Related Experiment Video
Updated: Aug 6, 2026
05:29
Self-standing Electrochemical Set-up to Enrich Anode-respiring Bacteria On-site
Published on: July 24, 2018
Multi-Omics Reveal Extracellular Electron Transfer Mechanism Under Deep-Sea High Salinity
Huangxin Chen1, Yue Wu1, Xin Wang2
1College of Oceanography and Ecological Science, Shanghai Ocean University, Shanghai, China.
Environmental Microbiology
|July 16, 2026
Summary
Marine Shewanella bacteria exhibit extracellular electron transfer (EET) crucial for deep-sea sediment processes. This study reveals how Shewanella piezotolerans WP3 uses riboflavin and metabolic pathways to perform EET under high salinity.
Area of Science:
- Microbiology
- Geochemistry
- Biotechnology
Background:
- Microorganism-mineral interactions drive organic matter degradation and electron exchange in marine sediments.
- Shewanella species are key metal-reducing bacteria with extracellular electron transfer (EET) capabilities.
- EET mechanisms in deep-sea Shewanella under high-salinity stress are not well understood.
Purpose of the Study:
- To investigate the EET process and metabolic mechanisms of the deep-sea bacterium Shewanella piezotolerans WP3.
- To elucidate the role of specific genes and metabolites in facilitating EET under high-salinity conditions.
Main Methods:
- Electrochemical analysis of S. piezotolerans WP3 electroactivity.
- Gene expression analysis (RT-qPCR) of key EET-related genes.
- Metabolomic profiling to assess central metabolic pathways.
Main Results:
- S. piezotolerans WP3 demonstrated significant electroactivity, comparable to S. oneidensis MR-1.
- The OmcA-MtrCAB complex was identified as crucial for direct EET, with specific omcA and mtr genes showing differential expression.
- Riboflavin secretion, enhanced glycolysis, and TCA cycle activity were observed under high anode potential and salinity, supporting EET.
- Metabolic shifts included downregulation of phosphoenolpyruvate and upregulation of pyk.
Conclusions:
- The study elucidates the EET mechanisms of marine Shewanella under high-salinity stress.
- Riboflavin and specific metabolic pathways are vital for facilitating EET in S. piezotolerans WP3.
- Findings support potential applications in bioelectronic sensors and high-salinity wastewater treatment.
Keywords:
bioelectrochemical systemdeep‐sea electroactive microorganismsextracellular electron transfermetabolomicstranscriptomicsMore Related Videos
09:00Electrochemical Detection of Deuterium Kinetic Isotope Effect on Extracellular Electron Transport in Shewanella oneidensis MR-1
Published on: April 16, 2018
10:23Characterizing Mediated Extracellular Electron Transfer in Lactic Acid Bacteria with a Three-Electrode, Two-Chamber Bioelectrochemical System
Published on: August 23, 2024
Related Concept Videos
01:18Deep Sea Microbial Ecology
The deep ocean and its underlying sediments represent vast, largely unexplored microbial habitats that extend far beyond the sunlit photic zone. The photic (euphotic) zone typically spans the upper ~100–200 meters of pelagic waters in the open ocean, but its depth varies geographically and seasonally, where sufficient light supports photosynthetic life. Below this lies the deep sea, spanning roughly 1000–6000 meters (bathypelagic to abyssal zones), with deeper hadal trenches extending beyond...
01:30Marine Microbial Ecology
Marine microbial ecosystems are shaped by distinct physicochemical limits, including high salinity, low nutrient availability, and fluctuating oxygen levels. These conditions favor smaller microbial cell sizes, which maximize their surface-to-volume ratio for efficient nutrient uptake.Microbial activity and community composition are closely linked to biogeochemical cycles, particularly in dynamic environments like estuaries, where halotolerant microbes thrive in response to variable salinity...
01:24Microbes and Other Elemental Cycles
Microbial activity plays a pivotal role in the biogeochemical cycling of iron and manganese, especially at the redox gradients characteristic of stratified aquatic environments. These cycles are driven by microbial transformations between oxidized and reduced forms of the metals, allowing organisms to exploit them for metabolic energy and structural purposes.Iron Cycling Across Redox GradientsIn neutral, oxygen-rich surface waters, iron is predominantly found in its oxidized, insoluble ferric...
01:32Chemiosmosis
Oxidative phosphorylation is a highly efficient process that generates large amounts of adenosine triphosphate (ATP), the basic unit of energy that drives many cellular processes. Oxidative phosphorylation involves two processes— the electron transport chain and chemiosmosis.
Electron Transport Chain
The electron transport chain involves a series of protein complexes on the inner mitochondrial membrane that undergo a series of redox reactions. At the end of this chain, the electrons reduce...
Electron Transport Chain
The electron transport chain involves a series of protein complexes on the inner mitochondrial membrane that undergo a series of redox reactions. At the end of this chain, the electrons reduce...
02:02Responses to Salt Stress
Salt stress—which can be triggered by high salt concentrations in a plant’s environment—can significantly affect plant growth and crop production by influencing photosynthesis and the absorption of water and nutrients.
01:25Microbial Mats
Microbial communities forming biofilms and mats represent complex, spatially structured ecosystems where metabolic processes are stratified according to light, oxygen, and nutrient gradients. Biofilms are initial colonization stages, only a few millimeters thick, while mature microbial mats can reach centimeter-scale thickness and display intricate vertical organization. Their structural and functional heterogeneity allows microorganisms to occupy distinct ecological niches within a few...