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Páez-Watson T, Tomás-Martínez S, de Wit R, Keisham S, Tateno H, van Loosdrecht MCM, Lin Y. Sweet Secrets: Exploring Novel Glycans and Glycoconjugates in the Extracellular Polymeric Substances of " Candidatus Accumulibacter". ACS ES&T WATER 2024; 4:3391-3399. [PMID: 39144681 PMCID: PMC11320575 DOI: 10.1021/acsestwater.4c00247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 06/20/2024] [Accepted: 06/21/2024] [Indexed: 08/16/2024]
Abstract
Biological wastewater treatment relies on microorganisms that grow as flocs, biofilms, or granules for efficient separation of biomass from cleaned water. This biofilm structure emerges from the interactions between microbes that produce, and are embedded in, extracellular polymeric substances (EPS). The true composition and structure of the EPS responsible for dense biofilm formation are still obscure. We conducted a bottom-up approach utilizing advanced glycomic techniques to explore the glycan diversity in the EPS from a highly enriched "Candidatus Accumulibacter" granular sludge. Rare novel sugar monomers such as N-Acetylquinovosamine (QuiNAc) and 2-O-Methylrhamnose (2-OMe-Rha) were identified to be present in the EPS of both enrichments. Further, a high diversity in the glycoprotein structures of said EPS was identified by means of lectin based microarrays. We explored the genetic potential of "Ca. Accumulibacter" high quality metagenome assembled genomes (MAGs) to showcase the shortcoming of top-down bioinformatics based approaches at predicting EPS composition and structure, especially when dealing with glycans and glycoconjugates. This work suggests that more bottom-up research is necessary to understand the composition and complex structure of EPS in biofilms since genome based inference cannot directly predict glycan structures and glycoconjugate diversity.
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Affiliation(s)
- Timothy Páez-Watson
- Department
of Biotechnology, Delft University of Technology, Van der Maasweg 9, Delft 2629 HZ, The Netherlands
| | - Sergio Tomás-Martínez
- Department
of Biotechnology, Delft University of Technology, Van der Maasweg 9, Delft 2629 HZ, The Netherlands
| | - Roeland de Wit
- Department
of Biotechnology, Delft University of Technology, Van der Maasweg 9, Delft 2629 HZ, The Netherlands
| | - Sunanda Keisham
- Cellular
and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology
(AIST), Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Hiroaki Tateno
- Cellular
and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology
(AIST), Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Mark C. M. van Loosdrecht
- Department
of Biotechnology, Delft University of Technology, Van der Maasweg 9, Delft 2629 HZ, The Netherlands
| | - Yuemei Lin
- Department
of Biotechnology, Delft University of Technology, Van der Maasweg 9, Delft 2629 HZ, The Netherlands
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Hong Y, Cheng H, Huangfu X, Li L, He Q. Inhibition of phosphorus removal performance in activated sludge by Fe(III) exposure: transitions in dominant metabolic pathways. Front Microbiol 2024; 15:1424938. [PMID: 38933032 PMCID: PMC11201142 DOI: 10.3389/fmicb.2024.1424938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Accepted: 05/20/2024] [Indexed: 06/28/2024] Open
Abstract
Introduction Simultaneous chemical phosphorus removal process using iron salts (Fe(III)) has been widely utilized in wastewater treatment to meet increasingly stringent discharge standards. However, the inhibitory effect of Fe(III) on the biological phosphorus removal system remains a topic of debate, with its precise mechanism yet to be fully understood. Methods Batch and long-term exposure experiments were conducted in six sequencing batch reactors (SBRs) operating for 155 days. Synthetic wastewater containing various Fe/P ratios (i.e., Fe/P = 1, 1.2, 1.5, 1.8, and 2) was slowly poured into the SBRs during the experimental period to assess the effects of acute and chronic Fe(III) exposure on polyphosphate-accumulating organism (PAO) growth and phosphorus metabolism. Results Experimental results revealed that prolonged Fe(III) exposure induced a transition in the dominant phosphorus removal mechanism within activated sludge, resulting in a diminished availability of phosphorus for bio-metabolism. In Fe(III)-treated groups, intracellular phosphorus storage ranged from 3.11 to 7.67 mg/g VSS, representing only 26.01 to 64.13% of the control. Although the abundance of widely reported PAOs (Candidatus Accumulibacter) was 30.15% in the experimental group, phosphorus release and uptake were strongly inhibited by high dosage of Fe(III). Furthermore, the abundance of functional genes associated with key enzymes in the glycogen metabolism pathway increased while those related to the polyphosphate metabolism pathway decreased under chronic Fe(III) stress. Discussion These findings collectively suggest that the energy generated from polyhydroxyalkanoates oxidation in PAOs primarily facilitated glycogen metabolism rather than promoting phosphorus uptake. Consequently, the dominant metabolic pathway of communities shifted from polyphosphate-accumulating metabolism to glycogen-accumulating metabolism as the major contributor to the decreased biological phosphorus removal performance.
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Affiliation(s)
| | | | | | - Lin Li
- Key Laboratory of the Three Gorges Reservoir Region’s Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing, China
| | - Qiang He
- Key Laboratory of the Three Gorges Reservoir Region’s Eco-Environment, Ministry of Education, College of Environment and Ecology, Chongqing University, Chongqing, China
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Nie J, Wang X, Sun P, Yu D, Yu Z, Qiu Y, Zhao J. Inadvertently enriched cyanobacteria prompted bacterial phosphorus uptake without aeration in a conventional anaerobic/oxic reactor. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 927:172313. [PMID: 38593871 DOI: 10.1016/j.scitotenv.2024.172313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 03/30/2024] [Accepted: 04/06/2024] [Indexed: 04/11/2024]
Abstract
The enhanced biological phosphorus removal (EBPR) process requires alternate anaerobic and aerobic conditions, which are regulated respectively by aeration off and on. Recently, in an ordinary EBPR reactor, an abnormal orthophosphate concentration (PO43--P) decline in the anaerobic stage (namely non-aerated phosphorus uptake) aroused attention. It was not occasionally but occurred in each cycle and lasted for 101 d and shared about 16.63 % in the total P uptake amount. After excluding bio-mineralization and surface re-aeration, indoor light conditions (180 to 260 lx) inducing non-aerated P uptake were confirmed. High-throughput sequencing analysis revealed that cyanobacteria could produce oxygen via photosynthesis and were inhabited inside wall biofilm. The cyanobacteria (Pantalinema and Leptolyngbya ANT.L52.2) were incubated in a feeding transparent silicone hose, entered the reactor along with influent, and outcompeted Chlorophyta, which existed in the inoculum. Eventually, this work deciphered the reason for non-aerated phosphorus uptake and indicated its potential application in reducing CO2 emissions and energy consumption via the cooperation of microalgal-bacterial and biofilm-sludge.
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Affiliation(s)
- Jiaxiang Nie
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, China
| | - Xiaoxia Wang
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, China
| | - Peng Sun
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, China
| | - Deshuang Yu
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, China
| | - Zhengda Yu
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, China
| | - Yanling Qiu
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, China
| | - Ji Zhao
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, China.
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Wang R, Lou J, Cai J. Strategies to attenuate ciprofloxacin inhibition on enhanced biological phosphorus removal from wastewater and its recoverability. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 354:120456. [PMID: 38412731 DOI: 10.1016/j.jenvman.2024.120456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 01/22/2024] [Accepted: 02/20/2024] [Indexed: 02/29/2024]
Abstract
The inhibiting effects of ciprofloxacin (CIP) on enhanced biological phosphorus removal (EBPR) were investigated with no change in reactor operation and with increased aeration rate and sludge retention time (SRT) to explore inhibition-alleviating solutions. Additionally, performance recoverability was evaluated. The results showed that the phosphorus removal efficiency in the presence of 0.002-0.092 mg/L CIP for 7 days was only 12.5%. Increasing the aeration rate relieved inhibition (33.5% phosphorus removal efficiency on Day 7), and increasing SRT slowed EBPR performance deterioration. The EBPR performance recovered from CIP inhibition and increases in the aeration rate and SRT resulted in different recovery phenomena. The maximum PO43--P release rate continued to decrease in the first 2 days of the recovery stage and then gradually increased. However, the maximum PO43--P uptake rate immediately increased at different rates among reactors, which might be attributed to variations in the microbial community structure, decreased poly-P content, and enhanced abundances of ABC transporters and quorum sensing. It was found that some microorganisms associated with phosphorus removal were more tolerant to CIP than glycogen accumulating organisms. Moreover, the increased relative abundance of the qepA gene indicated that the microorganisms in the EBPR system had strong antibiotic resistance capacity. The bacterial community structure was significantly affected by CIP and could not recover to the initial structure. The results help to provide technical support for the operation of the EBPR process in the presence of CIP and to increase the understanding of system recoverability.
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Affiliation(s)
- Ruyi Wang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China.
| | - Juqing Lou
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China.
| | - Jing Cai
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China.
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Zhao Y, Zhu Z, Chen X, Li Y. Discovery of a novel potential polyphosphate accumulating organism without denitrifying phosphorus uptake function in an enhanced biological phosphorus removal process. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:168952. [PMID: 38043807 DOI: 10.1016/j.scitotenv.2023.168952] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Revised: 11/14/2023] [Accepted: 11/25/2023] [Indexed: 12/05/2023]
Abstract
Enhanced biological phosphorus removal (EBPR) is an effective process for phosphorus removal from wastewater. In this study, two lab-scale sequencing batch reactors (SBR) were used to perform EBPR process, in which genus Propioniciclava was unexpectedly accumulated and its relative abundance was over 70 %. A series of tests were conducted to explore the role of Propioniciclava in the two EBPR systems. The two systems performed steadily throughout the study, and the phosphorus removal efficiencies were 96.6 % and 93.5 % for SBR1 and SBR2, respectively. The stoichiometric analysis related to polyphosphate accumulating organisms (PAOs) indicated that polyphosphate accumulating metabolism (PAM) was achieved in the anaerobic phase. It appeared that the Propioniciclava-dominated systems could not perform denitrifying phosphorus removal. Instead, phosphorus was released under anoxic conditions without carbon sources. According to the genomic information from Integrated Microbial Genomes (IMG) database, Propioniciclava owns ppk1, ppk2 and ppx genes that are associated with phosphorus release and uptake functions. By phylogenetic investigation of communities by reconstruction of unobserved states 2 (PICRUSt2) analysis, the abundance of genes related to phosphorus metabolism was much higher than that of genes related to denitrification. Therefore, Propioniciclava was presumed to be a potential PAO without denitrifying phosphorus uptake function. In addition to Propioniciclava, Tessaracoccus and Thiothrix were also enriched in both systems. Overall, this study proposes a novel potential PAO and broadens the understanding of EBPR microbial communities.
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Affiliation(s)
- Yiming Zhao
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Zhengyu Zhu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Xuyang Chen
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Yongmei Li
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
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Fan J, Yuan W, Zhang X, Ji B, Du X. Oxygen affinity and light intensity induced robust phosphorus removal and fragile ammonia removal in a non-aerated bacteria-algae system. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169013. [PMID: 38040345 DOI: 10.1016/j.scitotenv.2023.169013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 11/28/2023] [Accepted: 11/28/2023] [Indexed: 12/03/2023]
Abstract
Non-aerated bacteria-algae system gaining O2 through photosynthesis presents an alternative for costly mechanical aeration. This study investigated oxygen supply and performance of nutrients removal at low and high light intensity (LL and HL). The results showed that P removal was high and robust (LL 97 ± 1.8 %, HL 95 % ± 2.9 %), while NH4+-N removal fluctuated dramatically (LL 66 ± 14.7 %, HL 84 ± 8.6 %). Oxygen generated at illumination of 200 μmol m-2 s-1, 6 h was sufficient to sustain aerobic phase for 2.25 g/L MLSS. However, O2 produced by algae was preferentially captured in the order of heterotrophic bacteria (HB), ammonia oxidizing bacteria (AOB), nitrite oxidizing bacteria (NOB). Oxygen affinity coupled with light intensity led to NOB suppression with stable nitrite accumulation ratio of 57 %. Free nitrous acid (FNA) and light stimulated the abundance of denitrifying polyphosphate accumulating organism (DPAO) of Flavobacterium, but with declined P-accumulating metabolism (PAM) of P release, P/C, K/P and Mg/P ratios. Flavobacterium and cyanobacteria Leptolyngbya, along with biologically induced CaP in extracellular polymeric substances was the key to robust P removal. AOB of Ellin6067 and DPAO of Flavobacteria offer a promising scenario for partial nitrification-denitrifying phosphorus removal.
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Affiliation(s)
- Jie Fan
- College of Urban Construction, Wuhan University of Science and Technology, Wuhan 430065, China.
| | - Wu Yuan
- College of Urban Construction, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Xujie Zhang
- College of Urban Construction, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Bin Ji
- College of Urban Construction, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Xingyu Du
- College of Urban Construction, Wuhan University of Science and Technology, Wuhan 430065, China
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Meng Q, Zeng W, Liu H, Zhang J, Ma B, Peng Y. Optimizing sludge retention time for sustainable photo-enhanced biological phosphorus removal systems: Insights into nutrient fate, microbial community, and bacterial phototolerance. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 351:119839. [PMID: 38104464 DOI: 10.1016/j.jenvman.2023.119839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 11/26/2023] [Accepted: 12/05/2023] [Indexed: 12/19/2023]
Abstract
Photo-enhanced Biological Phosphorus Removal (PEBPR) systems, promising wastewater treatment technology, offer efficient phosphorus removal without external oxygen. However, comprehending the impact of sludge retention time (SRT) on the system is crucial for successful implementation. This study investigated the SRT effect on nutrient fate, microbial community, and bacterial phototolerance in PEBPR systems. PEBPR systems exhibited good bacterial phototolerance at SRT of 10, 15, and 20 d, with optimal phosphorus-accumulation metabolism observed at SRT of 10 and 15d. However, at SRT of 5d, increased light sensitivity and glycogen-accumulating organisms (GAOs) growth resulted in poor P removal (71.9%). Accumulibacter-IIC were the dominant P accumulating organisms (PAOs) at SRT of 10, 15, and 20 d. Accumulibacter-I, IIC and IIF were the major PAOs at SRT of 5 d. The decrease in SRT promoted the microalgal population diversity, and Dictyosphaerium and Chlorella were the major microalgal species in this study. Flow cytometry results revealed high light intensity triggered intracellular Fe2+ efflux, limiting translation activity and metabolism. Moreover, PAOs had lower phototolerance than GAOs due to Poly-P bound intracellular Mg2+ affecting enzyme activity. This study provides an in-depth understanding of PEBPR systems operation strategy toward environmentally sustainable wastewater treatment.
