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Chen R, Liu X, Wang J, Chen J, Wang X, Lv Y, Xu J, Wang S, Li D, He X, Hou J. Exploring organic matter conversion pathway and its effect on nitrogen removal in tidal flow constructed wetlands. CHEMOSPHERE 2024; 349:140927. [PMID: 38081523 DOI: 10.1016/j.chemosphere.2023.140927] [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: 10/08/2023] [Revised: 11/22/2023] [Accepted: 12/07/2023] [Indexed: 12/18/2023]
Abstract
Achieving effective nitrogen removal remains a significant challenge faced by constructed wetlands. Although organic matter is a crucial factor influencing nitrogen removal, little attention has been paid to the impact of organic matter conversion pathways on nitrogen removal in constructed wetlands. Here, we showed that endogenous microorganisms performing carbon internalization could be easily enriched in tidal flow constructed wetlands (TFCWs) under its special rhythmic cycle of anaerobic/aerobic operational mode. Endogenous microorganisms could translate influent carbon sources into intracellular carbons during the anaerobic stage and supply the carbon source for endogenous denitrification after the aerobic stage (rest period). Based on these findings, an innovative combined TFCW and Nitrifying-CW system was developed, and robust total nitrogen (TN) removal (82% on average) was achieved even under carbon source limiting conditions. This performance was a substantial improvement compared to the conventional single bed TFCW with multiple "tides" (corresponding to the multiple contact/rest periods) with TN removal of only 54% on average. Simultaneous nitrification-endogenous denitrification (SNED) was found to be the major nitrogen removal pathway in the proposed system. Compared with classical nitrification-denitrification, simultaneous nitrification-endogenous denitrification brings high nitrogen conversion rates and significantly reduces the demand for oxygen and organic carbon. Furthermore, microbial community analysis indicated that endogenous microorganisms such as Candidatus_Competibacter and Defluviicoccus were successfully enriched, accounting for 50.73% and 3.46% in CW1, and 25.25% and 1.76% in CW2, respectively. Together, these mechanisms allow the proposed system to achieve efficient TN removal.
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Affiliation(s)
- Ruiya Chen
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xueyu Liu
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jie Wang
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jieyu Chen
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xiaoning Wang
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yabing Lv
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
| | - Juchen Xu
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
| | - Shaodi Wang
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
| | - Dapeng Li
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China; Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan, 430070, China; Key Laboratory of Aquaculture Facilities Engineering, Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China
| | - Xugang He
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China; Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan, 430070, China; Key Laboratory of Aquaculture Facilities Engineering, Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China.
| | - Jie Hou
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China; Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Wuhan, 430070, China; Key Laboratory of Aquaculture Facilities Engineering, Ministry of Agriculture and Rural Affairs, Wuhan, 430070, China.
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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 Y, Celine Zhang Y, Hu X, Zhou Y, Bai Y, Xiang P, Zhang Z. Overlooked role in bacterial assembly of different-sized granules in same sequencing batch reactor: Insights into bacterial niche of nutrient removal. BIORESOURCE TECHNOLOGY 2024; 391:129992. [PMID: 37949147 DOI: 10.1016/j.biortech.2023.129992] [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: 09/19/2023] [Revised: 11/05/2023] [Accepted: 11/05/2023] [Indexed: 11/12/2023]
Abstract
The unique ecosystem within different-sized granules affects microbial assembly, which is crucial for wastewater treatment performance. This study operated an aerobic granular sludge system to evaluate its performance in treating synthetic municipal wastewater. Subsequently, the microbial community within different-sized granules was characterized to investigate bacterial assembly, and elucidated their biological potential for nutrient removal. The nutrient removal efficiencies were as follows: 93.8 ± 2.8 % chemical oxygen demand, 65.4 ± 4.0 % total nitrogen, and 93.8 ± 6.8 % total phosphorus. The analysis of microbial assembly unveiled remarkable diversity among different-sized sludges, the genus relative abundance displayed 61.4 % positive and 33.0 % negative correlation with sludge size. The excellent potential for organic degradation, denitrification, and polyphosphate accumulation occurred in sludge sizes of > 0.75 mm, 0.20-0.50 mm, and < 0.20 mm, respectively. Functional annotation further confirmed the nutrient removal potential within different-sized sludges. This study provides valuable insights into the bacterial niche of different-sized sludges, which can enhance their practical application.
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Affiliation(s)
- Yingying Zhou
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China; College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | | | - Xueli Hu
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Yuanhang Zhou
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Yun Bai
- College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Ping Xiang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China; College of Environment and Ecology, Chongqing University, Chongqing 400045, China
| | - Zhi Zhang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China; College of Environment and Ecology, Chongqing University, Chongqing 400045, China.
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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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Wang H, Lin L, Zhang L, Han P, Ju F. Microbiome assembly mechanism and functional potential in enhanced biological phosphorus removal system enriched with Tetrasphaera-related polyphosphate accumulating organisms. ENVIRONMENTAL RESEARCH 2023; 233:116494. [PMID: 37356531 DOI: 10.1016/j.envres.2023.116494] [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: 05/25/2023] [Revised: 06/17/2023] [Accepted: 06/22/2023] [Indexed: 06/27/2023]
Abstract
Tetrasphaera-related polyphosphate accumulating organisms (PAOs) are the key functional guilds for enhanced biological phosphorus removal (EBPR) systems. Their biomass enrichment can be enhanced by the nitrification inhibitor allylthiourea (ATU). However, the underlying assembly mechanism and the functional potential of the EBPR microbiome regulated by ATU are unclear. This study investigates the effect of ATU on microbiome assembly and functional potential by closely following the microbiota dynamics in an EBPR system enriched with Tetrasphaera-related PAOs for 288-days before, during and after ATU addition. The results showed that ATU addition increased microbiota structural similarity and compositional convergence, and enhanced determinism in the assembly of EBPR microbiome. During exposure to ATU, Tetrasphaera-related PAOs were governed by homogeneous selection and the dominant species revealed by 16S rRNA gene-based phylogenetic analysis shifted from clade III to clade I. Meanwhile, ATU supply promoted significant enrichment of functional genes involved in phosphate transport (pit) and polyphosphate synthesis and degradation (ppk1 and ppk2), whereas both Nitrosomonas and ammonia monooxygenase-encoding genes (amoA/B/C) assignable to this group of nitrifying bacteria decreased. Moreover, ATU addition relieved the significant abundance correlation between filamentous bacteria Ca. Promineofilum and denitrifying Brevundimonas (FDR-adjusted P < 0.01), damaging their potential synergic or cooperative interactions, thus weakening their competitiveness against Tetrasphaera-related PAOs. Notably, ATU withdrawn created opportunistic conditions for the unexpected explosive growth and predominance of Thiothrix filaments, leading to a serious bulking event. Our study provides new insights into the microbial ecology of Tetrasphaera-related PAOs in EBPR system, which could guide the establishment of an efficient microbiota for EBPR.
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Affiliation(s)
- Hui Wang
- Environmental Science and Engineering Department, Zhejiang University, Hangzhou, 310012, Zhejiang Province, China; Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, Hangzhou, 310030, Zhejiang Province, China; Center of Synthetic Biology and Integrated Bioengineering, Westlake University, Hangzhou, 310030, Zhejiang Province, China
| | - Limin Lin
- Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, Hangzhou, 310030, Zhejiang Province, China; Center of Synthetic Biology and Integrated Bioengineering, Westlake University, Hangzhou, 310030, Zhejiang Province, China
| | - Lu Zhang
- Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, Hangzhou, 310030, Zhejiang Province, China; Center of Synthetic Biology and Integrated Bioengineering, Westlake University, Hangzhou, 310030, Zhejiang Province, China
| | - Ping Han
- Key Laboratory of Geographic Information Science (Ministry of Education), School of Geographic Sciences, East China Normal University, Shanghai, China
| | - Feng Ju
- Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, Hangzhou, 310030, Zhejiang Province, China; Center of Synthetic Biology and Integrated Bioengineering, Westlake University, Hangzhou, 310030, Zhejiang Province, China; Institute of Advanced Technology, Westlake Institute for Advanced Study, Hangzhou, 310024, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, 310024, Zhejiang Province, China.
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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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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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Qiu G, Law Y, Zuniga-Montanez R, Deng X, Lu Y, Roy S, Thi SS, Hoon HY, Nguyen TQN, Eganathan K, Liu X, Nielsen PH, Williams RBH, Wuertz S. Global warming readiness: Feasibility of enhanced biological phosphorus removal at 35 °C. WATER RESEARCH 2022; 216:118301. [PMID: 35364353 DOI: 10.1016/j.watres.2022.118301] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 03/07/2022] [Accepted: 03/12/2022] [Indexed: 06/14/2023]
Abstract
Recent research has shown enhanced biological phosphorus removal (EBPR) from municipal wastewater at warmer temperatures around 30 °C to be achievable in both laboratory-scale reactors and full-scale treatment plants. In the context of a changing climate, the feasibility of EBPR at even higher temperatures is of interest. We operated two lab-scale EBPR sequencing batch reactors for > 300 days at 30 °C and 35 °C, respectively, and followed the dynamics of the communities of polyphosphate accumulating organisms (PAOs) and competing glycogen accumulating organisms (GAOs) using a combination of 16S rRNA gene metabarcoding, quantitative PCR and fluorescence in situ hybridization analyses. Stable and nearly complete phosphorus (P) removal was achieved at 30 °C; similarly, long term P removal was stable at 35 °C with effluent PO43-_P concentrations < 0.5 mg/L on half of all monitored days. Diverse and abundant Candidatus Accumulibacter amplicon sequence variants were closely related to those found in temperate environments, suggesting that EBPR at this temperature does not require a highly specialized PAO community. A slow-feeding strategy effectively limited the carbon uptake rates of GAOs, allowing PAOs to outcompete GAOs at both temperatures. Candidatus Competibacter was the main GAO, along with cluster III Defluviicoccus members. These organisms withstood the slow-feeding regime, suggesting that their bioenergetic characteristics of carbon uptake differ from those of their tetrad-forming relatives. Comparative cycle studies revealed higher carbon and P cycling activity of Ca. Accumulibacter when the temperature was increased from 30 °C to 35 °C, implying that the lowered P removal performance at 35 °C was not a direct effect of temperature, but a result of higher metabolic rates of carbon (and/or P) utilization of PAOs and GAOs, the resultant carbon deficiency, and escalated community competition. An increase in the TOC-to-PO43--P ratio (from 25:1 to 40:1) effectively eased the carbon deficiency and benefited PAOs. In general, a slow-feeding strategy and sufficiently high carbon input benefited a high and stable EBPR at 35 °C, representing basic conditions suitable for full-scale treatment plants experiencing higher water temperatures.
