Research progress on interspecies electron transfer mechanisms and their regulation in denitrification systems

JIANG Jiaxin; FANG Fang; ZHANG Jialing; LUO Jingyang; CAO Jiashun

doi:10.13205/j.hjgc.202603004

Volume 44 Issue 3

Mar. 2026

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JIANG Jiaxin, FANG Fang, ZHANG Jialing, LUO Jingyang, CAO Jiashun. Research progress on interspecies electron transfer mechanisms and their regulation in denitrification systems[J]. ENVIRONMENTAL ENGINEERING , 2026, 44(3): 46-57. doi: 10.13205/j.hjgc.202603004

Citation:

JIANG Jiaxin, FANG Fang, ZHANG Jialing, LUO Jingyang, CAO Jiashun. Research progress on interspecies electron transfer mechanisms and their regulation in denitrification systems[J]. ENVIRONMENTAL ENGINEERING , 2026, 44(3): 46-57. doi: 10.13205/j.hjgc.202603004

Citation:

JIANG Jiaxin, FANG Fang, ZHANG Jialing, LUO Jingyang, CAO Jiashun. Research progress on interspecies electron transfer mechanisms and their regulation in denitrification systems[J]. ENVIRONMENTAL ENGINEERING , 2026, 44(3): 46-57. doi: 10.13205/j.hjgc.202603004

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Research progress on interspecies electron transfer mechanisms and their regulation in denitrification systems

doi: 10.13205/j.hjgc.202603004

1. Key Laboratory of Shallow Lake Integrated Management and Resource Development，Ministry of Education，College of Environment，Hohai University，Nanjing 210098，China;
2. Nanjing Research Institute of Environmental Sciences，Ministry of Ecology and Environment，Nanjing 210042，China

Received Date: 2026-02-06
Available Online: 2026-04-11
Publish Date: 2026-03-01

Abstract

Abstract

Denitrification is a critical process for advanced nitrogen removal in wastewater treatment， fundamentally governed by microbially driven electron transfer and electron allocation. As research has shifted from macroscopic treatment metrics toward microscopic regulation， elucidating denitrification mechanisms from an electron-flow perspective has emerged as a major research frontier. This review systematically summarized the theoretical framework of electron flow in denitrification systems， compared intracellular electron transport pathways and energy allocation characteristics between heterotrophic and autotrophic denitrifiers， and highlighted the central role of the quinone pool in electron collection and redistribution. Furthermore， from the perspective of interspecies microbial interactions， recent advances in indirect interspecies electron transfer （IIET） and direct interspecies electron transfer （DIET） were summarized， and competitive as well as cooperative interactions among microorganisms in mixed systems during electron donor and electron acceptor utilization were analyzed. Building on this framework， the impacts of carbon source characteristics， pH， oxidation-reduction potential （ORP）， and coexisting contaminants on electron transport chains and electron allocation pathways were further discussed. Finally， in light of current limitations in the in situ quantification of electron fluxes， future research directions were proposed， including the development of multi-scale in situ characterization techniques， novel electron-conductive materials， and intelligent electron-flow regulation models.
- denitrification,
- electron allocation,
- intracellular/extracellular electron transport chain,
- microbial competition mechanism

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References(65)