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Affiliation(s)
- Qingan Meng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing, 100124, China
| | - Wei Zeng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing, 100124, China.
| | - Hongjun Liu
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing, 100124, China
| | - Jiayu Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing, 100124, China
| | - Biao Ma
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing, 100124, China
| | - Yongzhen Peng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing, 100124, China
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8
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Freeman CN, Russell JN, Yost CK. Temporal metagenomic characterization of microbial community structure and nitrogen modification genes within an activated sludge bioreactor system. Microbiol Spectr 2024; 12:e0283223. [PMID: 38018980 PMCID: PMC10783093 DOI: 10.1128/spectrum.02832-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 10/18/2023] [Indexed: 11/30/2023] Open
Abstract
IMPORTANCE Wastewater treatment plays an essential role in minimizing negative impacts on downstream aquatic environments. Microbial communities are known to play a vital role in the wastewater treatment process, particularly in the removal of nitrogen and phosphorus, which can be especially damaging to aquatic ecosystems. There is limited understanding of how these microbial communities may change in response to fluctuating temperatures or how seasonality may impact their ability to participate in the treatment process. The findings of this study indicate that the microbial communities of wastewater are relatively stable both compositionally and functionally across fluctuating temperatures.
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Affiliation(s)
- Claire N. Freeman
- Department of Biology, University of Regina, Regina, Saskatchewan, Canada
- Department of Large Animal Clinical Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | | | - Chris K. Yost
- Department of Biology, University of Regina, Regina, Saskatchewan, Canada
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Xie X, Deng X, Chen J, Chen L, Yuan J, Chen H, Wei C, Liu X, Qiu G. Two new clades recovered at high temperatures provide novel phylogenetic and genomic insights into Candidatus Accumulibacter. ISME COMMUNICATIONS 2024; 4:ycae049. [PMID: 38808122 PMCID: PMC11131965 DOI: 10.1093/ismeco/ycae049] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 05/30/2024]
Abstract
Candidatus Accumulibacter, a key genus of polyphosphate-accumulating organisms, plays key roles in lab- and full-scale enhanced biological phosphorus removal (EBPR) systems. A total of 10 high-quality Ca. Accumulibacter genomes were recovered from EBPR systems operated at high temperatures, providing significantly updated phylogenetic and genomic insights into the Ca. Accumulibacter lineage. Among these genomes, clade IIF members SCELSE-3, SCELSE-4, and SCELSE-6 represent the to-date known genomes encoding a complete denitrification pathway, suggesting that Ca. Accumulibacter alone could achieve complete denitrification. Clade IIC members SSA1, SCUT-1, SCELCE-2, and SCELSE-8 lack the entire set of denitrifying genes, representing to-date known non-denitrifying Ca. Accumulibacter. A pan-genomic analysis with other Ca. Accumulibacter members suggested that all Ca. Accumulibacter likely has the potential to use dicarboxylic amino acids. Ca. Accumulibacter aalborgensis AALB and Ca. Accumulibacter affinis BAT3C720 seemed to be the only two members capable of using glucose for EBPR. A heat shock protein Hsp20 encoding gene was found exclusively in genomes recovered at high temperatures, which was absent in clades IA, IC, IG, IIA, IIB, IID, IIG, and II-I members. High transcription of this gene in clade IIC members SCUT-2 and SCUT-3 suggested its role in surviving high temperatures for Ca. Accumulibacter. Ambiguous clade identity was observed for newly recovered genomes (SCELSE-9 and SCELSE-10). Five machine learning models were developed using orthogroups as input features. Prediction results suggested that they belong to a new clade (IIK). The phylogeny of Ca. Accumulibacter was re-evaluated based on the laterally derived polyphosphokinase 2 gene, showing improved resolution in differentiating different clades.
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Affiliation(s)
- Xiaojing Xie
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Xuhan Deng
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Jinling Chen
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Liping Chen
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Jing Yuan
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Hang Chen
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Chaohai Wei
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, Guangzhou 510006, China
| | - Xianghui Liu
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore
| | - Guanglei Qiu
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, Guangzhou 510006, China
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore
- The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, China
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Zhou T, Xiang Y, Liu S, Ma H, Shao Z, He Q, Chai H. Microbial community dynamics and metagenomics reveal the potential role of unconventional functional microorganisms in nitrogen and phosphorus removal biofilm system. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:167194. [PMID: 37741388 DOI: 10.1016/j.scitotenv.2023.167194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/24/2023] [Accepted: 09/16/2023] [Indexed: 09/25/2023]
Abstract
The conventional functional microorganisms for nitrogen and phosphorus removal, such as Nitrosomonas, Nitrobacter, Nitrospira and Candidatus Accumulibacter, were hotspots in past research. However, the role of diverse unconventional functional microorganisms was neglected. In this study, a biofilm system was developed to explore the potential role of unconventional functional microorganisms in nutrients removal. According to the results of microbial community dynamics and metagenomics, complete ammonia oxidizing (comammox) bacteria was 20 times more abundant than ammonia-oxidizing bacteria (AOB) at day 121 and its abundance of amoA gene was almost the same as AOB. Although Nitrospira dominated the nitrite-oxidizing bacteria (NOB), diverse unconventional nxrB-containing microorganisms, particularly Chloroflexi, also significantly contributed to the nitrite oxidation. Binning analysis showed that Myxococcota-affiliated Haliangium had the necessary genes owns by phosphorus-accumulating organisms (PAO) and was likely to be the primary PAO since its abundance (6.38 %) was much higher than other conventional PAO (0.70 %). Comparing metagenome-assembled genomes of comammox bacteria with AOB and ammonia-oxidizing archaea (AOA), it possessed potential metabolic versatility in hydrogen and phosphorus, which may be the primary reason for the positive effect of the alternating anaerobic and aerobic conditions on the enrichment of comammox bacteria. Collectively, our findings broaden the understanding on the microbial mechanism of nitrogen and phosphorus removal in biofilm system.
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Affiliation(s)
- Tengzhi Zhou
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Yu Xiang
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), College of Environment and Ecology, Chongqing University, Chongqing 400045, China; School of Architecture and Civil engineering, Xihua University, Chengdu 610039, China
| | - Shiyi Liu
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), College of Environment and Ecology, Chongqing University, Chongqing 400045, China; Department of Microbiology, Radboud University, Heyendaalseweg 135, Nijmegen 6525 AJ, the Netherlands
| | - Haiyuan Ma
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), College of Environment and Ecology, Chongqing University, Chongqing 400045, China.
| | - Zhiyu Shao
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Qiang He
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Hongxiang Chai
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), College of Environment and Ecology, Chongqing University, Chongqing 400045, China.
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Pelevina A, Gruzdev E, Berestovskaya Y, Dorofeev A, Nikolaev Y, Kallistova A, Beletsky A, Ravin N, Pimenov N, Mardanov A. New insight into the granule formation in the reactor for enhanced biological phosphorus removal. Front Microbiol 2023; 14:1297694. [PMID: 38163067 PMCID: PMC10755871 DOI: 10.3389/fmicb.2023.1297694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 11/15/2023] [Indexed: 01/03/2024] Open
Abstract
While granulated activated sludge exhibits high productivity, the processes of granule formation are incompletely studied. The processes of granule formation and succession of communities were investigated in a laboratory sequencing batch reactor (SBR) under conditions for enhanced biological phosphorus removal (EBPR) using microbiological and molecular techniques. Active consumption of acetate, primarily by the phosphate-accumulating organisms (PAO), commenced at day 150 of cultivation. This was indicated by the high ratio of molar P-released/acetate uptake (0.73-0.77 P-mol/C-mol), characteristic of PAO. During this period, two types of granule-like aggregates formed spontaneously out of the activated sludge flocs. The aggregates differed in morphology and microbial taxonomic composition. While both aggregate types contained phosphorus-enriched bacterial cells, PAO prevailed in those of morphotype I, and glycogen-accumulating organisms (GAOs) were predominant in the aggregates of morphotype II. After 250 days, the elimination of the morphotype II aggregates from the reactor was observed. The subsequent selection of the community was associated with the development of the morphotype I aggregates, in which the relative abundance of PAO increased significantly, resulting in higher efficiency of phosphorus removal. Metagenomic analysis revealed a predominance of the organisms closely related to Candidatus Accumulibacter IС and IIС and of Ca. Accumulibacter IIB among the PAO. Based on the content of the genes of the key metabolic pathways, the genomes of potential PAO belonging to the genera Amaricoccus, Azonexus, Thauera, Zoogloea, Pinisolibacter, and Siculibacillus were selected. The patterns of physicochemical processes and the microbiome structure associated with granule formation and succession of the microbial communities were revealed.
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Affiliation(s)
- Anna Pelevina
- Winogradsky Institute of Microbiology, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Evgeny Gruzdev
- K.G. Skryabin Institute of Bioengineering, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Yulia Berestovskaya
- Winogradsky Institute of Microbiology, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Alexander Dorofeev
- Winogradsky Institute of Microbiology, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Yury Nikolaev
- Winogradsky Institute of Microbiology, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Anna Kallistova
- Winogradsky Institute of Microbiology, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Alexey Beletsky
- K.G. Skryabin Institute of Bioengineering, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Nikolai Ravin
- K.G. Skryabin Institute of Bioengineering, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Nikolai Pimenov
- Winogradsky Institute of Microbiology, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
| | - Andrey Mardanov
- K.G. Skryabin Institute of Bioengineering, Federal Research Center of Biotechnology, Russian Academy of Sciences, Moscow, Russia
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12
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Chen L, Wei G, Zhang Y, Wang K, Wang C, Deng X, Li Y, Xie X, Chen J, Huang F, Chen H, Zhang B, Wei C, Qiu G. Candidatus Accumulibacter use fermentation products for enhanced biological phosphorus removal. WATER RESEARCH 2023; 246:120713. [PMID: 37839225 DOI: 10.1016/j.watres.2023.120713] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 09/17/2023] [Accepted: 10/07/2023] [Indexed: 10/17/2023]
Abstract
Previous research suggested that two major groups of polyphosphate-accumulating organisms (PAOs), i.e., Ca. Accumulibacter and Tetrasphaera, play cooperative roles in enhanced biological phosphorus removal (EBPR). The fermentation of complex organic compounds by Tetrasphaera provides carbon sources for Ca. Accumulibacter. However, the viability of the fermentation products (e.g., lactate, succinate, alanine) as carbon sources for Ca. Accumulibacter and their potential effects on the metabolism of Ca. Accumulibacter were largely unknown. This work for the first time investigated the capability and metabolic details of Ca. Accumulibacter cognatus clade IIC strain SCUT-2 (enriched in a lab-scale reactor with a relative abundance of 42.8%) in using these fermentation products for EBPR. The enrichment culture was able to assimilate lactate and succinate with the anaerobic P release to carbon uptake ratios of 0.28 and 0.36 P mol/C mol, respectively. In the co-presence of acetate, the uptake of lactate was strongly inhibited, since two substrates shared the same transporter as suggested by the carbon uptake bioenergetic analysis. When acetate and succinate were fed at the same time, Ca. Accumulibacter assimilated two carbon sources simultaneously. Proton motive force (PMF) was the key driving force (up to 90%) for the uptake of lactate and succinate by Ca. Accumulibacter. Apart from the efflux of proton in symport with phosphate via the inorganic phosphate transport system, translocation of proton via the activity of fumarate reductase contributed to the generation of PMF, which agreed with the fact that PHV was a major component of PHA when lactate and succinate were used as carbon sources, involving the succinate-propionate pathway. Metabolic models for the usage of lactate and succinate by Ca. Accumulibacter for EBPR were built based on the combined physiological, biochemical, metagenomic, and metatranscriptomic analyses. Alanine was shown as an invalid carbon source for Ca. Accumulibacter. Instead, it significantly and adversely affected Ca. Accumulibacter-mediated EBPR. Phosphate release was observed without alanine uptake. Significant inhibitions on the aerobic phosphate uptake was also evident. Overall, this study suggested that there might not be a simply synergic relationship between Ca. Accumulibacter and Tetrasphaera. Their interactions would largely be determined by the kind of fermentation products released by the latter.
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Affiliation(s)
- Liping Chen
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Gengrui Wei
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Yushen Zhang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Kaiying Wang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Cenchao Wang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Xuhan Deng
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Yaqian Li
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Xiaojing Xie
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Jinling Chen
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Fu Huang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Hang Chen
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China
| | - Bin Zhang
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, PR China
| | - Chaohai Wei
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, Guangzhou 510006, PR China; Key Laboratory of Pollution Control and Ecological Restoration in Industrial Clusters, Ministry of Education, Guangzhou 510006, PR China.
| | - Guanglei Qiu
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, Guangzhou 510006, PR China; Key Laboratory of Pollution Control and Ecological Restoration in Industrial Clusters, Ministry of Education, Guangzhou 510006, PR China.
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13
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Kleikamp HBC, Grouzdev D, Schaasberg P, van Valderen R, van der Zwaan R, Wijgaart RVD, Lin Y, Abbas B, Pronk M, van Loosdrecht MCM, Pabst M. Metaproteomics, metagenomics and 16S rRNA sequencing provide different perspectives on the aerobic granular sludge microbiome. WATER RESEARCH 2023; 246:120700. [PMID: 37866247 DOI: 10.1016/j.watres.2023.120700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 09/29/2023] [Accepted: 10/04/2023] [Indexed: 10/24/2023]
Abstract
The tremendous progress in sequencing technologies has made DNA sequencing routine for microbiome studies. Additionally, advances in mass spectrometric techniques have extended conventional proteomics into the field of microbial ecology. However, systematic studies that provide a better understanding of the complementary nature of these 'omics' approaches, particularly for complex environments such as wastewater treatment sludge, are urgently needed. Here, we describe a comparative metaomics study on aerobic granular sludge from three different wastewater treatment plants. For this, we employed metaproteomics, whole metagenome, and 16S rRNA amplicon sequencing to study the same granule material with uniform size. We furthermore compare the taxonomic profiles using the Genome Taxonomy Database (GTDB) to enhance the comparability between the different approaches. Though the major taxonomies were consistently identified in the different aerobic granular sludge samples, the taxonomic composition obtained by the different omics techniques varied significantly at the lower taxonomic levels, which impacts the interpretation of the nutrient removal processes. Nevertheless, as demonstrated by metaproteomics, the genera that were consistently identified in all techniques cover the majority of the protein biomass. The established metaomics data and the contig classification pipeline are publicly available, which provides a valuable resource for further studies on metabolic processes in aerobic granular sludge.