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Affiliation(s)
- Guanglei Qiu
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 637551, Singapore.
| | - Yingyu Law
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 637551, Singapore
| | - Rogelio Zuniga-Montanez
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 637551, Singapore; Department of Civil and Environmental Engineering, University of California, One Shields Avenue, Davis, CA 95616, United States
| | - Xuhan Deng
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Yang Lu
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 637551, Singapore
| | - Samarpita Roy
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 637551, Singapore
| | - Sara Swa Thi
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 637551, Singapore
| | - Hui Yi Hoon
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 637551, Singapore
| | - Thi Quynh Ngoc Nguyen
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 637551, Singapore
| | - Kaliyamoorthy Eganathan
- Singapore Centre for Environmental Life Sciences Engineering, National University of Singapore, 119077, Singapore
| | - Xianghui Liu
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 637551, Singapore
| | - Per H Nielsen
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 637551, Singapore; Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg DK-9220, Denmark
| | - Rohan B H Williams
- Singapore Centre for Environmental Life Sciences Engineering, National University of Singapore, 119077, Singapore
| | - Stefan Wuertz
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 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, 639798, Singapore.
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Chen L, Chen H, Hu Z, Tian Y, Wang C, Xie P, Deng X, Zhang Y, Tang X, Lin X, Li B, Wei C, Qiu G. Carbon uptake bioenergetics of PAOs and GAOs in full-scale enhanced biological phosphorus removal systems. WATER RESEARCH 2022; 216:118258. [PMID: 35320769 DOI: 10.1016/j.watres.2022.118258] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 03/01/2022] [Accepted: 03/04/2022] [Indexed: 06/14/2023]
Abstract
This work analyzed, for the first time, the bioenergetics of PAOs and GAOs in full-scale wastewater treatment plants (WWTPs) for the uptake of different carbon sources. Fifteen samples were collected from five full-scale WWTPs. Predominance of different PAOs, i.e., Ca. Accumulibacter (0.00-0.49%), Tetrasphaera (0.37-3.94%), Microlunatus phosphovorus (0.01-0.18%), etc., and GAOs, i.e., Ca. Competibacter (0.08-5.39%), Defluviicoccus (0.05-5.34%), Micropruina (0.17-1.87%), etc., were shown by 16S rRNA gene amplicon sequencing. Despite the distinct PAO/GAO community compositions in different samples, proton motive force (PMF) was found as the key driving force (up to 90.1%) for the uptake of volatile fatty acids (VFAs, acetate and propionate) and amino acids (glutamate and aspartate) by both GAOs and PAOs at the community level, contrasting the previous understanding that Defluviicoccus have a low demand of PMF for acetate uptake. For the uptake of acetate or propionate, PAOs rarely activated F1, F0- ATPase (< 11.7%) or fumarate reductase (< 5.3%) for PMF generation; whereas, intensive involvements of these two pathways (up to 49.2% and 61.0%, respectively) were observed for GAOs, highlighting a major and community-level difference in their VFA uptake biogenetics in full-scale systems. However, different from VFAs, the uptake of glutamate and aspartate by both PAOs and GAOs commonly involved fumarate reductase and F1, F0-ATPase activities. Apart from these major and community-level differences, high level fine-scale micro-diversity in carbon uptake bioenergetics was observed within PAO and GAO lineages, probably resulting from their versatilities in employing different pathways for reducing power generation. Ca. Accumulibacter and Halomonas seemed to show higher dependency on the reverse operation of F1, F0-ATPase than other PAOs, likely due to the low involvement of glyoxylate shunt pathway. Unlike Tetrasphaera, but similar to Ca. Accumulibacter, Microlunatus phosphovorus took up glutamate and aspartate via the proton/glutamate-aspartate symporter driven by PMF. This feature was testified using a pure culture of Microlunatus phosphovorus stain NM-1. The major difference between PAOs and GAOs highlights the potential to selectively suppress GAOs for community regulation in EBPR systems. The finer-scale carbon uptake bioenergetics of PAOs or GAOs from different lineages benefits in understanding their interactions in community assembly in complex environment.
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Affiliation(s)
- Liping Chen
- 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
| | - Zekun Hu
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Yucheng Tian
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Cenchao Wang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Peiran 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
| | - Yushen Zhang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Xia Tang
- Guangzhou Sewage Purification Co., Ltd, Guangzhou 510006, China
| | - Xueran Lin
- Guangzhou Sewage Purification Co., Ltd, Guangzhou 510006, China
| | - Biqing Li
- Guangzhou Sewage Purification Co., Ltd, Guangzhou 510006, China
| | - Chaohai Wei
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; Key Laboratory of Pollution Control and Ecological Restoration in Industrial Clusters, Ministry of Education, Guangzhou 510006, China
| | - Guanglei Qiu
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; Key Laboratory of Pollution Control and Ecological Restoration in Industrial Clusters, Ministry of Education, Guangzhou 510006, China.
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10
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Bessarab I, Maszenan AM, Haryono MAS, Arumugam K, Saw NMMT, Seviour RJ, Williams RBH. Comparative Genomics of Members of the Genus Defluviicoccus With Insights Into Their Ecophysiological Importance. Front Microbiol 2022; 13:834906. [PMID: 35495637 PMCID: PMC9041414 DOI: 10.3389/fmicb.2022.834906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 02/02/2022] [Indexed: 11/23/2022] Open
Abstract
Members of the genus Defluviicoccus occur often at high abundances in activated sludge wastewater treatment plants designed to remove phosphorus, where biomass is subjected to alternating anaerobic feed/aerobic famine conditions, believed to favor the proliferation of organisms like Ca. Accumulibacter and other phosphate-accumulating organisms (PAO), and Defluviicoccus. All have a capacity to assimilate readily metabolizable substrates and store them intracellularly during the anaerobic feed stage so that under the subsequent famine aerobic stage, these can be used to synthesize polyphosphate reserves by the PAO and glycogen by Defluviicoccus. Consequently, Defluviicoccus is described as a glycogen-accumulating organism or GAO. Because they share a similar anaerobic phenotype, it has been proposed that at high Defluviicoccus abundance, the PAO are out-competed for assimilable metabolites anaerobically, and hence aerobic P removal capacity is reduced. Several Defluviicoccus whole genome sequences have been published (Ca. Defluviicoccus tetraformis, Defluviicoccus GAO-HK, and Ca. Defluviicoccus seviourii). The available genomic data of these suggest marked metabolic differences between them, some of which have ecophysiological implications. Here, we describe the whole genome sequence of the type strain Defluviicoccus vanusT, the only cultured member of this genus, and a detailed comparative re-examination of all extant Defluviicoccus genomes. Each, with one exception, which appears not to be a member of this genus, contains the genes expected of GAO members, in possessing multiple copies of those for glycogen biosynthesis and catabolism, and anaerobic polyhydroxyalkanoate (PHA) synthesis. Both 16S rRNA and genome sequence data suggest that the current recognition of four clades is insufficient to embrace their phylogenetic biodiversity, but do not support the view that they should be re-classified into families other than their existing location in the Rhodospirillaceae. As expected, considerable variations were seen in the presence and numbers of genes encoding properties associated with key substrate assimilation and metabolic pathways. Two genomes also carried the pit gene for synthesis of the low-affinity phosphate transport protein, pit, considered by many to distinguish all PAO from GAO. The data re-emphasize the risks associated with extrapolating the data generated from a single Defluviicoccus population to embrace all members of that genus.
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Affiliation(s)
- Irina Bessarab
- Singapore Centre for Environmental Life Sciences Engineering, National University of Singapore, Singapore, Singapore
| | - Abdul Majid Maszenan
- Nanyang Environment & Water Research Institute (NEWRI), Nanyang Technological University, Singapore, Singapore.,NUS Environmental Research Institute, National University of Singapore, Singapore, Singapore
| | - Mindia A S Haryono
- Singapore Centre for Environmental Life Sciences Engineering, National University of Singapore, Singapore, Singapore
| | - Krithika Arumugam
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Nay Min Min Thaw Saw
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Robert J Seviour
- School of Life Sciences, La Trobe University, Melbourne, VIC, Australia
| | - Rohan B H Williams
- Singapore Centre for Environmental Life Sciences Engineering, National University of Singapore, Singapore, Singapore
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11
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Tian Y, Chen H, Chen L, Deng X, Hu Z, Wang C, Wei C, Qiu G, Wuertz S. Glycine adversely affects enhanced biological phosphorus removal. WATER RESEARCH 2022; 209:117894. [PMID: 34890912 DOI: 10.1016/j.watres.2021.117894] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 11/04/2021] [Accepted: 11/21/2021] [Indexed: 06/13/2023]
Abstract
Enhanced biological phosphorus removal (EBPR) is used extensively in full-scale wastewater treatment plants for the removal of phosphorus. Despite previous evidence showing that glycine is a carbon source for a certain lineage of polyphosphate accumulating organisms (PAOs) such as Tetrasphaera, it is still unknown whether glycine can support EBPR. We observed an overall adverse effect of glycine on EBPR using activated sludge from both full-scale wastewater treatment plants and lab-scale reactors harboring distant and diverse PAOs and glycogen accumulating organisms (GAOs), including Candidatus Accumulibacter, Thiothrix, Tetrasphaera, Dechloromonas, Ca. Competibacter, and Defluviicoccus, among others. Glycine induced phosphorus (P) release under anaerobic conditions without being effectively taken up by cells. The induced P release rate correlated with glycine concentration in the range of 10 to 50 mg C/L. PAOs continued to release P in the presence of glycine under aerobic conditions without any evident P uptake. Under mixed carbon conditions, the occurrence of glycine did not seem to affect acetate uptake; however, it significantly reduced the rate of P uptake in the aerobic phase. Overall, glycine did not appear to be an effective carbon source for a majority of PAOs and GAOs in full-scale and lab-scale systems, and neither did other community members utilize glycine under anaerobic or aerobic conditions. Metatranscriptomic analysis showed the transcription of glycine cleavage T, P and H protein genes, but not of the L protein or the downstream genes in the glycine cleavage pathway, suggesting barriers to metabolizing glycine. The high transcription of a gene encoding a drug/metabolite transporter suggests a potential efflux mechanism, where glycine transported into the cells is in turn exported at the expense of ATP, resulting in P release without affecting the glycine concentration in solution. The ability of glycine to induce P release without cellular uptake suggests a way to effectively recover P from P-enriched waste sludge.
