Deciphering the Dual Roles of an Alginate-Based Biodegradable Flocculant in Anaerobic Fermentation of Waste Activated Sludge: Dewaterability and Degradability

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: 58(32), P. 14282 - 14292

Published: July 31, 2024

Biodegradable flocculants are rarely used in waste activated sludge (WAS) fermentation. This study introduces an alginate-based biodegradable flocculant (ABF) to enhance both the dewatering and degradation of WAS during its Alginate was identified structural extracellular polymeric substances (St-EPS) WAS, with alginate-producing bacteria comprising ∼4.2% total bacterial population WAS. Owing larger floc size, higher contact angle, lower free energy resulting from Lewis acid-base interaction, addition prepared ABF a network structure significantly improved dewaterability reduced capillary suction time (CST) by 72%. The utilization enriched alginate-degrading consortium (ADC) resulted 35.5% increase methane yield owing hydrolytic activity on St-EPS. Additionally, after 30 day fermentation, CST decreased 62% enhanced St-EPS (74.4%) viscosity + ADC group. genus Bacteroides, 12% ADC, alginate lyase (EC 4.2.2.3) pectate 4.2.2.2 EC 4.2.2.9) degrade polygalacturonate St-EPS, respectively. Therefore, this new elucidates dual roles enhancing degradability These advancements improve production CSTs.

Language: Английский

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Little alginates synthesized in EPS: Evidences from high-throughput community and metagenes

Water Research, Journal Year: 2024, Volume and Issue: 265, P. 122211 - 122211

Published: Aug. 3, 2024

Language: Английский

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A genome-scale metabolic model for the denitrifying bacterium Thauera sp. MZ1T accurately predicts degradation of pollutants and production of polymers

PLoS Computational Biology, Journal Year: 2025, Volume and Issue: 21(1), P. e1012736 - e1012736

Published: Jan. 7, 2025

The denitrifying bacterium Thauera sp. MZ1T, a common member of microbial communities in wastewater treatment facilities, can produce different compounds from range carbon (C) and nitrogen (N) sources under aerobic anaerobic conditions. In these conditions, modifies its metabolism to that influence the community. particular, MZ1T produces exopolysaccharides with floc-forming properties, impacting physical disposition consortia efficiency nutrient assimilation by Under N-limiting decreases growth rate accelerates accumulation polyhydroxyalkanoate-related (PHA) including polyhydroxybutyrate (PHB), which plays fundamental role as C energy storage this β-proteobacterium. However, metabolic mechanisms employed assimilate catabolize many N conditions remain unknown. Systems biology approaches such genome-scale modeling have been successfully used unveil complex for various microorganisms. Here, we developed comprehensive model (M-model) (iThauera861), consisting 1,744 metabolites, 2,384 reactions, 861 genes. We validated experimentally using over 70 both iThauera861 achieved prediction accuracy 95% on close 85% aromatic M-model was subsequently deployed determine effects substrates, oxygen presence, C:N ratio production PHB (EPS), showing highest polymer yields are nucleotides amino acids This will help reveal processes ubiquitous species influences systems natural environments.

Language: Английский

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Elucidating the complex hydrolysis and conversion network of xanthan-like extracellular heteropolysaccharides in waste activated sludge fermentation

Water Research X, Journal Year: 2025, Volume and Issue: 27, P. 100303 - 100303

Published: Jan. 13, 2025

Language: Английский

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Preparation of saline-tolerant electroactive granular sludge and its application in treating saline azo-dye wastewater

Journal of Water Process Engineering, Journal Year: 2025, Volume and Issue: 71, P. 107268 - 107268

Published: Feb. 17, 2025

Language: Английский

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Viscosity is a nonnegligible factor in the waste activated sludge fermentation: taking hyaluronan as an example

Water Research, Journal Year: 2025, Volume and Issue: 279, P. 123465 - 123465

Published: March 9, 2025

Language: Английский

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Multiple extracellular polymeric substance pathways transcribed by Accumulibacter and the flanking community during aerobic granule formation and after influent modification

Applied and Environmental Microbiology, Journal Year: 2025, Volume and Issue: unknown