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Affiliation(s)
- Hugo B C Kleikamp
- Department of Biotechnology, Delft University of Technology, Delft, the Netherlands.
| | | | - Pim Schaasberg
- Department of Biotechnology, Delft University of Technology, Delft, the Netherlands
| | - Ramon van Valderen
- Department of Biotechnology, Delft University of Technology, Delft, the Netherlands
| | - Ramon van der Zwaan
- Department of Biotechnology, Delft University of Technology, Delft, the Netherlands
| | - Roel van de Wijgaart
- Department of Biotechnology, Delft University of Technology, Delft, the Netherlands
| | - Yuemei Lin
- Department of Biotechnology, Delft University of Technology, Delft, the Netherlands
| | - Ben Abbas
- Department of Biotechnology, Delft University of Technology, Delft, the Netherlands
| | - Mario Pronk
- Department of Biotechnology, Delft University of Technology, Delft, the Netherlands
| | | | - Martin Pabst
- Department of Biotechnology, Delft University of Technology, Delft, the Netherlands.
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14
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Meng Q, Zeng W, Liu H, Zhan M, Zhang J, Wu H. The successful application of light to the system of simultaneous nitrification/endogenous denitrification and phosphorus removal: Promotion of partial nitrification and glycogen accumulation metabolism. WATER RESEARCH 2023; 246:120742. [PMID: 37857010 DOI: 10.1016/j.watres.2023.120742] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 09/24/2023] [Accepted: 10/13/2023] [Indexed: 10/21/2023]
Abstract
Partial nitrification (PN) and high glycogen accumulating metabolism (GAM) activity are the basis for efficient nitrogen (N) and phosphorus (P) removal in simultaneous nitrification endogenous denitrification and phosphorus removal (SNDPR) systems. However, achieving these processes in practical operations is challenging. This study proposes that light irradiation is a novel strategy to enhance the nutrient removal performance of the SNDPR system with low carbon to nitrogen ratios (C/N of 3.3-4.1) domestic wastewater. Light energy densities (Es) of 55-135 J/g VSS were found to promote the activity of ammonia-oxidizing bacteria (AOB) and GAM, while inhibiting the activity of nitrite-oxidizing bacteria (NOB) and polyphosphate accumulating metabolism (PAM). Long-term exposure to different light patterns at Es of 55-135 J/g VSS revealed that continuous light rapidly achieved PN by inhibiting NOB activity and promoted the growth of glycogen accumulating organisms (GAOs), allowing the removal of above 82 % N and below 80 % P. Intermittent light maintained stable PN by inhibiting the activity and growth of NOB and promoted the growth of polyphosphate accumulating organisms (PAOs) with high GAM activity (Accmulibacer IIC-ii and IIC-iii), allowing the removal of above 82 % N and 95 % P. Flow cytometry and enzyme activity assays showed that light promoted GAM-related enzyme activity and the metabolic activity of partial Accmulibacer II over other endogenous denitrifying bacteria, while inhibiting NOB translation activity. These findings provide a new approach for enhancing nutrient removal, especially for achieving PN and promoting GAM activity, in SNDPR systems treating low C/N ratio domestic wastewater using light irradiation.
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Affiliation(s)
- Qingan Meng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China
| | - Wei Zeng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China.
| | - Hongjun Liu
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China
| | - Mengjia Zhan
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China
| | - Jiayu Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China
| | - Hongan Wu
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China
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15
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Wang Z, Song W, Zhang X, Zheng M, Li H, Yu K, Guo F. Expanding the Diversity of Accumulibacter with a Novel Type and Deciphering the Transcriptional and Morphological Features among Co-Occurring Strains. Appl Environ Microbiol 2023; 89:e0077123. [PMID: 37466435 PMCID: PMC10467341 DOI: 10.1128/aem.00771-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 06/25/2023] [Indexed: 07/20/2023] Open
Abstract
"Candidatus Accumulibacter" is the major polyphosphate-accumulating organism (PAO) in global wastewater treatment systems, and its phylogenetic and functional diversity have expanded in recent years. In addition to the widely recognized type I and II sublineages, we discovered a novel type enriched in laboratory bioreactors. Core gene and machine learning-based gene feature profiling supported the assertion that type III "Ca. Accumulibacter" is a potential PAO with the unique function of using dimethyl sulfoxide as an electron acceptor. Based on the correlation between ppk1 and genome similarity, the species-level richness of Accumulibacter was estimated to be over 100, suggesting that the currently recognized species are only the tip of the iceberg. Meanwhile, the interstrain transcriptional and morphological features of multiple "Ca. Accumulibacter" strains co-occurring in a bioreactor were investigated. Metatranscriptomics of seven co-occurring strains indicated that the expression level and interphasic dynamics of PAO phenotype-related genes had minimal correlation with their phylogeny. In particular, the expression of denitrifying and polyphosphate (poly-P) metabolism genes exhibited higher interstrain and interphasic divergence than expression of glycogen and polyhydroxyalkanoate metabolic genes. A strategy of cloning rRNA genes from different strains based on similar genomic synteny was successfully applied to differentiate their morphology via fluorescence in situ hybridization. Our study further expands the phylogenetic and functional diversity of "Ca. Accumulibacter" and proposes that deciphering the function and capability of certain "Ca. Accumulibacter" should be tailored to the environment and population in question. IMPORTANCE In the last 2 decades, "Ca. Accumulibacter" has garnered significant attention as the core functional but uncultured taxon for enhanced biological phosphorus removal due to its phylogenetic and functional diversity and intragenus niche differentiation. Since 2002, it has been widely known that this genus has two sublineages (type I and II). However, in this study, a metagenomic approach led to the discovery of a novel type (type III) with proposed novel functional features. By comparing the average nucleotide identity of "Ca. Accumulibacter" genomes and the similarity of ppk1, a phylogenetic biomarker largely deposited in databases, the global species-level richness of "Ca. Accumulibacter" was estimated for the first time to be over 100. Furthermore, we observed the co-occurrence of multiple "Ca. Accumulibacter" strains in a single bioreactor and found the simultaneous transcriptional divergence of these strains intriguing with regard to their niche differentiation within a single community. Our results indicated a decoupling feature between transcriptional pattern and phylogeny for co-occurring strains.
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Affiliation(s)
- Zhongjie Wang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Wei Song
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Xue Zhang
- School of Environment and Energy, Peking University Shenzhen Graduate School, Peking University, Shenzhen, China
| | - Minjia Zheng
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Hao Li
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Ke Yu
- School of Environment and Energy, Peking University Shenzhen Graduate School, Peking University, Shenzhen, China
| | - Feng Guo
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China
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16
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Meng Q, Zeng W, Fan Z, Li S, Peng Y. Sulfide inhibition on polyphosphate accumulating organisms and glycogen accumulating organisms: Cumulative inhibitory effect and recoverability. JOURNAL OF HAZARDOUS MATERIALS 2023; 451:131157. [PMID: 36889076 DOI: 10.1016/j.jhazmat.2023.131157] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 02/14/2023] [Accepted: 03/03/2023] [Indexed: 06/18/2023]
Abstract
Sulfate in wastewater can be reduced to sulfide and its impact on the stability of enhanced biological phosphorus removal (EBPR) is still unclear. In this study, the metabolic changes and subsequent recovery of polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) were investigated at different sulfide concentrations. The results showed that the metabolic activity of PAOs and GAOs was mainly related to H2S concentration. Under anaerobic conditions, the catabolism of PAOs and GAOs was promoted at H2S concentrations below 79 mg/L S and 271 mg/L S, respectively, and inhibited above these concentrations; whereas anabolism was consistently inhibited in the presence of H2S. The phosphorus (P) release was also pH-dependent due to the intracellular free Mg2+ efflux from PAOs. H2S was more destructive to the esterase activity and membrane permeability of PAOs than those of GAOs and prompted intracellular free Mg2+ efflux of PAOs, resulting in worse aerobic metabolism and subsequent recovery of PAOs than GAOs. Additionally, sulfides facilitated the production of extracellular polymeric substances (EPS), especially tightly bound EPS. The amount of EPS in GAOs was significantly higher than that in PAOs. The above results indicated that sulfide had a stronger inhibition to PAOs than GAOs, and when sulfide was present, GAOs had a competitive advantage over PAOs in EBPR.
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Affiliation(s)
- Qingan Meng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China
| | - Wei Zeng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China.
| | - Zhiwei Fan
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China
| | - Shuangshuang Li
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China
| | - Yongzhen Peng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Beijing University of Technology, Beijing 100124, China
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17
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Izadi P, Andalib M. Anaerobic zone Functionality, Design and Configurations for a Sustainable EBPR process: A Critical Review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 870:162018. [PMID: 36740070 DOI: 10.1016/j.scitotenv.2023.162018] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/15/2023] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
Stringent discharge phosphorus limits and rising urge to reach very low effluent total phosphorus concentrations have challenged the available technologies to further remove phosphorus. The significance of Enhanced Biological Phosphorus Removal (EBPR) process may have been overshadowed by the design and operation limitations. These scarcities mainly root back to the lack of knowledge and understanding of fundamental mechanisms, design standards, and operational guidance. Anaerobic biomass fraction design and operation as a primary driving force for biological phosphorus removal process is commonly outweighed by aerobic and total plant sludge retention operation and design criteria. This paper tends to critically review the different perspectives of mainstream and side-stream EBPR processes and to particularly target contrasting views on hydrolysis and fermentation rates as well as anaerobic condition implementation and magnitude. Subsequently, from distinct point of views, knowledge gaps are comprehensively discussed to eventually recognize the advances and drawbacks aimed to reach a sustainable EBPR process.
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Affiliation(s)
- Parnian Izadi
- Stantec Consulting Ltd, Stantec Institute for water Technology and Policy, Waterloo, ON, Canada.
| | - Mehran Andalib
- Stantec Consulting Ltd, Stantec Institute for water Technology and Policy, Boston, MA, United States.
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18
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Haaksman VA, Schouteren M, van Loosdrecht MCM, Pronk M. Impact of the anaerobic feeding mode on substrate distribution in aerobic granular sludge. WATER RESEARCH 2023; 233:119803. [PMID: 36870106 DOI: 10.1016/j.watres.2023.119803] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 01/20/2023] [Accepted: 02/24/2023] [Indexed: 06/18/2023]
Abstract
There is a growing interest to implement aerobic granular sludge (AGS) in existing conventional activated sludge (CAS) systems with a continuous flow-through configuration. The mode of anaerobic contact of raw sewage with the sludge is an important aspect in the adaptation of CAS systems to accommodate AGS. It remains unclear how the distribution of substrate over the sludge by a conventional anaerobic selector compares to the distribution via bottom-feeding applied in sequencing batch reactors (SBRs). This study investigated the effect of the anaerobic contact mode on the substrate (and storage) distribution by operating two lab-scale SBRs; one with the traditional bottom-feeding through a settled sludge bed similar to full-scale AGS systems, and one where the synthetic wastewater was fed as a pulse at the start of the anaerobic phase while the reactor was mixed through sparging of nitrogen gas (mimicking a plug-flow anaerobic selector in continuous flow-through systems). The distribution of the substrate over the sludge particle population was quantified via PHA analysis, combined with the obtained granule size distribution. Bottom-feeding was found to primarily direct substrate towards the large granular size classes (i.e. large volume and close to the bottom), while completely mixed pulse-feeding gives a more equal distribution of substrate over all granule sizes (i.e. surface area dependant). The anaerobic contact mode directly controls the substrate distribution over the different granule sizes, irrespective of the solids retention time of a granule as an entity. Preferential feeding of the larger granules will enhance and stabilise the granulation compared to pulse-feeding, certainly under less advantageous conditions imposed by real sewage.
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Affiliation(s)
- V A Haaksman
- Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, Delft, 2629 HZ, The Netherlands.
| | - M Schouteren
- Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, Delft, 2629 HZ, The Netherlands
| | - M C M van Loosdrecht
- Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, Delft, 2629 HZ, The Netherlands
| | - M Pronk
- Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, Delft, 2629 HZ, The Netherlands; Royal HaskoningDHV, Laan 1914 35, Amersfoort, 3800 AL, The Netherlands
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19
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Zhao B, Yang Y, Zhao C, Zhang C, Zhang Z, Wang L, Wang S, Wang J. Exploration of the metabolic flexibility of glycogen accumulating organisms through metatranscriptome analysis and metabolic characterization. J Environ Sci (China) 2023; 126:234-248. [PMID: 36503752 DOI: 10.1016/j.jes.2022.05.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 05/06/2022] [Accepted: 05/06/2022] [Indexed: 06/17/2023]
Abstract
Glycogen accumulating organisms (GAOs) are closely related to the deterioration of enhanced biological phosphorus removal systems. However, the metabolic mechanisms that drive GAOs remain unclear. Here, the two-thirds supernatant of a reactor were decanted following the anaerobic period to enrich GAOs. Long-term monitoring demonstrated that the system was stable and exhibited typical characteristics of GAOs metabolism. Acetate was completely consumed after 60 min of the anaerobic phase. The level of glycogen decreased from 0.20 to 0.14 g/gSS during the anaerobic phase, whereas the level of glycogen significantly increased to 0.21g/gSS at the end of the aerobic period. Moreover, there was almost no phosphate release and absorption in the complete periods, thus confirming the successful construction of a GAOs enrichment system. Microbial community analysis demonstrated that Ca. Contendobacter was among the core functional genera and showed the highest activity among all of the communities. Furthermore, our study is the first to identify the involvement of the ethyl-malonyl-CoA pathway in the synthesis of polyhydroxyvalerate via croR, ccr, ecm, mcd, mch and mcl genes. The Embden-Meyerhof-Parnas (EMP) pathway was preferentially used via glgP. Furthermore, the glyoxylate cycle was the main source of ATP under anaerobic conditions, whereas the tricarboxylic acid cycle provided ATP under aerobic conditions. aceA and mdh appeared to be major modulators of the glyoxylate pathway for controlling energy flow. Collectively, our findings not only revealed the crucial metabolic mechanisms in a GAOs enrichment system but also provided insights into the potential application of Ca. Contendobacter for wastewater treatment.
