{"title":"间歇甘油喂养形成糖原储存表型,通过顺序反硝化增强亚硝酸盐积累","authors":"Shi-Man Liang, Jia-Qi Zhou, Hai-Tian Xu, Shu-Yang Fang, Yu Zhang, Zheng-Zhe Zhang, Ren-Cun Jin","doi":"10.1016/j.watres.2025.124646","DOIUrl":null,"url":null,"abstract":"<div><div>Achieving stable and efficient denitratation is a promising strategy to supply nitrite for mainstream anammox processes, yet the underlying microbial mechanisms remain poorly understood, especially with alternative carbon sources like glycerol. Here, we hypothesized that intermittent feeding regimes could drive higher nitrite accumulation by selecting for specific metabolic phenotypes. To test this, an intermittently-fed sequencing batch reactor (SBR) and a continuously-fed up-flow anaerobic sludge blanket (UASB) reactor were operated under identical carbon-restricted conditions (COD/NO₃⁻-<em>N</em> = 3.5). The SBR achieved a significantly higher and stable nitrite accumulation efficiency (NiAE) of 43.0 ± 4.1 % compared to the UASB (18.9 ± 5.4 %). Genome-resolved metagenomics revealed that the SBR community was enriched in species with glycogen-storing potential, leading to a 45.8 % greater overall abundance of genes related to glycogen metabolism compared to the UASB. Phenotypic analyses confirmed that the SBR sludge contained significantly more intracellular glycogen and displayed a nitrate reductase (NAR) to nitrite reductase (NIR) activity ratio that was an order of magnitude higher than the UASB sludge. This kinetic imbalance underpinned a “sequential denitrification” phenotype, where nitrate was preferentially reduced to nitrite. Critically, the UASB-enriched community, when subjected to batch-fed conditions, also exhibited a high denitratation potential close to the SBR culture, demonstrating that this phenotype is a plastic trait regulated by the glycerol feeding strategy rather than a fixed attribute of the community structure. This study uncovers a fundamental mechanism where intermittent glycerol availability directs metabolic flux towards glycogen storage, which in turn regulates electron partitioning between NAR and NIR. This highlights a significant divergence between genotypic potential and realized phenotype, offering a new paradigm for controlling nitrogen transformation pathways in engineered ecosystems.</div></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"288 ","pages":"Article 124646"},"PeriodicalIF":12.4000,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Intermittent glycerol feeding shapes a glycogen-storing phenotype for enhanced nitrite accumulation via sequential denitrification\",\"authors\":\"Shi-Man Liang, Jia-Qi Zhou, Hai-Tian Xu, Shu-Yang Fang, Yu Zhang, Zheng-Zhe Zhang, Ren-Cun Jin\",\"doi\":\"10.1016/j.watres.2025.124646\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Achieving stable and efficient denitratation is a promising strategy to supply nitrite for mainstream anammox processes, yet the underlying microbial mechanisms remain poorly understood, especially with alternative carbon sources like glycerol. Here, we hypothesized that intermittent feeding regimes could drive higher nitrite accumulation by selecting for specific metabolic phenotypes. To test this, an intermittently-fed sequencing batch reactor (SBR) and a continuously-fed up-flow anaerobic sludge blanket (UASB) reactor were operated under identical carbon-restricted conditions (COD/NO₃⁻-<em>N</em> = 3.5). The SBR achieved a significantly higher and stable nitrite accumulation efficiency (NiAE) of 43.0 ± 4.1 % compared to the UASB (18.9 ± 5.4 %). Genome-resolved metagenomics revealed that the SBR community was enriched in species with glycogen-storing potential, leading to a 45.8 % greater overall abundance of genes related to glycogen metabolism compared to the UASB. Phenotypic analyses confirmed that the SBR sludge contained significantly more intracellular glycogen and displayed a nitrate reductase (NAR) to nitrite reductase (NIR) activity ratio that was an order of magnitude higher than the UASB sludge. This kinetic imbalance underpinned a “sequential denitrification” phenotype, where nitrate was preferentially reduced to nitrite. Critically, the UASB-enriched community, when subjected to batch-fed conditions, also exhibited a high denitratation potential close to the SBR culture, demonstrating that this phenotype is a plastic trait regulated by the glycerol feeding strategy rather than a fixed attribute of the community structure. This study uncovers a fundamental mechanism where intermittent glycerol availability directs metabolic flux towards glycogen storage, which in turn regulates electron partitioning between NAR and NIR. This highlights a significant divergence between genotypic potential and realized phenotype, offering a new paradigm for controlling nitrogen transformation pathways in engineered ecosystems.