Published: March 31, 2025

Aerobic granular sludge is a biological wastewater treatment process in which microbial community forms biofilm. The role of Candidatus Accumulibacter the production biofilm matrix composed extracellular polymeric substances was studied sequencing batch reactor enriched with polyphosphate-accumulating organisms. metabolisms populations were investigated using de novo metatranscriptomics analysis. Finally, effect decreasing influent phosphate concentration on granule stability and activity investigated. A few weeks after start-up, dominated by up to nine species active parallel. However, most differed according sampling time. Decreasing drastically led dominance glycogen-accumulating organism Propionivibrio, some still abundant. De analysis indicated high diversity potential produced mainly Accumulibacter, Azonexus, Contendobacter, Propionivibrio. Moreover, results suggest that Propionivibrio recycle neuraminic acids Accumulibacter. Changes did not cause granules disintegrate, indicating Propionivibrio-dominated can maintain stable granules.IMPORTANCEOne main advantages aerobic higher settling velocities compared conventional activated sludge-based process. In sludge, biomass concentrated into biopolymers, providing micro-niches different types populations. We demonstrate help formation highly dynamic process, even when enriching for guild, such as phosphate-accumulating Often underestimated, flanking organisms population nonetheless transcribing genes related substance pathways. multiplicity probably helped remain stable, thanks their specific properties. interactions recycling between be helpful prevent disruption while stressing out community.

Language: Английский

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Linking Oxygen-Induced Oxidative Stress to Resource Recovery by Enhancing the Production of Extracellular Polymeric Substances in Activated Sludge Microbial Communities

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: April 29, 2025

Abstract As the global transition toward circular wastewater treatment intensifies, extracellular polymeric substances (EPS) have emerged as valuable targets for resource recovery. Although most efforts focused on aerobic granular sludge, conventional activated sludge systems, which account treatment, remain underexploited EPS Building established link between oxidative stress and biosynthesis in pure strains, we propose that strategically manipulating oxygen exposure patterns to intensify microbial communities could enhance production. To test this, applied continuous perturbation under stress. Compared a stable condition simulating typical aeration, considerably enhanced yield 74.4□mg/L/day, 90.5% increase over (39.0□mg/L/day). validate role of enhancement, intermittent anoxic phases were introduced into pattern relieve stress, causing EPS-enhancing effect disappear, with dropping 9.8□mg/L/day. Mechanistically, intensified was primarily driven by elevated reducing substrates non-respiratory flavoenzymes, exemplified glutamate synthase, glutathione reductase, dihydrolipoamide dehydrogenase, are prone generate H 2 O an unintended metabolic byproduct. Among multiple groups contributing production, Methylophilaceae, Comamonadaceae , Rhodobacteraceae distinguished simultaneously exhibiting upregulation proteins, suggesting taxa within these families collectively mediated both production enhancement. By modulating this study offers chemical-free, controllable strategy enhancing systems. Graphical abstract

Language: Английский

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Rethinking characterization, application, and importance of extracellular polymeric substances in water technologies

Current Opinion in Biotechnology, Journal Year: 2024, Volume and Issue: 89, P. 103192 - 103192

Published: Aug. 30, 2024

Biofilms play important roles in water technologies such as membrane treatments and activated sludge. The extracellular polymeric substances (EPS) are key components of biofilms. However, the precise nature these how they influence biofilm formation behavior remain critical knowledge gaps. EPS produced by many different microorganisms span multiple biopolymer classes, which each require distinct strategies for characterization. biopolymers additionally associate with other to form insoluble complexes. Here, we explore recent progress toward resolving structures functions EPS, where a shift towards direct functional assessments advanced characterization techniques is necessary. This will enable integration better microbial community omics analyses understand biosynthesis pathways create further opportunities control valorization.

Language: Английский

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Visualization of Syntrophic Benzene-Fermenting Desulfobacterota ORM2 in a Methanogenic Enrichment Culture Using Fluorescence In Situ Hybridization

Environmental Science & Technology, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 3, 2025

Benzene degradation under anoxic conditions was first reported more than 25 years ago; however, the activation mechanism in absence of oxygen remains elusive. Progress has been hindered by difficulty cultivating anaerobic benzene-degrading enrichment cultures. Our laboratory sustained a methanogenic culture harboring

Language: Английский

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