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Affiliation(s)
- Bin Zhao
- School of Environmental Science Engineering, Tiangong University, Tianjin 300387, China
| | - Yanping Yang
- School of Environmental Science Engineering, Tiangong University, Tianjin 300387, China; Department of Hygienic Toxicology and Environmental Hygiene, Tianjin Institute of Environmental and Operational Medicine, Tianjin 300201, China
| | - Chen Zhao
- Department of Hygienic Toxicology and Environmental Hygiene, Tianjin Institute of Environmental and Operational Medicine, Tianjin 300201, China
| | - Chunchun Zhang
- School of Environmental Science Engineering, Tiangong University, Tianjin 300387, China; Department of Hygienic Toxicology and Environmental Hygiene, Tianjin Institute of Environmental and Operational Medicine, Tianjin 300201, China
| | - Zhaohui Zhang
- School of Environmental Science Engineering, Tiangong University, Tianjin 300387, China
| | - Liang Wang
- School of Environmental Science Engineering, Tiangong University, Tianjin 300387, China
| | - Shang Wang
- Department of Hygienic Toxicology and Environmental Hygiene, Tianjin Institute of Environmental and Operational Medicine, Tianjin 300201, China.
| | - Jingfeng Wang
- Department of Hygienic Toxicology and Environmental Hygiene, Tianjin Institute of Environmental and Operational Medicine, Tianjin 300201, China.
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20
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Tomás-Martínez S, Zwolsman EJ, Merlier F, Pabst M, Lin Y, van Loosdrecht MCM, Weissbrodt DG. Turnover of the extracellular polymeric matrix of granules performing biological phosphate removal. Appl Microbiol Biotechnol 2023; 107:1997-2009. [PMID: 36759376 PMCID: PMC10006046 DOI: 10.1007/s00253-023-12421-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 11/14/2022] [Accepted: 01/31/2023] [Indexed: 02/11/2023]
Abstract
Polyphosphate accumulating organisms (PAOs) are responsible for enhanced biological phosphate removal (EBPR) from wastewater, where they grow embedded in a matrix of extracellular polymeric substances (EPS). EPSs comprise a mixture of biopolymers like polysaccharides or (glyco)proteins. Despite previous studies, little is known about the dynamics of EPS in mixed cultures, and their production by PAOs and potential consumption by flanking microbes. EPSs are biodegradable and have been suggested to be a substrate for other organisms in the community. Studying EPS turnover can help elucidate their biosynthesis and biodegradation cycles. We analyzed the turnover of proteins and polysaccharides in the EPS of an enrichment culture of PAOs relative to the turnover of internal proteins. An anaerobic-aerobic sequencing batch reactor (SBR) simulating EBPR conditions was operated to enrich for PAOs. After achieving a stable culture, carbon source was switched to uniformly 13C-labeled acetate. Samples were collected at the end of each aerobic phase. EPSs were extracted by alkaline treatment. 13C enrichment in proteins and sugars (after hydrolysis of polysaccharides) in the extracted EPS were measured by mass spectrometry. The average turnover rate of sugars and proteins (0.167 and 0.192 d-1 respectively) was higher than the expected value based on the solid removal rate (0.132 d-1), and no significant difference was observed between intracellular and extracellular proteins. This indicates that EPS from the PAO enriched community is not selectively degraded by flanking populations under stable EBPR process conditions. Instead, we observed general decay of biomass, which corresponds to a value of 0.048 d-1. KEY POINTS: • Proteins showed a higher turnover rate than carbohydrates. • Turnover of EPS was similar to the turnover of intracellular proteins. • EPS is not preferentially consumed by flanking populations.
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Affiliation(s)
- Sergio Tomás-Martínez
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9,2629, HZ, Delft, The Netherlands.
| | - Erwin J Zwolsman
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9,2629, HZ, Delft, The Netherlands
| | - Franck Merlier
- CNRS Enzyme and Cell Engineering Laboratory, Université de Technologie de Compiègne, Rue du Docteur Schweitzer, 60319, 60203, Compiègne Cedex, CS, France
| | - Martin Pabst
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9,2629, HZ, Delft, The Netherlands
| | - Yuemei Lin
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9,2629, HZ, Delft, The Netherlands
| | - Mark C M van Loosdrecht
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9,2629, HZ, Delft, The Netherlands
| | - David G Weissbrodt
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9,2629, HZ, Delft, The Netherlands
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21
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Lin Y, Sun Y, Zhang L, Zhang Q, Li X, Sui J, Peng Y. Balancing denitrifying phosphorus-accumulating organisms and denitrifying glycogen-accumulating organisms for advanced nitrogen and phosphorus removal from municipal wastewater. BIORESOURCE TECHNOLOGY 2023; 369:128444. [PMID: 36493952 DOI: 10.1016/j.biortech.2022.128444] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/27/2022] [Accepted: 12/01/2022] [Indexed: 06/17/2023]
Abstract
Given the carbon limitation of municipal wastewater, the balance of biological nitrogen and phosphorus removal remains a challenging task. In this study, an anaerobic-anoxic-oxic combining with biological contact oxidation (A2/O-BCO) system treating real municipal wastewater was operated for 205 days, and COD-to-PO43--P ratio was confirmed as the key parameter for balancing denitrifying phosphorus-accumulating organisms (DPAOs) and denitrifying glycogen-accumulating organisms (DGAOs) to enhance N and P removal. When DPAOs dominated in nutrients removal, the increase in COD/P from 17.1 to 38.1 caused the deterioration in nitrogen removal performance decreasing to 71.8 %. As COD/P ratio decreased from 81.3 to 46.8, Ca.Competibacter proliferated from 3.11 % to 6.00 %, contributing to 58.9 % of nitrogen removal. The nitrogen and phosphorus removal efficiency reached up to 79.3 % and 95.2 %. Overall, establishing DGAOs-DPAOs balance by strengthening the effect of DGAOs could enhance the nutrients removal performance and accordingly improve the stability and efficiency of the system.
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Affiliation(s)
- Yangang Lin
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Yawen Sun
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Liyuan Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Qiong Zhang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Xiyao Li
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China
| | - Jun Sui
- Guangdong Shouhui Lantian Engineering and Technology Co. Ltd, Guangzhou 510030, PR China
| | - Yongzhen Peng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
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22
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Zhang C, Guisasola A, Baeza JA. Exploring the stability of an A-stage-EBPR system for simultaneous biological removal of organic matter and phosphorus. CHEMOSPHERE 2023; 313:137576. [PMID: 36529170 DOI: 10.1016/j.chemosphere.2022.137576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 10/27/2022] [Accepted: 12/14/2022] [Indexed: 06/17/2023]
Abstract
This work evaluates the performance and stability of a continuous anaerobic/aerobic A-stage system with integrated enhanced biological phosphorus removal (A-stage-EBPR) under different operational conditions. Dissolved oxygen (DO) in the aerobic reactor was tested in the 0.2-2 mgDO/L range using real wastewater amended with propionic acid, obtaining almost full simultaneous COD and P removal without nitrification in the range 0.5-1 mgDO/L, but failing at 0.2 mgDO/L. Anaerobic purge was tested to evaluate a possible mainstream P-recovery strategy, generating a P-enriched stream containing 22% of influent P. COD and N mass balances indicated that about 43% of the influent COD could be redirected to the anaerobic digestion for methane production and 66% of influent NH4+-N was discharged in the effluent for the following N-removal B-stage. Finally, when the system was switched to glutamate as sole carbon source, successful EBPR activity and COD removal were maintained for two months, but after this period settleability problems appeared with biomass loss. Microbial community analysis indicated that Propionivibrio, Thiothrix and Lewinella were the most abundant species when propionic acid was the carbon source and Propionivibrio was the most favoured with glutamate. Thiothrix, Hydrogenophaga, Dechloromonas and Desulfobacter appeared as the dominant polyphosphate-accumulating organisms (PAOs) under different operation stages.
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Affiliation(s)
- Congcong Zhang
- GENOCOV. Departament d'Enginyeria Química, Biològica i Ambiental. Escola d'Enginyeria. Universitat Autònoma de Barcelona, 08193, Bellaterra, Barcelona, Spain.
| | - Albert Guisasola
- GENOCOV. Departament d'Enginyeria Química, Biològica i Ambiental. Escola d'Enginyeria. Universitat Autònoma de Barcelona, 08193, Bellaterra, Barcelona, Spain.
| | - Juan Antonio Baeza
- GENOCOV. Departament d'Enginyeria Química, Biològica i Ambiental. Escola d'Enginyeria. Universitat Autònoma de Barcelona, 08193, Bellaterra, Barcelona, Spain.
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23
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Páez-Watson T, van Loosdrecht MCM, Wahl SA. Predicting the impact of temperature on metabolic fluxes using resource allocation modelling: Application to polyphosphate accumulating organisms. WATER RESEARCH 2023; 228:119365. [PMID: 36413834 DOI: 10.1016/j.watres.2022.119365] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 11/07/2022] [Accepted: 11/15/2022] [Indexed: 06/16/2023]
Abstract
The understanding of microbial communities and the biological regulation of its members is crucial for implementation of novel technologies using microbial ecology. One poorly understood metabolic principle of microbial communities is resource allocation and biosynthesis. Resource allocation theory in polyphosphate accumulating organisms (PAOs) is limited as a result of their slow imposed growth rate (typical sludge retention times of at least 4 days) and limitations to quantify changes in biomass components over a 6 hours cycle (less than 10% of their growth). As a result, there is no direct evidence supporting that biosynthesis is an exclusive aerobic process in PAOs that alternate continuously between anaerobic and aerobic phases. Here, we apply resource allocation metabolic flux analysis to study the optimal phenotype of PAOs over a temperature range of 4 °C to 20 °C. The model applied in this research allowed to identify optimal metabolic strategies in a core metabolic model with limited constraints based on biological principles. The addition of a constraint limiting biomass synthesis to be an exclusive aerobic process changed the metabolic behaviour and improved the predictability of the model over the studied temperature range by closing the gap between prediction and experimental findings. The results validate the assumption of limited anaerobic biosynthesis in PAOs, specifically "Candidatus Accumulibacter" related species. Interestingly, the predicted growth yield was lower, suggesting that there are mechanistic barriers for anaerobic growth not yet understood nor reflected in the current models of PAOs. Moreover, we identified strategies of resource allocation applied by PAOs at different temperatures as a result of the decreased catalytic efficiencies of their biochemical reactions. Understanding resource allocation is paramount in the study of PAOs and their currently unknown complex metabolic regulation, and metabolic modelling based on biological first principles provides a useful tool to develop a mechanistic understanding.
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Affiliation(s)
- Timothy Páez-Watson
- Department of Biotechnology, Delft University of Technology, Delft, the Netherlands.
| | | | - S Aljoscha Wahl
- Department of Biotechnology, Delft University of Technology, Delft, the Netherlands
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24
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Diaz R, Mackey B, Chadalavada S, Kainthola J, Heck P, Goel R. Enhanced Bio-P removal: Past, present, and future - A comprehensive review. CHEMOSPHERE 2022; 309:136518. [PMID: 36191763 DOI: 10.1016/j.chemosphere.2022.136518] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 09/14/2022] [Accepted: 09/15/2022] [Indexed: 06/16/2023]
Abstract
Excess amounts of phosphorus (P) and nitrogen (N) from anthropogenic activities such as population growth, municipal and industrial wastewater discharges, agriculture fertilization and storm water runoffs, have affected surface water chemistry, resulting in episodes of eutrophication. Enhanced biological phosphorus removal (EBPR) based treatment processes are an economical and environmentally friendly solution to address the present environmental impacts caused by excess P present in municipal discharges. EBPR practices have been researched and operated for more than five decades worldwide, with promising results in decreasing orthophosphate to acceptable levels. The advent of molecular tools targeting bacterial genomic deoxyribonucleic acid (DNA) has also helped us reveal the identity of potential polyphosphate-accumulating organisms (PAO) and denitrifying PAO (DPAO) responsible for the success of EBPR. Integration of process engineering and environmental microbiology has provided much-needed confidence to the wastewater community for the successful implementation of EBPR practices around the globe. Despite these successes, the process of EBPR continues to evolve in terms of its microbiology and application in light of other biological processes such as anaerobic ammonia oxidation and on-site carbon capture. This review provides an overview of the history of EBPR, discusses different operational parameters critical for the successful operation of EBPR systems, reviews current knowledge of EBPR microbiology, the influence of PAO/DPAO on the disintegration of microbial communities, stoichiometry, EBPR clades, current practices, and upcoming potential innovations.
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Affiliation(s)
- Ruby Diaz
- Department of Civil and Environmental Engineering, University of Utah, Salt Lake City, UT, 84112, USA
| | - Brendan Mackey
- Department of Civil and Environmental Engineering, University of Utah, Salt Lake City, UT, 84112, USA
| | - Sreeni Chadalavada
- School of Engineering, University of Southern Queensland Springfield, Queensland, 4350, Australia.
| | - Jyoti Kainthola
- Department of Civil Engineering, École Centrale School of Engineering, Mahindra University, Hyderabad, India, 500043
| | - Phil Heck
- Central Valley Water Reclamation Facility, Salt Lake City, UT, USA
| | - Ramesh Goel
- Department of Civil and Environmental Engineering, University of Utah, Salt Lake City, UT, 84112, USA.
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25
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Zhao W, Bi X, Peng Y, Bai M. Research advances of the phosphorus-accumulating organisms of Candidatus Accumulibacter, Dechloromonas and Tetrasphaera: Metabolic mechanisms, applications and influencing factors. CHEMOSPHERE 2022; 307:135675. [PMID: 35842039 DOI: 10.1016/j.chemosphere.2022.135675] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 06/19/2022] [Accepted: 07/08/2022] [Indexed: 06/15/2023]
Abstract
Phosphorus-accumulating organisms (PAOs), which harbor metabolic mechanisms for phosphorus removal, are widely applied in wastewater treatment. Recently, novel PAOs and phosphorus removal metabolic pathways have been identified and studied. Specifically, Dechloromonas and Tetrasphaera can remove phosphorus via the denitrifying phosphorus removal and fermentation phosphorus removal pathways, respectively. As the main PAOs in biological phosphorus removal systems, the conventional PAO Candidatus Accumulibacter and the novel PAOs Dechloromonas and Tetrasphaera are thoroughly discussed in this paper, with a specific focus on their phosphorus removal metabolic mechanisms, process applications, community abundance and influencing factors. Dechloromonas can achieve simultaneous nitrogen and phosphorus removal in an anoxic environment through the denitrifying phosphorus removal metabolic pathway, which can further reduce carbon source requirements and aeration energy consumption. The metabolic pathways of Tetrasphaera are diverse, with phosphorus removal occurring in conjunction with macromolecular organics degradation through anaerobic fermentation. A collaborative oxic phosphorus removal pathway between Tetrasphaera and Ca. Accumulibacter, or a collaborative anoxic denitrifying phosphorus removal pathway between Tetrasphaera and Dechloromonas are future development directions for biological phosphorus removal technologies, which can further reduce carbon source and energy consumption while achieving enhanced phosphorus removal.