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Affiliation(s)
- Yucheng Tian
- 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
| | - Liping Chen
- 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
| | - Zekun Hu
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Cenchao Wang
- 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; Key Laboratory of Pollution Control and Ecological Restoration in Industrial Clusters, Ministry of Education, Guangzhou 510006, China
| | - Guanglei Qiu
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore; Key Laboratory of Pollution Control and Ecological Restoration in Industrial Clusters, Ministry of Education, Guangzhou 510006, China.
| | - Stefan Wuertz
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 639798, Singapore.
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12
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Petriglieri F, Singleton C, Peces M, Petersen JF, Nierychlo M, Nielsen PH. "Candidatus Dechloromonas phosphoritropha" and "Ca. D. phosphorivorans", novel polyphosphate accumulating organisms abundant in wastewater treatment systems. THE ISME JOURNAL 2021; 15:3605-3614. [PMID: 34155336 PMCID: PMC8630035 DOI: 10.1038/s41396-021-01029-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 05/22/2021] [Accepted: 06/02/2021] [Indexed: 02/06/2023]
Abstract
Members of the genus Dechloromonas are often abundant in enhanced biological phosphorus removal (EBPR) systems and are recognized putative polyphosphate accumulating organisms (PAOs), but their role in phosphate removal is still unclear. Here, we used 16S rRNA gene sequencing and fluorescence in situ hybridization (FISH) to investigate the abundance and distribution of Dechloromonas spp. in Danish and global wastewater treatment plants. The two most abundant species worldwide revealed in situ dynamics of important intracellular storage polymers, measured by FISH-Raman in activated sludge from four full-scale EBPR plants and from a lab-scale reactor fed with different substrates. Moreover, seven distinct Dechloromonas species were determined from a set of ten high-quality metagenome-assembled genomes (MAGs) from Danish EBPR plants, each encoding the potential for polyphosphate (poly-P), glycogen, and polyhydroxyalkanoates (PHA) accumulation. The two species exhibited an in situ phenotype in complete accordance with the metabolic information retrieved by the MAGs, with dynamic levels of poly-P, glycogen, and PHA during feast-famine anaerobic-aerobic cycling, legitimately placing these microorganisms among the important PAOs. They are potentially involved in denitrification showing niche partitioning within the genus and with other important PAOs. As no isolates are available for the two species, we propose the names Candidatus Dechloromonas phosphoritropha and Candidatus Dechloromonas phosphorivorans.
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Affiliation(s)
- Francesca Petriglieri
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Caitlin Singleton
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Miriam Peces
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Jette F Petersen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Marta Nierychlo
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Per H Nielsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark.
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13
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Mu DS, Wang S, Liang QY, Du ZZ, Tian R, Ouyang Y, Wang XP, Zhou A, Gong Y, Chen GJ, Van Nostrand J, Yang Y, Zhou J, Du ZJ. Bradymonabacteria, a novel bacterial predator group with versatile survival strategies in saline environments. MICROBIOME 2020; 8:126. [PMID: 32867860 PMCID: PMC7460792 DOI: 10.1186/s40168-020-00902-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 07/27/2020] [Indexed: 05/04/2023]
Abstract
BACKGROUND Bacterial predation is an important selective force in microbial community structure and dynamics. However, only a limited number of predatory bacteria have been reported, and their predatory strategies and evolutionary adaptations remain elusive. We recently isolated a novel group of bacterial predators, Bradymonabacteria, representative of the novel order Bradymonadales in δ-Proteobacteria. Compared with those of other bacterial predators (e.g., Myxococcales and Bdellovibrionales), the predatory and living strategies of Bradymonadales are still largely unknown. RESULTS Based on individual coculture of Bradymonabacteria with 281 prey bacteria, Bradymonabacteria preyed on diverse bacteria but had a high preference for Bacteroidetes. Genomic analysis of 13 recently sequenced Bradymonabacteria indicated that these bacteria had conspicuous metabolic deficiencies, but they could synthesize many polymers, such as polyphosphate and polyhydroxyalkanoates. Dual transcriptome analysis of cocultures of Bradymonabacteria and prey suggested a potential contact-dependent predation mechanism. Comparative genomic analysis with 24 other bacterial predators indicated that Bradymonabacteria had different predatory and living strategies. Furthermore, we identified Bradymonadales from 1552 publicly available 16S rRNA amplicon sequencing samples, indicating that Bradymonadales was widely distributed and highly abundant in saline environments. Phylogenetic analysis showed that there may be six subgroups in this order; each subgroup occupied a different habitat. CONCLUSIONS Bradymonabacteria have unique living strategies that are transitional between the "obligate" and the so-called facultative predators. Thus, we propose a framework to categorize the current bacterial predators into 3 groups: (i) obligate predators (completely prey-dependent), (ii) facultative predators (facultatively prey-dependent), and (iii) opportunistic predators (prey-independent). Our findings provide an ecological and evolutionary framework for Bradymonadales and highlight their potential ecological roles in saline environments. Video abstract.
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Affiliation(s)
- Da-Shuai Mu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, No. 72, Jimo Binhai Road, Jimo, Qingdao, 266237, China
- Marine College, Shandong University, Weihai, 264209, China
| | - Shuo Wang
- Marine College, Shandong University, Weihai, 264209, China
| | - Qi-Yun Liang
- Marine College, Shandong University, Weihai, 264209, China
| | - Zhao-Zhong Du
- Marine College, Shandong University, Weihai, 264209, China
| | - Renmao Tian
- Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Yang Ouyang
- Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Xin-Peng Wang
- Marine College, Shandong University, Weihai, 264209, China
| | - Aifen Zhou
- Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Ya Gong
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, No. 72, Jimo Binhai Road, Jimo, Qingdao, 266237, China
- Marine College, Shandong University, Weihai, 264209, China
| | - Guan-Jun Chen
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, No. 72, Jimo Binhai Road, Jimo, Qingdao, 266237, China
- Marine College, Shandong University, Weihai, 264209, China
| | - Joy Van Nostrand
- Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, 73019, USA
| | - Yunfeng Yang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Jizhong Zhou
- Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, 73019, USA
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, 100084, China
| | - Zong-Jun Du
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, No. 72, Jimo Binhai Road, Jimo, Qingdao, 266237, China.
- Marine College, Shandong University, Weihai, 264209, China.
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14
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Qiu G, Liu X, Saw NMMT, Law Y, Zuniga-Montanez R, Thi SS, Ngoc Nguyen TQ, Nielsen PH, Williams RBH, Wuertz S. Metabolic Traits of Candidatus Accumulibacter clade IIF Strain SCELSE-1 Using Amino Acids As Carbon Sources for Enhanced Biological Phosphorus Removal. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:2448-2458. [PMID: 31790213 DOI: 10.1021/acs.est.9b02901] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Despite recent evidence from full-scale plants suggesting that Candidatus Accumulibacter may be capable of using amino acids, this metabolic trait has never been confirmed in a bioreactor experiment. Here we show that an enriched culture of Ca. Accumulibacter clade IIF strain SCELSE-1 could metabolize 11 of 20 α-amino acids, with aspartate, glutamate, asparagine, and glutamine resulting in the highest phosphorus removal. The anaerobic uptake of aspartate and glutamate was achieved through a glutamate/aspartate-proton symporter fully powered by the proton motive force (PMF). Under anaerobic conditions aspartate was deaminized and routed into core carbon metabolic pathways to form polyhydroxyalkanoates (PHA). The lack of genes encoding NADH dependent isocitrate dehydrogenase in the Ca. Accumulibacter genome resulted in a kinetic barrier for glutamate to be channelled to the TCA cycle. Glutamate was stored as glutamate polymer. When amino acids (aspartate or glutamate) and acetate were supplied together, Ca. Accumulibacter took up both carbon sources simultaneously, with the uptake rate of each carbon source largely preserved. Overall energy savings (up to 17%) were achieved under mixed carbon scenarios, due to the ability of Ca. Accumulibacter to rearrange its anaerobic carbon metabolism based on the reducing power, PMF and ATP balance.
