Peng Wang , Di He , Jianshu Zhao , Zhenxiong Xiao , Jun Tan , Jinxing Ma , Min Zheng
{"title":"Transition from Anammox to Feammox metabolic modes: Regulation strategies for nitrite in Anammox enrichment cultures","authors":"Peng Wang , Di He , Jianshu Zhao , Zhenxiong Xiao , Jun Tan , Jinxing Ma , Min Zheng","doi":"10.1016/j.biortech.2025.132674","DOIUrl":null,"url":null,"abstract":"<div><div>This study<!--> <!-->achieved<!--> <!-->the metabolic transition from anaerobic ammonium oxidation (Anammox) to Fe(III)-mediated ammonium oxidation (Feammox)<!--> <!-->using<!--> <!-->iron-carbon micro-electrolytic spheres as a slow-release iron source<!--> <!-->through<!--> <!-->a stepwise reduction<!--> <!-->in influent NO<sub>2</sub><sup>−</sup>-N concentration. The results demonstrated that sustained Feammox activity<!--> <!-->was governed by<!--> <!-->nitrate-dependent ferrous oxidation (NDFO) metabolism<!--> <!-->combined with<!--> <!-->oxygen-regulated Fe(III) regeneration,<!--> <!-->resulting in<!--> <!-->a peak total nitrogen removal efficiency of 91.6 %<!--> <!-->at<!--> <!-->40 mg/L NO<sub>2</sub><sup>−</sup>-N.<!--> <!-->While<!--> <!-->exclusive NH<sub>4</sub><sup>+</sup>-N feeding inhibited Feammox activity,<!--> <!-->this suppression was reversible upon NO<sub>2</sub><sup>−</sup>-N supplementation. Intriguingly, Anammox activity<!--> <!-->remained robust<!--> <!-->despite decreasing NO<sub>2</sub><sup>−</sup>-N levels<!--> <!-->and showed<!--> <!-->significant positive correlation with Feammox activity,<!--> <!-->suggesting shared metabolic modules. Metagenomic profiling<!--> <!-->further identified<!--> <em>Ca.</em> Brocadia as the core functional genus driving NH<sub>4</sub><sup>+</sup>-N oxidation,<!--> <!-->highlighting its niche adaptation<!--> <!-->in iron-mediated systems.<!--> <!-->These mechanistic insights establish a framework for<!--> <!-->designing energy-efficient nitrogen removal processes<!--> <!-->leveraging iron-redox cycling.</div></div>","PeriodicalId":258,"journal":{"name":"Bioresource Technology","volume":"432 ","pages":"Article 132674"},"PeriodicalIF":9.7000,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bioresource Technology","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0960852425006406","RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"AGRICULTURAL ENGINEERING","Score":null,"Total":0}
引用次数: 0
Abstract
This study achieved the metabolic transition from anaerobic ammonium oxidation (Anammox) to Fe(III)-mediated ammonium oxidation (Feammox) using iron-carbon micro-electrolytic spheres as a slow-release iron source through a stepwise reduction in influent NO2−-N concentration. The results demonstrated that sustained Feammox activity was governed by nitrate-dependent ferrous oxidation (NDFO) metabolism combined with oxygen-regulated Fe(III) regeneration, resulting in a peak total nitrogen removal efficiency of 91.6 % at 40 mg/L NO2−-N. While exclusive NH4+-N feeding inhibited Feammox activity, this suppression was reversible upon NO2−-N supplementation. Intriguingly, Anammox activity remained robust despite decreasing NO2−-N levels and showed significant positive correlation with Feammox activity, suggesting shared metabolic modules. Metagenomic profiling further identified Ca. Brocadia as the core functional genus driving NH4+-N oxidation, highlighting its niche adaptation in iron-mediated systems. These mechanistic insights establish a framework for designing energy-efficient nitrogen removal processes leveraging iron-redox cycling.
期刊介绍:
Bioresource Technology publishes original articles, review articles, case studies, and short communications covering the fundamentals, applications, and management of bioresource technology. The journal seeks to advance and disseminate knowledge across various areas related to biomass, biological waste treatment, bioenergy, biotransformations, bioresource systems analysis, and associated conversion or production technologies.
Topics include:
• Biofuels: liquid and gaseous biofuels production, modeling and economics
• Bioprocesses and bioproducts: biocatalysis and fermentations
• Biomass and feedstocks utilization: bioconversion of agro-industrial residues
• Environmental protection: biological waste treatment
• Thermochemical conversion of biomass: combustion, pyrolysis, gasification, catalysis.