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Affiliation(s)
- Weihua Zhao
- State and Local Joint Engineering Research Center of Municipal Wastewater Treatment and Resource Recycling, Qingdao University of Technology, Qingdao, 266033, PR China; National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, China
| | - Xuejun Bi
- State and Local Joint Engineering Research Center of Municipal Wastewater Treatment and Resource Recycling, Qingdao University of Technology, Qingdao, 266033, PR China
| | - Yongzhen Peng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing, 100124, China.
| | - Meng Bai
- State and Local Joint Engineering Research Center of Municipal Wastewater Treatment and Resource Recycling, Qingdao University of Technology, Qingdao, 266033, PR China
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26
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Ni M, Pan Y, Li D, Huang Y, Chen Z, Li L, Song Z, Zhao Y. Metagenomics reveals the metabolism of polyphosphate-accumulating organisms in biofilm sequencing batch reactor: A new model. BIORESOURCE TECHNOLOGY 2022; 360:127603. [PMID: 35835418 DOI: 10.1016/j.biortech.2022.127603] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 07/04/2022] [Accepted: 07/07/2022] [Indexed: 06/15/2023]
Abstract
This study assessed the impact of the operating conditions of the biofilm sequencing batch reactor (BSBR) on the community structure and the growth/metabolic pathways of its polyphosphate-accumulating organisms (PAOs). There are significant difference with reference to the enhanced biological phosphorus removal (EBPR) process. The leading PAOs in BSBR generally are capable of high affinity acetate metabolism, gluconeogenesis, and low affinity phosphate transport, and have various carbon source supplementation pathways to ensure the efficient circulation of energy and reducing power. A new model of the metabolic mechanism of PAOs in the BSBR was formulated, which features low glycogen metabolism with simultaneous gluconeogenesis and glycogenolysis and differs significantly from the classic mechanism based on Candidatus_Accumulibacter and Tetrasphaera. The findings will assist the efficient recovery of low concentration phosphate in municipal wastewater.
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Affiliation(s)
- Min Ni
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China; Jiangsu Key Laboratory of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Yang Pan
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China; National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou 215009, China.
| | - Dapeng Li
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China; National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Yong Huang
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China; National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Zhiqiang Chen
- Harbin Institute of Technology, Harbin 150006, China
| | - Lu Li
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China; National and Local Joint Engineering Laboratory of Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou 215009, China
| | | | - Yimeng Zhao
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
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27
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Maszenan AM, Bessarab I, Williams RBH, Petrovski S, Seviour RJ. The phylogeny, ecology and ecophysiology of the glycogen accumulating organism (GAO) Defluviicoccus in wastewater treatment plants. WATER RESEARCH 2022; 221:118729. [PMID: 35714465 DOI: 10.1016/j.watres.2022.118729] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/22/2022] [Accepted: 06/08/2022] [Indexed: 06/15/2023]
Abstract
This comprehensive review looks critically what is known about members of the genus Defluviicoccus, an example of a glycogen accumulating organism (GAO), in wastewater treatment plants, but found also in other habitats. It considers the operating conditions thought to affect its performance in activated sludge plants designed to remove phosphorus microbiologically, including the still controversial view that it competes with the polyphosphate accumulating bacterium Ca. Accumulibacter for readily biodegradable substrates in the anaerobic zone receiving the influent raw sewage. It looks at its present phylogeny and what is known about it's physiology and biochemistry under the highly selective conditions of these plants, where the biomass is recycled continuously through alternative anaerobic (feed); aerobic (famine) conditions encountered there. The impact of whole genome sequence data, which have revealed considerable intra- and interclade genotypic diversity, on our understanding of its in situ behaviour is also addressed. Particular attention is paid to the problems in much of the literature data based on clone library and next generation DNA sequencing data, where Defluviicoccus identification is restricted to genus level only. Equally problematic, in many publications no attempt has been made to distinguish between Defluviicoccus and the other known GAO, especially Ca. Competibacter, which, as shown here, has a very different ecophysiology. The impact this has had and continues to have on our understanding of members of this genus is discussed, as is the present controversy over its taxonomy. It also suggests where research should be directed to answer some of the important research questions raised in this review.
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Affiliation(s)
- Abdul M Maszenan
- E2S2, NUS Environmental Research Institute, National University of Singapore, 117411, Singapore
| | - Irina Bessarab
- Singapore Centre for Environmental Life Sciences Engineering, National University of Singapore, 117456, Singapore
| | - Rohan B H Williams
- Singapore Centre for Environmental Life Sciences Engineering, National University of Singapore, 117456, Singapore
| | - Steve Petrovski
- Department of Microbiology, Anatomy, Physiology and Pharmacology, La Trobe University, 3086 Victoria, Australia
| | - Robert J Seviour
- Department of Microbiology, Anatomy, Physiology and Pharmacology, La Trobe University, 3086 Victoria, Australia.
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28
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Reevaluation of the Phylogenetic Diversity and Global Distribution of the Genus " Candidatus Accumulibacter". mSystems 2022; 7:e0001622. [PMID: 35467400 PMCID: PMC9238405 DOI: 10.1128/msystems.00016-22] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
“Candidatus Accumulibacter” was the first microorganism identified as a polyphosphate-accumulating organism (PAO) important for phosphorus removal from wastewater. Members of this genus are diverse, and the current phylogeny and taxonomic framework appear complicated, with most publicly available genomes classified as “Candidatus Accumulibacter phosphatis,” despite notable phylogenetic divergence. The ppk1 marker gene allows for a finer-scale differentiation into different “types” and “clades”; nevertheless, taxonomic assignments remain inconsistent across studies. Therefore, a comprehensive reevaluation is needed to establish a common understanding of this genus, in terms of both naming and basic conserved physiological traits. Here, we provide this reassessment using a comparison of genome, ppk1, and 16S rRNA gene-based approaches from comprehensive data sets. We identified 15 novel species, along with “Candidatus Accumulibacter phosphatis,” “Candidatus Accumulibacter delftensis,” and “Candidatus Accumulibacter aalborgensis.” To compare the species in situ, we designed new species-specific fluorescence in situ hybridization (FISH) probes and revealed their morphology and arrangement in activated sludge. Based on the MiDAS global survey, “Ca. Accumulibacter” species were widespread in wastewater treatment plants (WWTPs) with phosphorus removal, indicating process design as a major driver for their abundance. Genome mining for PAO-related pathways and FISH-Raman microspectroscopy confirmed the potential for PAO metabolism in all “Ca. Accumulibacter” species, with detection in situ of the typical PAO storage polymers. Genome annotation further revealed differences in the nitrate/nitrite reduction pathways. This provides insights into the niche differentiation of these lineages, potentially explaining their coexistence in the same ecosystem while contributing to overall phosphorus and nitrogen removal. IMPORTANCE “Candidatus Accumulibacter” is the most studied PAO, with a primary role in biological nutrient removal. However, the species-level taxonomy of this lineage is convoluted due to the use of different phylogenetic markers or genome sequencing approaches. Here, we redefined the phylogeny of these organisms, proposing a comprehensive approach which could be used to address the classification of other diverse and uncultivated lineages. Using genome-resolved phylogeny, compared to phylogeny based on the 16S rRNA gene and other phylogenetic markers, we obtained a higher-resolution taxonomy and established a common understanding of this genus. Furthermore, genome mining of genes and pathways of interest, validated in situ by application of a new set of FISH probes and Raman microspectroscopy, provided additional high-resolution metabolic insights into these organisms.
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29
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Kaiyue H, Lishuai Z, Yongchen Z, Qiang H, Mingzhe G. The relationship analysis and reaction mechanism of carbon, nitrogen, and phosphorus metabolism in sewage treatment in plateau habitat. ENVIRONMENTAL MONITORING AND ASSESSMENT 2022; 194:520. [PMID: 35731326 DOI: 10.1007/s10661-022-10151-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 05/28/2022] [Indexed: 06/15/2023]
Abstract
The efficiency of pollutant removal in sewage is mainly determined by the structure and abundance of microbial flora, which is essentially represented by the type and abundance of genes and enzymes, and the reaction mechanism is the abundance and degree of reaction of metabolic pathways and metabolic modules. In order to study the mechanism of carbon, nitrogen, and phosphorus metabolism of activated sludge microflora in the A2O process at high altitudes at different temperatures, so as to improve the removal rate of pollutants and reduce the discharge concentration of pollutants. Based on the research environment of high-altitude environmental research, the author used the A2O system as the treatment process and put Illumina MiSeq high-through sequencing technology to comprehensively dissect the reaction relationship of carbon, nitrogen and phosphorus metabolic pathways, and derived the main functional genes and enzymes of carbon, nitrogen, and phosphorus metabolism. It was demonstrated that the abundance of the most metabolic modules and functional genes tended to increase and then decrease with increasing temperature. In particular, the highest abundance and activity and the best pollutant removal efficiency were observed at 20 °C. This study will provide a valuable reference for the study of carbon metabolism, nitrogen metabolism, and phosphorus metabolism of microbial flora in sewage treatment under plateau habitats.
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Affiliation(s)
- Hao Kaiyue
- Water Conservancy Project & Civil Engineering College, Tibet Agriculture & Animal Husbandry University, Linzhi, 860000, China
| | - Zhao Lishuai
- Water Conservancy Project & Civil Engineering College, Tibet Agriculture & Animal Husbandry University, Linzhi, 860000, China
| | - Zong Yongchen
- Water Conservancy Project & Civil Engineering College, Tibet Agriculture & Animal Husbandry University, Linzhi, 860000, China.
| | - He Qiang
- Water Conservancy Project & Civil Engineering College, Tibet Agriculture & Animal Husbandry University, Linzhi, 860000, China.
| | - Guo Mingzhe
- Water Conservancy Project & Civil Engineering College, Tibet Agriculture & Animal Husbandry University, Linzhi, 860000, China
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30
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Zhang H, Zhang SS, Zhu L, Li YP, Chen L. Phosphorus recovery in the alternating aerobic/anaerobic biofilm system: Performance and mechanism. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 810:152297. [PMID: 34896486 DOI: 10.1016/j.scitotenv.2021.152297] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/17/2021] [Accepted: 12/06/2021] [Indexed: 06/14/2023]
Abstract
To balance the high phosphorus concentration in recirculated solution and the stability of biofilm system, this study explored the performance and mechanism of phosphorus uptake/release for recovering phosphorus from sewage when the phosphorus content in biofilm (Pbiofilm) changed. The results showed that the maximum phosphorus concentration in the concentrated solution reached 171.2 ± 2.5 mg·L-1 in harvest 1st-5th stages. Polyphosphate accumulating organisms (PAOs) performed a metabolic shift from glycogen accumulation metabolism (GAM) to polyphosphate accumulation metabolism (PAM) when Pbiofilm increased at each phosphorus enrichment stage, and more phosphorus was absorbed/released by PAOs. Nevertheless, the release of poly-phosphate from PAOs was inhibited after phosphorus concentration stabilized, and PAOs were unable to absorb phosphorus from wastewater as it reached the phosphorus saturation stage. To maintain the stability of the system, phosphorus had to be harvested so that the saturated phosphorus in PAOs was easily released in a new recirculated solution, resulting in adequate storage space for PAOs to absorb phosphorus. Meanwhile, the 31P NMR analysis demonstrated that phosphorus was stored in EPS and cell of PAOs, whereas EPS played a significant role than cell at the anaerobic phase. Particularly, ortho-phosphate was the major component of phosphorus release by EPS and poly-phosphate was the major part of phosphorus release by cell. Furthermore, the change of Pbiofilm had no impact on biofilm characteristics and microbial communities, whereas some PAOs would be enriched, and others that were not suitable for this process would be inhibited with repeated cycles of alternating aerobic/anaerobic operation.
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Affiliation(s)
- Hao Zhang
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
| | | | - Liang Zhu
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China.
| | - Yi-Ping Li
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China.
| | - Lin Chen
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing 210098, China; College of Environment, Hohai University, Nanjing 210098, China
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31
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Song X, Yu D, Qiu Y, Qiu C, Xu L, Zhao J, Wang X. Unexpected phosphorous removal in a Candidatus_Competibacter and Defluviicoccus dominated reactor. BIORESOURCE TECHNOLOGY 2022; 345:126540. [PMID: 34902483 DOI: 10.1016/j.biortech.2021.126540] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/04/2021] [Accepted: 12/06/2021] [Indexed: 06/14/2023]
Abstract
Competition between polyphosphate- and glycogen-accumulating organisms (PAOs and GAOs) is problematic in the enhanced biological phosphorus removal (EBPR) process. Aiming at a high phosphorus removal efficiency (PRE), the phosphorus release amount (PRA) is considered an essential evaluating indicator. However, the correlations between PRE and PRA and the abundance of PAOs are not clear. In this study, the EBPR was established and optimized via adjusting influent carbon to phosphorus ratio (C/P). After 110-day operation, 17.67 mg/L of PRA and 75.86% of PRE simultaneously achieved with influent C/P of 40 mgCOD/mgP. As for PAOs, Candidatus_Accumulibacter and Tetrasphaera were absent, while Hypomicrobium (3.69%), Pseudofulvimonas (1.02%), and unclassified_f_Rhodobacteraceae (2.41%) were found at a low level. On the contrary, Candidatus_Competibacter and Defluviicoccus were unexpectedly enriched with high abundance (24.94% and 16.04%, respectively). These results also suggested that it was difficult to distinguish whether PAOs were enriched merely based on the variations of PRA and PRE.
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Affiliation(s)
- Xia Song
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Deshuang Yu
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Yanling Qiu
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Chenguang Qiu
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Lingna Xu
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Ji Zhao
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China
| | - Xiaoxia Wang
- School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, PR China.
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32
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Zheng J, Wang N, Zhao L, Li Y, Yu J, Wang S. Microbial population changes and metabolic shift of candidatus accumulibacter under low temperature and limiting polyphosphate. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2022; 85:1107-1119. [PMID: 35228357 DOI: 10.2166/wst.2022.036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
This study explored the microbial population dynamics of Accumulibacter (Acc) at low temperature and metabolic shift to limiting polyphosphate (Poly-P) in enhanced biological phosphorus removal (EBPR) system. The Accumulibacter-enriched EBPR systems, fed with acetate (HAc) and propionate (HPr) at 10 ± 1 °C respectively, were operated for 60 days in two identical SBR reactors (SBR-1 and SBR-2). The phosphorus removal performance in two systems was stable at 10 ± 1 °C, while the microbial community structure changed. Compared with the population structure in seed sludge, Accumulibacter clades reduced in the HAc system, while Acc I increased significantly in the HPr system. Low temperature was beneficial to the formation of granular sludge in the EBPR system, and the sludge granulation in the HAc system was more homogeneous than that in the HPr system. Accumulibacter in the HPr system can get ATP through glycogen accumulating metabolism (GAM) under limiting Poly-P condition at 10 ± 1 °C, while that in the HAc system cannot. This work suggests that poly-P levels can affect the metabolic pathway of Accumulibacter in EBPR systems under low temperature.