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Affiliation(s)
- Guanglei Qiu
- Singapore Centre for Environmental Life Sciences Engineering , Nanyang Technological University , Singapore 637551 , Singapore
- School of Environment and Energy , South China University of Technology , Guangzhou 510006 , China
| | - Xianghui Liu
- Singapore Centre for Environmental Life Sciences Engineering , Nanyang Technological University , Singapore 637551 , Singapore
| | - Nay Min Min Thaw Saw
- Singapore Centre for Environmental Life Sciences Engineering , Nanyang Technological University , Singapore 637551 , Singapore
| | - Yingyu Law
- Singapore Centre for Environmental Life Sciences Engineering , Nanyang Technological University , Singapore 637551 , Singapore
| | - Rogelio Zuniga-Montanez
- Singapore Centre for Environmental Life Sciences Engineering , Nanyang Technological University , Singapore 637551 , Singapore
- Department of Civil and Environmental Engineering, One Shields Avenue , University of California , Davis , California 95616 , United States
| | - Sara Swa Thi
- Singapore Centre for Environmental Life Sciences Engineering , Nanyang Technological University , Singapore 637551 , Singapore
| | - Thi Quynh Ngoc Nguyen
- Singapore Centre for Environmental Life Sciences Engineering , Nanyang Technological University , Singapore 637551 , Singapore
| | - Per H Nielsen
- Singapore Centre for Environmental Life Sciences Engineering , Nanyang Technological University , Singapore 637551 , Singapore
- Centre for Microbial Communities, Department of Chemistry and Bioscience , Aalborg University , DK-9220 , Aalborg , Denmark
| | - Rohan B H 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, One Shields Avenue , University of California , Davis , California 95616 , United States
- School of Civil and Environmental Engineering , Nanyang Technological University , Singapore 639798 , Singapore
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15
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The Proteome of Tetrasphaera elongata is adapted to Changing Conditions in Wastewater Treatment Plants. Proteomes 2019; 7:proteomes7020016. [PMID: 31027192 PMCID: PMC6630437 DOI: 10.3390/proteomes7020016] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 04/19/2019] [Accepted: 04/23/2019] [Indexed: 12/04/2022] Open
Abstract
The activated sludge in wastewater treatment plants (WWTP) designed for enhanced biological phosphorus removal (EBPR) experiences periodically changing nutrient and oxygen availability. Tetrasphaera is the most abundant genus in Danish WWTP and represents up to 20–30% of the activated sludge community based on 16S rRNA amplicon sequencing and quantitative fluorescence in situ hybridization analyses, although the genus is in low abundance in the influent wastewater. Here we investigated how Tetrasphaera can successfully out-compete most other microorganisms in such highly dynamic ecosystems. To achieve this, we analyzed the physiological adaptations of the WWTP isolate T. elongata str. LP2 during an aerobic to anoxic shift by label-free quantitative proteomics and NMR-metabolomics. Escherichia coli was used as reference organism as it shares several metabolic capabilities and is regularly introduced to wastewater treatment plants without succeeding there. When compared to E. coli, only minor changes in the proteome of T. elongata were observed after the switch to anoxic conditions. This indicates that metabolic pathways for anaerobic energy harvest were already expressed during the aerobic growth. This allows continuous growth of Tetrasphaera immediately after the switch to anoxic conditions. Metabolomics furthermore revealed that the substrates provided were exploited far more efficiently by Tetrasphaera than by E. coli. These results suggest that T. elongata prospers in the dynamic WWTP environment due to adaptation to the changing environmental conditions.
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16
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Re-evaluating the microbiology of the enhanced biological phosphorus removal process. Curr Opin Biotechnol 2019; 57:111-118. [PMID: 30959426 DOI: 10.1016/j.copbio.2019.03.008] [Citation(s) in RCA: 112] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 02/01/2019] [Accepted: 03/03/2019] [Indexed: 10/27/2022]
Abstract
We have critically assessed some of the dogmas in the microbiology of enhanced biological phosphorus removal (EBPR) and argue that the genus Tetrasphaera can be as important as Ca. Accumulibacter for phosphorus removal; and that proliferation of their competitors, the glycogen accumulating organisms, does not appear to be a practical problem for EBPR efficiency even under tropical conditions. An increasing number of EBPR-related genomes are changing our understanding of their physiology, for example, their potential to participate in denitrification. Rather than trying to identify organisms that adhere to strict phenotype metabolic models, we advocate for broader analyses of the whole microbial communities in EBPR plants by iterative studies with isolates, lab enrichments, and full-scale systems.
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17
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Onetto CA, Grbin PR, McIlroy SJ, Eales KL. Genomic insights into the metabolism of ‘CandidatusDefluviicoccus seviourii’, a member ofDefluviicoccuscluster III abundant in industrial activated sludge. FEMS Microbiol Ecol 2018; 95:5210054. [DOI: 10.1093/femsec/fiy231] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 11/24/2018] [Indexed: 11/14/2022] Open
Affiliation(s)
- Cristobal A Onetto
- Department of Wine & Food Science, University of Adelaide, Adelaide 5064, Australia
| | - Paul R Grbin
- Department of Wine & Food Science, University of Adelaide, Adelaide 5064, Australia
| | - Simon J McIlroy
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia 4072, Brisbane, Australia
| | - Kathryn L Eales
- Department of Wine & Food Science, University of Adelaide, Adelaide 5064, Australia
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18
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Sulfurimonas subgroup GD17 cells accumulate polyphosphate under fluctuating redox conditions in the Baltic Sea: possible implications for their ecology. ISME JOURNAL 2018; 13:482-493. [PMID: 30291329 DOI: 10.1038/s41396-018-0267-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 05/04/2018] [Accepted: 05/11/2018] [Indexed: 12/16/2022]
Abstract
The central Baltic Sea is characterized by a pelagic redox zone exhibiting high dark CO2 fixation rates below the chemocline. These rates are mainly driven by chemolithoautotrophic and denitrifying Sulfurimonas GD17 subgroup cells which are motile and fast-reacting r-strategists. Baltic Sea redox zones are unstable and a measurable overlap of nitrate and reduced sulfur, essential for chemosynthesis, is often only available on small scales and short times due to local mixing events. This raises the question of how GD17 cells gain access to electron donors or acceptors over longer term periods and under substrate deficiency. One possible answer is that GD17 cells store high-energy-containing polyphosphate during favorable nutrient conditions to survive periods of nutrient starvation. We used scanning electron microscopy with energy-dispersive X-ray spectroscopy to investigate potential substrate enrichments in single GD17 cells collected from Baltic Sea redox zones. More specific substrate enrichment features were identified in experiments using Sulfurimonas gotlandica GD1T, a GD17 representative. Sulfurimonas cells accumulated polyphosphate both in situ and in vitro. Combined genome and culture-dependent analyses suggest that polyphosphate serves as an energy reservoir to maintain cellular integrity at unfavorable substrate conditions. This redox-independent energy supply would be a precondition for sustaining the r-strategy lifestyle of GD17 and may represent a newly identified survival strategy for chemolithoautotrophic prokaryotes occupying eutrophic redox zones.
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19
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Wan R, Chen Y, Zheng X, Su Y, Huang H. Effect of CO 2 on NADH production of denitrifying microbes via inhibiting carbon source transport and its metabolism. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 627:896-904. [PMID: 29426214 DOI: 10.1016/j.scitotenv.2018.01.315] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 01/19/2018] [Accepted: 01/30/2018] [Indexed: 05/24/2023]
Abstract
The potential effect of CO2 on environmental microbes has drawn much attention recently. As an important section of the nitrogen cycle, biological denitrification requires electron donor to reduce nitrogen oxide. Nicotinamide adenine dinucleotide (NADH), which is formed during carbon source metabolism, is a widely reported electron donor for denitrification. Here we studied the effect of CO2 on NADH production and carbon source utilization in the denitrifying microbe Paracoccus denitrificans. We observed that NADH level was decreased by 45.5% with the increase of CO2 concentration from 0 to 30,000ppm, which was attributed to the significantly decreased utilization of carbon source (i.e., acetate). Further study showed that CO2 inhibited carbon source utilization because of multiple negative influences: (1) suppressing the growth and viability of denitrifier cells, (2) weakening the driving force for carbon source transport by decreasing bacterial membrane potential, and (3) downregulating the expression of genes encoding key enzymes involved in intracellular carbon metabolism, such as citrate synthase, aconitate hydratase, isocitrate dehydrogenase, succinate dehydrogenase, and fumarate reductase. This study suggests that the inhibitory effect of CO2 on NADH production in denitrifiers might deteriorate the denitrification performance in an elevated CO2 climate scenario.
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Affiliation(s)
- Rui Wan
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Anhui Provincial Engineering Laboratory of Water and Soil Pollution Control and Remediation, College of Environmental Science and Engineering, Anhui Normal University, 189 South of Jiuhua Road, Wuhu, Anhui 241002, China
| | - Yinguang Chen
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
| | - Xiong Zheng
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Yinglong Su
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Haining Huang
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
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20
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Stokholm-Bjerregaard M, McIlroy SJ, Nierychlo M, Karst SM, Albertsen M, Nielsen PH. A Critical Assessment of the Microorganisms Proposed to be Important to Enhanced Biological Phosphorus Removal in Full-Scale Wastewater Treatment Systems. Front Microbiol 2017; 8:718. [PMID: 28496434 PMCID: PMC5406452 DOI: 10.3389/fmicb.2017.00718] [Citation(s) in RCA: 137] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 04/06/2017] [Indexed: 11/13/2022] Open
Abstract
Understanding the microbiology of phosphorus (P) removal is considered essential to knowledge-based optimization of enhanced biological P removal (EBPR) systems. Biological P removal is achieved in these systems by promoting the growth of organisms collectively known as the polyphosphate accumulating organisms (PAOs). Also considered important to EBPR are the glycogen accumulating organisms (GAOs), which are theorized to compete with the PAOs for resources at the expense of P removal efficiency. Numerous studies have sought to identify the PAOs and their GAOs competitors, with several candidates proposed for each over the last few decades. The current study collectively assessed the abundance and diversity of all proposed PAOs and GAOs in 18 Danish full-scale wastewater treatment plants with well-working biological nutrient removal over a period of 9 years using 16S rRNA gene amplicon sequencing. The microbial community structure in all plants was relatively stable over time. Evidence for the role of the proposed PAOs and GAOs in EBPR varies and is critically assessed, in light of their calculated amplicon abundances, to indicate which of these are important in full-scale systems. Bacteria from the genus Tetrasphaera were the most abundant of the PAOs. The “Candidatus Accumulibacter” PAOs were in much lower abundance and appear to be biased by the amplicon-based method applied. The genera Dechloromonas, Microlunatus, and Tessaracoccus were identified as abundant putative PAO that require further research attention. Interestingly, the actinobacterial Micropruina and sbr-gs28 phylotypes were among the most abundant of the putative GAOs. Members of the genera Defluviicoccus, Propionivibrio, the family Competibacteraceae, and the spb280 group were also relatively abundant in some plants. Despite observed high abundances of GAOs (periodically exceeding 20% of the amplicon reads), P removal performance was maintained, indicating that these organisms were not outcompeting the PAOs in these EBPR systems. Phylogenetic diversity within each of the PAOs and GAOs genera was observed, which is consistent with reported metabolic diversity for these. Whether or not key traits can be assigned to sub-genus level clades requires further investigation.
