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Ye Q, Gong X, Li A, Shao S, Ji B. A typical acidic extracellular polysaccharide alludes to algae-bacteria-collaboration in microalgal-bacterial symbiosis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 929:172545. [PMID: 38636868 DOI: 10.1016/j.scitotenv.2024.172545] [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: 03/08/2024] [Revised: 04/12/2024] [Accepted: 04/15/2024] [Indexed: 04/20/2024]
Abstract
Microalgal-bacterial symbioses are prevalent in aquatic ecosystems and play a pivotal role in carbon sequestration, significantly contributing to global carbon cycling. The understanding of the contribution of exopolysaccharides (EPSs), a crucial carbon-based component, to the structural integrity of microalgal-bacterial symbioses remains insufficiently elucidated. To address this gap, our study aims to enhance our comprehension of the composition and primary structure of EPSs within a specific type of granular microalgal-bacterial symbiosis named microalgal-bacterial granular sludge (MBGS). Our investigation reveals that the acidic EPSs characteristic of this symbiosis have molecular weights ranging from several hundred thousand to over one million Daltons, including components like glucopyranose, galactopyranose, mannose, and rhamnose. Our elucidation of the backbone linkage of a representative exopolysaccharide revealed a →3)-β-D-Galp-(1→4)-β-D-Glcp-(1→ glycosidic linkage. This linear structure closely resembles bacterial xanthan, while the branched chain structure bears similarities to algal EPSs. Our findings highlight the collaborative synthesis of acidic EPSs by both microalgae and bacteria, emphasizing their joint contribution in the production of macromolecules within microalgal-bacterial symbiosis. This collaborative synthesis underscores the intricate molecular interactions contributing to the stability and function of these symbiotic relationships.
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Affiliation(s)
- Qinyi Ye
- Department of Water and Wastewater Engineering, School of Urban Construction, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Xiping Gong
- Department of Water and Wastewater Engineering, School of Urban Construction, Wuhan University of Science and Technology, Wuhan 430065, China
| | - Anjie Li
- Key Laboratory of Water and Sediment Sciences of Ministry of Education, State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China
| | - Senlin Shao
- School of Civil Engineering, Wuhan University, Wuhan 430072, China
| | - Bin Ji
- Department of Water and Wastewater Engineering, School of Urban Construction, Wuhan University of Science and Technology, Wuhan 430065, China.
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Zhong J, Tang L, Gao M, Wang S, Wang X. Beyond feast and famine: Cultivating hydrodynamic oxygenic photogranules with better performances under permanent feast regime. BIORESOURCE TECHNOLOGY 2024; 401:130752. [PMID: 38685514 DOI: 10.1016/j.biortech.2024.130752] [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: 02/15/2024] [Revised: 04/26/2024] [Accepted: 04/26/2024] [Indexed: 05/02/2024]
Abstract
Oxygenic photogranules (OPGs) are currently obtained in permanent famine or cyclic feast-famine regimes. Whether photogranulation occurs under a permanent feast regime and how these regimes impact OPGs are unknown. Herein, the three regimes, each applied in two replicate hydrodynamic reactors, were established by different feeding frequencies. Results showed that OPGs were successfully cultivated in all regimes after 24-36 days of photogranulation phases with similar microbial community functions, including filamentous gliding, extracellular polymeric substances production, and carbon/nitrogen metabolism. The OPGs were then operated under the same sequencing batch mode and all achieved efficient removal of chemical oxygen demand (>91 %), ammonium (>96 %), and total nitrogen (>76 %) after different adaptation periods (19-41 days). Notably, the permanent feast regime obtained OPGs with the best physicochemical properties, the shortest adaptation period, and the lowest effluent turbidity, thus representing a novel means of hydrodynamic cultivating OPGs with better performances for sustainable wastewater treatment.
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Affiliation(s)
- Jiewen Zhong
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, Shandong Key Laboratory of Environmental Processes and Health, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
| | - Liaofan Tang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, Shandong Key Laboratory of Environmental Processes and Health, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
| | - Mingming Gao
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, Shandong Key Laboratory of Environmental Processes and Health, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China
| | - Shuguang Wang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, Shandong Key Laboratory of Environmental Processes and Health, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China; Weihai Research Institute of Industrial Technology of Shandong University, Weihai 264209, China
| | - Xinhua Wang
- Shandong Key Laboratory of Water Pollution Control and Resource Reuse, Shandong Key Laboratory of Environmental Processes and Health, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, China.
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Wu X, Kong L, Feng Y, Zheng R, Zhou J, Sun J, Liu S. Communication mediated interaction between bacteria and microalgae advances photogranulation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 914:169975. [PMID: 38218496 DOI: 10.1016/j.scitotenv.2024.169975] [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: 10/21/2023] [Revised: 12/16/2023] [Accepted: 01/04/2024] [Indexed: 01/15/2024]
Abstract
Recently, photogranules composed of bacteria and microalgae for carbon-negative nitrogen removal receive extensive attention worldwide, yet which type of bacteria is helpful for rapid formation of photogranules and whether they depend on signaling communication remain elusive. Varied signaling communication was analyzed using metagenomic method among bacteria and microalgae in via of two types of experimentally verified signaling molecule from bacteria to microalgae, which include indole-3-acetic acid (IAA) and N-acyl homoserine lactones (AHLs) during the operation of photo-bioreactors. Signaling communication is helpful for the adaptability of bacteria to survive with algae. Compared with non-signaling bacteria, signaling bacteria more easily adapt to the varied conditions, evidenced by the increased abundance in the operated reactors. Signaling bacteria are easier to enter the phycosphere, and they dominate the interactions between bacteria and algae rather than non-signaling bacteria. The co-abundance groups (CAGs) with signaling bacteria possess higher abundance than that without signaling bacteria (22.27 % and 6.67 %). Importantly, signaling bacteria accessibly interact with microalgae, which possess higher degree centralities and 32.50 % of them are keystone nodes in the network, in contrast to only 18.66 % of non-signaling bacteria. Thauera carrying both IAA and AHLs synthase genes are highly enriched and positively correlated with nitrogen removal rate. Our work not only highlights the essential roles of signaling communication between microalgae and bacteria in the development of photogranules, but also enriches our understanding of microbial sociobiology.
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Affiliation(s)
- Xiaogang Wu
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; Key Laboratory of Water and Sediment Sciences, Ministry of Education, Peking University, Beijing 100871, China
| | - Lingrui Kong
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; Key Laboratory of Water and Sediment Sciences, Ministry of Education, Peking University, Beijing 100871, China
| | - Yiming Feng
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; Key Laboratory of Water and Sediment Sciences, Ministry of Education, Peking University, Beijing 100871, China
| | - Ru Zheng
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; Key Laboratory of Water and Sediment Sciences, Ministry of Education, Peking University, Beijing 100871, China
| | - Jianhang Zhou
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; Key Laboratory of Water and Sediment Sciences, Ministry of Education, Peking University, Beijing 100871, China
| | - Jingqi Sun
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; Key Laboratory of Water and Sediment Sciences, Ministry of Education, Peking University, Beijing 100871, China
| | - Sitong Liu
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; Key Laboratory of Water and Sediment Sciences, Ministry of Education, Peking University, Beijing 100871, China.
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