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Affiliation(s)
- Jianfeng Zheng
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China E-mail: ; Tianjin Key Laboratory of Aquatic Science and Technology, Jinjing Road 26, Tianjin, China; Joint Research Centre for Protective Infrastructure Technology and Environmental Green Bioprocess, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China
| | - Nan Wang
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China E-mail: ; Tianjin Key Laboratory of Aquatic Science and Technology, Jinjing Road 26, Tianjin, China; Joint Research Centre for Protective Infrastructure Technology and Environmental Green Bioprocess, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China
| | - Ledan Zhao
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China E-mail: ; Tianjin Key Laboratory of Aquatic Science and Technology, Jinjing Road 26, Tianjin, China; Joint Research Centre for Protective Infrastructure Technology and Environmental Green Bioprocess, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China
| | - Yajing Li
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China E-mail: ; Tianjin Key Laboratory of Aquatic Science and Technology, Jinjing Road 26, Tianjin, China; Joint Research Centre for Protective Infrastructure Technology and Environmental Green Bioprocess, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China
| | - Jingjie Yu
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China E-mail: ; Tianjin Key Laboratory of Aquatic Science and Technology, Jinjing Road 26, Tianjin, China; Joint Research Centre for Protective Infrastructure Technology and Environmental Green Bioprocess, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China
| | - Shaopo Wang
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Jinjing Road 26, Tianjin 300384, China E-mail: ; Tianjin Key Laboratory of Aquatic Science and Technology, Jinjing Road 26, Tianjin, China; Joint Research Centre for Protective Infrastructure Technology and Environmental Green Bioprocess, School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin 300384, China
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Massoompour AR, Raie M, Borghei SM, Dewil R, Appels L. Role of carrier characteristics affecting microbial density and population in enhanced nitrogen and phosphorus removal from wastewater. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 302:113976. [PMID: 34749080 DOI: 10.1016/j.jenvman.2021.113976] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 10/16/2021] [Accepted: 10/17/2021] [Indexed: 06/13/2023]
Abstract
This research aims to improve simultaneous nitrification-denitrification and phosphorus removal (SNDPR) using novel carriers and to demonstrate the effect of carrier characteristics on nutrient removal in a biofilm reactor. For this purpose, biofilms enriched with both polyphosphate-accumulating organisms (PAOs) and nitrifiers were cultivated in two parallel sequencing batch reactors containing conventional moving bed bioreactor carriers (MBBR) and a novel type of carriers (carbon-based moving carriers (CBMC)). The new carriers were produced based on recycled waste materials via a chemical-thermal process and their specific surface area were 10.4 times higher than typical MBBR carriers of similar dimensions. The results showed that the use of CBMC carriers increased bacterial adhesion by about 18.5% and also affected the microbial population inside the biofilms, leading to an increase in PAOs abundancy and thus an increase in biological phosphorus removal up to 12.5%. Additionally, it was corroborated that the volume of the anoxic zones with dynamic behavior is strictly influenced by the carrier structure and biofilm thickness due to a limitation in oxygen penetration. Accordingly, the formation of broader anoxic zones and shrinkage of these zones to a lesser extent resulted in the continuation of anoxic reactions for longer periods using the novel carriers. Thereby, an increase in nitrogen removal by about 15% was obtained mainly by denitrifying PAOs. The results also exhibited that a higher simultaneous nitrification-denitrification (SND) efficiency can be achieved by selecting an appropriate aeration program influencing the dynamic changes of anoxic zones. Overall, a biofilm system using the new carriers, with phosphorus and nitrogen removal efficiencies of 97.5% and 92.3%, was presented as an efficient, compact, and simple operation SNDPR process.
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Affiliation(s)
- Ali Reza Massoompour
- Civil Engineering Department, Sharif University of Technology, Azadi Ave., P.O. Box. 11365-11155, Tehran, Iran.
| | - Mohammad Raie
- Civil Engineering Department, Sharif University of Technology, Azadi Ave., P.O. Box. 11365-11155, Tehran, Iran.
| | - S Mehdi Borghei
- Chemical and Petroleum Engineering Department, Sharif University of Technology, Azadi Ave., P.O. Box. 11365-11155, Tehran, Iran
| | - Raf Dewil
- KU Leuven, Department of Chemical Engineering, Process and Environmental Technology Lab, Jan Pieter De Nayerlaan 5, B-2860 Sint-Katelijne-Waver, Belgium
| | - Lise Appels
- KU Leuven, Department of Chemical Engineering, Process and Environmental Technology Lab, Jan Pieter De Nayerlaan 5, B-2860 Sint-Katelijne-Waver, Belgium
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34
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Izadi P, Izadi P, Eldyasti A. Evaluation of PAO adaptability to oxygen concentration change: Development of stable EBPR under stepwise low-aeration adaptation. CHEMOSPHERE 2022; 286:131778. [PMID: 34426132 DOI: 10.1016/j.chemosphere.2021.131778] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 07/13/2021] [Accepted: 08/01/2021] [Indexed: 06/13/2023]
Abstract
Recent research has shown the adaptability of Biological Nutrient Removal (BNR) systems to very low level dissolved oxygen (DO) concentration, mainly focusing in the nitrification ability that maintains the nitrogen oxidation process even at very low DO levels. Although step-wise aeration decrease on Enhanced Biological Phosphorus Removal (EBPR) is not fully comprehended. This study investigated the effect of reaching micro-aeration with adaptation strategies on EBPR performance. A step-wise oxygen concentration decrease, arriving at an average aeration level of 0.4 mgO2/L was evaluated, with an outcome of approximately 90 % phosphorus removal efficiency. Compared with different aeration modes, the highest phosphorus (P)-removal efficiency, P-release and lowest effluent phosphorus was achieved in gradual DO decrease strategy. On the other hand, an instant decrease in aeration from stable EBPR process from 2 mgO2/L to 0.4 mgO2/L adversely impacted P-removal by decreasing the efficiency to average 60 % and deteriorating the phosphorus removing microbial consortium. Comparison of results between instant and gradual DO-decrease, indicated the sensitivity of microorganisms to aeration. Microbial adaptation to decreased oxygen availability is crucial to reach high process performance. This study proposes, a potential aeration mode, which contributes in reduction of energy consumption in BNR systems through wastewater treatment.
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Affiliation(s)
- Parnian Izadi
- Civil Engineering, York University, 4700 Keele St, Toronto, M3J 1P3, ON, Canada.
| | - Parin Izadi
- Civil Engineering, York University, 4700 Keele St, Toronto, M3J 1P3, ON, Canada.
| | - Ahmed Eldyasti
- Civil Engineering, York University, 4700 Keele St, Toronto, M3J 1P3, ON, Canada.
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Rey-Martínez N, Merdan G, Guisasola A, Baeza JA. Nitrite and nitrate inhibition thresholds for a glutamate-fed bio-P sludge. CHEMOSPHERE 2021; 283:131173. [PMID: 34182653 DOI: 10.1016/j.chemosphere.2021.131173] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 04/30/2021] [Accepted: 06/06/2021] [Indexed: 06/13/2023]
Abstract
Enhanced biological phosphorus removal (EBPR) is an efficient and sustainable technology to remove phosphorus from wastewater. A widely known cause of EBPR deterioration in wastewater treatment plants (WWTPs) is the presence of nitrate/nitrite or oxygen in the anaerobic reactor. Moreover, most existing studies on the effect of either permanent aerobic conditions or inhibition of EBPR by nitrate or free nitrous acid (FNA) have been conducted with a "Candidatus Accumulibacter" or Tetrasphaera-enriched sludge, which are the two major reported groups of polyphosphate accumulating organisms (PAO) with key roles in full-scale EBPR WWTPs. This work reports the denitrification capabilities of a bio-P microbial community developed using glutamate as the sole source of carbon and nitrogen. This bio-P sludge exhibited a high denitrifying PAO (DPAO) activity, in fact, 56% of the phosphorus was uptaken under anoxic conditions. Furthermore, this mixed culture was able to use nitrite and nitrate as electron acceptor for P-uptake, being 1.8 μg HNO2-N·L-1 the maximum FNA concentration at which P-uptake can occur. Net P-removal was observed under permanent aerobic conditions. However, this microbial culture was more sensitive to FNA and permanent aerobic conditions compared to "Ca. Accumulibacter"-enriched sludge.
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Affiliation(s)
- Natalia Rey-Martínez
- GENOCOV. Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona, Spain.
| | - Gökçe Merdan
- GENOCOV. Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona, Spain; Department of Environmental Engineering, Namık Kemal University, Turkey.
| | - Albert Guisasola
- GENOCOV. Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona, Spain.
| | - Juan Antonio Baeza
- GENOCOV. Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona, Spain.
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Srinivasan VN, Li G, Wang D, Tooker NB, Dai Z, Onnis-Hayden A, Bott C, Dombrowski P, Schauer P, Pinto A, Gu AZ. Oligotyping and metagenomics reveal distinct Candidatus Accumulibacter communities in side-stream versus conventional full-scale enhanced biological phosphorus removal (EBPR) systems. WATER RESEARCH 2021; 206:117725. [PMID: 34653799 DOI: 10.1016/j.watres.2021.117725] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 09/23/2021] [Accepted: 09/24/2021] [Indexed: 06/13/2023]
Abstract
Candidatus Accumulibacter phosphatis (CAP) and its clade-level micro-diversity has been associated with and implicated in functional differences in phosphorus removal performance in enhanced biological phosphorus removal (EBPR) systems. Side-stream EBPR (S2EBPR) is an emerging process that has been shown to present a suite of advantages over the conventional EBPR design, however, large knowledge gaps remain in terms of its underlying ecological mechanisms. Here, we compared and revealed the higher-resolution differences in microbial ecology of CAP between a full-scale side-stream EBPR configuration and a conventional A2O EBPR process that were operated in parallel and with the same influent feed. Even though the relative abundance of CAP, revealed by 16S rRNA gene amplicon sequencing, was similar in both treatment trains, a clade-level analysis, using combined 16S rRNA-gene based amplicon sequencing and oligotyping analysis and metagenomics analysis, revealed the distinct CAP microdiversity between the S2EBPR and A2O configurations that likely attributed to the improved performance in S2EBPR in comparison to conventional EBPR. Furthermore, genome-resolved metagenomics enabled extraction of three metagenome-assembled genomes (MAGs) belonging to CAP clades IIB (RCAB4-2), IIC (RC14) and II (RC18), from full-scale EBPR sludge for the first time, including a distinct Ca. Accumulibacter clade that is dominant and associated only with the S2EBPR configuration. The results also revealed the temporally increasing predominance of RC14, which belonged to Clade IIC, during the implementation of the S2EBPR configuration. Finally, we also show the existence of previously uncharacterized diversity of clades of CAP, namely the clades IIB and as yet unidentified clade of type II, in full-scale EBPR communities, highlighting the unknown diversity of CAP communities in full-scale EBPR systems.
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Affiliation(s)
- Varun N Srinivasan
- Department of Civil and Environmental Engineering, Northeastern University, Boston, MA 02115, United States; Brown and Caldwell, One Tech Drive, Andover, MA 01810, United States
| | - Guangyu Li
- Department of Civil and Environmental Engineering, Northeastern University, Boston, MA 02115, United States
| | - Dongqi Wang
- Department of Civil and Environmental Engineering, Northeastern University, Boston, MA 02115, United States; State Key Laboratory of Eco-hydraulics in Northwest Arid Region, Xi'an University of Technology, Xi'an, Shaanxi 710048, China
| | - Nicholas B Tooker
- Department of Civil and Environmental Engineering, Northeastern University, Boston, MA 02115, United States; Department of Civil and Environmental Engineering, University of Massachusetts-Amherst, Amherst, MA 01002, United States
| | - Zihan Dai
- Infrastructure and Environment Division, University of Glasgow, Glasgow G12 8LT, United Kingdom
| | - Annalisa Onnis-Hayden
- Department of Civil and Environmental Engineering, Northeastern University, Boston, MA 02115, United States
| | - Charles Bott
- Hampton Roads Sanitation District, 1434 Air Rail Avenue, Virginia Beach, VA 23454, United States
| | - Paul Dombrowski
- Woodard & Curran, Inc., 1699 King Street, Enfield, CT 06082, United States
| | - Peter Schauer
- Clean Water Services, 16060 SW 85th Avenue, Tigard, OR 97224, United States
| | - Ameet Pinto
- Department of Civil and Environmental Engineering, Northeastern University, Boston, MA 02115, United States; Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30318, United States
| | - April Z Gu
- Department of Civil and Environmental Engineering, Northeastern University, Boston, MA 02115, United States; Civil and Environmental Engineering, Cornell University, Ithaca NY 14853, United States.
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37
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Lu X, Duan H, Oehmen A, Carvalho G, Yuan Z, Ye L. Achieving combined biological short-cut nitrogen and phosphorus removal in a one sludge system with side-stream sludge treatment. WATER RESEARCH 2021; 203:117563. [PMID: 34419918 DOI: 10.1016/j.watres.2021.117563] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 08/01/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
Biological nitrogen (N) removal via the short-cut pathway (NH4+-N→NO2--N→N2) is economically attractive in wastewater treatment plants (WWTPs). However, biological phosphorus (P) removal processes remain a bottleneck in these systems due to the strong inhibitory effect of nitrite or its protonated form (HNO2, free nitrous acid - FNA) on polyphosphate accumulating organisms (PAOs). In this study, a novel combined nitrogen and phosphorus removal strategy was verified and achieved in a biological short-cut nitrogen removal system via side-stream sludge treatment with FNA, and the mechanisms impacting this process were investigated. The side-stream FNA treatment process applied here led to a significant reduction in the real sludge retention time (SRT) in the mainstream (approximately 2.7 days) based on the biocidal effect of FNA to the majority of the organisms. This work also found that around 40% of the P uptake activity was still maintained at a much higher FNA level of 38 μg N/L with potential PAOs, which highly broadened the current knowledge of PAOs community. An economic analysis revealed advantages of the proposed as compared to conventional biological nitrogen and phosphorus removal (13% savings in total cost), biological short-cut nitrogen removal (via FNA treatment) with chemical phosphorus precipitation (21% savings) and conventional biological nitrogen removal with chemical precipitation (27% savings). Overall, this study presents a novel and viable retrofit strategy in integrating biological short-cut nitrogen removal with EBPR for next generation WWTPs.
