Related Experiment Video
Updated: Apr 3, 2026
09:00
Electrochemical Detection of Deuterium Kinetic Isotope Effect on Extracellular Electron Transport in Shewanella oneidensis MR-1
Published on: April 16, 2018
10.8K
Single cell activity reveals direct electron transfer in methanotrophic consortia
Shawn E McGlynn1, Grayson L Chadwick1, Christopher P Kempes2,3,4
1Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA.
Nature
|September 17, 2015
Summary
Microbial consortia use direct electron transfer for syntrophic coupling, not just molecular exchange. This finding challenges traditional models of metabolic interactions between methane-oxidizing archaea and sulphate-reducing bacteria.
Area of Science:
- Microbiology
- Biogeochemistry
- Biophysics
Background:
- Microbial multicellular assemblages facilitate metabolic coupling for challenging reactions.
- Methane-oxidizing archaea and sulphate-reducing bacteria consortia are key in anaerobic methane oxidation.
- Mechanisms of metabolic coupling in these consortia remain poorly understood.
Purpose of the Study:
- To investigate the influence of spatial positioning on biosynthetic activity in uncultured methane-oxidizing microbial consortia.
- To elucidate the metabolic interactions and coupling mechanisms between syntrophic archaea and bacteria.
- To challenge conventional models of syntrophy.
Main Methods:
- Stable isotope incorporation measurements in individual archaeal and bacterial cells.
- Analysis of interspecies spatial positioning and cellular activities.
- Genomic analysis for multi-haem cytochromes and matrix staining.
Main Results:
- Cellular activities were independent of species intermixing and distance.
- A model of electric conductivity best explained the empirical data.
- Evidence for direct electron transfer via multi-haem cytochromes and matrix redox activity was found.
Conclusions:
- Syntrophic coupling in these microbial consortia occurs through direct interspecies electron transfer (DIET).
- This challenges the paradigm of syntrophy relying solely on molecular intermediate exchange.
- DIET offers a new perspective on microbial interactions in methane cycling and other biogeochemical processes.
Related Concept Videos
01:25Microbial Interactions: Mutualism
39
Mutualism is a symbiotic interaction in which all participating organisms benefit. These relationships can be obligate or facultative and are fundamental to ecosystem functions across diverse biological systems.Plant–Fungi MutualismOne well-known example is the association between plant roots and mycorrhizal fungi, such as Rhizophagus species. The fungal hyphae penetrate the root hairs and the epidermis, forming an extensive hyphal network that establishes a symbiotic association. Through...
39
01:26Microbes and Methanogenesis
30
Methanogenesis is a critical microbial process in anaerobic ecosystems responsible for the biological production of methane, a potent greenhouse gas and valuable biofuel. This metabolic pathway is primarily facilitated by methanogenic archaea, which thrive in anoxic environments such as wetlands, sediments, and animal gastrointestinal tracts. The absence of oxygen in these habitats prevents aerobic respiration, thereby favoring alternative biochemical pathways for organic matter degradation.In...
30
01:25Microbial Mats
50
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...
50
01:15Metabolism of Chemolithotrophs
1.2K
Chemolithotrophs are microorganisms that obtain energy by oxidizing inorganic molecules such as hydrogen gas (H₂), ammonia (NH₃), reduced sulfur compounds (H₂S, S²⁻), and ferrous iron (Fe²⁺). Unlike heterotrophic organisms that rely on organic carbon, chemolithotrophs transfer electrons from these inorganic donors to the electron transport chain (ETC), generating a proton motive force (PMF) that drives ATP synthesis through oxidative phosphorylation.
1.2K
01:18Deep Sea Microbial Ecology
40
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...
40
01:28Microbial Nutrition
2.0K
Organisms exhibit remarkable metabolic diversity, categorized based on how they acquire energy and carbon. These strategies enable survival in various ecological niches and are essential for maintaining energy flow and nutrient cycling within ecosystems.Energy and Carbon SourcesOrganisms are classified as phototrophs or chemotrophs based on energy acquisition. Phototrophs use light as their energy source, while chemotrophs rely on oxidizing chemical compounds. Further differentiation arises...
2.0K