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Affiliation(s)
- Mikkel Stokholm-Bjerregaard
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg UniversityAalborg, Denmark
| | - Simon J McIlroy
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg UniversityAalborg, Denmark
| | - Marta Nierychlo
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg UniversityAalborg, Denmark
| | - Søren M Karst
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg UniversityAalborg, Denmark
| | - Mads Albertsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg UniversityAalborg, Denmark
| | - Per H Nielsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg UniversityAalborg, Denmark
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21
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Welles L, Abbas B, Sorokin DY, Lopez-Vazquez CM, Hooijmans CM, van Loosdrecht MCM, Brdjanovic D. Metabolic Response of " Candidatus Accumulibacter Phosphatis" Clade II C to Changes in Influent P/C Ratio. Front Microbiol 2017; 7:2121. [PMID: 28111570 PMCID: PMC5216660 DOI: 10.3389/fmicb.2016.02121] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 12/15/2016] [Indexed: 11/13/2022] Open
Abstract
The objective of this study was to investigate the ability of a culture highly enriched with the polyphosphate-accumulating organism, “Candidatus Accumulibacter phosphatis” clade IIC, to adjust their metabolism to different phosphate availabilities. For this purpose the biomass was cultivated in a sequencing batch reactor with acetate and exposed to different phosphate/carbon influent ratios during six experimental phases. Activity tests were conducted to determine the anaerobic kinetic and stoichiometric parameters as well as the composition of the microbial community. Increasing influent phosphate concentrations led to increased poly-phosphate content and decreased glycogen content of the biomass. In response to higher biomass poly-phosphate content, the biomass showed higher specific phosphate release rates. Together with the phosphate release rates, acetate uptake rates also increased up to an optimal poly-phosphate/glycogen ratio of 0.3 P-mol/C-mol. At higher poly-phosphate/glycogen ratios (obtained at influent P/C ratios above 0.051 P-mol/C-mol), the acetate uptake rates started to decrease. The stoichiometry of the anaerobic conversions clearly demonstrated a metabolic shift from a glycogen dominated to a poly-phosphate dominated metabolism as the biomass poly-phosphate content increased. FISH and DGGE analyses confirmed that no significant changes occurred in the microbial community, suggesting that the changes in the biomass activity were due to different metabolic behavior, allowing the organisms to proliferate under conditions with fluctuating phosphate levels.
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Affiliation(s)
- Laurens Welles
- Department of Environmental Engineering and Water Technology, UNESCO-IHE Institute for Water EducationDelft, Netherlands; Department of Biotechnology, Delft University of TechnologyDelft, Netherlands
| | - Ben Abbas
- Department of Biotechnology, Delft University of Technology Delft, Netherlands
| | - Dimitry Y Sorokin
- Department of Biotechnology, Delft University of TechnologyDelft, Netherlands; Winogradsky Institute of Microbiology, Research Center of Biotechnology, Russian Academy of Sciences (RAS)Moscow, Russia
| | - Carlos M Lopez-Vazquez
- Department of Environmental Engineering and Water Technology, UNESCO-IHE Institute for Water Education Delft, Netherlands
| | - Christine M Hooijmans
- Department of Environmental Engineering and Water Technology, UNESCO-IHE Institute for Water Education Delft, Netherlands
| | | | - Damir Brdjanovic
- Department of Environmental Engineering and Water Technology, UNESCO-IHE Institute for Water EducationDelft, Netherlands; Department of Biotechnology, Delft University of TechnologyDelft, Netherlands
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22
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Ribera-Guardia A, Marques R, Arangio C, Carvalheira M, Oehmen A, Pijuan M. Distinctive denitrifying capabilities lead to differences in N2O production by denitrifying polyphosphate accumulating organisms and denitrifying glycogen accumulating organisms. BIORESOURCE TECHNOLOGY 2016; 219:106-113. [PMID: 27479801 DOI: 10.1016/j.biortech.2016.07.092] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 07/20/2016] [Accepted: 07/22/2016] [Indexed: 06/06/2023]
Abstract
This study aims at investigating the denitrification kinetics in two separate enriched cultures of denitrifying polyphosphate accumulating organisms (dPAO) and denitrifying glycogen accumulating organisms (dGAO) and compare their N2O accumulation potential under different conditions. Two sequencing batch reactors were inoculated to develop dPAO and dGAO enriched microbial communities separately. Seven batch tests with different combinations of electron acceptors (nitrate, nitrite and/or nitrous oxide) were carried out with the enriched biomass from both reactors. Results indicate that in almost all batch tests, N2O accumulated for both cultures, however dPAOs showed a higher denitrification capacity compared to dGAOs due to their higher nitrogen oxides reduction rates. Additionally, the effect of the simultaneous presence of several electron acceptors in the reduction rates of the different nitrogen oxides was also assessed in dPAOs and dGAOs.
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Affiliation(s)
- Anna Ribera-Guardia
- Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, 17003 Girona, Spain
| | - Ricardo Marques
- UCIBIO, REQUIMTE, Chemistry Department, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Corrado Arangio
- Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, 17003 Girona, Spain; Dipartimento di ingegneria civile e architettura (DICAR), Università di Catania, 95100 Catania, Sicily, Italy
| | - Monica Carvalheira
- UCIBIO, REQUIMTE, Chemistry Department, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Adrian Oehmen
- UCIBIO, REQUIMTE, Chemistry Department, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Maite Pijuan
- Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, 17003 Girona, Spain.
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23
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Albertsen M, McIlroy SJ, Stokholm-Bjerregaard M, Karst SM, Nielsen PH. "Candidatus Propionivibrio aalborgensis": A Novel Glycogen Accumulating Organism Abundant in Full-Scale Enhanced Biological Phosphorus Removal Plants. Front Microbiol 2016; 7:1033. [PMID: 27458436 PMCID: PMC4930944 DOI: 10.3389/fmicb.2016.01033] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 06/20/2016] [Indexed: 01/16/2023] Open
Abstract
Enhanced biological phosphorus removal (EBPR) is widely used to remove phosphorus from wastewater. The process relies on polyphosphate accumulating organisms (PAOs) that are able to take up phosphorus in excess of what is needed for growth, whereby phosphorus can be removed from the wastewater by wasting the biomass. However, glycogen accumulating organisms (GAOs) may reduce the EBPR efficiency as they compete for substrates with PAOs, but do not store excessive amounts of polyphosphate. PAOs and GAOs are thought to be phylogenetically unrelated, with the model PAO being the betaproteobacterial “Candidatus Accumulibacter phosphatis” (Accumulibacter) and the model GAO being the gammaproteobacterial “Candidatus Competibacter phosphatis”. Here, we report the discovery of a GAO from the genus Propionivibrio, which is closely related to Accumulibacter. Propionivibrio sp. are targeted by the canonical fluorescence in situ hybridization probes used to target Accumulibacter (PAOmix), but do not store excessive amounts of polyphosphate in situ. A laboratory scale reactor, operated to enrich for PAOs, surprisingly contained co-dominant populations of Propionivibrio and Accumulibacter. Metagenomic sequencing of multiple time-points enabled recovery of near complete population genomes from both genera. Annotation of the Propionivibrio genome confirmed their potential for the GAO phenotype and a basic metabolic model is proposed for their metabolism in the EBPR environment. Using newly designed fluorescence in situ hybridization (FISH) probes, analyses of full-scale EBPR plants revealed that Propionivibrio is a common member of the community, constituting up to 3% of the biovolume. To avoid overestimation of Accumulibacter abundance in situ, we recommend the use of the FISH probe PAO651 instead of the commonly applied PAOmix probe set.
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Affiliation(s)
- Mads Albertsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University Aalborg, Denmark
| | - Simon J McIlroy
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University Aalborg, Denmark
| | - Mikkel Stokholm-Bjerregaard
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg UniversityAalborg, Denmark; Krüger A/SAalborg, Denmark
| | - Søren M Karst
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University Aalborg, Denmark
| | - Per H Nielsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University Aalborg, Denmark
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24
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Myung J, Flanagan JC, Waymouth RM, Criddle CS. Methane or methanol-oxidation dependent synthesis of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) by obligate type II methanotrophs. Process Biochem 2016. [DOI: 10.1016/j.procbio.2016.02.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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25
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Oyserman BO, Moya F, Lawson CE, Garcia AL, Vogt M, Heffernen M, Noguera DR, McMahon KD. Ancestral genome reconstruction identifies the evolutionary basis for trait acquisition in polyphosphate accumulating bacteria. ISME JOURNAL 2016; 10:2931-2945. [PMID: 27128993 PMCID: PMC5148189 DOI: 10.1038/ismej.2016.67] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 03/21/2016] [Accepted: 03/24/2016] [Indexed: 12/13/2022]
Abstract
The evolution of complex traits is hypothesized to occur incrementally. Identifying the transitions that lead to extant complex traits may provide a better understanding of the genetic nature of the observed phenotype. A keystone functional group in wastewater treatment processes are polyphosphate accumulating organisms (PAOs), however the evolution of the PAO phenotype has yet to be explicitly investigated and the specific metabolic traits that discriminate non-PAO from PAO are currently unknown. Here we perform the first comprehensive investigation on the evolution of the PAO phenotype using the model uncultured organism Candidatus Accumulibacter phosphatis (Accumulibacter) through ancestral genome reconstruction, identification of horizontal gene transfer, and a kinetic/stoichiometric characterization of Accumulibacter Clade IIA. The analysis of Accumulibacter's last common ancestor identified 135 laterally derived genes, including genes involved in glycogen, polyhydroxyalkanoate, pyruvate and NADH/NADPH metabolisms, as well as inorganic ion transport and regulatory mechanisms. In contrast, pathways such as the TCA cycle and polyphosphate metabolism displayed minimal horizontal gene transfer. We show that the transition from non-PAO to PAO coincided with horizontal gene transfer within Accumulibacter's core metabolism; likely alleviating key kinetic and stoichiometric bottlenecks, such as anaerobically linking glycogen degradation to polyhydroxyalkanoate synthesis. These results demonstrate the utility of investigating the derived genome of a lineage to identify key transitions leading to an extant complex phenotype.
