A/Prof Amelia-Elena Rotaru

Event Date: 
Wednesday, March 16, 2016 - 15:30 - 16:00
Nordic Centre for Earth Evolution, University of Southern Denmark

Electric interspecies cooperations


The electroactive properties of microorganisms are poorly understood, like the ability of certain bacteria to donate electrons to electrodes (electrogens) or to retrieve electrons from electrodes (electrotrophs). Recently, we have learned that certain electrogenic and electrotrophic microogranisms establish an unusual type of microbial interactions via direct electric contact. During direct interspecies electron transfer (DIET) an electrogenic Geobacter, utilizes ethanol only in the presence of cytochrome-containing methanogens (Methanosarcinales), but not with non- cytochrome containing methanogens. The interaction between Geobacter and Methanosarcinales relies on an extracellular network of pili and cytochromes. The same extracellular network of pili and cytochromes was many times implicated in interactions between Geobacter and solid electron acceptors such as electrodes or iron oxides.
On the other hand, the natural manifestation of DIET associations remains mysterious. One case, of a DIET driven process, is the treatment of brewery waste in 24 UASB reactors in the United States. Geobacter and Methanosaeta essentially dominated the granules in these UASB reactors. However DIET syntrophy is not a common trait in UASB reactor granules worldwide. Moreover, we still do not know what other environments are accommodating DIET, rather than H2/formate-transfer. Thus, we recently started investigating if DIET could drive methanogenesis in natural systems, and discovered supporting evidence for DIET driven methanogenesis in iron rich aquatic sediments. More importantly, we are now investigating what drives direct electron uptake in methanogens, which is of significance for future’s biorefineries, recycling of materials and storage of excess renewable electricity. 

I’m a recently appointed Assistant Prof. at the University of Southern Denmark. In my research group we are searching for solutions to harness microbial metabolism in order to produce fossil fuel free renewable resources and control harmful microbial processes.

Previously, I worked as a postdoc on direct interspecies interactions at the University of Massachusetts Amherst, and biorecovery of rare metals from waste at the University of Aarhus. I did my PhD at the Max Planck Institute for Marine Microbiology in Bremen, Germany – studying anaerobic biodegradation of hydrocarbons. Part of my PhD was dedicated to syntrophic interactions - topic which I’m still exploring today.