</div></div>\",\"PeriodicalId\":443,\"journal\":{\"name\":\"Water Research\",\"volume\":\"288 \",\"pages\":\"Article 124646\"},\"PeriodicalIF\":12.4000,\"publicationDate\":\"2025-09-20\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Water Research\",\"FirstCategoryId\":\"93\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0043135425015490\",\"RegionNum\":1,\"RegionCategory\":\"环境科学与生态学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENGINEERING, ENVIRONMENTAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Water Research","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0043135425015490","RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
Intermittent glycerol feeding shapes a glycogen-storing phenotype for enhanced nitrite accumulation via sequential denitrification
Achieving stable and efficient denitratation is a promising strategy to supply nitrite for mainstream anammox processes, yet the underlying microbial mechanisms remain poorly understood, especially with alternative carbon sources like glycerol. Here, we hypothesized that intermittent feeding regimes could drive higher nitrite accumulation by selecting for specific metabolic phenotypes. To test this, an intermittently-fed sequencing batch reactor (SBR) and a continuously-fed up-flow anaerobic sludge blanket (UASB) reactor were operated under identical carbon-restricted conditions (COD/NO₃⁻-N = 3.5). The SBR achieved a significantly higher and stable nitrite accumulation efficiency (NiAE) of 43.0 ± 4.1 % compared to the UASB (18.9 ± 5.4 %). Genome-resolved metagenomics revealed that the SBR community was enriched in species with glycogen-storing potential, leading to a 45.8 % greater overall abundance of genes related to glycogen metabolism compared to the UASB. Phenotypic analyses confirmed that the SBR sludge contained significantly more intracellular glycogen and displayed a nitrate reductase (NAR) to nitrite reductase (NIR) activity ratio that was an order of magnitude higher than the UASB sludge. This kinetic imbalance underpinned a “sequential denitrification” phenotype, where nitrate was preferentially reduced to nitrite. Critically, the UASB-enriched community, when subjected to batch-fed conditions, also exhibited a high denitratation potential close to the SBR culture, demonstrating that this phenotype is a plastic trait regulated by the glycerol feeding strategy rather than a fixed attribute of the community structure. This study uncovers a fundamental mechanism where intermittent glycerol availability directs metabolic flux towards glycogen storage, which in turn regulates electron partitioning between NAR and NIR. This highlights a significant divergence between genotypic potential and realized phenotype, offering a new paradigm for controlling nitrogen transformation pathways in engineered ecosystems.
期刊介绍:
Water Research, along with its open access companion journal Water Research X, serves as a platform for publishing original research papers covering various aspects of the science and technology related to the anthropogenic water cycle, water quality, and its management worldwide. The audience targeted by the journal comprises biologists, chemical engineers, chemists, civil engineers, environmental engineers, limnologists, and microbiologists. The scope of the journal include:
•Treatment processes for water and wastewaters (municipal, agricultural, industrial, and on-site treatment), including resource recovery and residuals management;
•Urban hydrology including sewer systems, stormwater management, and green infrastructure;
•Drinking water treatment and distribution;
•Potable and non-potable water reuse;
•Sanitation, public health, and risk assessment;
•Anaerobic digestion, solid and hazardous waste management, including source characterization and the effects and control of leachates and gaseous emissions;
•Contaminants (chemical, microbial, anthropogenic particles such as nanoparticles or microplastics) and related water quality sensing, monitoring, fate, and assessment;
•Anthropogenic impacts on inland, tidal, coastal and urban waters, focusing on surface and ground waters, and point and non-point sources of pollution;
•Environmental restoration, linked to surface water, groundwater and groundwater remediation;
•Analysis of the interfaces between sediments and water, and between water and atmosphere, focusing specifically on anthropogenic impacts;
•Mathematical modelling, systems analysis, machine learning, and beneficial use of big data related to the anthropogenic water cycle;
•Socio-economic, policy, and regulations studies.