References

[1]	GUO H Y，XI Z P，AI S S，et al. Optimization of operation mode for sequencing batch MPR reactor treating low C/N urban sewage[J]. Water Treatment Technology，2023，49（9）：107-112. 郭海燕，奚志鹏，艾胜书，等序批式MPR反应器处理低C/N城市污水运行方式优化研究[J]. 水处理技术，2023，49（9）：107-112.
[2]	KUYPERS M M M，MARCHANT H K，KARTAL B. The microbial nitrogen-cycling network[J]. Nature Reviews Microbiology，2018，16（5）：263-276.
[3]	JIANG M，ZHENG X，CHEN Y. Enhancement of denitrification performance with reduction of nitrite accumulation and N₂O emission by Shewanella oneidensis MR-1 in microbial denitrifying process[J]. Water Research，2020，169：115242.
[4]	YANG J，FENG L，PI S，et al. A critical review of aerobic denitrification：Insights into the intracellular electron transfer[J]. Science of the Total Environment，2020，731：139080.
[5]	AKRAM J，SONG C，MASHAD H M EL，et al. Advances in microbial community，mechanisms and stimulation effects of direct interspecies electron transfer in anaerobic digestion[J]. Biotechnology Advances，2024，76：108398.
[6]	WANG D，HE Y，CHEN Y，et al. Electron transfer enhancing the Mn(Ⅱ)/Mn(Ⅲ) cycle in MnO/CN towards catalytic ozonation of atrazine via a synergistic effect between MnO and CN[J]. Water Research，2023，230：119574.
[7]	ZHAO C，DUAN X，LIU C，et al. Metabolite cross-feeding promoting NADH production and electron transfer during efficient SMX Biodegradation by a Denitrifier and S. oneidensis MR-1 in the presence of nitrate[J]. Environmental Science& Technology，2023，57（46）：18306-18316.
[8]	LóPEZ RIVERO A S，ROSSI M A，CECCARELLI E A，et al. A bacterial 2[4Fe₄S] ferredoxin as redox partner of the plastidic-type ferredoxin-NADP+ reductase from Leptospira interrogans[J]. Biochimica et Biophysica Acta（BBA）-General Subjects，2019，1863（4）：651-660.
[9]	PALMER K，DRAKE HAROLD L，HORN MARCUS A. Association of novel and highly diverse acid-tolerant denitrifiers with N₂O fluxes of an Acidic Fen[J]. Applied and Environmental Microbiology，2010，76（4）：1125-1134.
[10]	ZHANG Y H，LI X L，CHEN Y，et al. Effect of C/S on biological nitrogen transfer pathway[J]. Environmental Engineering，2019，37（12）：6-11. 张宇浩，李晓玲，陈莹，等. C/S对生物氮转移途径的影响[J]. 环境工程，2019，37（12）：6-11.
[11]	WANG Y，XIE S，ZHOU J，et al. Sulfur cycle contributes to stable autotrophic denitrification and lower N₂O accumulation in electrochemically integrated constructed wetlands：Electron transfers patterns and metagenome insights[J]. Chemical Engineering Journal，2023，451：138658.
[12]	LAHME S，CALLBECK C M，ELAND L E，et al. Comparison of sulfide-oxidizing Sulfurimonas strains reveals a new mode of thiosulfate formation in subsurface environments[J]. Environmental Microbiology，2020，22（5）：1784-800.
[13]	OBEROI A S，HUANG H，KHANAL S K，et al. Electron distribution in sulfur-driven autotrophic denitrification under different electron donor and acceptor feeding schemes[J]. Chemical Engineering Journal，2021，404：126486.
[14]	HUANG J，MELLAGE A，GARCIA JULIAN P，et al. Metabolic performance and fate of electrons during nitrate-reducing Fe(Ⅱ) oxidation by the autotrophic enrichment culture KS Grown at different initial Fe/N ratios[J]. Applied and Environmental Microbiology，2023，89（3）：e00196-23.
[15]	BECKER S，DANG T T，WEI R，et al. Evaluation of Thiobacillus denitrificans’ sustainability in nitrate-reducing Fe(Ⅱ) oxidation and the potential significance of Fe(Ⅱ) as a growth-supporting reductant[J]. FEMS Microbiology Ecology，2025，101（4）：fiaf024.
[16]	XU H，CHANG J，WANG H，et al. Enhancing direct interspecies electron transfer in syntrophic-methanogenic associations with（semi）conductive iron oxides：Effects and mechanisms[J]. Science of the Total Environment，2019，695：133876.
[17]	BAEK G，KIM J，KIM J，et al. Role and potential of direct interspecies electron transfer in anaerobic digestion[J]. Energies，2018，11（1）：107.
[18]	MORRIS B E L，HENNEBERGER R，HUBER H，et al. Microbial syntrophy：interaction for the common good[J]. FEMS Microbiology Reviews，2013，37（3）：384-406.
[19]	MCINERNEY M J，SIEBER J R，GUNSALUS R P. Syntrophy in anaerobic global carbon cycles[J]. Current Opinion in Biotechnology，2009，20（6）：623-632.
[20]	YI X，LIANG J L，SU J Q，et al. Globally distributed mining-impacted environments are underexplored hotspots of multidrug resistance genes[J]. The ISME Journal，2022，16（9）：2099-2113.
[21]	JIANG Y，SHEN F，JIANG B，et al. The swelling induced choline alkali-urea（SICAU）process for sustainable crop straw upgrading[J]. Chemical Engineering Journal，2024，479：147610.
[22]	REGUERA G，MCCARTHY K D，MEHTA T，et al. Extracellular electron transfer via microbial nanowires[J]. Nature，2005，435（7045）：1098-1101.
[23]	KONG T，ZHANG W. Enhanced anaerobic digestion using conductive materials through mediation of direct microbial interspecies electron transfer：a review[J]. Fermentation，2023，9（10）：904.
