Research Diana Vasquez Cardenas

Abstract

Long filamentous cable bacteria are capable of generating and mediating electricity over centimeter-scale distances, thus extending the known length scale of biological electron transport by three orders of magnitude. Up until present, research efforts have concentrated on the cable bacteria themselves, yet recent data provide indications of a tight coupling between cable bacteria and associated microorganisms. Possible interactions include a mutualistic exchange of metabolic substrates (classical syntrophy) or, more intriguingly, indirect and direct mechanisms such as direct interspecies electron transfer or electron shuttles. In this project we will investigate the presence and nature of such interactions. Our hypothesis is that long-distance electron transport in aquatic sediments is not exclusively mediated by cable bacteria, but could involve a consortium of cable bacteria and associated partner microbes. Field sampling in marine and brackish environments will be combined with targeted incubation experiments in the laboratory. Next generation sequencing methods and microscopy will be applied, and correlation analysis will unravel associations between cable bacteria and other microbes. Metatranscriptomes will shed light on potential electric or metabolic interactions. The project will improve our understanding of electrogenic sediments, with potentially important implications for sediment biogeochemistry and microbial ecology.

Researcher(s)

• Promoter: Meysman Filip
• Co-promoter: Geelhoed Jeanine
• Co-promoter: Vasquez Cardenas Diana
• Fellow: Ley Philip

Research team(s)

• Geobiology

Project type(s)

• Research Project

Abstract

A decade ago a unique electrical microbial metabolism was discovered in the seafloor that is revolutionizing our long-held views of biogeochemistry and microbial ecosystems. These multicellular microbes are referred to as "cable bacteria", as they transport electrical currents over long distances, much like electricity cables. Cable bacteria form dense networks in the environment that drastically change the geochemical makeup of the seafloor. This electricity-based metabolism sidesteps the traditional "redox ladder" and thus questions the current knowledge of how oxidation-reduction reactions occur in natural systems. Interestingly, cable bacteria appear to not work alone, but rather engage in electrical interactions with other microbes. The associated microbes are hypothesized to use the filaments as an "electron highway" by exchanging electrons with the cable bacteria. Such a cooperation allows microbes to access electron sinks (or sources) centimeters away via the cable bacteria filament. This research aims to provide insight into this new form of microbial cooperation and the underlying mechanisms that drive the "electrical ecosystem". A multidisciplinary approach combining molecular biology, geochemistry and inventive cultivation systems is proposed.

Researcher(s)

• Promoter: Meysman Filip
• Fellow: Vasquez Cardenas Diana

Research team(s)

• Geobiology

Project type(s)

• Research Project