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Affiliation(s)
- Xuanyu Lu
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia; School of Chemical Engineering, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Haoran Duan
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia; School of Chemical Engineering, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Adrian Oehmen
- School of Chemical Engineering, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Gilda Carvalho
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Zhiguo Yuan
- Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Liu Ye
- School of Chemical Engineering, The University of Queensland, St. Lucia, QLD 4072, Australia.
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38
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Long XY, Tang R, Wang T, Tao GJ, Wang JY, Zhou HW, Xue M, Yu YP. Characteristics of enhanced biological phosphorus removal (EBPR) process under the combined actions of intracellular and extracellular polyphosphate. CHEMOSPHERE 2021; 279:130912. [PMID: 34134440 DOI: 10.1016/j.chemosphere.2021.130912] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/23/2021] [Accepted: 05/13/2021] [Indexed: 06/12/2023]
Abstract
The characteristics of enhanced biological phosphorus removal (EBPR) process under the combined actions of intracellular and extracellular polyphosphate (polyP) were investigated with the 31P Nuclear Magnetic Resonance (NMR) and the fractionation extracting the loosely-bound and tightly-bound extracellular polymer substances (i.e., LB-EPS and TB-EPS) and bacterial cells in EBPR sludge. The hydrolysis/synthesis of extracellular and intracellular polyP was a key step of the phosphate migration and transformation in EBPR sludge. The orthophosphate (orthoP) produced from the intracellular and extracellular polyP anaerobic-hydrolysis was partially accumulated in the bacterial cells and TB-EPS, and then the accumulated orthoP was main composition for these polyP aerobic-synthesis. Importantly, the anaerobic-hydrolysis enhancement of intracellular and extracellular ployP could promote EBPR sludge to absorb volatile fatty acids (VFAs) followed by being transformed into intracellular poly-hydroxy-alkanoates (PHAs). The mechanism for VFAs passing through the LB-EPS and TB-EPS should be an anion-exchange action between orthoP and VFAs. The orthoP accumulation in the TB-EPS kept an orthoP concentration gradient among the TB-EPS, LB-EPS and bulk solution, driving orthoP and VFAs migrations. The orthoP accumulation in the bacterial cells could keep an orthoP concentration difference between the cell-membrane two sides of phosphorus accumulating organisms (PAOs) to promote VFAs passing through the cell membrane considered as an anion exchange membrane. The intracellular PHAs continuously hydrolyzed accompanied with the average chain-length increases of the extracellular and intracellular polyP during the whole aerobic stage. Additionally, the energy of the extracellular polyP synthesized in situ should came from the intracellular PHAs hydrolysis.
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Affiliation(s)
- Xiang-Yu Long
- Department of Military Installation, Army Logistics Academy of the People's Liberation Army, University Town, Shapingba District, Chongqing, 401311, China.
| | - Ran Tang
- College of Chemistry and Chemical Engineering, Chongqing University of Science and Technology, University Town, Shapingba District, Chongqing, 401331, China.
| | - Tao Wang
- Department of Military Installation, Army Logistics Academy of the People's Liberation Army, University Town, Shapingba District, Chongqing, 401311, China.
| | - Guang-Jian Tao
- Department of Military Installation, Army Logistics Academy of the People's Liberation Army, University Town, Shapingba District, Chongqing, 401311, China.
| | - Jia-Yue Wang
- Department of Military Installation, Army Logistics Academy of the People's Liberation Army, University Town, Shapingba District, Chongqing, 401311, China.
| | - Hai-Wei Zhou
- Department of Military Installation, Army Logistics Academy of the People's Liberation Army, University Town, Shapingba District, Chongqing, 401311, China.
| | - Ming Xue
- Department of Military Installation, Army Logistics Academy of the People's Liberation Army, University Town, Shapingba District, Chongqing, 401311, China.
| | - Yong-Ping Yu
- Department of Military Installation, Army Logistics Academy of the People's Liberation Army, University Town, Shapingba District, Chongqing, 401311, China.
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Metabolic Differentiation of Co-occurring Accumulibacter Clades Revealed through Genome-Resolved Metatranscriptomics. mSystems 2021; 6:e0047421. [PMID: 34227830 PMCID: PMC8407102 DOI: 10.1128/msystems.00474-21] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Natural microbial communities consist of closely related taxa that may exhibit phenotypic differences and inhabit distinct niches. However, connecting genetic diversity to ecological properties remains a challenge in microbial ecology due to the lack of pure cultures across the microbial tree of life. "Candidatus Accumulibacter phosphatis" (Accumulibacter) is a polyphosphate-accumulating organism that contributes to the enhanced biological phosphorus removal (EBPR) biotechnological process for removing excess phosphorus from wastewater and preventing eutrophication from downstream receiving waters. Distinct Accumulibacter clades often coexist in full-scale wastewater treatment plants and laboratory-scale enrichment bioreactors and have been hypothesized to inhabit distinct ecological niches. However, since individual strains of the Accumulibacter lineage have not been isolated in pure culture to date, these predictions have been made solely on genome-based comparisons and enrichments with varying strain compositions. Here, we used genome-resolved metagenomics and metatranscriptomics to explore the activity of coexisting Accumulibacter strains in an engineered bioreactor environment. We obtained four high-quality genomes of Accumulibacter strains that were present in the bioreactor ecosystem, one of which is a completely contiguous draft genome scaffolded with long Nanopore reads. We identified core and accessory genes to investigate how gene expression patterns differed among the dominating strains. Using this approach, we were able to identify putative pathways and functions that may confer distinct functions to Accumulibacter strains and provide key functional insights into this biotechnologically significant microbial lineage. IMPORTANCE "Candidatus Accumulibacter phosphatis" is a model polyphosphate-accumulating organism that has been studied using genome-resolved metagenomics, metatranscriptomics, and metaproteomics to understand the EBPR process. Within the Accumulibacter lineage, several similar but diverging clades are defined by the shared sequence identity of the polyphosphate kinase (ppk1) locus. These clades are predicted to have key functional differences in acetate uptake rates, phage defense mechanisms, and nitrogen-cycling capabilities. However, such hypotheses have largely been made based on gene content comparisons of sequenced Accumulibacter genomes, some of which were obtained from different systems. Here, we performed time series genome-resolved metatranscriptomics to explore gene expression patterns of coexisting Accumulibacter clades in the same bioreactor ecosystem. Our work provides an approach for elucidating ecologically relevant functions based on gene expression patterns between closely related microbial populations.
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Kolakovic S, Freitas EB, Reis MAM, Carvalho G, Oehmen A. Accumulibacter diversity at the sub-clade level impacts enhanced biological phosphorus removal performance. WATER RESEARCH 2021; 199:117210. [PMID: 34004444 DOI: 10.1016/j.watres.2021.117210] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 04/07/2021] [Accepted: 04/26/2021] [Indexed: 06/12/2023]
Abstract
Accumulibacter is a well-known group of organisms, typically considered to be polyphosphate accumulating organisms (PAOs), but potentially capable of glycogen accumulating organism (GAO) metabolism under limiting influent phosphate levels. Metabolic features of Accumulibacter are typically linked to its phylogenetic identity at the Type or clade level, though it is unclear the extent to which Accumulibacter diversity can correlate with its capacity to perform P removal. This paper investigates the fine-scale diversity of Accumulibacter and its link with enhanced biological phosphorus removal (EBPR) performance under various operating conditions, to understand the conditions and community structure leading to successful and unsuccessful EBPR operation. For this purpose, the organic carbon feeding rate and total organic carbon concentration were varied during three distinct operational periods, where influent phosphate was never limiting. Accumulibacter was always the dominant microbial group (>80% of all bacteria according to quantitative fluorescence in situ hybridisation - FISH) and low levels of Competibacter and other GAOs were consistently observed (<15% of all bacteria). Steady state was achieved in each of the three periods, with average phosphorus removal levels of 36%, 99% and >99%, respectively. Experimentally determined stoichiometric activity supported the expression of a mixed PAO/GAO metabolism in the first steady state period and the typical PAO metabolism in the other two steady state periods. FISH quantification and amplicon sequencing of the polyphosphate kinase (ppk1) functional gene indicated that Accumulibacter clade IIC was selected in the first steady state period, which shifted to clade IA after decreasing the carbon feeding rate in steady state period 2, and finally shifted back to clade IIC in the third steady state period. Fine-resolution Ppk-based phylogenetic analysis revealed three different clusters within Accumulibacter clade IIC, where clusters IICii and IICiii were linked to poor EBPR performance in period 1, and cluster IICi was linked to good EBPR performance in period 3. This study shows that the deterioration of EBPR processes through GAO activity at non-limiting P concentrations can be linked to organisms that are typically classified as PAOs, not only to known GAOs such as Competibacter. Intra-clade phylogenetic diversity within Accumulibacter showed that some clusters actually behave similarly to GAOs even without influent phosphate limitation. This study highlights the need to closely re-examine traditional interpretations regarding the link between the microbial community composition and identity with the performance and metabolism of EBPR systems.
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Affiliation(s)
- Srdana Kolakovic
- UCIBIO, REQUIMTE, Department of Chemistry, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Elisabete B Freitas
- UCIBIO, REQUIMTE, Department of Chemistry, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Maria A M Reis
- UCIBIO, REQUIMTE, Department of Chemistry, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Gilda Carvalho
- UCIBIO, REQUIMTE, Department of Chemistry, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal; Advanced Water Management Centre (AWMC), The University of Queensland, St Lucia, Queensland, 4072, Australia
| | - Adrian Oehmen
- UCIBIO, REQUIMTE, Department of Chemistry, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal; School of Chemical Engineering, The University of Queensland, St Lucia, Queensland, 4072, Australia.
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41
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Izadi P, Izadi P, Eldyasti A. A review of biochemical diversity and metabolic modeling of EBPR process under specific environmental conditions and carbon source availability. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 288:112362. [PMID: 33831633 DOI: 10.1016/j.jenvman.2021.112362] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 02/25/2021] [Accepted: 03/09/2021] [Indexed: 05/25/2023]
Abstract
Enhanced biological phosphorus removal (EBPR) is one of the most promising technologies as an economical and environmentally sustainable technique for removal of phosphorus from wastewater (WW). However, with high capacity of EBPR, insufficient P-removal is a major yet common issue of many full-scale wastewater treatment plants (WWTP), due to misinterpreted environmental and microbial disturbance. By developing a rather extensive understanding on biochemical pathways and metabolic models governing the anaerobic and aerobic/anoxic processes; the optimal operational conditions, environmental changes and microbial population interaction are efficiently predicted. Therefore, this paper critically reviews the current knowledge on biochemical pathways and metabolic models of phosphorus accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) as the most abundant microbial populations in EBPR process with an insight on the effect of available carbon source types in WW on phosphorus removal performance. Moreover, this paper critically assesses the gaps and potential future research in metabolic modeling area. With all the developments on EBPR process in the past few decades, there is still lack of knowledge in this critical sector. This paper hopes to touch on this problem by gathering the existing knowledge and to provide farther insights on the future work onto chemical transformations and metabolic strategies in different conditions to benefit the quantitative model as well as WWTP designs.
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Affiliation(s)
- Parnian Izadi
- Civil engineering, York university, 4700 Keele St, Toronto, M3J 1P3, ON, Canada.
| | - Parin Izadi
- Civil engineering, York university, 4700 Keele St, Toronto, M3J 1P3, ON, Canada.
| | - Ahmed Eldyasti
- Civil engineering, York university, 4700 Keele St, Toronto, M3J 1P3, ON, Canada.
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Roy S, Guanglei Q, Zuniga-Montanez R, Williams RB, Wuertz S. Recent advances in understanding the ecophysiology of enhanced biological phosphorus removal. Curr Opin Biotechnol 2021; 67:166-174. [PMID: 33582603 DOI: 10.1016/j.copbio.2021.01.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 01/11/2021] [Accepted: 01/12/2021] [Indexed: 01/02/2023]
Abstract
Enhanced biological phosphorus removal (EBPR) is an efficient, cost-effective, and sustainable method for removing excess phosphorus from wastewater. Polyphosphate accumulating organisms (PAOs) exhibit a unique physiology alternating between anaerobic conditions for uptake of carbon substrates and aerobic or anoxic conditions for phosphorus uptake. The implementation of high-throughput sequencing technologies and advanced molecular tools along with biochemical characterization has provided many new perspectives on the EBPR process. These approaches have helped identify a wide range of carbon substrates and electron acceptors utilized by PAOs that in turn influence interactions with microbial community members and determine overall phosphorus removal efficiency. In this review, we systematically discuss the microbial diversity and metabolic response to a range of environmental conditions and process control strategies in EBPR.
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Affiliation(s)
- Samarpita Roy
- Singapore Centre for Environmental Life Sciences Engineering, National University of Singapore, Singapore 119077, Singapore
| | - Qiu Guanglei
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Rogelio Zuniga-Montanez
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore; Department of Civil and Environmental Engineering, University of California, One Shields Avenue, Davis, CA 95616, United States
| | - Rohan Bh Williams
- Singapore Centre for Environmental Life Sciences Engineering, National University of Singapore, Singapore 119077, Singapore
| | - Stefan Wuertz
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore; Department of Civil and Environmental Engineering, University of California, One Shields Avenue, Davis, CA 95616, United States; School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 639798, Singapore.
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Mohamed AYA, Welles L, Siggins A, Healy MG, Brdjanovic D, Rada-Ariza AM, Lopez-Vazquez CM. Effects of substrate stress and light intensity on enhanced biological phosphorus removal in a photo-activated sludge system. WATER RESEARCH 2021; 189:116606. [PMID: 33189975 DOI: 10.1016/j.watres.2020.116606] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 11/03/2020] [Accepted: 11/04/2020] [Indexed: 06/11/2023]
Abstract
Photo-activated sludge (PAS) systems are an emerging wastewater treatment technology where microalgae provide oxygen to bacteria without the need for external aeration. There is limited knowledge on the optimal conditions for enhanced biological phosphorus removal (EBPR) in systems containing a mixture of polyphosphate accumulating organisms (PAOs) and microalgae. This research aimed to study the effects of substrate composition and light intensity on the performance of a laboratory-scale EBPR-PAS system. Initially, a model-based design was developed to study the effect of organic carbon (COD), inorganic carbon (HCO3) and ammonium-nitrogen (NH4-N) in nitrification deprived conditions on phosphorus (P) removal. Based on the mathematical model, two different synthetic wastewater compositions (COD:HCO3:NH4-N: 10:20:1 and 10:10:4) were examined at a light intensity of 350 µmol m-2 sec-1. Add to this, the performance of the system was also investigated at light intensities: 87.5, 175, and 262.5 µmol m-2 sec-1 for short terms. Results showed that wastewater having a high level of HCO3 and low level of NH4-N (ratio of 10:20:1) favored only microalgal growth, and had poor P removal due to a shortage of NH4-N for PAOs growth. However, lowering the HCO3 level and increasing the NH4-N level (ratio of 10:10:4) balanced PAOs and microalgae symbiosis, and had a positive influence on P removal. Under this mode of operation, the system was able to operate without external aeration and achieved a net P removal of 10.33 ±1.45 mg L-1 at an influent COD of 100 mg L-1. No significant variation was observed in the reactor performance for different light intensities, indicating the EBPR-PAS system can be operated at low light intensities with a positive influence on P removal.