[24]	YANG J，LIU K，YI W，et al. Effects of biochar，granular activated carbon，and magnetite on the electron transfer of microbials during the anaerobic digestion process：Insights into nitrogen heterocyclic compounds degradation[J]. Fuel，2024，358：130079.
[25]	YIN Q，WU G. Advances in direct interspecies electron transfer and conductive materials：electron flux，organic degradation and microbial interaction[J]. Biotechnology Advances，2019，37（8）：107443.
[26]	DESMOND-LE QUéMéNER E，MOSCOVIZ R，BERNET N，et al. Modeling of interspecies electron transfer in anaerobic microbial communities[J]. Current Opinion in Biotechnology，2021，67：49-57.
[27]	DING K，XU L，CHEN Y，et al. Mechanistic insights into polyhydroxyalkanoate-enhanced denitrification capacity of microbial community：Evolution of community structure and intracellular electron transfer of nitrogen metabolism[J]. Science of the Total Environment，2023，856：159147.
[28]	ESTÉVEZ-ALONSO Á，VAN LOOSDRECHT M C M，KLEEREBEZEM R，et al. Simultaneous nitrification and denitrification in microbial community-based polyhydroxyalkanoate production[J]. Bioresource Technology，2021，337：125420.
[29]	TU W，ZHANG D，WANG H，et al. Polyhydroxyalkanoates（PHA）production from fermented thermal-hydrolyzed sludge by PHA-storing denitrifiers integrating PHA accumulation with nitrate removal[J]. Bioresource Technology，2019，292：121895.
[30]	WEN W R，LIU T C，FAN S Q，et al. Dissimilatory nitrate reduction to ammonium driven by different electron donors：Mechanisms，recent advances，and future perspectives[J]. Chemical Engineering Journal，2025，507：160625.
[31]	DAR S A，KLEEREBEZEM R，STAMS A J M，et al. Competition and coexistence of sulfate-reducing bacteria，acetogens and methanogens in a lab-scale anaerobic bioreactor as affected by changing substrate to sulfate ratio[J]. Applied Microbiology and Biotechnology，2008，78（6）：1045-55.
[32]	ZHU Y，DAI H，YUAN S. The competition between heterotrophic denitrification and DNRA pathways in hyporheic zone and its impact on the fate of nitrate[J]. Journal of Hydrology，2023，626：130175.
[33]	LIAO Y，HE T，WANG C，et al. Dissimilatory nitrate reduction to ammonium has a competitive advantage over denitrification under nitrate-limited conditions[J]. Reviews in Environmental Science and Bio/Technology，2025，24（1）：97-114.
[34]	LI S，JIANG Z，JI G. Effect of sulfur sources on the competition between denitrification and DNRA[J]. Environmental Pollution，2022，305：119322.
[35]	WANG Q，ZHAO Y，CHEN Z，et al. Nitrate bioreduction under Cr（VI）Stress：crossroads of denitrification and dissimilatory nitrate reduction to ammonium[J]. Environmental Science& Technology，2023，57（29）：10662-10672.
[36]	HAN F，ZHANG M，SHANG H，et al. Microbial community succession，species interactions and metabolic pathways of sulfur-based autotrophic denitrification system in organic-limited nitrate wastewater[J]. Bioresource Technology，2020，315：123826.
[37]	GONG Q，ZENG W，MA B，et al. Ultra-stable mixotrophic denitrification coupled with anammox under organic stress for mainstream municipal wastewater treatment[J]. Water Research，2024，249：120932.
[38]	XU H，LIN X，XIONG L，et al. Deciphering the synergy between autotrophic and heterotrophic electron donors in pyrite driven mixotrophic denitrification for advanced nitrogen removal[J]. Water Research，2025，287：124371.
[39]	TANG X，HUANG Y，TAN S，et al. Vertical spatial denitrification performance and microbial community composition in denitrification biofilters coupled with water electrolysis[J]. RSC Advances，2024，14（22）：15431-15440.
[40]	ZHAO C，SUN N，CHEN N，et al. Unraveling the synergistic interplay of sulfur and wheat straw in heterotrophic-autotrophic denitrification for sustainable groundwater nitrate remediation[J]. Environmental Research，2024，263：120166.
[41]	GAO T，LI Y，DAI K，et al. Electric syntrophy-driven modulation of Fe⁰-dependent microbial denitrification[J]. Water Research，2025，268：122722.
[42]	LIANG D，LI C，HE W，et al. Response of exoelectrogens centered consortium to nitrate on collaborative metabolism，microbial community，and spatial structure[J]. Chemical Engineering Journal，2021，426：130975.
[43]	HE L，HE X，FAN X，et al. Accelerating denitrification and mitigating nitrite accumulation by multiple electron transfer pathways between Shewanella oneidensis MR-1 and denitrifying microbial community[J]. Bioresource Technology，2023，368：128336.
[44]	BROZINČEVIĆ A，GRGAS D，ŠTEFANAC T，et al. Cost reduction in the process of biological denitrification by choosing traditional or alternative carbon sources[J]. Energies，2024，17（15）：3660.