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Affiliation(s)
- Ben O Oyserman
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Francisco Moya
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Christopher E Lawson
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Antonio L Garcia
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Mark Vogt
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Mitchell Heffernen
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Daniel R Noguera
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Katherine D McMahon
- Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI, USA.,Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA
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26
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Li WW, Zhang HL, Sheng GP, Yu HQ. Roles of extracellular polymeric substances in enhanced biological phosphorus removal process. WATER RESEARCH 2015; 86:85-95. [PMID: 26143588 DOI: 10.1016/j.watres.2015.06.034] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Revised: 06/17/2015] [Accepted: 06/20/2015] [Indexed: 05/06/2023]
Abstract
Enhanced biological phosphorus removal (EBPR) process is known to mainly rely on the ability of phosphorus-accumulating organisms to take up, transform and store excess amount of phosphorus (P) inside the cells. However, recent studies have revealed considerable accumulation of P also in the extracellular polymeric substances (EPS) of sludge, implying a non-negligible role of EPS in P removal by EBPR sludge. However, the contribution of EPS to P uptake and the forms of accumulated extracellular P vary substantially in different studies, and the underlying mechanism of P transformation and transportation in EPS remains poorly understood. This review provides a new recognition into the P removal process in EBPR system by incorporating the role of EPS. It overviews on the characteristics of P accumulation in EPS, explores the mechanism of P transformation and transportation in EBPR sludge and EPS, summarizes the main influential factors for the P-accumulation properties of EPS, and discusses the remaining knowledge gaps and needed future efforts that may lead to better understanding and use of such an EPS role for maximizing P recovery from wastewater.
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Affiliation(s)
- Wen-Wei Li
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, 230026, China
| | - Hai-Ling Zhang
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, 230026, China
| | - Guo-Ping Sheng
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, 230026, China
| | - Han-Qing Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, 230026, China.
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27
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Oyserman BO, Noguera DR, del Rio TG, Tringe SG, McMahon KD. Metatranscriptomic insights on gene expression and regulatory controls in Candidatus Accumulibacter phosphatis. ISME JOURNAL 2015; 10:810-22. [PMID: 26555245 PMCID: PMC4796919 DOI: 10.1038/ismej.2015.155] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 07/07/2015] [Accepted: 07/15/2015] [Indexed: 01/08/2023]
Abstract
Previous studies on enhanced biological phosphorus removal (EBPR) have focused on reconstructing genomic blueprints for the model polyphosphate-accumulating organism Candidatus Accumulibacter phosphatis. Here, a time series metatranscriptome generated from enrichment cultures of Accumulibacter was used to gain insight into anerobic/aerobic metabolism and regulatory mechanisms within an EBPR cycle. Co-expressed gene clusters were identified displaying ecologically relevant trends consistent with batch cycle phases. Transcripts displaying increased abundance during anerobic acetate contact were functionally enriched in energy production and conversion, including upregulation of both cytoplasmic and membrane-bound hydrogenases demonstrating the importance of transcriptional regulation to manage energy and electron flux during anerobic acetate contact. We hypothesized and demonstrated hydrogen production after anerobic acetate contact, a previously unknown strategy for Accumulibacter to maintain redox balance. Genes involved in anerobic glycine utilization were identified and phosphorus release after anerobic glycine contact demonstrated, suggesting that Accumulibacter routes diverse carbon sources to acetyl-CoA formation via previously unrecognized pathways. A comparative genomics analysis of sequences upstream of co-expressed genes identified two statistically significant putative regulatory motifs. One palindromic motif was identified upstream of genes involved in PHA synthesis and acetate activation and is hypothesized to be a phaR binding site, hence representing a hypothetical PHA modulon. A second motif was identified ~35 base pairs (bp) upstream of a large and diverse array of genes and hence may represent a sigma factor binding site. This analysis provides a basis and framework for further investigations into Accumulibacter metabolism and the reconstruction of regulatory networks in uncultured organisms.
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Affiliation(s)
- Ben O Oyserman
- Department of Civil and Environmental Engineering, University of Wisconsin at Madison, Madison, WI, USA
| | - Daniel R Noguera
- Department of Civil and Environmental Engineering, University of Wisconsin at Madison, Madison, WI, USA
| | | | - Susannah G Tringe
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
| | - Katherine D McMahon
- Department of Civil and Environmental Engineering, University of Wisconsin at Madison, Madison, WI, USA.,Department of Bacteriology, University of Wisconsin at Madison, Madison, WI, USA
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28
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Jones DS, Flood BE, Bailey JV. Metatranscriptomic insights into polyphosphate metabolism in marine sediments. ISME JOURNAL 2015; 10:1015-9. [PMID: 26381585 DOI: 10.1038/ismej.2015.169] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 08/04/2015] [Accepted: 08/10/2015] [Indexed: 11/09/2022]
Abstract
Microorganisms can influence inorganic phosphate (Pi) in pore waters, and thus the saturation state of phosphatic minerals, by accumulating and hydrolyzing intracellular polyphosphate (poly-P). Here we used comparative metatranscriptomics to explore microbial poly-P utilization in marine sediments. Sulfidic marine sediments from methane seeps near Barbados and from the Santa Barbara Basin (SBB) oxygen minimum zone were incubated under oxic and anoxic sulfidic conditions. Pi was sequestered under oxic conditions and liberated under anoxic conditions. Transcripts homologous to poly-P kinase type 2 (ppk2) were 6-22 × more abundant in metatranscriptomes from the anoxic incubations, suggesting that reversible poly-P degradation by Ppk2 may be an important metabolic response to anoxia by marine microorganisms. Overall, diverse taxa differentially expressed homologues of genes for poly-P degradation (ppk2 and exopolyphosphatase) under different incubation conditions. Sulfur-oxidizing microorganisms appeared to preferentially express genes for poly-P degradation under anoxic conditions, which may impact phosphorus cycling in a wide range of oxygen-depleted marine settings.
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Affiliation(s)
- Daniel S Jones
- Department of Earth Sciences, University of Minnesota, Minneapolis, MN, USA
| | - Beverly E Flood
- Department of Earth Sciences, University of Minnesota, Minneapolis, MN, USA
| | - Jake V Bailey
- Department of Earth Sciences, University of Minnesota, Minneapolis, MN, USA
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29
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Wang Y, Qin J, Zhou S, Lin X, Ye L, Song C, Yan Y. Identification of the function of extracellular polymeric substances (EPS) in denitrifying phosphorus removal sludge in the presence of copper ion. WATER RESEARCH 2015; 73:252-64. [PMID: 25697691 DOI: 10.1016/j.watres.2015.01.034] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 01/01/2015] [Accepted: 01/22/2015] [Indexed: 05/19/2023]
Abstract
Industrial wastewater containing heavy metals that enters municipal wastewater treatment plants inevitably has a toxic impact on biological treatment processes. In this study, the impact of Cu(II) (0, 1.5, 2, 2.5, 3 mg/L) on the performance of denitrifying phosphorus removal (DPR) and microbial community structures was investigated. Particularly, the dynamic change in the amount and composition of extracellular polymeric substances (EPS), and the role of EPS in P removal, were assessed using three-dimensional excitation-emission matrix fluorescence spectroscopy combined with parallel factor (PARAFAC) analysis. The results showed that, after long-term adjustment, the P removal efficiency was maintained at 95 ± 2.7% at Cu(II) addition up to 2.5 mg/L, but deteriorated when the Cu(II) addition was 3 mg/L. The EPS content, including proteins and humic substances, increased with increasing Cu(II) additions at concentrations ≤2.5 mg/L. This property of EPS was beneficial for protecting phosphate-accumulating organisms (PAOs) against heavy metals, as both proteins and humic substances are strong ligands for Cu(II). Therefore, the PAOs abundance was still relatively high (67 ± 3%) when Cu(II) accumulation in sludge was up to 10 mg/g SS. PARAFAC confirmed that aromatic proteins could be transformed into soluble microbial byproduct-like material when microorganisms were subjected to Cu(II) stress, owing to their strong metal ion complexing capacity. The increase in the percentage of humic-like substances enhanced the detoxification function of the sludge EPS. EPS accounted for approximately 26-47% of P removed by adsorption when Cu(II) additions were between 0 and 2.5 mg/L. The EPS function, including binding toxic heavy metals and P storage, enhanced the operating stability of DPR systems. This study provides us with a better understanding of (1) the tolerance of DPR sludge to copper toxicity and (2) the function of sludge EPS in the presence of heavy metals in biological P removal systems.
