Satoh ◽  
T. Mino

The microbial community in a biological phosphorus removal process under different electron acceptor conditions was estimated by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) assay and principal-component analysis (PCA). For this purpose, a lab-scale sequencing batch reactor (SBR) fed with municipal wastewater was operated under anaerobic–aerobic, anaerobic–anoxic–aerobic and anaerobic–anoxic conditions. The results of PCR-DGGE targeting the 16S rRNA gene indicated a significant shift in the microbial community with electron acceptor conditions. From the 16S rRNA-based PCA, the microbial shift implies that little oxygen supply caused the deterioration of aerobic bacteria, including aerobic polyphosphate-accumulating organisms (PAOs). Moreover, it also reflects the existence of nitrate-utilizing denitrifiers. On the other hand, although the band patterns of DGGE targeting a functional gene of denitrification (nirS) also showed the microbial shift, the result of PCA differed from that of 16S rRNA-based analysis. There is no conclusive proof that the bacteria represented as the dominant bands detected in the present study are denitrifying-PAOs so far, it should be worthwhile to identify the detected bacteria and to examine their traits as new denitrifying-PAO candidates.

1998 ◽  
Vol 37 (4-5) ◽  
pp. 481-484 ◽  
Author(s):  
Mamoru Kawaharasaki ◽  
Takahiro Kanagawa ◽  
Hideo Tanaka ◽  
Kazunori Nakamura

A 16S rRNA-targeted oligonucletide probe (MP2) specific for the phosphate-accumulating bacterium (PAB) M. phosphovorus was designed and applied to a sludge from an enhanced biological phosphorus removal (EBPR) process. Probes specific for defined phylogenetic groups and the polyphosphate staining dye, DAPI (4′, 6-diamidino-2-phenylindol dihydrochloride) were also used to analyze the activated sludge community. M. phosphovorus was about 3% of the total bacteria in the EBPR sludge used. Proteobacteria belonging to the beta subclass were the most abundant. Many coccoid bacteria similar to M. phosphovorus were stained with DAPI. The percentage of PABs detected by DAPI stain was about 9% of the total bacteria.


2002 ◽  
Vol 46 (4-5) ◽  
pp. 249-255 ◽  
Author(s):  
M. Valve ◽  
P. Rantanen ◽  
J. Kallio

Pilot-scale tests to enhance phosphorus removal with ferrous sulphate in a biological phosphorus and nitrogen removal process (modified UCT) for treating municipal wastewater were performed. The results indicated that Fe(II) competes with the BioP organisms and will inhibit the biological phosphorus removal process completely at doses exceeding 9 g m−3 of Fe(II). The goal of an effluent P level of 0.5 mg l−1 can be attained with 5 g m−3 of Fe(II). A consistent effluent concentration of 0.3 mg l−1 could not be achieved with this method. A centrifugation method to evaluate the dewatering properties of sludge was developed. Comparison of the settling and dewatering properties between activated sludge from the pilot plant and a full-scale simultaneous precipitation process indicated no consistent differences between them. The poor settling properties are due to the long sludge retention time needed by nitrification and not to the biological phosphorus removal process.


2021 ◽  
Author(s):  
Guanglei Qiu ◽  
Yingyu Law ◽  
Rogelio Zuniga-Montanez ◽  
Yang Lu ◽  
Samarpita Roy ◽  
...  

AbstractRecent research has shown enhanced biological phosphorus removal (EBPR) from municipal wastewater at warmer temperatures around 30°C to be stable in both laboratory-scale reactors and full-scale treatment plants. In the context of a changing climate, the feasibility of EBPR at even higher temperatures is of interest. We operated two lab-scale EBPR sequencing batch reactors with alternating anaerobic and aerobic phases for over 300 days at 30°C and 35°C, respectively, and followed the dynamics of the communities of phosphorus accumulating organisms (PAOs) and competing glycogen accumulating organisms (GAOs) using a combination of 16S rRNA gene metabarcoding, quantitative PCR and fluorescent in-situ hybridization analyses. Stable and nearly complete P removal was achieved at 30°C; similarly, long term P removal was stable at 35°C with effluent PO43−-P concentrations < 0.5 mg/L on half of all monitored days. Diverse and abundant Ca. Accumulibacter amplicon sequence variants were closely related to those found in temperate environments, suggesting that EBPR at this temperature does not require a highly specialized PAO community. The slow-feeding strategy used effectively limited the carbon uptake rates of GAOs, allowing PAOs to outcompete GAOs at both temperatures. Candidatus Competibacter was the main GAO, along with cluster III Defluviicoccus members. These organisms withstood the slow-feeding regime, suggesting that their bioenergetic characteristics of carbon uptake differ from those of their tetrad-forming relatives. This specific lineage of GAOs warrants further study to establish how complete P removal can be maintained. Comparative cycle studies at two temperatures for each reactor revealed higher activity of Ca. Accumulibacter when the temperature was increased from 30°C to 35°C, suggesting that the stress was a result of the higher carbon (and/or P) metabolic rates of PAOs and GAOs, the resultant carbon deficiency, and additional community competition. An increase in the TOC to PO43--P ratio (from 25:1 to 40:1) effectively eased the carbon deficiency and benefited the proliferation of PAOs. In general, the slow-feeding strategy and sufficiently high carbon input benefited a high and stable EBPR at elevated temperature and represent basic conditions for full-scale applications.


2019 ◽  
Author(s):  
Varun N. Srinivasan ◽  
Guangyu Li ◽  
Dongqi Wang ◽  
Nicholas B. Tooker ◽  
Zihan Dai ◽  
...  

AbstractCandidatusAccumulibacter phosphatis (CAP) and its sub-clades-level diversity has been associated and implicated in successful phosphorus removal performance in enhanced biological phosphorus removal (EBPR). Development of high-throughput untargeted methods to characterize clades of CAP in EBPR communities can enable a better understanding of Accumulibacter ecology at a higher-resolution beyond OTU-level in wastewater resource recovery facilities (WRRFs). In this study, for the first time, using integrated 16S rRNA gene sequencing, oligotyping and genome-resolved metagenomics, we were able to reveal clade-level differences in Accumulibacter communities and associate the differences with two different full-scale EBPR configurations. The results led to the identification and characterization of a distinct and dominant Accumulibacter oligotype - Oligotype 2 (belonging to Clade IIC) and its matching MAG (RC14) associated with side-stream EBPR configuration. We are also able to extract MAGs belonging to CAP clades IIB (RCAB4-2) and II (RC18) which did not have representative genomes before. This study demonstrates and validates the use of a high-throughput approach of oligotyping analysis of 16S rRNA gene sequences to elucidate CAP clade-level diversity. We also show the existence of a previously uncharacterized diversity of CAP clades in full-scale EBPR communities through extraction of MAGs, for the first time from full-scale facilities.


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