Rotaru Lab

University of Southern Denmark

Welcome to Amelia-Elena Rotaru’s lab at the University of Southern Denmark. We investigate how to harness microbial metabolisms to produce fossil fuel-free renewable resources and control harmful microbial processes. For these purposes, we look at extracellular electron transfer for energy metabolism in various microorganisms. We do so by carrying analyses at the interface of microbial physiology, functional genomics, and electrochemistry. The primary research aim is to learn how microbes make use of solid surfaces (minerals, metal structures, electrodes, cell-to-cell) to gain energy and/or to respire. 

Recent discoveries in our lab

Yee & Rotaru 2020, Scientific Reports

  • we tested 11 new co-culture combinations for the possibility to carry out direct interespecies electron transfer. Of these eleven, 8 were capable of syntrophic metabolism. 
  • we provide the first proof that Methanosarcina do not require multiheme c-type cytochromes to carry out extracellular electron uptake from syntrophic partners or from an electrode.

Palacios et al. 2019. The ISME Journal

  • the first demonstration of metallic iron corrosion by an environmental Methanosarcina from the Baltic Sea.
  • this Methanosarcina was competing for electrons from iron with Baltic-acetogenic Sporomusa, rather than using the acetate produced by the acetogen. Thus we challenge previous views that corrosion by Methanosarcina’s (often found associated with corroded structures) is rather the result of these methanogens utilizing substrates generated by microorganisms directly accessing the metallic surface.
  • this is significant because the Baltic Sea is the dumping ground for radionuclide and chemical waste (including chemical weapons) stored in steel containers. Now we know who may be bio-deteriorating these iron structure in the depths of the Baltic Sea.

Yee et al. 2019. Front. Energy. Res. 

  • first 1st author paper for Mon – and quite an exciting one
  • the first demonstration of electromethanogenesis by Methanosarcina barkeri. However, we learned that not all Methanosarcina capable of DIET can retrieve electrons via elecromethanogenesis from a fixed-potential cathode.  We propose that electromethanogenesis at a set cathode-potential cannot match the redox requirements for each type of electroactive Methanosarcina. On the other hand during DIET, the partner electrogen would modulate its outermembrane cytochrome expression to match the redox requirements of its partner Methanosarcina.
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Vision

Mads Schou Vammen (directed) and Mon Oo Yee helped create this video a couple of years ago. Although it was intended for a Johnson & Johnson award (which I never got) it gives a fantastic 1-minute overview of my labs’ research vision.