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Affiliation(s)
- Yayi Wang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, PR China.
| | - Jian Qin
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, PR China
| | - Shuai Zhou
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, PR China
| | - Ximao Lin
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, PR China
| | - Liu Ye
- School of Chemical Engineering, The University of Queensland, St Lucia, Brisbane 4072, Australia
| | - Chengkang Song
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, PR China
| | - Yuan Yan
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, PR China
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30
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Lanham AB, Oehmen A, Saunders AM, Carvalho G, Nielsen PH, Reis MAM. Metabolic modelling of full-scale enhanced biological phosphorus removal sludge. WATER RESEARCH 2014; 66:283-295. [PMID: 25222332 DOI: 10.1016/j.watres.2014.08.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 08/01/2014] [Accepted: 08/23/2014] [Indexed: 06/03/2023]
Abstract
This study investigates, for the first time, the application of metabolic models incorporating polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) towards describing the biochemical transformations of full-scale enhanced biological phosphorus removal (EBPR) activated sludge from wastewater treatment plants (WWTPs). For this purpose, it was required to modify previous metabolic models applied to lab-scale systems by incorporating the anaerobic utilisation of the TCA cycle and the aerobic maintenance processes based on sequential utilisation of polyhydroxyalkanoates, followed by glycogen and polyphosphate. The abundance of the PAO and GAO populations quantified by fluorescence in situ hybridisation served as the initial conditions of each biomass fraction, whereby the models were able to describe accurately the experimental data. The kinetic rates were found to change among the four different WWTPs studied or even in the same plant during different seasons, either suggesting the presence of additional PAO or GAO organisms, or varying microbial activities for the same organisms. Nevertheless, these variations in kinetic rates were largely found to be proportional to the difference in acetate uptake rate, suggesting a viable means of calibrating the metabolic model. The application of the metabolic model to full-scale sludge also revealed that different Accumulibacter clades likely possess different acetate uptake mechanisms, as a correlation was observed between the energetic requirement for acetate transport across the cell membrane with the diversity of Accumulibacter present. Using the model as a predictive tool, it was shown that lower acetate concentrations in the feed as well as longer aerobic retention times favour the dominance of the TCA metabolism over glycolysis, which could explain why the anaerobic TCA pathway seems to be more relevant in full-scale WWTPs than in lab-scale systems.
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Affiliation(s)
- Ana B Lanham
- REQUIMTE/CQFB, Chemistry Department FCT-UNL, 2829-516 Caparica, Portugal.
| | - Adrian Oehmen
- REQUIMTE/CQFB, Chemistry Department FCT-UNL, 2829-516 Caparica, Portugal.
| | - Aaron M Saunders
- Center for Microbial Communities, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Denmark.
| | - Gilda Carvalho
- REQUIMTE/CQFB, Chemistry Department FCT-UNL, 2829-516 Caparica, Portugal; Instituto de Biologia Experimental e Tecnológica, Apt.12, 2781-901 Oeiras, Portugal.
| | - Per H Nielsen
- Center for Microbial Communities, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Denmark.
| | - Maria A M Reis
- REQUIMTE/CQFB, Chemistry Department FCT-UNL, 2829-516 Caparica, Portugal.
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31
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Nobu MK, Tamaki H, Kubota K, Liu WT. Metagenomic characterization of ‘Candidatus Defluviicoccus tetraformis strain TFO71’, a tetrad-forming organism, predominant in an anaerobic-aerobic membrane bioreactor with deteriorated biological phosphorus removal. Environ Microbiol 2014; 16:2739-51. [DOI: 10.1111/1462-2920.12383] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 01/01/2014] [Indexed: 11/29/2022]
Affiliation(s)
- Masaru K. Nobu
- Department of Civil and Environmental Engineering; University of Illinois at Urbana-Champaign; 205 North Mathews Ave Urbana IL 61801 USA
| | - Hideyuki Tamaki
- Bioproduction Research Institute; National Institute of Advanced Industrial Science and Technology (AIST); Central 6, Higashi 1-1-1 Tsukuba Ibaraki 305-8566 Japan
| | - Kengo Kubota
- Department of Civil and Environmental Engineering; Tohoku University; 6-6-06 Aza-Aoba, Aramaki, Aoba-ku Sendai Miyagi 980-8579 Japan
| | - Wen-Tso Liu
- Department of Civil and Environmental Engineering; University of Illinois at Urbana-Champaign; 205 North Mathews Ave Urbana IL 61801 USA
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McIlroy SJ, Albertsen M, Andresen EK, Saunders AM, Kristiansen R, Stokholm-Bjerregaard M, Nielsen KL, Nielsen PH. 'Candidatus Competibacter'-lineage genomes retrieved from metagenomes reveal functional metabolic diversity. ISME JOURNAL 2013; 8:613-624. [PMID: 24173461 DOI: 10.1038/ismej.2013.162] [Citation(s) in RCA: 147] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 07/19/2013] [Accepted: 08/17/2013] [Indexed: 11/09/2022]
Abstract
The glycogen-accumulating organism (GAO) 'Candidatus Competibacter' (Competibacter) uses aerobically stored glycogen to enable anaerobic carbon uptake, which is subsequently stored as polyhydroxyalkanoates (PHAs). This biphasic metabolism is key for the Competibacter to survive under the cyclic anaerobic-'feast': aerobic-'famine' regime of enhanced biological phosphorus removal (EBPR) wastewater treatment systems. As they do not contribute to phosphorus (P) removal, but compete for resources with the polyphosphate-accumulating organisms (PAO), thought responsible for P removal, their proliferation theoretically reduces the EBPR capacity. In this study, two complete genomes from Competibacter were obtained from laboratory-scale enrichment reactors through metagenomics. Phylogenetic analysis identified the two genomes, 'Candidatus Competibacter denitrificans' and 'Candidatus Contendobacter odensis', as being affiliated with Competibacter-lineage subgroups 1 and 5, respectively. Both have genes for glycogen and PHA cycling and for the metabolism of volatile fatty acids. Marked differences were found in their potential for the Embden-Meyerhof-Parnas and Entner-Doudoroff glycolytic pathways, as well as for denitrification, nitrogen fixation, fermentation, trehalose synthesis and utilisation of glucose and lactate. Genetic comparison of P metabolism pathways with sequenced PAOs revealed the absence of the Pit phosphate transporter in the Competibacter-lineage genomes--identifying a key metabolic difference with the PAO physiology. These genomes are the first from any GAO organism and provide new insights into the complex interaction and niche competition between PAOs and GAOs in EBPR systems.
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Affiliation(s)
- Simon J McIlroy
- Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Aalborg, Denmark
| | - Mads Albertsen
- Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Aalborg, Denmark
| | - Eva K Andresen
- Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Aalborg, Denmark
| | - Aaron M Saunders
- Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Aalborg, Denmark
| | - Rikke Kristiansen
- Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Aalborg, Denmark
| | - Mikkel Stokholm-Bjerregaard
- Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Aalborg, Denmark.,Krüger A/S, Veolia Water Solutions and Technologies, Aalborg, Denmark
| | - Kåre L Nielsen
- Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Aalborg, Denmark
| | - Per H Nielsen
- Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Aalborg, Denmark.
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McIlroy SJ, Kristiansen R, Albertsen M, Karst SM, Rossetti S, Nielsen JL, Tandoi V, Seviour RJ, Nielsen PH. Metabolic model for the filamentous 'Candidatus Microthrix parvicella' based on genomic and metagenomic analyses. ISME JOURNAL 2013; 7:1161-72. [PMID: 23446830 DOI: 10.1038/ismej.2013.6] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
'Candidatus Microthrix parvicella' is a lipid-accumulating, filamentous bacterium so far found only in activated sludge wastewater treatment plants, where it is a common causative agent of sludge separation problems. Despite attracting considerable interest, its detailed physiology is still unclear. In this study, the genome of the RN1 strain was sequenced and annotated, which facilitated the construction of a theoretical metabolic model based on available in situ and axenic experimental data. This model proposes that under anaerobic conditions, this organism accumulates preferentially long-chain fatty acids as triacylglycerols. Utilisation of trehalose and/or polyphosphate stores or partial oxidation of long-chain fatty acids may supply the energy required for anaerobic lipid uptake and storage. Comparing the genome sequence of this isolate with metagenomes from two full-scale wastewater treatment plants with enhanced biological phosphorus removal reveals high similarity, with few metabolic differences between the axenic and the dominant community 'Ca. M. parvicella' strains. Hence, the metabolic model presented in this paper could be considered generally applicable to strains in full-scale treatment systems. The genomic information obtained here will provide the basis for future research into in situ gene expression and regulation. Such information will give substantial insight into the ecophysiology of this unusual and biotechnologically important filamentous bacterium.
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Affiliation(s)
- Simon Jon McIlroy
- Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Aalborg, Denmark
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Ye L, Pijuan M, Yuan Z. The effect of free nitrous acid on key anaerobic processes in enhanced biological phosphorus removal systems. BIORESOURCE TECHNOLOGY 2013; 130:382-389. [PMID: 23313766 DOI: 10.1016/j.biortech.2012.11.127] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 10/15/2012] [Accepted: 11/28/2012] [Indexed: 06/01/2023]
Abstract
In this study, the effect of nitrite/FNA on the anaerobic metabolism of polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) is investigated. The results clearly show that FNA has a detrimental effect on the acetate uptake rate by both PAOs and GAOs, but this adverse effect is much stronger on PAOs than on GAOs. Also, when FNA was increased, phosphate release to acetate uptake ratio by PAOs increased substantially (250-300% compared to control), which was accompanied by decreases (40-60%) in glycogen degradation and PHA production to VFA uptake. In contrast, these ratios for GAOs remained constant or increased slightly towards the highest FNA concentration applied. These results indicate that the anaerobic metabolism of PAOs is more adversely affected than that of GAOs when FNA is present. This might provide a competitive advantage to GAOs over PAOs in enhanced biological phosphorus removal systems when nitrite is present.
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Affiliation(s)
- Liu Ye
- Advanced Water Management Centre (AWMC), The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia
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35
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Kawakoshi A, Nakazawa H, Fukada J, Sasagawa M, Katano Y, Nakamura S, Hosoyama A, Sasaki H, Ichikawa N, Hanada S, Kamagata Y, Nakamura K, Yamazaki S, Fujita N. Deciphering the genome of polyphosphate accumulating actinobacterium Microlunatus phosphovorus. DNA Res 2012; 19:383-94. [PMID: 22923697 PMCID: PMC3473371 DOI: 10.1093/dnares/dss020] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Polyphosphate accumulating organisms (PAOs) belong mostly to Proteobacteria and Actinobacteria and are quite divergent. Under aerobic conditions, they accumulate intracellular polyphosphate (polyP), while they typically synthesize polyhydroxyalkanoates (PHAs) under anaerobic conditions. Many ecological, physiological, and genomic analyses have been performed with proteobacterial PAOs, but few with actinobacterial PAOs. In this study, the whole genome sequence of an actinobacterial PAO, Microlunatus phosphovorus NM-1T (NBRC 101784T), was determined. The number of genes for polyP metabolism was greater in M. phosphovorus than in other actinobacteria; it possesses genes for four polyP kinases (ppks), two polyP-dependent glucokinases (ppgks), and three phosphate transporters (pits). In contrast, it harbours only a single ppx gene for exopolyphosphatase, although two copies of ppx are generally present in other actinobacteria. Furthermore, M. phosphovorus lacks the phaABC genes for PHA synthesis and the actP gene encoding an acetate/H+ symporter, both of which play crucial roles in anaerobic PHA accumulation in proteobacterial PAOs. Thus, while the general features of M. phosphovorus regarding aerobic polyP accumulation are similar to those of proteobacterial PAOs, its anaerobic polyP use and PHA synthesis appear to be different.