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Affiliation(s)
- A Y A Mohamed
- Environmental Engineering and Water Technology Department. IHE Delft Institute for Water Education, Westvest 7, 2611 AX Delft, The Netherlands; Civil Engineering and Ryan Institute, College of Science and Engineering, NUI Galway, Republic of Ireland; Animal and Grassland Research and Innovation Centre, Teagasc, Moorepark, Fermoy, Co. Cork, Ireland.
| | - L Welles
- Environmental Engineering and Water Technology Department. IHE Delft Institute for Water Education, Westvest 7, 2611 AX Delft, The Netherlands
| | - A Siggins
- Civil Engineering and Ryan Institute, College of Science and Engineering, NUI Galway, Republic of Ireland
| | - M G Healy
- Civil Engineering and Ryan Institute, College of Science and Engineering, NUI Galway, Republic of Ireland
| | - D Brdjanovic
- Environmental Engineering and Water Technology Department. IHE Delft Institute for Water Education, Westvest 7, 2611 AX Delft, The Netherlands; Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629 HZ, Delft, the Netherlands
| | - A M Rada-Ariza
- Environmental Engineering and Water Technology Department. IHE Delft Institute for Water Education, Westvest 7, 2611 AX Delft, The Netherlands
| | - C M Lopez-Vazquez
- Environmental Engineering and Water Technology Department. IHE Delft Institute for Water Education, Westvest 7, 2611 AX Delft, The Netherlands
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Revealing the Metabolic Flexibility of " Candidatus Accumulibacter phosphatis" through Redox Cofactor Analysis and Metabolic Network Modeling. Appl Environ Microbiol 2020; 86:AEM.00808-20. [PMID: 33008826 DOI: 10.1128/aem.00808-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 09/21/2020] [Indexed: 12/27/2022] Open
Abstract
Environmental fluctuations in the availability of nutrients lead to intricate metabolic strategies. "Candidatus Accumulibacter phosphatis," a polyphosphate-accumulating organism (PAO) responsible for enhanced biological phosphorus removal (EBPR) from wastewater treatment systems, is prevalent in aerobic/anaerobic environments. While the overall metabolic traits of these bacteria are well described, the nonavailability of isolates has led to controversial conclusions on the metabolic pathways used. In this study, we experimentally determined the redox cofactor preferences of different oxidoreductases in the central carbon metabolism of a highly enriched "Ca Accumulibacter phosphatis" culture. Remarkably, we observed that the acetoacetyl coenzyme A reductase engaged in polyhydroxyalkanoate (PHA) synthesis is NADH preferring instead of showing the generally assumed NADPH dependency. This allows rethinking of the ecological role of PHA accumulation as a fermentation product under anaerobic conditions and not just a stress response. Based on previously published metaomics data and the results of enzymatic assays, a reduced central carbon metabolic network was constructed and used for simulating different metabolic operating modes. In particular, scenarios with different acetate-to-glycogen consumption ratios were simulated, which demonstrated optima using different combinations of glycolysis, glyoxylate shunt, or branches of the tricarboxylic acid (TCA) cycle. Thus, optimal metabolic flux strategies will depend on the environment (acetate uptake) and on intracellular storage compound availability (polyphosphate/glycogen). This NADH-related metabolic flexibility is enabled by the NADH-driven PHA synthesis. It allows for maintaining metabolic activity under various environmental substrate conditions, with high carbon conservation and lower energetic costs than for NADPH-dependent PHA synthesis. Such (flexible) metabolic redox coupling can explain the competitiveness of PAOs under oxygen-fluctuating environments.IMPORTANCE Here, we demonstrate how microbial storage metabolism can adjust to a wide range of environmental conditions. Such flexibility generates a selective advantage under fluctuating environmental conditions. It can also explain the different observations reported in PAO literature, including the capacity of "Ca Accumulibacter phosphatis" to act like glycogen-accumulating organisms (GAOs). These observations stem from slightly different experimental conditions, and controversy arises only when one assumes that metabolism can operate only in a single mode. Furthermore, we also show how the study of metabolic strategies is possible when combining omics data with functional cofactor assays and modeling. Genomic information can only provide the potential of a microorganism. The environmental context and other complementary approaches are still needed to study and predict the functional expression of such metabolic potential.
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Li H, Zhong Y, Huang H, Tan Z, Sun Y, Liu H. Simultaneous nitrogen and phosphorus removal by interactions between phosphate accumulating organisms (PAOs) and denitrifying phosphate accumulating organisms (DPAOs) in a sequencing batch reactor. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 744:140852. [PMID: 32702541 DOI: 10.1016/j.scitotenv.2020.140852] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/07/2020] [Accepted: 07/08/2020] [Indexed: 06/11/2023]
Abstract
The identification of phosphate-accumulating organisms (PAOs), denitrifying phosphate-accumulating organisms (DPAOs) and their relationship is a key pathway for optimizing nitrate and phosphate removal efficiency in activated sludge. In this study, the acclimatization of microorganisms in sequencing batch reactor were performed with anaerobic/aerobic (A/O) and anaerobic/anoxic (A/A) cycles, the biomass changes of PAOs and DPAOs and the correlations were then discussed. The results indicated that after acclimatization, the nutrient removal efficiencies reached to 85.34% (COD), 93.64% (PO43--P) and 92.34% (NO3--N), respectively, with NO3--N:PO43-P of 1.5:1. The successful enrichment of PAOs and DPAOs (reached 97.9%) was verified by the change of relative metabolic activities, which was further proved by the change of bacterial diversity. The number of Candidatus Accumulibacter, Zoogloea, and Dechloromonas all increased at A/O and A/A stages while the number of Acinetobacter only increased at A/O stage. So Accumulibacter sp. was DPAO while Acinetobacter sp. was only PAO in this process, and genera Accumulibacter, Dechloromonas and Zoogloea greatly coordinated in denitrification and accumulating phosphorous though RDA and chord plot. This was worthy of attention and development to explore enhanced biological phosphorus removal (EBPR) in practical wastewater treatment via improving identification of bacterial species and symbiosis of bacteria community.
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Affiliation(s)
- Huankai Li
- Innovative Institute of Animal Healthy Breeding, Department of Environmental Science and Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China; Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau SAR 999078, China
| | - Yuming Zhong
- Innovative Institute of Animal Healthy Breeding, Department of Environmental Science and Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Hui Huang
- Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Macau SAR 999078, China
| | - Zexing Tan
- Innovative Institute of Animal Healthy Breeding, Department of Environmental Science and Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Yan Sun
- Guangdong Institute of Eco-environmental Science & Technology, Guangzhou, Guangdong 510650, China
| | - Hui Liu
- Innovative Institute of Animal Healthy Breeding, Department of Environmental Science and Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China.
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Majed N, Gu AZ. Phenotypic dynamics in polyphosphate and glycogen accumulating organisms in response to varying influent C/P ratios in EBPR systems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 743:140603. [PMID: 32758819 DOI: 10.1016/j.scitotenv.2020.140603] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 06/17/2020] [Accepted: 06/27/2020] [Indexed: 06/11/2023]
Abstract
This study employed molecular tools and single cell Raman micro-spectroscopy techniques to reveal the single cell- and population-level phenotypic dynamics and changes in functionally relevant organisms, namely polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs), in response to influent loading readily biodegradable carbon to phosphorus ratio (C/P) changes in enhanced biological phosphorus removal (EBPR) systems. The results, for the first time, provided direct and cellular evidence confirming the adaptive anaerobic metabolic pathway shifts in PAOs in response to influent loading variations. Increase in influent readily biodegradable carbon to phosphorus (C/P) ratio from 20 to 50 led to nearly 50% decline in polyphosphate content and drastic rise of intracellular polyβhydroxybutyrate (PHB) to polyphosphate (polyP) ratio by nearly 6 times in PAOs, indicating corresponding diminishing reliance on polyP hydrolysis for energy as P becomes limiting. Influent carbon availability surge also impacted the intracellular carbon polymers in GAOs, with significant increase in the mean PHB content level but no observed changes in the intracellular glycogen level. Furthermore, the Raman-based quantification of differentiated intracellular polymer content associated with PAOs and GAOs, revealed new insights into the quantitative shift in intracellular carbon storage distribution between the two populations and their variations between the two carbon polymers (PHB, Glycogen). In summary, this investigation revealed high-resolution cellular level information regarding the metabolic flexibility in PAOs, phenotypic stoichiometry changes and carbon flux and distribution among PAOs and GAOs, in response to influent loading conditions. The new information will contribute to improvement in mechanistic EBPR modeling and design.
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Affiliation(s)
- Nehreen Majed
- Department of Civil Engineering, University of Asia Pacific, 74/A Green Road, Dhaka 1205, Bangladesh; Department of Civil & Environmental Engineering, Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA.
| | - April Z Gu
- Department of Civil & Environmental Engineering, Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA.
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Wu Z, Guo G, Kumar Biswal B, Dai J, Chen G. Denitrifying sulfur conversion-EBPR (DS-EBPR) process for treatment of seawater-based highly saline wastewater: Evaluation on performance, kinetics and microbial community structure. BIORESOURCE TECHNOLOGY 2020; 313:123574. [PMID: 32512430 DOI: 10.1016/j.biortech.2020.123574] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/19/2020] [Accepted: 05/21/2020] [Indexed: 06/11/2023]
Abstract
DS-EBPR is an alternative to the conventional activated sludge process which face great challenge for treatment of seawater-based highly saline wastewater. This study aims to investigate the impacts of long-term (248 days) 20% and 30% seawater fractions and short-term shock of 30%, 40%, 70% and 100% seawater fractions (corresponding to 1.0, 1.4, 2.5 and 3.5% of salinity) on the DS-EBPR performance, kinetics and microbial community structure. Long-term operation with high fraction (30%) of seawater marginally decreased the sulfur conversion and phosphorus uptake, which correlated well with the microbial dynamics. Temporal salinity shock from 1.0% (30% seawater) to 3.5% (100% seawater) remarkably reduced the phosphorus release/uptake by 36-44%, which was partly due to the decrease in the abundance of functional bacteria and chlorapatite (Ca5[PO4]3Cl) forming as P precipitates with 70-100% seawater addition. The formed chlorapatite contributed to approximately 8-26% of total P removal estimated by X-ray photoelectron spectroscopy analysis.
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Affiliation(s)
- Zhongwei Wu
- Department of Civil & Environmental Engineering and Hong Kong Branch of the Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Gang Guo
- School of Environmental Science and Engineering, Huazhong University of Science and Technology (HUST), Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China.
| | - Basanta Kumar Biswal
- Department of Civil & Environmental Engineering and Hong Kong Branch of the Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Ji Dai
- Department of Civil & Environmental Engineering and Hong Kong Branch of the Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Guanghao Chen
- Department of Civil & Environmental Engineering and Hong Kong Branch of the Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Hong Kong, China
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Wang B, Jiao E, Guo Y, Zhang L, Meng Q, Zeng W, Peng Y. Investigation of the polyphosphate-accumulating organism population in the full-scale simultaneous chemical phosphorus removal system. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:37877-37886. [PMID: 32617817 DOI: 10.1007/s11356-020-09912-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 06/26/2020] [Indexed: 06/11/2023]
Abstract
The simultaneous chemical phosphorus removal (SCPR) process has been widely applied in wastewater treatment plants (WWTPs) due to the high phosphorus removal efficiency through the synergy of biological and chemical phosphorus removal (BPR and CPR). However, phosphorus removal reagents could affect the bacterial community structure in the SCPR system and further affect the BPR process. The BPR phenotypes and community structures in the SCPR system, especially the population of polyphosphate-accumulating organisms (PAOs), are not completely clear. In order to clarify these problems, the phosphorus removal performance and the PAO population in a full-scale SCPR system were investigated. Results showed that diverse PAOs still existed in the SCPR system though the BPR phenotypes were not observed. However, the relative abundances of Accumulibacter and Tetrasphaera, the two most important genera of PAOs, were only 0.59% and 0.20%, respectively, while the relative abundances of Competibacter and Defluviicoccus, two genera of glycogen-accumulating organisms (GAOs), were as high as 5.77% and 1.28%, respectively. Batch tests showed that PAOs in the SCPR system still had a certain polyphosphate accumulating metabolic activity, which could gradually recover after stopping the addition of chemical reagents. This study provided a microbiological basis for the SCPR system to recover the enhanced biological phosphorus removal (EBPR) performance under suitable conditions, which could reduce the dosage of chemical reagents and the operational cost.
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Affiliation(s)
- Baogui Wang
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Department of Environmental Engineering, Beijing University of Technology, No.100 Pingleyuan, Chaoyang District, Beijing, 100124, China
| | - Erlong Jiao
- Beijing Drainage Group Co., Ltd., Beijing, 100037, China
| | - Yu Guo
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Department of Environmental Engineering, Beijing University of Technology, No.100 Pingleyuan, Chaoyang District, Beijing, 100124, China
| | - Lifang Zhang
- Beijing Drainage Group Co., Ltd., Beijing, 100037, China
| | - Qingan Meng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Department of Environmental Engineering, Beijing University of Technology, No.100 Pingleyuan, Chaoyang District, Beijing, 100124, China
| | - Wei Zeng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Department of Environmental Engineering, Beijing University of Technology, No.100 Pingleyuan, Chaoyang District, Beijing, 100124, China.
| | - Yongzhen Peng
- National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Department of Environmental Engineering, Beijing University of Technology, No.100 Pingleyuan, Chaoyang District, Beijing, 100124, China
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Insights into the effects of acetate on the community structure of Candidatus Accumulibacter in biological phosphorus removal system using DNA stable-isotope probing (DNA-SIP). Enzyme Microb Technol 2020; 139:109567. [DOI: 10.1016/j.enzmictec.2020.109567] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 11/22/2022]
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50
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Verhagen KJA, van Gulik WM, Wahl SA. Dynamics in redox metabolism, from stoichiometry towards kinetics. Curr Opin Biotechnol 2020; 64:116-123. [DOI: 10.1016/j.copbio.2020.01.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 01/05/2020] [Accepted: 01/06/2020] [Indexed: 12/12/2022]
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