[45]	WEI Q，ZHANG J，LUO F，et al. Molecular mechanisms through which different carbon sources affect denitrification by Thauera linaloolentis：Electron generation，transfer，and competition[J]. Environment International，2022，170：107598.
[46]	LI S，WANG S，JI G. Influences of carbon sources on N₂O production during denitrification in freshwaters：Activity，isotopes and functional microbes[J]. Water Research，2022，226：119315.
[47]	LI Y，HU R，YANG Z，et al. Denitrification efficiency and accumulation characteristics of residual organics for the main compositions in woody biomass using a carbon source[J]. Journal of Water Process Engineering，2025，70：106959.
[48]	FU X，HOU R，YANG P，et al. Application of external carbon source in heterotrophic denitrification of domestic sewage：a review[J]. Science of the Total Environment，2022，817：153061.
[49]	SUN Q，LIN Y，PING Q，et al. Exploring recycled agricultural wastes for high-rate removal of nitrogen in wastewater：Emphasizing on the investigation of the inner driving force and comparison with conventional liquid carbon sources[J]. Water Research，2022，226：119292.
[50]	LENG J，LU J，HAI C，et al. Exploring influence mechanism of small-molecule carbon source on heterotrophic nitrification-aerobic denitrification process from carbon metabolism，nitrogen metabolism and electron transport process[J]. Bioresource Technology，2023，387：129681.
[51]	BLUM J-M，SU Q，MA Y，et al. The pH dependency of N-converting enzymatic processes，pathways and microbes：effect on net N₂O production[J]. Environmental Microbiology，2018，20（5）：1623-40.
[52]	ALBINA P，DURBAN N，BERTRON A，et al. Influence of hydrogen electron donor，alkaline pH，and high nitrate concentrations on microbial denitrification：a review[J]. International Journal of Molecular Sciences，2019，20（20）：5163-5163.
[53]	OLAYA-ABRIL A，HIDALGO-CARRILLO J，LUQUE-ALMAGRO V M，et al. Effect of pH on the denitrification proteome of the soil bacterium Paracoccus denitrificans PD1222[J]. Scientific Reports，2021，11（1）：17276.
[54]	SONG S H，YEOM S，CHOI S，et al. Effect of oxidation-reduction potential on denitrification by Ochrobactrum anthropi SY509[J]. Journal of Microbiology and Biotechnology，2003，13：473-476.
[55]	PANG R，SHAO B，CHEN Q，et al. The co-occurrent microplastics and nano-CuO showed antagonistic inhibitory effects on bacterial denitrification：Interaction of pollutants and regulations on functional genes[J]. Science of the Total Environment，2023，862：160892.
[56]	ZHANG B，QI B，SHI W，et al. Impaired denitrification of aerobic granules in response to micro/nanoplastic stress：Insights from interspecies interactions and electron transfer processes[J]. Water Research，2025，279：123472.
[57]	WAN R，LI X，WANG L，et al. Ionic copper strengthens the toxicity of tetrabromobisphenol A（TBBPA）to denitrification by decreasing substrate transport and electron transfer[J]. Journal of Hazardous Materials，2021，416：126203.
[58]	LIU Y，HAN Y，GUO J，et al. New insights of simultaneous partial nitritation，anammox and denitrification（SNAD）system to Zn(Ⅱ) exposure：Focus on affecting the regulation of quorum sensing on extracellular electron transfer and microbial metabolism[J]. Bioresource Technology，2022，346：126602.
[59]	CHEN C，FANG Y，ZHOU D. Selective pressure of PFOA on microbial community：Enrichment of denitrifiers harboring ARGs and the transfer of ferric-electrons[J]. Water Research，2023，233：119813.
[60]	CHENG B，JIANG J，ZHOU L，et al. Elemental sulfur enhances autotrophic denitrifying phosphorus removal from carbon-deficient wastewater through microbial synergy and electron transfer optimization[J]. Water Research，2026，288：124710.
[61]	XU A，GAO D，WU W M，et al. Enhanced denitrification using iron modified biochar under low carbon source condition：Modulating community assembly，allocating carbon metabolism and facilitating electron transfer[J]. Journal of Environmental Management，2025，381：125354.
[62]	KHIDR R，QURBANI K，MUHAMMED V，et al. Synergistic effects of indigenous bacterial consortia on heavy metal tolerance and reduction[J]. Environmental Geochemistry and Health，2025，47（3）：79.
[63]	NNAJI D N，ANYANWU U C，MIRI T，et al. Mechanisms of heavy metal tolerance in bacteria：a review[J]. Sustainability，2024，16（24）：11124.
[64]	JIN X，YANG N，XU D，et al. Insight into a single-chamber air-cathode microbial fuel cell for nitrate removal and ecological roles[J]. Frontiers in Bioengineering and Biotechnology，2024，2024，12：1454760.
[65]	DOMINGO-FÉLEZ C，SMETS B F. Modeling denitrification as an electric circuit accurately captures electron competition between individual reductive steps：the activated sludge model-electron competition model[J]. Environmental Science& Technology，2020，54（12）：7330-7338.