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Affiliation(s)
- Akatsuki Kawakoshi
- Biological Resource Center, National Institute of Technology and Evaluation, 2-10-49 Nishihara, Tokyo 151-0066, Japan
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36
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Gebremariam SY, Beutel MW, Christian D, Hess TF. Research advances and challenges in the microbiology of enhanced biological phosphorus removal--a critical review. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2011; 83:195-219. [PMID: 21466069 DOI: 10.2175/106143010x12780288628534] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Enhanced biological phosphorus removal (EBPR) is a well-established technology for removing phosphorus from wastewater. However, the process remains operationally unstable in many systems, primarily because there is a lack of understanding regarding the microbiology of EBPR. This paper presents a review of advances made in the study of EBPR microbiology and focuses on the identification, enrichment, classification, morphology, and metabolic capacity of polyphosphate- and glycogen-accumulating organisms. The paper also highlights knowledge gaps and research challenges in the field of EBPR microbiology. Based on the review, the following recommendations regarding the future direction of EBPR microbial research were developed: (1) shifting from a reductionist approach to a more holistic system-based approach, (2) using a combination of culture-dependent and culture-independent techniques in characterizing microbial composition, (3) integrating ecological principles into system design to enhance stability, and (4) reexamining current theoretical explanations of why and how EBPR occurs.
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Affiliation(s)
- Seyoum Yami Gebremariam
- Washington State University, Department of Civil and Environmental Engineering, Pullman, Washington 99164-2910, USA.
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Abstract
‘Candidatus Accumulibacter’ is a biotechnologically important bacterial group that can accumulate large amounts of intracellular polyphosphate, contributing to biological phosphorus removal in wastewater treatment. Since its first molecular identification more than a decade ago, this bacterial group has drawn significant research attention due to its high abundance in many biological phosphorus removal systems. In the past 6 years, our understanding of Accumulibacter microbiology and ecophysiology has advanced rapidly, largely owing to genomic information obtained through shotgun metagenomic sequencing efforts. In this review, we focus on the metabolism, physiology, fine‐scale population structure and ecological distribution of Accumulibacter, aiming to integrate the information learned so far and to present a more complete picture of the microbiology of this important bacterial group.
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Affiliation(s)
- Shaomei He
- Department of Civil and Environmental Engineering Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
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Oehmen A, Carvalho G, Lopez-Vazquez CM, van Loosdrecht MCM, Reis MAM. Incorporating microbial ecology into the metabolic modelling of polyphosphate accumulating organisms and glycogen accumulating organisms. WATER RESEARCH 2010; 44:4992-5004. [PMID: 20650504 DOI: 10.1016/j.watres.2010.06.071] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Revised: 06/25/2010] [Accepted: 06/30/2010] [Indexed: 05/29/2023]
Abstract
In the enhanced biological phosphorus removal (EBPR) process, the competition between polyphosphate accumulating organisms (PAO) and glycogen accumulating organisms (GAO) has been studied intensively in recent years by both microbiologists and engineers, due to its important effects on phosphorus removal performance and efficiency. This study addresses the impact of microbial ecology on assessing the PAO-GAO competition through metabolic modelling, focussing on reviewing recent developments, discussion of how the results from molecular studies can impact the way we model the process, and offering perspectives for future research opportunities based on unanswered questions concerning PAO and GAO metabolism. Indeed, numerous findings that are seemingly contradictory could in fact be explained by the metabolic behaviour of different sub-groups of PAOs and/or GAOs exposed to different environmental and operational conditions. Some examples include the glycolysis pathway (i.e. Embden-Meyerhof-Parnas (EMP) vs. Entner-Doudoroff (ED)), denitrification capacity, anaerobic tricarboxylic acid (TCA) cycle activity and PAOs' ability to adjust their metabolism to e.g. a GAO-like metabolism. Metabolic modelling may further yield far-reaching influences on practical applications as well, and serves as a bridge between molecular/biochemical research studies and the optimisation of wastewater treatment plant operation.
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Affiliation(s)
- A Oehmen
- REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
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39
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Anaerobic glyoxylate cycle activity during simultaneous utilization of glycogen and acetate in uncultured Accumulibacter enriched in enhanced biological phosphorus removal communities. ISME JOURNAL 2008; 2:1040-51. [PMID: 18784756 DOI: 10.1038/ismej.2008.45] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Enhanced biological phosphorus removal (EBPR) communities protect waterways from nutrient pollution and enrich microorganisms capable of assimilating acetate as polyhydroxyalkanoate (PHA) under anaerobic conditions. Accumulibacter, an important uncultured polyphosphate-accumulating organism (PAO) enriched in EBPR, was investigated to determine the central metabolic pathways responsible for producing PHA. Acetate uptake and assimilation to PHA in Accumulibacter was confirmed using fluorescence in situ hybridization (FISH)-microautoradiography and post-FISH chemical staining. Assays performed with enrichments of Accumulibacter using an inhibitor of glyceraldehyde-3-phosphate dehydrogenase inferred anaerobic glycolysis activity. Significant decrease in anaerobic acetate uptake and PHA production rates were observed using inhibitors targeting enzymes within the glyoxylate cycle. Bioinformatic analysis confirmed the presence of genes unique to the glyoxylate cycle (isocitrate lyase and malate synthase) and gene expression analysis of isocitrate lyase demonstrated that the glyoxylate cycle is likely involved in PHA production. Reduced anaerobic acetate uptake and PHA production was observed after inhibition of succinate dehydrogenase and upregulation of a succinate dehydrogenase gene suggested anaerobic activity. Cytochrome b/b(6) activity inferred that succinate dehydrogenase activity in the absence of external electron acceptors may be facilitated by a novel cytochrome b/b(6) fusion protein complex that pushes electrons uphill to more electronegative electron carriers. Identification of phosphoenolpyruvate carboxylase and phosphoenolpyruvate carboxykinase genes in Accumulibacter demonstrated the potential for interconversion of C(3) intermediates of glycolysis and C(4) intermediates of the glyoxylate cycle. Our findings along with previous hypotheses from analysis of microbiome data and metabolic models for PAOs were used to develop a model for anaerobic carbon metabolism in Accumulibacter.
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Burow LC, Mabbett AN, McEwan AG, Bond PL, Blackall LL. Bioenergetic models for acetate and phosphate transport in bacteria important in enhanced biological phosphorus removal. Environ Microbiol 2008; 10:87-98. [PMID: 18211269 DOI: 10.1111/j.1462-2920.2007.01432.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Most of our understanding of the physiology of microorganisms is the result of investigations in pure culture. However, in order to understand complex environmental processes, there is a need to investigate mixed microbial communities. This is true for enhanced biological phosphorus removal (EBPR), an environmental process that results in the enrichment of the polyphosphate-accumulating organism Accumulibacter spp. and the glycogen non-polyphosphate accumulating organism Defluviicoccus spp. We investigated acetate and inorganic phosphate (P(i)) uptake in enrichments of Accumulibacter spp. and acetate uptake in enrichments of Defluviicoccus spp. For both enrichments, anaerobic acetate uptake assays in the presence of the protonophore, carbonyl cyanide m-chlorophenylhydrazone (CCCP) or the membrane potential (Delta psi) uncoupler valinomycin, indicated that acetate is likely to be taken up by a permease-mediated process driven by the Delta psi. Further investigation with the sodium ionophore monensin suggested that anaerobic acetate uptake by Defluviicoccus spp. may in part be dependent on a sodium potential. Results of this study also suggest that Accumulibacter spp. generate a proton motive force (pmf or Delta p) for anaerobic acetate uptake by efflux of protons in symport with P(i) through an inorganic phosphate transport (Pit) system. In contrast, we suggest that the anaerobic Delta p in Defluviicoccus spp. is generated by an efflux of protons across the cell membrane by the fumarate respiratory system, or by extrusion of sodium ions via decarboxylation of methylmalonyl-CoA. Aerobic P(i) uptake by the Accumulibacter spp. enrichment was strongly inhibited in the presence of an ATPase inhibitor, suggesting that the phosphate-specific transport (Pst) system is important even under relatively high concentrations of P(i). Acetate permease activity in these microorganisms may play an important role in the competition for acetate in the often acetate-limited EBPR process. Activity of a high-velocity Pst system in Accumulibacter spp. may further explain its ability to compete strongly in EBPR.
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Affiliation(s)
- Luke C Burow
- Advanced Wastewater Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia
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The microbiology of phosphorus removal in activated sludge processes-the current state of play. J Microbiol 2008; 46:115-24. [PMID: 18545960 DOI: 10.1007/s12275-008-0051-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2008] [Accepted: 03/18/2008] [Indexed: 10/22/2022]
Abstract
This review discusses critically what we know and would like to know about the microbiology of phosphorus (P) removal in activated sludge systems. In particular, the description of the genome sequences of two strains of the polyphosphate accumulating organism found in these processes, Candidatus 'Accumulibacter phosphatis', allows us to address many of the previously unanswered questions relating to how these processes behave, and to raise new questions about the microbiology of P removal. This article attempts to be deliberately speculative, and inevitably subjective, but hopefully at the same time useful to those who have an active interest in these environmentally very important processes.
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